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1. A ot ct Both of svndumpfilter s subcommands accept options for deciding how to deal with empty revisions If a given revision contained only changes to paths that were filtered out that now empty revision could be considered uninter esting or even unwanted So to give the user control over what to do with those revisions svndumpfilter provides the following command line options drop empty revs Do not generate empty revisions at all just omit them renumber revs If empty revisions are dropped using the drop empt y revs option change the revision numbers of the re maining revisions so that there are no gaps in the numeric sequence preserve revprops If empty revisions are not dropped preserve the revision properties log message author date custom proper ties etc for those empty revisions Otherwise empty revisions will only contain the original datestamp and a generated log message that indicates that this revision was emptied by svndumpfilter While svndumpfilter can be very useful and a huge timesaver there are unfortunately a couple of gotchas First this utility is overly sensitive to path semantics Pay attention to whether paths in your dumpfile are specified with or without leading slashes You ll want to look at the Node path and Copyfrom path headers Node path spreadsheet Makefil If the paths have leading slashes you should include leading slashes in the paths you pass to sv
2. ssl trust default ca ssl client cert file ssl client cert password ER Software Tigris org Subversion Config auth ds no ER Software Tigris org Subversion Config helpers HKEY_CURRENT_US store auth cr HKEY_CURRENT_US teditor cmd notepad diff cma diff3 cmd diff3 has program arg HKEY_CURRENT_USER Software Tigris org Subversion Config miscellany global ignores o lo la rej rej log encoding tuse commit times template root fenable auto props HKEY_CURRENT_USER Software Tigris org Subversion Config tunnels HKEY_CURRENT_USER Software Tigris org Subversion Config auto props The previous example shows the contents of a reg file which contains some of the most commonly used configu ration options and their default values Note the presence of both system wide for network proxy related options and per user settings editor programs and password storage among others Also note that all the options are effec tively commented out You need only to remove the hash character from the beginning of the option names and set the values as you desire Configuration Options In this section we will discuss the specific run time configuration options that are currently supported by Subver sion Servers
3. 118 Advanced Topics Unless otherwise noted using a versioned file s svn mime type property Subversion assumes the file contains hu man readable data Generally speaking Subversion only uses this knowledge to determine if contextual difference reports for that file are possible Otherwise to Subversion bytes are bytes This means that by default Subversion doesn t pay any attention to the type of end of line EOL markers used in your files Unfortunately different operating system use different tokens to represent the end of a line of text in a file For example the usual line ending token used by software on the Windows platform is a pair of ASCII control characters carriage return CR and line feed LF Unix software however just uses the LF character to denote the end of a line Not all of the various tools on these operating systems are prepared to understand files that contain line endings in a format that differs from the native line ending style of the operating system on which they are running Common re sults are that Unix programs treat the CR character present in Windows files as a regular character usually rendered as M and that Windows programs combine all of the lines of a Unix file into one giant line because no carriage re turn linefeed or CRLF character combination was found to denote the end of line This sensitivity to foreign EOL markers can become frustrating for folks who share a file across dif
4. In other words an update moves your working copy through time A switch moves your working copy through time and space Because svn switch is essentially a variant of svn update it shares the same behaviors any local modifications in your working copy are preserved when new data arrives from the repository This allows you to perform all sorts of clever tricks For example suppose you have a working copy of calc trunk and make a number of changes to it Then you suddenly realize that you meant to make the changes to a branch instead No problem When you svn switch your working copy to the branch the local changes will remain You can then test and commit them to the branch Tags Another common version control concept is a tag A tag is just a snapshot of a project in time In Subversion this idea already seems to be everywhere Each repository revision is exactly that a snapshot of the filesystem after each commit However people often want to give more human friendly names to tags like release 1 0 And they want to make snapshots of smaller subdirectories of the filesystem After all it s not so easy to remember that release 1 0 of a piece of software is a particular subdirectory of revision 4822 Creating a Simple Tag 11You can however use svn switch with the relocate switch if the URL of your server changes and you don t want to abandon an existing working copy See the svn switch section in Chapter 9 Su
5. svn status A real c svn commit m Resurrected real c from revision 807 calc trunk real c Adding real c Transmitting file data Committed revision 1390 The plus sign in the status output indicates that the item isn t merely scheduled for addition but scheduled for addi tion with history Subversion remembers where it was copied from In the future running svn log on this file will traverse back through the file s resurrection and through all the history it had prior to revision 807 In other words this new real c isn t really new it s a direct descendant of the original deleted file Although our example shows us resurrecting a file note that these same techniques work just as well for resurrecting deleted directories Switching a Working Copy The svn switch command transforms an existing working copy into a different branch While this command isn t strictly necessary for working with branches it provides a nice shortcut to users In our earlier example after creat ing your private branch you checked out a fresh working copy of the new repository directory Instead you can simply ask Subversion to change your working copy of calc trunk to mirror the new branch location cd calc svn info grep URL URL http svn example com repos calc trunk svn switch http svn example com repos calc branches my calc branch U integer c U button c U Makefile Updated to revision 341 svn in
6. svn export a wc my export Export complete 166 Subversion Complete Reference Export directly from the repository prints every file and directory svn export file tmp repos my export A my export test A my export quiz Exported revision 15 167 Subversion Complete Reference Name svn help Help svn help Synopsis svn help SUBCOMMAND Description This is your best friend when you re using Subversion and this book isn t within reach Alternate Names h Changes Nothing Accesses Repository Switches version quiet a 168 Subversion Complete Reference Name svn import Recursively commit a copy of PATH to URL svn import Synopsis svn import PATH URL Description Recursively commit a copy of PATH to URL If PATH is omitted is assumed Parent directories are created in the repository as necessary Alternate Names None Changes Repository Accesses Repository Yes Switches message m TEXT file F FILE quiet a non recursiv N username USER password PASS no auth cach non interactiv force log editor cmd EDITOR encoding ENC config dir DIR auto props no auto props Examples This imports the local directory myproj into the root of your repository svn import m New import myproj http svn red bean com repos test Adding myproj sample txt
7. Description List the value of a property on a path in the repository Alternate Names pg pget Switches revision 1 transaction t Examples This shows the value of the seasonings property on the file t runk sandwich in the HEAD revision svnlook pg usr local svn repos seasonings trunk sandwich mustard 232 Subversion Complete Reference Name svnlook proplist Print the names and values of versioned file and directory properties svnlook proplist Synopsis svnlook proplist REPOS_PATH PATH_IN_REPOS Description List the properties of a path in the repository With verbose show the property values too Alternate Names pl plist Switches revision 1 transaction t verbose v Examples This shows the names of properties set on the file t runk README in the HEAD revision svnlook proplist usr local svn repos trunk README original author svn mime type This is the same command as in the previous example but this time showing the property values as well td svnlook proplist usr local svn repos trunk READM original author fitz svn mime type text plain 233 Subversion Complete Reference Name svnlook tree Print the tree svnlook tree Synopsis svnlook tree REPOS_PATH PATH_IN_REPOS Description Print the tree starting at PATH_IN_REPOS if supplied at th
8. Examples Copy an item within your working copy just schedules the copy nothing goes into the repository until you com mit svn copy foo txt bar txt A bar txt svn status A bar txt Copy an item in your working copy to a URL in the repository an immediate commit so you must supply a commit message svn copy near txt file tmp repos test far away txt m Remote copy Committed revision 8 Copy an item from the repository to your working copy just schedules the copy nothing goes into the repository until you commit Tip This is the recommended way to resurrect a dead file in your repository svn copy file tmp repos test far away near her A near here And finally copying between two URLs svn copy file tmp repos test far away file tmp repos test over ther m remote copy Committed revision 9 Tip This is the easiest way to tag a revision in your repository just svn copy that revision usually HEAD into your tags directory svn copy file tmp repos test trunk file tmp repos test tags 0 6 32 prerelease m tag tree Committed revision 12 And don t worry if you forgot to tag you can always specify an older revision and tag anytime 159 Subversion Complete Reference svn copy r 11 file tmp repos test trunk file tmp repos test tags 0 6 32 prerelease m Forg Committed revision 13 160 Subversion Complete Reference
9. cat usr local bin svn bin sh umask 002 usr local subversion bin svn e Another common problem is often encountered on Unix like systems As a repository is used BerkeleyDB occa sionally creates new logfiles to journal its actions Even if the repository is wholly owned by the svn group these newly created files won t necessarily be owned by that same group which then creates more permissions problems for your users A good workaround is to set the group SUID bit on the repository s db directory This causes all newly created logfiles to have the same group owner as the parent directory Once you ve jumped through these hoops your repository should be accessible by all the necessary processes It may seem a bit messy and complicated but the problems of having multiple users sharing write access to common files are classic ones that are not often elegantly solved Fortunately most repository administrators will never need to have such a complex configuration Users who wish to access repositories that live on the same machine are not limited to using file access URLs they can typi cally contact the Apache HTTP server or svnserve using localhost for the server name in their http or svn URLs And to maintain multiple server processes for your Subversion repositories is likely to be more of a headache than necessary We recommend you choose the server that best meets your needs and stick with it The svn ssh server chec
10. Note While your working copy is just like any other collection of files and directories on your system you need to let Subversion know if you re going to be rearranging anything inside of your working copy If you want to copy or move an item in a working copy you should use svn copy or svn move instead of the copy and move commands provided by your operating system We ll talk more about them later in this chapter Unless you re ready to commit a new file or directory or changes to existing ones there s no need to further notify the Subversion server that you ve done anything What s with the svn directory Every directory in a working copy contains an administrative area a subdirectory named svn Usually directory listing commands won t show this subdirectory but it is nevertheless an important directory Whatever you do don t delete or change anything in the administrative area Subversion depends on it to manage your working copy While you can certainly check out a working copy with the URL of the repository as the only argument you can also specify a directory after your repository URL This places your working copy into the new directory that you name For example svn checkout http svn collab net repos svn trunk subv A subv subversion dsw A subv svn_check dsp 23 Guided Tour A subv COMMITTERS A subv configure in A subv IDEAS Checked out revision 2499 That will place your working co
11. which means all users x E This is a common setup notice that there s no repository name mentioned in the section name This makes all repos itories world readable to all users whether you re using SVNPath or SVNParentPath Once all users have read access to the repositories you can give explicit rw permission to certain users on specific subdirectories within spe cific repositories The asterisk variable is also worth special mention here it s the only pattern which matches an anonymous user If you ve configured your Location block to allow a mixture of anonymous and authenticated access all users start out accessing Apache anonymously mod_authz_svn looks for a value defined for the path being accessed if it can t find one then Apache demands real authentication from the client The access file also allows you to define whole groups of users much like the Unix etc group file groups calc developers harry sally joe 101 Extra Server Configuration paint developers frank sally jane everyone harry sally joe frank sally jane Groups can be granted access control just like users Distinguish them with an at prefix calc projects calc calc developers rw paint projects paint fpaint developers rw jane r and that s pretty much all there is to it Goodies We ve covered most of the authentication and authorization options for Apache and mod_dav_sv
12. Changes Working copy repository only if operating on a URL Accesses Repository Only if operating on a URL Switches quiet a recursiv R r evisi n r REV revprop username USER password PASS no auth cach non interactiv config dir DIR Examples Delete a property from a file in your working copy svn propdel svn mime type some script property svn mime type deleted from some script Delete a revision property 185 Subversion Complete Reference svn propdel revprop r 26 release dat property release date deleted from repository revision 26 186 Subversion Complete Reference Name svn propedit Edit the property of one or more items under version control svn propedit Synopsis svn propedit PROPNAME PATH T svn propedit PROPNAME revprop r REV URL Description Edit one or more properties using your favorite editor The first form edits versioned properties in your working copy while the second edits unversioned remote properties on a repository revision Alternate Names pedit pe Changes Working copy repository only if operating on a URL Accesses Repository Only if operating on a URL Switches E lt revision r RI revprop username USER password PASS no auth cach non interactiv encoding ENC editor cmd EDITOR config dir DIR Examples svn propedit
13. Name svn delete Delete an item from a working copy or the repository svn delete Synopsis svn delete PATH svn delete URL Description Items specified by PATH are scheduled for deletion upon the next commit Files and directories that have not been committed are immediately removed from the working copy The command will not remove any unversioned or modified items use the force switch to override this behavior Items specified by URL are deleted from the repository via an immediate commit Multiple URLs are committed atomically Alternate Names del remove rm Changes Working copy if operating on files Repository if operating on URLs Accesses Repository Only if operating on URLs switches force force log message m TEXT file F FILE quiet a targets FILENAME username USER password PASS no auth cach non interactiv editor cmd EDITOR encoding ENC config dir DIR Examples 161 Subversion Complete Reference Using svn to delete a file from your working copy merely schedules it to be deleted When you commit the file is deleted in the repository svn delete myfile D myfile svn commit m Deleted file myfile Deleting myfile Transmitting file data Committed revision 14 Deleting a URL however is immediate so you have to supply a log message svn delet m Deleting file yourfile file tmp repos test
14. twithstanding the foregoing two 2 sentences if Creative expressly identified itself as the Licensor hereunder it the limited purpose of indicating to the public that the nsed under the CCPL neither party will use the trademark hout the prior written consent of Creative Commons Any t trademark usage guidelines as may be published on its website or otherwise made available upon request from time to time Creative Commons may be contacted at http creativecommons org 261 Colophon Etc 262
15. we run svn add on those to get them under version control The missing files are files that were in 1 0 but not in 1 1 and on those paths we run svn remove Finally once our cur rent working copy contains only the libcomplex 1 1 code we commit the changes we made to get it looking that way Our current branch now contains the new vendor drop We tag the new version in the same way we previously tagged the version 1 0 vendor drop and then merge the differences between the tag of the previous version and the new current version into our main development branch cd working copies calc svn merge http svn example com repos vendor libcomplex 1 0 http svn example com repos vendor libcomplex current libcomplex resolve all the conflicts between their changes and our changes svn commit m merging libcomplex 1 1 into the main branch In the trivial use case the new version of our third party tool would look from a files and directories point of view just like the previous version None of the libcomplex source files would have been deleted renamed or moved to different locations the new version would contain only textual modifications against the previous one In a perfect world our modifications would apply cleanly to the new version of the library with absolutely no complications or conflicts But things aren t always that simple and in fact it is quite common for source files to get moved around between re
16. 303 which changed integer c is completely wrong It never should have been committed You can use svn merge to undo the change in your working copy and then commit the local modification to the repository All you need to do is to specify a reverse difference svn merge r 303 302 http svn example com repos calc trunk integer c q ur svn status integer c Zum Ur svn diff se i verify that the change is removed svn commit m Undoing change committed in r303 Sending integer c Transmitting file data Committed revision 350 One way to think about a repository revision is as a specific group of changes some version control systems call these changesets By using the r switch you can ask svn merge to apply a changeset or whole range of change sets to your working copy In our case of undoing a change we re asking svn merge to apply changeset 303 to our working copy backwards Keep in mind that rolling back a change like this is just like any other svn merge operation so you should use svn status and svn diff to confirm that your work is in the state you want it to be in and then use svn commit to send the final version to the repository After committing this particular changeset is no longer reflected in the HEAD revi sion 53 Branching and Merging Again you may be thinking well that really didn t undo the commit did 1t The change still exists in revision 303 If somebody chec
17. Berkeley DB environment Berkeley checks for the presence of a file named DB_CONFIG in each environment direc tory and parses the options found in that file for use with that particular Berkeley environment The Berkeley configuration file for your repository is located in the db environment directory at repos db DB_CONFIG Subversion itself creates this file when it creates the rest of the repository The file initially con tains some default options as well as pointers to the Berkeley DB online documentation so you can read about what those options do Of course you are free to add any of the supported Berkeley DB options to your DB_CONFIG file Just be aware that while Subversion never attempts to read or interpret the contents of the file and makes no use of the option settings in it you ll want to avoid any configuration changes that may cause Berkeley DB to behave in a fashion that is unexpected by the rest of the Subversion code Also changes made to DB_CONFIG won t take effect until you recover the database environment using svnadmin recover Repository Maintenance Maintaining a Subversion repository can be a daunting task mostly due to the complexities inherent in systems which have a database backend Doing the task well is all about knowing the tools what they are when to use them and how to use them This section will introduce you to the repository administration tools provided by Sub version and how to wield them to accom
18. D stuff fish c svn status also has a verbose v switch which will show you the status of every item in your working copy even if it has not been changed svn status verbose M 44 2 3 sally READM 44 30 sally INSTALL M 44 20 harry bar c 44 18 ira stuff 28 Guided Tour 44 35 harry stuff trout c D 44 19 ira stuff fish c 44 21 sally stuff things A 0 stuff things bloo h 44 36 harry stuff things gloo c This is the long form output of svn status The first column remains the same but the second column shows the working revision of the item The third and fourth columns show the revision in which the item last changed and who changed it None of the above invocations to svn status contact the repository they work only locally by comparing the meta data in the svn directory with the working copy Finally there is the show updates u switch which con tacts the repository and adds information about things that are out of date svn status show updates verbos M 3 44 23 sally README M 44 20 harry bar c 44 35 harry stuff trout c D 44 19 ira stuff fish c A 0 stuff things bloo h Status against revision 46 Notice the two asterisks if you were to run svn update at this point you would receive changes to README and trout c This tells you some very useful information you ll need to update and get the server changes on README before you commit or the r
19. Extra GOOdles Ni AAA ds a Magee 102 Supporting Multiple Repository Access Methods oocoooccnoconoconoconccnnonnncnnnconoronconnconnccnnccnnconoconicinass 103 7 Adyanced TOPICS a ii a Seer eereeedeles Runtime Configuration Area sencilla rinitis E Ee re an p E STES tai 105 Configuration Area Layout eeng torcido o is E EEE NES EE E EAEE R 105 Configuration and the Windows Registry oooccnoconccnnccnnccnnncnncnnnconocnnconnconnccnnccnncnnnconnconinnnnss 106 Configuration Options sss eni ee hene EE EEEE E EEEE EE AE rE SAE E E AGES EEEE Sees ie 107 Properties sirios rail ati 110 Why Properties einen nosa A A REE S T E TEE 111 Manipulating Properties seeni a a a a A ES 111 Special Properties ssie e ep e ER E E AS EEEa sewer shed IEAS EE E EER EERE 114 Automatic Property Setting cipal iii e italia E N 120 Externals Defi tions 25 seca sacs ia ia fra aii de isa 120 Vendor branches iii ro id 121 General Vendor Branch Management Procedure oooconocnnccnnccnncnnnronccnnccnnconnccnnccnnccnncnnncnnncnnnss 122 A O loc pveeg let A ETE ees 124 8 Developer Informatio sisson cies e E poc ss obsess sates A aa E REE E Layered Library DESigN cuisine iene ree Er aE est 126 R pository Layer e sei daere O RN 127 Repository Access Layer siset esoe e e o E a a EE EEE 131 a 133 Using the APIS etnias lares leete arcada 134 The Apache Portable Runtime Library ooocoooccnnconcconccnnccnnonnncnnnrnnocnnconnconnccnnccnncnnnconnconaconiss 134 URL and Path Req
20. Let s assume that as repository adminis trator you will be responsible for supporting the version control system for several projects The first decision is whether to use a single repository for multiple projects or to give each project its own repository or some compro mise of these two There are benefits to using a single repository for multiple projects most obviously the lack of duplicated mainte nance A single repository means that there is one set of hook scripts one thing to routinely backup one thing to dump and load if Subversion releases an incompatible new version and so on Also you can move data between projects easily and without losing any historical versioning information The downside of using a single repository is that different projects may have different commit mailing lists or differ ent authentication and authorization requirements Also remember that Subversion uses repository global revision numbers Some folks don t like the fact that even though no changes have been made to their project lately the youngest revision number for the repository keeps climbing because other projects are actively adding new revi sions A middle ground approach can be taken too For example projects can be grouped by how well they relate to each other You might have a few repositories with a handful of projects in each repository That way projects that are likely to want to share data can do so easily and as new revisions ar
21. The servers file contains Subversion configuration options related to the network layers There are two special section names in this file groups and global The groups section is essentially a cross reference table The keys in this section are the names of other sections in the file their values are globs textual tokens which possibly con tain wildcard characters that are compared against the hostnames of the machine to which Subversion requests are sent groups beanie babies red bean com collabnet svn collab net beanie babies collabnet 107 Advanced Topics When Subversion is used over a network it attempts to match the name of the server it is trying to reach with a group name under the groups section If a match is made Subversion then looks for a section in the servers file whose name is the matched group s name From that section it reads the actual network configuration settings The global section contains the settings that are meant for all of the servers not matched by one of the globs under the groups section The options available in this section are exactly the same as those valid for the other server sec tions in the file except of course the special groups section and are as follows http proxy host This specifies the hostname of the proxy computer through which your HTTP based Subversion requests must pass It defaults to an empty value which means that Subversion will not attempt
22. Using the Repository Layer with Python 00 0 0 cece ee cece cece cece asec ne ceneeeeeeeeeeeeeeeeeaeseaeeeaeeea sean eeaes 135 8 3 A Simple Script to Check Out a Working Copy cocccoccncccnnconoconoconocnnncnnnnnnroncnnccnnconnccnnccnnconnconncinncos 136 8 4 Contents ofa Typical svn entries Files scerna ered coast bates sauvedon dee dauw ay eS as an besten sueetges IESS ES 137 8 5 Effective Pool Usage ocioteca da Load ise 140 Foreword A bad Frequently Asked Questions FAQ sheet is one that is composed not of the questions people actually asked but of the questions the FAQ s author wished people had asked Perhaps you ve seen the type before Q How can I use Glorbosoft XYZ to maximize team productivity A Many of our customers want to know how they can maximize productivity through our patented office groupware innovations The answer is simple first click on the File menu scroll down to Increase Productivity then The problem with such FAQs is that they are not in a literal sense FAQs at all No one ever called the tech support line and asked How can we maximize productivity Rather people asked highly specific questions like How can we change the calendaring system to send reminders two days in advance instead of one and so on But it s a lot easier to make up imaginary Frequently Asked Questions than it is to discover the real ones Compiling a true FAQ sheet requires a sustained organized
23. VR VCRs and VRs are still ordinary web resources defined by URLs Specific VRs can have human friendly names as well Server side working copy model Some DeltaV servers support the ability to create a virtual workspace on the server where all of your work is performed Clients use the MKWORKSPACE method to create a private area then indicate they want to change specific VCRs by checking them out into the workspace editing them and checking them in again In HTTP terms the sequence of methods would be CHECKOUT PUT CHECKIN After each CHECKIN a new VR is created and the edited VCR s contents now point to the latest VR Each VCR has also has a history re source which tracks and orders its various VR states Client side working copy model Some DeltaV servers also support the idea that the client may have a private working copy full of specific VRs This is how CVS and Subversion work When the client wants to commit changes to the server it begins by creating a temporary server transaction called an activity with the MKACTIVITY method The client then per forms a CHECKOUT on each VR it wishes to change which creates a number of temporary working resources in the activity that can be modified using PUT and PROPPATCH methods Finally the client performs a CHECKIN on each working resource which creates a new VR within each VCR and the entire activity is deleted Configuratio
24. and the script will perform the new import without incident If however there are discrepancies in the file layouts between versions svn_load_dirs pl will prompt you for how you would like to resolve those differences For example you will have the opportunity to tell the script that you know that the file math c in version 1 0 of lib complex was renamed to arithmetic c in libcomplex 1 1 Any discrepancies not explained by moves are treated as regular additions and deletions The script also accepts a separate configuration file for setting properties on files and directories matching a regular expression that are added to the repository This configuration file is specified to svn_load_dirs pl using the p command line option Each line of the configuration file is a whitespace delimited set of two or four values a Perl style regular expression to match the added path against a control keyword either break or cont and then op tionally a property name and value png break svn mime type image png 124 Advanced Topics jpe gs break svn mime type image jpeg m3us cont svn mime type audio x mpegurl m3u break svn eol style LF E break svn eol style native For each added path the configured property changes whose regular expression matches the path are applied in or der unless the control specification is break which means that no more property changes should be applied to that path If the control specification is c
25. copy of the file as it existed in the last revision called the BASE revision that you updated it to in your working copy We refer to this file as the pris tine copy or text base version of your file and it s always an exact byte for byte copy of the file as it exists in the repository HEAD The latest revision in the repository BASE The pristine revision of an item in a working copy COMMITTED The last revision in which an item changed before or at BAS El PREV The revision just before the last revision in which an item changed Technically COMMITTED 1 Note PREV BASE and COMMITTED can be used to refer to local paths but not to URLs Here are some examples of revision keywords in action Don t worry if the commands don t make sense yet we ll be explaining these commands as we go through the chapter svn diff revision PREV COMMITTED foo c shows the last change committed to foo c svn log revision HEAD shows log message for the latest repository commit svn diff revision HEAD compares your working file with local mods to the latest version in the repository svn diff revision BASE HEAD foo c compares your pristine foo c no local mods with the latest version in the repository svn log revision BASE HEAD shows all commit logs since you last updated svn update revision PREV foo c rewinds the last change
26. enforceability of the remainder of the terms of this License and without further action by the parties to this agreement such provision shall be reformed to the minimum extent necessary to make such provision valid and enforceable No term or provision of this License shall be deemed waived and no breach consented to unless such waiver or consent shall be in writing and signed by the party to be charged with such waiver or consent This License constitutes th ntire agreement between th parties with respect to the Work licensed here There are no understandings agreements or representations with respect to the Work not specified here Licensor shall not be bound by any additional provisions that may appear in any communication from You This License may not be modified without the mutual written agreement of the Licensor and You ive Commons is not a party to this License and makes no warranty oever in connection with the Work Creative Commons will not be e to You or any party on any legal theory for any damages oever including without limitation any general special ental or consequential damages arising in connection to this 260 Copyright license No Commons has shall have all rights and obligations of Licensor Except for Work is lic Creative Commons or any related trademark or logo of Creative Commons wit permitted use will be in compliance with Creative Commons then curren
27. moved_dir README added with history and has local modifications D stuff fish c this file is scheduled for deletion A stuff loot bloo h this file is scheduled for addition E stuff loot lump c this file has conflicts from an update Ss stuff squawk this file or dir has been switched to a branch In this output format svn status prints five columns of characters followed by several whitespace characters fol lowed by a file or directory name The first column tells the status of a file or directory and or its contents The codes printed here are A file _or_dir The file or directory file_or_dir has been scheduled for addition into the repository C file The file file is in a state of conflict That is changes received from the server during an update overlap with local changes that you have in your working copy You must resolve this conflict before committing your changes to the repository D file_or_dir The file or directory file_or_dir has been scheduled for deletion from the repository M file The contents of the file file have been modified X dir 27 Guided Tour The directory dir is unversioned but is related to a Subversion externals definition To find out more about ex ternals definitions see Section Externals Definitions file_or_dir The file or directory file_or_dir is not under version control You can silence the question marks by either passing the quiet a switch to svn status or by setti
28. revprop command line parameter and specify the revision whose property you wish to modify Since revisions are global you don t need to specify a path in this case as long as you are positioned in the working copy of the repository whose revision property you wish to modify For example you might want to replace the commit log message of an existing revision 27 svn propset svn log button c Fix a compiler warning r11 revprop property svn log set on repository revision 11 Note that the ability to modify these unversioned properties must be explicitly added by the repository administrator see Section Hook Scripts Since the properties aren t versioned you run the risk of losing information if you aren t careful with your edits The repository administrator can setup methods to protect against this loss and by de fault modification of unversioned properties is disabled And as with file contents your property changes are local modifications only made permanent when you commit them to the repository with svn commit Your property changes can be easily unmade too the svn revert com mand will restore your files and directories to their un edited states contents properties and all Also you can re ceive interesting information about the state of your file and directory properties by using the svn status and svn diff commands svn status calc button c M calc button c S svn diff calc button c Property chang
29. svn log r 2001 12 04 2002 02 17 svn log r 1729 2002 02 17 UN Ut Ut UY Ur See Section Revision Keywords for more information revprop Operates on a revision property instead of a Subversion property specific to a file or directory This switch re quires that you also pass a revision with the revision r switch See Section Unversioned Properties for more details on unversioned properties show updates u Causes the client to display information about which files in your working copy are out of date This doesn t ac tually update any of your files it just shows you which files will be updated if you run svn update stop on Ccopy Causes a Subversion subcommand which is traversing the history of a versioned resource to stop harvesting that historical information when a copy that is a location in history where that resource was copied from another location in the repository is encountered Sstrict Causes Subversion to use strict semantics a notion which is rather vague unless talking about specific subcom mands 146 Subversion Complete Reference targets FILENAME Tells Subversion to get the list of files that you wish to operate on from the filename you provide instead of list ing all the files on the command line username NAME Indicates that you are providing your username for authentication on the command line otherwise if it is needed Subversion will prompt yo
30. version If there s a deleted directory or file that you d like to bring back into HEAD simply use svn copy r to copy 1t from the old revision svn copy r 374 http svn example com repos calc branches my calc branch http svn example com repos calc branches my calc branch Committed revision 376 In our example your personal branch had a relatively short lifetime you may have created it to fix a bug or imple ment a new feature When your task is done so is the branch In software development though it s also common to have two main branches running side by side for very long periods For example suppose it s time to release a stable calc project to the public and you know it s going to take a couple of months to shake bugs out of the soft ware You don t want people to add new features to the project but you don t want to tell all developers to stop pro gramming either So instead you create a stable branch of the software that won t change much svn copy http svn example com repos calc trunk http svn example com repos calc branches stable 1 0 m Creating stable branch of calc project Committed revision 377 And now developers are free to continue adding cutting edge or experimental features to calc trunk and you can declare a project policy that only bugfixes are to be committed to calc branches stable 1 0 That is as people continue to work on the trunk a human selectively p
31. 2 lines Changed paths A calc branches my calc branch from calc trunk 340 As expected the final revision printed by this command is the revision in which my calc branch was created by copying Here s the final merging procedure then cd calc trunk svn update At revision 405 svn merge r 341 HEAD http svn example com repos calc branches my calc branch U integer c U button c U Makefile svn status M integer c M button c M Makefile examine the diffs compile test etc svn commit m Merged my calc branch changes r341 405 into the trunk Sending integer c Sending button c Sending Makefile Transmitting file data Committed revision 406 Again notice that the commit log message very specifically mentions the range of changes that was merged into the trunk Always remember to do this because it s critical information you ll need later on For example suppose you decide to keep working on your branch for another week in order to complete an en hancement to your original feature or bugfix The repository s HI other merge from your private branch to the trunk But as discussed in Section Best Practices for Merging you don t want to merge the changes you ve already merged before you only want to merge everything new on your branch since the last time you merged The trick is to figure out what s new The first step is to run svn log on the trunk and look for a log
32. 3 Notice that the second method however 43 Branching and Merging performs an immediate commit 7 It s an easier procedure because it doesn t require you to check out a large mirror of the repository In fact this technique doesn t even require you to have a working copy at all Figure 4 3 Repository with new copy al trunk 7 branches E Cheap Copies Subversion s repository has a special design When you copy a directory you don t need to worry about the reposi tory growing huge Subversion doesn t actually duplicate any data Instead it creates a new directory entry that points to an existing tree If you re a Unix user this is the same concept as a hard link From there the copy is said to be lazy That is if you commit a change to one file within the copied directory then only that file changes the rest of the files continue to exist as links to the original files in the original directory This is why you ll often hear Subversion users talk about cheap copies It doesn t matter how large the directory is it takes a very tiny constant amount of time to make a copy of it In fact this feature is the basis of how com mits work in Subversion each revision is a cheap copy of the previous revision with a few items lazily changed within To read more about this visit Subversion s website and read about the bubble up method in Subversion s design documents Of course these internal
33. 43 13 0600 Mon 13 Jan 2003 Text Last Updated 2003 01 16 21 18 16 0600 Thu 16 Jan 2003 Properties Last Updated 2003 01 13 21 50 19 0600 Mon 13 Jan 2003 Checksum 3L38YwzhT93BWvgpdF 6Zw It will also show information for directories svn info vendors Path trunk URL http svn red bean com repos test vendors Revision 19 ode Kind directory Schedule normal Last Changed Author harry Last Changed Rev 19 Last Changed Date 2003 01 16 23 21 19 0600 Thu 16 Jan 2003 172 Subversion Complete Reference Name svn list List directory entries in the repository svn list Synopsis svn list TARGET Description List each TARGET file and the contents of each TARGET directory as they exist in the repository If TARGET is a working copy path the corresponding repository URL will be used ee 99 The default TARGET is meaning the repository URL of the current working copy directory With verbose the following fields show the status of the item Revision number of the last commit e Author of the last commit e Size in bytes Date and time of the last commit Alternate Names ls Changes Nothing Accesses Repository Yes Switches revision r REV verbose v recursiv R username USER password PASS no auth cach non interactiv config dir DIR 173 Subversion Complete Reference Examples svn
34. Chapter 4 Branching and Merging your structure should contain three top level directories named branches tags and trunk tmp project branches tmp project tags tmp project trunk foo c bar c Makefile Once you have a tree of data ready to go import the data into the repository with the svn import command see Sec tion svn import svn import tmp project file path to repos m initial import Adding tmp project branches Adding tmp project tags Adding tmp project trunk Adding tmp project trunk foo c Adding tmp project trunk bar c Adding tmp project trunk Makefile Committed revision 1 Now the repository contains your tree of data At this point you create a working copy of the trunk directory This is where your actual work will happen svn checkout file path to repos trunk project A project foo c A project bar c A project Makefile Checked out revision 1 Now you have a personal copy of part of the repository in a new directory named project You can edit the files in your working copy and then commit those changes back into the repository Introduction e Enter your working copy and edit a file s contents e Run svn diff to see unified diff output of your changes e Run svn commit to commit the new version of your file to the repository e Run svn update to bring your working copy up to date with the repository For a full tour of all the things you can do
35. For more information on this keyword and its use see Section Externals Definitions Automatic Property Setting Properties are a powerful feature of Subversion acting as key components of many Subversion features discussed elsewhere in this and other chapters textual diff and merge support keyword substitution newline translation etc But to get the full benefit of properties they must be set on the right files and directories Unfortunately that can be a step easily forgotten in the routine of things especially since failing to set a property doesn t usually result in an obvious error condition at least compared to say failing to add a file to version control To help your properties get applied to the places that need them Subversion provides a couple of simple but useful features Whenever you introduce a file to version control using the svn add or svn import commands Subversion runs a very basic heuristic to determine if that file consists of human readable or non human readable content If the latter is the decision made Subversion will automatically set the svn mime type property on that file to application octet stream the generic this is a collection of bytes MIME type Of course 1f Subversion guesses incor rectly or if you wish to set the svn mime type property to something more precise perhaps image png or ap plication x shockwave flash you can always remove or edit that property Subversion also prov
36. Mortadella Prosciutto Sauerkraut Grilled Chicken gt gt gt gt gt gt gt 1r2 Creole Mustard Bottom piece of bread The strings of less than signs equal signs and greater than signs are conflict markers and are not part of the actual data in conflict You generally want to ensure that those are removed from the file before your next commit The text between the first two sets of markers is composed of the changes you made in the conflicting area lt lt lt lt lt lt lt mine Salami Mortadella Prosciutto Sauerkraut Grilled Chicken gt gt gt gt gt gt gt 1r2 Usually you won t want to just delete the conflict markers and Sally s changes she s going to be awfully surprised when the sandwich arrives and it s not what she wanted So this is where you pick up the phone or walk across the office and explain to Sally that you can t get sauerkraut from an Italian deli 5 Once you ve agreed on the changes you will check in edit your file and remove the conflict markers op piece of bread Mayonnaise Lettuce Tomato Provolone Salami ortadella Prosciutto Creole Mustard Bottom piece of bread Now run svn resolved and you re ready to commit your changes svn resolved sandwich txt svn commit m Go ahead and use my sandwich discarding Sally s edits 5And if you ask them for it they may very well ride you out of town on a rail 33 Guided Tour Remember if you ever get confused wh
37. Synopsis svn mkdir PATH svn mkdir URL Description Create a directory with a name given by the final component of the PATH or URL A directory specified by a work ing copy PATH is scheduled for addition in the working copy A directory specified by a URL is created in the repos itory via an immediate commit Multiple directory URLs are committed atomically In both cases all the intermedi ate directories must already exist Alternate Names None Changes Working copy repository if operating on a URL Accesses Repository Only if operating on a URL Switches message m TEXT file F FILE quiet q username USER password PASS no auth cach non interactiv editor cmd EDITOR encoding ENC force log config dir DIR Examples Create a directory in your working copy svn mkdir newdir 181 Subversion Complete Reference A newdir Create one in the repository instant commit so a log message is required svn mkdir m Making a new dir http svn red bean com repos newdir Committed revision 26 182 Subversion Complete Reference Name svn move Move a file or directory svn move Synopsis svn move SRC DST This command moves a file or directory in your working copy or in the repository Tip This command is equivalent to an svn copy followed by svn delete Note Subversion does not support moving between working copies and URLs
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40. When a client connects to an svnserve process the following things happen e The client selects a specific repository e The server processes the repository s conf svnserve conf file and begins to enforce any authentication and authorization policies defined therein e Depending on the situation and authorization policies e the client may be allowed to make requests anonymously without ever receiving an authentication chal lenge OR e the client may be challenged for authentication at any time OR e if operating in tunnel mode the client will declare itself to be already externally authenticated 89 Server Configuration At the time of writing the server only knows how to send a CRAM MDS 21 authentication challenge In essence the server sends a bit of data to the client The client uses the MDS hash algorithm to create a fingerprint of the data and password combined then sends the fingerprint as a response The server performs the same computation with the stored password to verify that the result is identical At no point does the actual password travel over the net work It s also possible of course for the client to be externally authenticated via a tunnel agent such as SSH In that case the server simply examines the user it s running as and uses it as the authenticated username As you ve already guessed a repository s svnserve conf file is the central mechanism for controlling authentica tion and author
41. Y I Ur svn import file path to repos message Initial repository layout Adding projectA Adding projectA trunk Adding projectA branches Adding projectA tags Adding projectB Adding projectB trunk Adding projectB branches Adding projectB tags Committed revision 1 cd rm rf tmpdir You can verify the results of the import by running the svn list command svn list verbose file path to repos 1 harry May 08 21 48 projectA 83 Repository Administration 1 harry May 08 21 48 projectB Once you have your skeletal layout in place you can begin importing actual project data into your repository if any such data exists yet Once again there are several ways to do this You could use the svn import command You could checkout a working copy from your new repository move and arrange project data inside the working copy and use the svn add and svn commit commands But once we start talking about such things we re no longer dis cussing repository administration If you aren t already familiar with the svn client program see Chapter 3 Guided Tour Summary By now you should have a basic understanding of how to create configure and maintain Subversion repositories We ve introduced you to the various tools that will assist you with this task Throughout the chapter we ve noted common administration pitfalls and suggestions for avoiding them All that remains is for you to decide what exciting dat
42. a new user Since svn merge operates like svn diff comparing the latest trunk and branch trees will not merely describe the set of changes you made to your branch Such a comparison shows too many changes it would not only show the addi tion of your branch changes but also the removal of trunk changes that never happened on your branch To express only the changes that happened on your branch you need to compare the initial state of your branch to its final state Using svn log on your branch you can see that your branch was created in revision 341 And the final state of your branch is simply a matter of using the HEAD revision That means you want to compare revisions 341 and HEAD of your branch directory and apply those differences to a working copy of the trunk Tip A nice way of finding the revision in which a branch was created the base of the branch is to use the stop on copy option to svn log The log subcommand will normally show every change ever made to the branch including tracing back through the copy which created the branch So normally you ll see his tory from the trunk as well The stop on copy will halt log output as soon as svn log detects that its target was copied or renamed 51 Branching and Merging So in our continuing example svn log verbos stop on copy http svn example com repos calc branches my calc branch r341 user 2002 11 03 15 27 56 0600 Thu 07 Nov 2002
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44. and files Subversion provides interfaces for adding modifying and re moving versioned metadata on each of your versioned directories and files We refer to this metadata as properties and they can be thought of as two column tables that map property names to arbitrary values attached to each item in your working copy Generally speaking the names and values of the properties can be whatever you want them to be with the constraint that the names must be human readable text And the best part about these properties is that they too are versioned just like the textual contents of your files You can modify commit and revert property changes as easily as committing textual changes And you receive other people s property changes as you update your working copy Other Properties in Subversion Properties show up elsewhere in Subversion too Just as files and directories may have arbitrary property names and values attached to them each revision as a whole may have arbitrary properties attached to it The same constraints apply human readable text names and anything you want binary values except that revision properties are not versioned See Section Unversioned Properties for more information on these unversioned properties 110 Advanced Topics In this section we will examine the utility both to users of Subversion and to Subversion itself of property sup port You ll learn about the property related svn sub
45. bin diff x b E This switch can only be used if you also pass the diff cmd switch file F FILENAME Uses the contents of the file passed as an argument to this switch for the specified subcommand force Forces a particular command or operation to run There are some operations that Subversion will prevent you from doing in normal usage but you can pass the force switch to tell Subversion I know what I m doing as well as the possible repercussions of doing it so let me at em This switch is the programmatic equivalent of doing your own electrical work with the power on if you don t know what you re doing you re likely to get a nasty shock force log Forces a suspicious parameter passed to the message m or file F options to be accepted as valid By default Subversion will produce an error if parameters to these options look like they might instead be tar gets of the subcommand For example if you pass a versioned file s path to the fi1le F option Subversion will assume you ve made a mistake that the path was instead intended as the target of the operation and that you simply failed to provide some other unversioned file as the source of your log message To assert your intent and override these types of errors pass the force log option to commands that accept log messages help h or If used with one or more subcommands shows the built in help text for each subcommand If used alo
46. by members of Subversion s own development community Others include Chia liang Kao s Subversion converter plugin to the VCP tool http svn clkao org revml branches svn perl and Lev Serebryakov s RefineCVS http lev serebryakov spb ru refinecvs These tools have various levels of completeness and may make entirely different decisions about how to handle your CVS repository history Whichever tool you decide to use be sure to perform as much verification as you can stand on the conversion results after all you ve worked hard to build that history For an updated collection of links to known converter tools visit the Links page of the Subversion website http subversion tigris org project_links html 242 Appendix B Troubleshooting Common Problems There are a number of problems you may run into in the course of installing and using Subversion Some of these will be resolved once you get a better idea of how Subversion does things while others are caused because you re used to the way that other version control systems work Still other problems might be unsolvable due to bugs in some of the operating systems that Subversion runs on considering the wide array of OS es that Subversion runs on it s amazing that we don t encounter many more of these The following list has been compiled over the course of years of Subversion usage If you can t find the problem you re having here look at the most up to date version of the
47. change it use revprop and set svn log to the new log message svn propset revprop r 25 svn log Journaled about trip to New York property svn log set on repository revision 25 Or if you don t have a working copy you can provide a URL S svn propset revprop r 26 svn log Document nap http svn red bean com repos property svn log set on repository revision 25 Lastly you can tell propset to take its input from a file You could even use this to set the contents of a property to something binary svn propset owner pic F sally jpg moo c property owner pic set on moo c Note By default you cannot modify revision properties in a Subversion repository Your repository administrator must explicitly enable revision property modifications by creating a hook named pre revprop change See Section Hook Scripts for more information on hook scripts 194 Subversion Complete Reference Name svn resolved Remove conflicted state on working copy files or directories svn resolved Synopsis svn resolved PATH Description Remove conflicted state on working copy files or directories This routine does not semantically resolve conflict markers it merely removes conflict related artifact files and allows PATH to be committed again that is it tells Subversion that the conflicts have been resolved See Section Resolve Conflicts Merging Others Changes for a
48. client known as WebFolders On Windows 98 the fea ture might need to be explicitly installed if present a WebFolders directory appears directly within My Com puter On Windows 2000 and XP simply open My Network Places and run the Add Network Place icon When prompted enter the WebDAV URL The shared folder will appear within My Network Places Most write operations work fine against an autoversioning mod_dav_svn server but there are a few problems e Ifthe computer is a member of an NT Domain then it seems to be unable to connect to the WebDAV share It repeatedly asks for a name and password even when the Apache server isn t issuing an authentication challenge Some have speculated that this might happen because WebFolders is specifically designed to operate against Mi crosoft s SharePoint DAV server If the machine isn t part of an NT Domain then the share is mounted without a problem This mystery is not yet solved e A file can t be opened for direct editing from the share it always comes up read only The mod_dav_lock tech nique doesn t help because WebFolders doesn t use the LOCK method at all The previously mentioned copy edit re copy method does work however The file on the share can be successfully overwritten by a locally edited copy Mac OS X Unix Apple s OS X operating system has an integrated WebDAV client From the Finder select the Connect to Server item from the Go menu Enter a WebDA
49. controlling access to your repositories Blanket Access Control The simplest form of access control is to authorize certain users for either read only access to a repository or read write access to a repository You can restrict access on all repository operations by adding the Require valid user directive to your Loca lt tion gt block Using our previous example this would mean that only clients that claimed to be either harry or sally and provided the correct password for their respective username would be allowed to do anything with the Subversion repository lt Location svn gt DAV svn SVNParentPath usr local svn how to authenticate a user AuthType Basic AuthName Subversion repository AuthUserFile path to users file only authenticated users may access the repository Require valid user lt Location gt Sometimes you don t need to run such a tight ship For example Subversion s own source code repository at http svn collab net repos svn allows anyone in the world to perform read only repository tasks like checking out working copies and browsing the repository with a web browser but restricts all write operations to authenticated users To do this type of selective restriction you can use the Limit and LimitExcept configuration directives Like the Location directive these blocks have starting and ending tags and you would nest them inside your lt Location gt block The parameters present
50. development shown in Figure 4 4 happening on integer c Figure 4 4 The branching of one file s history copied changed my calc branch integer r343 han l changed i credited Changed 198 303 341 1344 time Things get interesting when you look at the history of changes made to your copy of integer c pwd home user my calc branch svn log verbose integer c r343 user 2002 11 07 15 27 56 0600 Thu 07 Nov 2002 2 lines Changed paths M calc branches my calc branch integer c integer c frozzled the wazjub r341 user 2002 11 03 15 27 56 0600 Thu 07 Nov 2002 2 lines 45 Branching and Merging Changed paths A calc branches my calc branch from calc trunk 340 Creating a private branch of calc trunk r303 sally 2002 10 29 21 14 35 0600 Tue 29 Oct 2002 2 lines Changed paths M calc trunk integer c integer c Changed a docstring r98 sally 2002 02 22 15 35 29 0600 Fri 22 Feb 2002 2 lines Changed paths M calc trunk integer c integer c adding this file to the project Notice that Subversion is tracing the history of your branch s integer c all the way back through time even traversing the point where it was copied It shows the creation of the branch as an event in the history because in teger c was implicitly copied when all of calc trunk was copied Now look what happens when Sally runs the same command on her copy of th
51. dir prop base files Each of these property files working and base versions uses a simple hash on disk file format for storing the property names and values WebDAV WebDAV shorthand for Web based Distributed Authoring and Versioning is an extension of the standard HTTP 37That is the URL for the entry is the same as the concatenation of the parent directory s URL and the entry s name 138 Developer Information protocol designed to make the web into a read write medium instead of the basically read only medium that exists today The theory is that directories and files can be shared as both readable and writable objects over the web RFCs 2518 and 3253 describe the WebDAV DeltaV extensions to HTTP and are available along with a lot of other useful information at http www webdav org A number of operating system file browsers are already able to mount networked directories using WebDAV On Win32 the Windows Explorer can browse what it calls WebFolders which are just WebDAV ready network loca tions as if they were regular shared folders Mac OS X also has this capability as do the Nautilus and Konqueror browsers under GNOME and KDE respectively How does all of this apply to Subversion The mod_dav_svn Apache module uses HTTP extended by WebDAV and DeltaV as one of its network protocols Subversion uses mod_dav_svn to map between Subversion s versioning concepts and those of RFCs 2518 an
52. httpd conf syn tax lt Location repos gt DAV svn SVNPath absolute path to repository lt Location gt If you plan to support multiple Subversion repositories that will reside in the same parent directory on your local disk you can use an alternative directive the SVNParentPath directive to indicate that common parent directory For example if you know you will be creating multiple Subversion repositories in a directory usr local svn that would be accessed via URLs like http my server com svn reposl http my server com svn repos2 and so on you could use the httpd conf configuration syntax in the following example lt Location svn gt DAV svn any svn foo URL will map to a repository usr local svn foo SVNParentPath usr local svn lt Location gt Using the previous syntax Apache will delegate the handling of all URLs whose path portions begin with svn to the Subversion DAV provider which will then assume that any items in the directory specified by the SVNParent Path directive are actually Subversion repositories This is a particularly convenient syntax in that unlike the use of the SVNPath directive you don t have to restart Apache in order to create and network new repositories Be sure that when you define your new Location it doesn t overlap with other exported Locations For example if your main DocumentRoot is www do not export a Subversion repository in lt Location www repos gt If a re quest
53. joe Beesd Or if you want to disable credential caching permanently you can edit your runtime config file located next to the auth directory Simply set store auth creds to no and no credentials will be cached on disk ever auth store auth creds no Sometimes users will want to remove specific credentials from the disk cache To do this you need to navigate into the auth area and manually delete the appropriate cache file Credentials are cached in individual files if you look inside each file you will see keys and values The svn realmstring key describes the particular server realm that the file is associated with ls subversion auth svn simple 5671adf2865e267db74f09ba6f872c28 3893ed123b39500bca8a0b382839198e 5c3c22968347b390 349ff340196ed39 cat subversion auth svn simple 5671adf2865e267db74f0 ba6f872c28 K 8 username V 3 joe K 8 password v 4 blah K 15 svn realmstring V 45 lt https svn domain com 443 gt Joe s repository END Once you have located the proper cache file just delete it One last word about client authentication behavior a bit of explanation about the username and password options is needed Many client subcommands accept these options however it is important to understand using these options does not automatically send credentials to the server As discussed earlier the server pulls credentials from the client when it deems necessary the client cannot
54. leases of software This complicates the process of ensuring that our modifications are still valid for the new version of code and can quickly degrade into a situation where we have to manually recreate our customizations in the new version Once Subversion knows about the history of a given source file including all its previous locations the process of merging in the new version of the library is pretty simple But we are responsible for telling Subversion how the source file layout changed from vendor drop to vendor drop 32And entirely bug free of course 123 Advanced Topics svn_load_dirs pl Vendor drops that contain more than a few deletes additions and moves complicate the process of upgrading to each successive version of the third party data So Subversion supplies the svn_load_dirs pl script to assist with this pro cess This script automates the importing steps we mentioned in the general vendor branch management procedure to make sure that mistakes are minimized You will still be responsible for using the merge commands to merge the new versions of the third party data into your main development branch but svn_load_dirs pl can help you more quickly and easily arrive at that stage In short svn_load_dirs pl is an enhancement to svn import that has several important characteristics e Jt can be run at any point in time to bring an existing directory in the repository to exactly match an external di rectory performing
55. lock the file the repository will deny the request All she can do is read the file and wait for Harry to finish his changes and release his lock After Harry unlocks the file his turn is over and now Sally can take her turn by locking and editing Figure 2 3 demonstrates this simple solution 9 Basic Concepts Figure 2 3 The lock modify unlock solution Marry lacks file A then copies While Marry edits Sally s lock it for editing attempt fails Repository Repository i A if ea Y lx Harry Sally Harry Sally Harry writes his version then Now Sally can lock read and releases his lock edit the lotes version Repository Repository Ls Y E Harry Sally Harry Sally The problem with the lock modify unlock model is that it s a bit restrictive and often becomes a roadblock for Users Locking may cause administrative problems Sometimes Harry will lock a file and then forget about it Mean while because Sally is still waiting to edit the file her hands are tied And then Harry goes on vacation Now Sally has to get an administrator to release Harry s lock The situation ends up causing a lot of unnecessary delay and wasted time Locking may cause unnecessary serialization What 1f Harry is editing the beginning of a text file and Sally sim ply wants to edit the end of the same file These changes don t overlap at all They could easily edit the file si multaneously and no great harm would come assum
56. makes it easy to modify properties that have multiple values svn propedit svn keywords foo c lt svn will launch your favorite editor here with a buffer open containing the current contents of the svn keywords property You can add multiple values to a property easily here by entering one value per line gt Set new value for property svn keywords on foo c 187 Subversion Complete Reference 188 Subversion Complete Reference Name svn propget Print the value of a property svn propget Synopsis svn propget PROPNAME PATH svn propget PROPNAME revprop r REV URL Description Print the value of a property on files directories or revisions The first form prints the versioned property of an item or items in your working copy while the second prints unversioned remote property on a repository revision See Section Properties for more information on properties Alternate Names pget pg Changes Working copy repository only if operating on a URL Accesses Repository Only if operating on a URL Switches recursiv R revision r REV revprop strict username USER password PASS no auth cach non interactiv config dir DIR Examples Examine a property of a file in your working copy svn propget svn keywords foo c Author Date Rev 189 Subversion Complete Reference The same goes for a revision property
57. mechanics of copying and sharing data are hidden from the user who simply sees copies of trees The main point here is that copies are cheap both in time and space Make branches as often as you want 7Subversion does not support cross repository copying When using URLs with svn copy or svn move you can only copy items within the same repository 44 Branching and Merging Working with Your Branch Now that you ve created a branch of the project you can check out a new working copy to start using it svn checkout http svn example com repos calc branches my calc branch A my calc branch Makefile A my calc branch integer c A my calc branch button c Checked out revision 341 There s nothing special about this working copy it simply mirrors a different directory in the repository When you commit changes however Sally won t ever see them when she updates Her working copy is of calc trunk Be sure to read Section Switching a Working Copy later in this chapter the svn switch command is an alternate way of creating a working copy of a branch Let s pretend that a week goes by and the following commits happen e You make a change to calc branches my calc branch button c which creates revision 342 e You make a change to calc branches my calc branch integer c which creates revision 343 e Sally makes a change to calc trunk integer c which creates revision 344 There are now two independent lines of
58. mechanism directory copies and because branches and tags appear in normal filesystem space many people find Subversion intimidating It s almost too flexible In this section we ll offer some sugges tions for arranging and managing your data over time Repository Layout There are some standard recommended ways to organize a repository Most people create a trunk directory to hold the main line of development a branches directory to contain branch copies and a tags directory to contain tag copies If a repository holds only one project then often people create these top level directories trunk branches tags If a repository contains multiple projects admins typically index their layout by project see Section Choosing a Repository Layout to read more about project roots paint trunk paint branches paint tags calc trunk calc branches calc tags Of course you re free to ignore these common layouts You can create any sort of variation whatever works best for you or your team Remember that whatever you choose it s not a permanent commitment You can reorganize your repository at any time Because branches and tags are ordinary directories the svn move command can move or re name them however you wish Switching from one layout to another is just a matter of issuing a series of server side moves if you don t like the way things are organized in the repository just juggle the directories around R
59. modifications to tree structure or tweaks to metadata In more common speak a changeset is just a patch with a name you can refer to In Subversion a global revision number N names a tree in the repository it s the way the repository looked after the Nth commit It s also the name of an implicit changeset if you compare tree N with tree N 1 you can derive the ex act patch that was committed For this reason it s easy to think of revision N as not just a tree but a changeset as well If you use an issue tracker to manage bugs you can use the revision numbers to refer to particular patches that fix bugs for example this issue was fixed by revision 9238 Somebody can then run svn log r9238 to read about the exact changeset which fixed the bug and run svn diff r9237 9238 to see the patch itself And Subver sion s merge command also uses revision numbers You can merge specific changesets from one branch to another by naming them in the merge arguments svn merge r9237 9238 would merge changeset 9238 into your working copy Noticing or Ignoring Ancestry When conversing with a Subversion developer you might very likely hear reference to the term ancestry This word is used to describe the relationship between two objects in a repository if they re related to each other than one ob ject is said to be an ancestor of the other For example suppose you commit revision 100 which includes a change to a file foo c Then
60. not by code outside that library and found inside the library directories themselves differ from this naming scheme in that instead of a single underscore after the library code they use a double underscore __ Functions that are private to a given source file have no special prefixing and are declared static Of course a compiler isn t interested in these naming conventions but they definitely help to clarify the scope of a given function or datatype The Apache Portable Runtime Library Along with Subversion s own datatype you will see many references to datatypes that begin with apr_ symbols from the Apache Portable Runtime APR library APR is Apache s portability library originally carved out of its server code as an attempt to separate the OS specific bits from the OS independent portions of the code The result was a library that provides a generic API for performing operations that differ mildly or wildly from OS to OS While Apache HTTP Server was obviously the first user of the APR library the Subversion developers immediately recognized the value of using APR as well This means that there are practically no OS specific code portions in Subversion itself Also it means that the Subversion client compiles and runs anywhere that the server does Cur rently this list includes all flavors of Unix Win32 BeOS OS 2 and Mac OS X In addition to providing consistent implementations of system calls that differ across operating syst
61. of If you don t foresee yourself participating with the software at such a level feel free to skip this chapter with confidence that your experience as a Subversion user will not be affected Layered Library Design Subversion has a modular design implemented as a collection of C libraries Each library has a well defined pur pose and interface and most modules are said to exist in one of three main layers the Repository Layer the Repos itory Access RA Layer or the Client Layer We will examine these layers shortly but first see our brief inventory of Subversion s libraries in Table 8 1 For the sake of consistency we will refer to the libraries by their extensionless Unix library names e g libsvn_fs libsvn_wc mod_dav_svn Table 8 1 A Brief Inventory of the Subversion Libraries Library Description libsvn_client Primary interface for client programs libsvn_delta Tree and text differencing routines libsvn_fs The Subversion filesystem library libsvn_ra Repository Access commons and module loader libsvn_ra_dav The WebDAV Repository Access module libsvn_ra_local The local Repository Access module libsvn_ra_svn A custom protocol Repository Access module libsvn_repos Repository interface libsvn_subr Miscellaneous helpful subroutines libsvn_we The working copy management library mod_authz_svn Apache authorization module for Subversion repositories access via WebDAV mod_dav_svn Apache
62. of files into a repository creating intermediate directories as necessary svnadmin create usr local svn newrepos svn import mytree file usr local svn newrepos some project Adding mytree foo c Adding mytree bar c Adding mytree subdir Adding mytree subdir quux h Committed revision 1 The previous example copied the contents of directory myt ree under the directory some project in the reposi tory svn ls file usr local svn newrepos some project bar c foo c subdir Summary Now we ve covered most of the Subversion client commands Notable exceptions are those dealing with branching and merging see Chapter 4 Branching and Merging and properties see Section Properties However you may want to take a moment to skim through Chapter 9 Subversion Complete Reference to get an idea of all the many dif ferent commands that Subversion has and how you can use them to make your work easier 40 Chapter 4 Branching and Merging Branching tagging and merging are concepts common to almost all version control systems If you re not familiar with these ideas we provide a good introduction in this chapter If you are familiar then hopefully you ll find it in teresting to see how Subversion implements these ideas Branching is a fundamental part of version control If you re going to allow Subversion to manage your data then this is a feature you ll eventually come to depend on This chapter assumes that
63. of how you might use this program We discuss elsewhere see Section Choosing a Repository Layout the process of deciding how to choose a layout for the data in your repositories using one repository per project or combining them arranging stuff within your repository and so on But sometimes after new revisions start flying in you rethink your layout and would like to make some changes A common change is the decision to move multiple projects which are sharing a single repository into separate repositories for each project Our imaginary repository contains three projects calc calendar and spreadsheet They have been living side by side in a layout like this calc trunk branches tags calendar trunk branches tags spreadsheet trunk branches tags To get these three projects into their own repositories we first make a dumpfile of the whole repository svnadmin dump path to repos gt repos dumpfile Dumped revision 0 Dumped revision 1 Dumped revision 2 Dumped revision 3 Next run that dumpfile through the filter each time including only one of our top level directories and resulting in three new dumpfiles cat repos dumpfile svndumpfilter include calc gt calc dumpfile cat repos dumpfile svndumpfilter include calendar gt cal dumpfile cat repos dumpfile svndumpfilter include spreadsheet gt ss dumpfile E At this point you have to make a decision Each of
64. of your project Checking out a repository creates a copy of it on your local machine This copy contains the HEAD latest revision of the Subversion repository that you specify on the command line 22 Guided Tour svn checkout http svn collab net repos svn trunk A trunk subversion dsw A trunk svn_check dsp A trunk COMMITTERS A A trunk configure in trunk IDEAS Checked out revision 2499 Repository Layout If you re wondering what trunk is all about in the above URL it s part of the way we recommend you lay out your Subversion repository which we ll talk a lot more about in Chapter 4 Branching and Merging Although the above example checks out the trunk directory you can just as easily check out any deep subdirectory of a repository by specifying the subdirectory in the checkout URL svn checkout http svn collab net repos svn trunk doc book tools A tools readme dblite html A tools fo stylesheet xsl A tools svnbook el A tools dtd A tools dtd dblite dtd Checked out revision 2499 Since Subversion uses a copy modify merge model instead of lock modify unlock see Chapter 2 Basic Con cepts you re already able to start making changes to the files and directories in your working copy Your working copy is just like any other collection of files and directories on your system You can edit and change them move them around you can even delete the entire working copy and forget about it
65. on the Limit and LimitExcept directives are HTTP request types that are affected by that block For example if you wanted to disallow all access to your repository except the currently supported read only operations you would use the LimitExcept directive passing the GET PROPFIND OPTIONS and REPORT request type parameters Then the previously mentioned Require valid user directive would be placed inside the lt LimitExcept gt block instead of just inside the lt Location gt block Location svn gt DAV svn SVNParentPath usr local svn A how to authenticate a user AuthType Basic AuthName Subversion repository AuthUserFile path to users file 24More security conscious folk might not want to store the client certificate password in the runtime servers file 98 Server Configuration For any operations other than these require an authenticated user lt LimitExcept GET PROPFIND OPTIONS REPORT gt Require valid user lt LimitExcept gt lt Location gt These are only a few simple examples For more in depth information about Apache access control and the Re quire directive take a look at the Security section of the Apache documentation s tutorials collection at http httpd apache org docs 2 0 misc tutorials html Per Directory Access Control It s possible to set up finer grained permissions using a second Apache httpd module mod_authz_svn This module grabs the variou
66. operating system s patch command to accomplish the same job For example svn diff r 343 344 http svn example com repos calc trunk gt patchfile patch p0 lt patchfile Patching file integer c using Plan A Hunk 1 succeeded at 147 48 Branching and Merging Hunk 2 succeeded at 164 Hunk 3 succeeded at 241 Hunk 4 succeeded at 249 done In this particular case yes there really is no difference But svn merge has special abilities that surpass the patch program The file format used by patch is quite limited it s only able to tweak file contents There s no way to rep resent changes to trees such as the addition removal or renaming of files and directories If Sally s change had say added a new directory the output of svn diff wouldn t have mentioned it at all svn diff only outputs the limited patch format so there are some ideas it simply can t express 8 The svn merge command however can express tree changes by directly applying them to your working copy A word of warning while svn diff and svn merge are very similar in concept they do have different syntax in many cases Be sure to read about them in Chapter 8 for details or ask svn help For example svn merge requires a work ing copy path as a target i e a place where it should apply the tree changes If the target isn t specified it assumes you are trying to perform one of the following common operations 1 You want to merge direc
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68. output of svn merge shows that your copy of integer c was patched It now contains Sally s change the change has been copied from the trunk to your working copy of your private branch and now exists as a local modification At this point it s up to you to review the local modification and make sure it works correctly In another scenario it s possible that things may not have gone so well and that integer c may have entered a conflicted state You might need to resolve the conflict using standard procedures see Chapter 3 or if you decide that the merge was a bad idea altogether simply give up and svn revert the local change But assuming that you ve reviewed the merged change you can svn commit the change as usual At that point the change has been merged into your repository branch In version control terminology this act of copying changes be tween branches is commonly called porting changes When you commit the local modification make sure your log message mentions that you re porting a specific change from one branch to another For example svn commit m integer c ported r344 spelling fixes from trunk Sending integer c Transmitting file data Committed revision 360 As you ll see in the next sections this is a very important best practice to follow Why Not Use Patches Instead A question may be on your mind especially if you re a Unix user why bother to use svn merge at all Why not sim ply use the
69. own use In fact Subversion defines certain properties that have magical effects on the files and directories to which they are attached In this section we ll untangle the mystery and describe how these special properties make your life just a little easier svn executable The svn executable property is used to control a versioned file s filesystem level execute permission bit in a semi automated way This property has no defined values its mere presence indicates a desire that the execute per mission bit be kept enabled by Subversion Removing this property will restore full control of the execute bit back to the operating system On many operating systems the ability to execute a file as a command is governed by the presence of an execute 114 Advanced Topics permission bit This bit usually defaults to being disabled and must be explicitly enabled by the user for each file that needs it In a working copy new files are being created all the time as new versions of existing files are received during an update This means that you might enable the execute bit on a file then update your working copy and if that file was changed as part of the update its execute bit might get disabled So Subversion provides the svn executable property as a way to keep the execute bit enabled This property has no effect on filesystems that have no concept of an executable permission bit such as FAT32 and NTES 28 Also although it has no de
70. prevent you from accidentally destroying changes you ve not yet seen Second you cannot commit a metadata change to a directory unless it s fully up to date You ll learn about attaching properties to items in Chapter 6 A directory s working revision defines a specific set of entries and properties and thus committing a property change to an out of date directory may destroy properties you ve not yet seen Summary We ve covered a number of fundamental Subversion concepts in this chapter e We ve introduced the notions of the central repository the client working copy and the array of repository revi sion trees e We ve seen some simple examples of how two collaborators can use Subversion to publish and receive changes from one another using the copy modify merge model e We ve talked a bit about the way Subversion tracks and manages information in a working copy At this point you should have a good idea of how Subversion works in the most general sense Armed with this knowledge you should now be ready to jump into the next chapter which is a detailed tour of Subversion s com mands and features 19 Chapter 3 Guided Tour Now we will go into the details of using Subversion By the time you reach the end of this chapter you will be able to perform almost all the tasks you need to use Subversion in a normal day s work You ll start with an initial check out of your code and walk through making changes and examin
71. previous version in at least the area where the keyword anchor was placed However this is actually not the case While checking for local modifications during svn diff and before transmitting those local modifications during svn commit Subversion un substitutes any keywords that it previously substituted The re sult is that the versions of the file that are stored in the repository contain only the real modifications that users make to the file Immediately after you commit this property change Subversion will update your working file with the new substi tute text Instead of seeing your keyword anchor LastChangedDate you ll see its substituted result That result also contains the name of the keyword and continues to be bounded by the dollar sign characters And as we predicted the Rev keyword was not substituted because we didn t ask for it to be Here is the latest report from the front lines SLastChangedDate 2002 07 22 21 42 37 0700 Mon 22 Jul 2002 SRevS Cumulus clouds are appearing more frequently as summer approaches If someone else now commits a change to weather txt your copy of that file will continue to display the same substituted keyword value as before until you update your working copy At that time the keywords in your weather txt file will be re substituted with information that reflects the most recent known commit to that file svn eol style 31 or maybe even a section of a book
72. push them at will If a username and or password are passed as options they will only be presented to the server if the server requests them 20 Typically these options are used when e the user wants to authenticate as a different user than her system login name or e ascript wants to authenticate without using cached credentials Here is a final summary that describes how a Subversion client behaves when it receives an authentication chal lenge 20A gain a common mistake is to misconfigure a server so that it never issues an authentication challenge When users pass username and password options to the client they re surprised to see that they re never used i e new revisions still appear to have been committed anony mously 87 Server Configuration 1 Check whether the user specified any credentials as commandline options via username and or password If not or if these options fail to authenticate successfully then 2 Look up the server s realm in the runtime auth area to see if the user already has the appropriate credentials cached If not or if the cached credentials fail to authenticate then 3 Resort to prompting the user If the client successfully authenticates by any of the methods listed above it will attempt to cache the credentials on disk unless the user has disabled this behavior as mentioned earlier svnserve a custom server The svnserve program is a lightweight server capabl
73. re worried about password snooping it may be best to use some sort of SSL encryption so that clients authenticate via https instead of http at a bare minimum you can configure Apache to use a self signed server certificate 23 Consult Apache s documentation and OpenSSL documentation about how to do that SSL Certificate Management Businesses that need to expose their repositories for access outside the company firewall should be conscious of the possibility that unauthorized parties could be sniffing their network traffic SSL makes that kind of unwanted at tention less likely to result in sensitive data leaks If a Subversion client is compiled to use OpenSSL then it gains the ability to speak to an Apache server via https URLs The Neon library used by the Subversion client is not only able to verify server certificates but can also supply client certificates when challenged When the client and server have exchanged SSL certificates and successfully authenticated one another all further communication is encrypted via a session key It s beyond the scope of this book to describe how to generate client and server certificates and how to configure Apache to use them Many other books including Apache s own documentation describe this task But what can be covered here is how to manage server and client certificates from an ordinary Subversion client When speaking to Apache via https a Subversion client can recei
74. received Derivative Works or Collective Works from You under this License however will not have their licenses terminated provided such individuals or entities remain in full compliance with those licenses Sections 1 2 5 6 7 and 8 will survive any termination of this License Subject to the above terms and conditions the license granted here is perpetual for the duration of the applicable copyright in the Work Notwithstanding the above Licensor reserves th right to release the Work under different license terms or to stop distributing the Work at any time provided however that any such election will not serve to withdraw this License or any other license that has been or is required to be granted under the terms of this License and this License will continue in full force and effect unless terminated as stated above scellaneous Each time You distribute or publicly digitally perform the Work or a Collective Work the Licensor offers to the recipient a license to the Work on the same terms and conditions as the license granted to You under this License Each time You distribute or publicly digitally perform a Derivative Work Licensor offers to the recipient a license to the original Work on the same terms and conditions as the license granted to You under this License If any provision of this License is invalid or unenforceable under applicable law it shall not affect the validity or
75. repository as in svn log r 2 http svn collab net repos svn svn diff We ve already seen svn diff before it displays file differences in unified diff format it was used to show the local modifications made to our working copy before committing to the repository In fact it turns out that there are three distinct uses of svn diff e Examine local changes e Compare your working copy to the repository e Compare repository to repository Examining Local Changes As we ve seen invoking svn diff with no switches will compare your working files to the cached pristine copies in the svn area svn diff Index rules txt rules txt revision 3 rules txt working copy 1 4 1 5 ee Be kind to others Freedom Responsibility Everything in moderation Chew with your mouth open Chew with your mouth closed Listen when others are speaking Comparing Working Copy to Repository If a single revision r number is passed then your working copy is compared to the specified revision in the repository svn diff revision 3 rules txt Index rules txt rules txt revision 3 rules txt working copy 37 Guided Tour ee 1 4 1 5 Ce Be kind to others Freedom Responsibility Everything in moderation Chew with your mouth open Chew with your mouth closed Listen when others are speaking Comparing Repository to Repository If two rev
76. request that describes the mixed revision and mixed url state of the working copy The server sends a custom response that describes which items need updating The client loops over the response performing GET and PROPFIND requests as needed For updates and switches install the new data in the work ing copy For diff and merge commands compare the data to the working copy possibly applying changes as local modifications Autoversioning Support At the time of writing the truth is that there are very few DeltaV clients in the world RFC 3253 is still relatively new However users do have access to generic clients because almost every modern operating system now has an integrated basic WebDAV client With this in mind Subversion developers realized that if Subversion 1 0 was to have any interoperability features support for DeltaV autoversioning would be the best approach To activate autoversioning in mod_dav_svn use the SVNAutoversioning directive within the httpd conf Lo cation block like so lt Location repos gt DAV svn SVNPath absolute path to repository SVNAutoversioning on lt Location gt Normally if a generic WebDAV client attempted a PUT to a path within your repository location mod_dav_svn would outright reject the request It normally only allows such operations on working resources within DeltaV activities With SVNAutoversioning turned on however the server interprets the PUT request a
77. revision 1729 Checks out a new working copy at r1729 svn update revision 1729 Updates an existing working copy to r1729 Other Useful Commands While not as frequently used as the commands previously discussed in this chapter you will occasionally need these commands svn cleanup When Subversion modifies your working copy or any information within svn it tries to do so as safely as possi ble Before changing anything it writes its intentions to a log file executes the commands in the log file then re moves the log file this is similar in design to a journaled filesystem If a Subversion operation is interrupted if the process is killed or if the machine crashes for example the log files remain on disk By re executing the log files Subversion can complete the previously started operation and your working copy can get itself back into a consis 6See We told you that Subversion was a time machine 39 Guided Tour tent state And this is exactly what svn cleanup does it searches your working copy and runs any leftover logs removing locks in the process If Subversion ever tells you that some part of your working copy is locked then this is the command that you should run Also svn status will display an L next to locked items svn status L somedir M somedir foo c svn cleanup svn status M somedir foo c svn import The svn import command is a quick way to copy an unversioned tree
78. site Now consider the same setup using Subversion s file properties Imagine having a single image file image123 jpg and then properties set on that file named caption datestamp and even thumbnail Now your working copy directory looks much more manageable in fact it looks like there are nothing but image files in it But your automation scripts know better They know that they can use svn or better yet they can use the Subver sion language bindings see Section Using Languages Other than C and C to dig out the extra information that your site needs to display without having to read an index file or play path manipulation games How and if you use Subversion properties is up to you As we mentioned Subversion has it own uses for proper ties which we ll discuss a little later in this chapter But first let s discuss how to manipulate options using the svn program Manipulating Properties The svn command affords a few ways to add or modify file and directory properties For properties with short hu man readable values perhaps the simplest way to add a new property is to specify the property name and value on the command line of the propset subcommand svn propset copyright c 2003 Red Bean Software calc button c property copyright set on calc button c But we ve been touting the flexibility that Subversion offers for your property values And if you are planning to have a multi line textual or even binar
79. sshd launch it for you Once the client has selected a repository by transmitting its URL svnserve reads a file named conf svnserve conf in the repository directory to determine repository specific settings such as what authentication database to use and what authorization policies to apply See Section svnserve a custom server for details of the svnserve conf file svnserve Switches Unlike the previous commands we ve described svnserve has no subcommands svnserve is controlled exclusively by switches daemon d Causes svnserve to run in daemon mode svnserve backgrounds itself and accepts and serves TCP IP connec tions on the svn port 3690 by default 1listen port PORT Causes svnserve to listen on PORT when run in daemon mode listen host HOST Causes svnserve to listen on the interface specified by HOST which may be either a hostname or an IP address foreground When used together with d this switch causes svnserve to stay in the foreground This switch is mainly useful for debugging inetd i 236 Subversion Complete Reference Causes svnserve to use the stdin stdout file descriptors as is appropriate for a daemon running out of inetd help h Displays a usage summary and exits root ROOT r ROOT Sets the virtual root for repositories served by svnserve The pathname in URLs provided by the client will be interpreted relative to this root and will not be allowed to e
80. svn propset PROPNAME revprop r REV PROPVAL F VALFILE URL Description Set PROPNAME to PROPVAL on files directories or revisions The first example creates a versioned local property change in the working copy and the second creates an unversioned remote property change on a repository revi sion Tip Subversion has a number of special properties that affect its behavior See Section Special Properties for more on these properties Alternate Names pset ps Changes Working copy repository only if operating on a URL Accesses Repository Only if operating on a URL Switches file F FILE quiet a revision r REV targets FILENAME recursiv R revprop username USER password PASS no auth cach non interactiv encoding ENC force config dir DIR 193 Subversion Complete Reference Examples Set the mimetype on a file svn propset svn mime type image jpeg foo jpg property svn mime type set on foo jpg On a UNIX system if you want a file to have the executable permission set svn propset svn executable ON somescript property svn executable set on somescript Perhaps you have an internal policy to set certain properties for the benefit of your coworkers svn propset owner sally foo c property owner set on foo c If you made a mistake in a log message for a particular revision and want to
81. svnadmin s subcommands is set log When a transaction is committed to the repository and promoted to a revision the descriptive log message associated with that new revision and provided by the user is stored as an unversioned property attached to the revision itself In other words the repository re members only the latest value of the property and discards previous ones Sometimes a user will have an error in her log message a misspelling or some misinformation perhaps If the repository is configured using the pre revprop change and post revprop change hooks see Section Hook Scripts to accept changes to this log message after the commit is finished then the user can fix her log message remotely using the svn program s propset command see Chapter 9 Subversion Complete Reference However because of the potential to lose information forever Subversion repositories are not by default config ured to allow changes to unversioned properties except by an administrator If a log message needs to be changed by an administrator this can be done using svnadmin setlog This command changes the log message the svn log property on a given revision of a repository reading the new value from a provided file echo Here is the new correct log message gt newlog txt svnadmin setlog myrepos newlog txt r 388 The svnadmin setlog command alone is still bound by the same protections against modifying unversioned pr
82. the Administrative Areas of Subversion and CVS A glance inside the typical svn directory turns up a bit more than what CVS maintains in its CVS administrative di rectories The entries file contains XML which describes the current state of the working copy directory and basi cally serves the purposes of CVS s Entries Root and Repository files combined The following is an example of an actual entries file Example 8 4 Contents of a Typical svn entries File lt xml version 1 0 encoding utf 8 gt lt wc entries xml1lns svn gt lt entry committed rev 1 name svn this_dir committed date 2002 09 24T17 12 44 0644752Z url http svn red bean com tests greek repo A D kind dir revision 1 gt lt entry committed rev 1 name gamma text time 2002 09 26T21 09 02 0000002Z committed date 2002 09 24T17 12 44 0644752Z checksum QSE4vWd9ZM0cMvr7 YkXQ kind file prop time 2002 09 26T21 09 02 000000Z gt lt entry 137 Developer Information name zeta kind file schedule add revision 0 gt lt entry url http svn red bean com tests greek repo A B delta name delta kind file schedule add revision 0 gt lt entry name G kind dir gt lt entry name H kind dir schedule delete gt lt wc entries gt As you can see the entries file is essentially a list of entries Each entry tag represents one of th
83. the PKZIP and gzip programs so re quests can be sent in smaller compressed chunks across the wire Other complex features that Subversion hopes to support in the future include the ability to automatically handle server specified redirects for example when a repository has been moved to a new canonical URL and taking advantage of HTTP pipelining RA SVN Custom Protocol Repository Access In addition to the standard HTTP WebDAV protocol Subversion also provides an RA implementation that uses a custom protocol The libsvn_ra_svn module implements its own network socket connectivity and communicates with a stand alone server the svnserve program on the machine that hosts the repository Clients access the repository using the svn schema This RA implementation lacks most of the advantages of Apache mentioned in the previous section however it may be appealing to some sysadmins nonetheless It is dramatically easier to configure and run setting up an svnserve process is nearly instantaneous It is also much smaller in terms of lines of code than Apache making it 132 Developer Information much easier to audit for security reasons or otherwise Furthermore some sysadmins may already have an SSH se curity infrastructure in place and want Subversion to use it Clients using ra_svn can easily tunnel the protocol over SSH RA Local Direct Repository Access Not all communications with a Subversion repository require
84. the tunnel agent svnserve is aware that it s run ning as the user harry and if the client performs a commit the authenticated username will be attributed as the au thor of the new revision When running over a tunnel authorization is primarily controlled by operating system permissions to the reposi tory s database files it s very much the same as if Harry were accessing the repository directly via a file URL If multiple system users are going to be accessing the repository directly you may want to place them into a common group and you ll need to be careful about umasks Be sure to read Section Supporting Multiple Reposi tory Access Methods But even in the case of tunneling the svnserve conf file can still be used to block access by simply setting auth access readorauth access non You d think that the story of SSH tunneling would end here but it doesn t Subversion allows you to create custom tunnel behaviors in your run time config file see Section Runtime Configuration Area For example suppose you want to use RSH instead of SSH In the tunnels section of your config file simply define it like this 91 Server Configuration tunnels rsh rsh And now you can use this new tunnel definition by using a URL schema that matches the name of your new vari able svn rsh host path When using the new URL schema the Subversion client will actually be running the command rsh host svnserve t
85. this section we ll show real examples of Subversion being used 12 Basic Concepts Working Copies You ve already read about working copies now we ll demonstrate how the Subversion client creates and uses them A Subversion working copy is an ordinary directory tree on your local system containing a collection of files You can edit these files however you wish and if they re source code files you can compile your program from them in the usual way Your working copy is your own private work area Subversion will never incorporate other people s changes nor make your own changes available to others until you explicitly tell 1t to do so After you ve made some changes to the files in your working copy and verified that they work properly Subversion provides you with commands to publish your changes to the other people working with you on your project by writing to the repository If other people publish their own changes Subversion provides you with commands to merge those changes into your working directory by reading from the repository A working copy also contains some extra files created and maintained by Subversion to help it carry out these com mands In particular each directory in your working copy contains a subdirectory named svn also known as the working copy administrative directory The files in each administrative directory help Subversion recognize which files contain unpublished changes and which file
86. to route HTTP requests through a proxy computer and will instead attempt to contact the destination machine directly http proxy port This specifies the port number on the proxy host to use It defaults to an empty value http proxy usernam This specifies the username to supply to the proxy machine It defaults to an empty value http proxy password This specifies the password to supply to the proxy machine It defaults to an empty value http timeout This specifies the amount of time in seconds to wait for a server response If you experience problems with a slow network connection causing Subversion operations to timeout you should increase the value of this op tion The default value is 0 which instructs the underlying HTTP library Neon to use its default timeout set ting http compression This specifies whether or not Subversion should attempt to compress network requests made to DAV ready servers The default value is yes though compression will only occur if that capability is compiled into the net work layer Set this to no to disable compression such as when debugging network transmissions neon debug mask This is an integer mask that the underlying HTTP library Neon uses for choosing what type of debugging out put to yield The default value is 0 which will silence all debugging output For more information about how Subversion makes use of Neon see Chapter 8 Developer Information ssl authority file
87. to supply the recursive flag if you want that behavior is intended to make you really think about what you re doing because once your files are reverted your local modifi cations are gone forever When start Apache mod_dav_svn complains about a bad database ver 245 Troubleshooting sion that it found db 3 X rather than db 4 X Your apr util linked against DB 3 and svn linked against DB 4 Unfortunately the DB symbols aren t different When mod_dav_svn is loaded into Apache s process space it ends up resolving the symbol names against apr util s DB 3 library The solution is to make sure apr util compiles against DB 4 You can do this by passing specific switches to either apr util s or apache s configure with dbm db4 with berkeley db the db prefix I m getting Function not implemented errors on RedHat 9 and nothing works How do fix this This is not really a problem with Subversion but it often affects Subversion users RedHat 9 and Fedora ship with a Berkeley DB library that relies on the kernel support for NPTL the Native Posix Threads Library The kernels that RedHat provides have this support built in but if you compile your own kernel then you may well not have the NPTL support If that is the case then you will see errors like this svn Berkeley DB error svn Berkeley DB error while creating environment for filesystem tester db Function not implemented This can be fixed in one of sev
88. to txn info sh path to repos The output is basically a concatenation of several chunks of svnlook info output see Section svnlook and will look something like txn info sh myrepos Transaction 19 se sally 2001 09 04 11 57 19 0500 Tue 04 Sep 2001 0 Transaction 3al harry 2001 09 10 16 50 30 0500 Mon 10 Sep 2001 39 Trying to commit over a faulty network Transaction a45 sally 2001 09 12 11 09 28 0500 Wed 12 Sep 2001 0 Usually if you see a dead transaction that has no log message attached to it this is the result of a failed update or update like operation These operations use Subversion transactions under the hood to mimic working copy state Since they are never intended to be committed Subversion doesn t require a log message for those transactions Transactions that do have log messages attached are almost certainly failed commits of some sort Also a transac tion s datestamp can provide interesting information for example how likely is it that an operation begun nine months ago is still active In short transaction cleanup decisions need not be made unwisely Various sources of information including Apache s error and access logs the logs of successful Subversion commits and so on can be employed in the deci sion making process Finally an administrator can often simply communicate with a seemingly dead transaction s owner via email for example to v
89. two things e You will always find the latest version of this book in Subversion s own source tree e You can distribute and make changes to this book however you wish it s under a free license Of course rather than distribute your own private version of this book we d much rather you send feedback and patches to the Subversion developer community See Section Contributing to Subversion to learn about joining this com munity You can send publishing comments and questions to O Reilly here insert boilerplate A relatively recent online version of this book can be found at http svnbook red bean com Acknowledgments From This book would not be possible nor very useful if Subversion did not exist For that the authors would like to thank Brian Behlendorf and CollabNet for the vision to fund such a risky and ambitious new Open Source project Jim Blandy for the original Subversion name and design we love you Jim Karl Fogel for being such a good friend and a great community leader in that order 1 Thanks to O Reilly and our editors Linda Mui and Tatiana Diaz for their patience and support Finally we thank the countless people who contributed to this book with informal reviews suggestions and fixes While this is undoubtedly not a complete list this book would be incomplete and incorrect without the help of Jani Averbach Ryan Barrett Francois Beausoleil Jennifer Bevan Matt Blais Zack Brown Martin Buchholz B
90. with fix myproj foo txt myproj bar txt myproj baz c myproj qux c aaa a 203 Subversion Complete Reference Updated to revision 31 And to switch back just provide the URL to the location in the repository from which you originally checked out your working copy svn switch http svn red bean com repos trunk vendors myproj foo txt myproj bar txt myproj baz c myproj qux c pdated to revision 31 Gaqaqqqn Tip You can just switch part of your working copy to a branch if you don t want to switch your entire working copy If the location of your repository changes and you have an existing working copy that you d like to continue to use you can use svn switch relocate to change your working copy from one URL to another svn checkout file tmp repos test A test a A test b mv repos newlocation cd test svn update svn Unable to open an ra_local session to URL svn Unable to open repository file tmp repos svn switch relocate file tmp repos file tmp newlocation svn update At revision 3 204 Subversion Complete Reference Name svn update Update your working copy svn update Synopsis svn update PATH Description svn update brings changes from the repository into your working copy If no revision given it brings your working copy up to date with the HI revision switch EAD revision Otherwise it synchronizes the working copy to the re
91. with your working copy read Chapter 3 Guided Tour At this point you have the option of making your repository available to others over a network See Chapter 6 Server Configuration to learn about the different sorts of server processes available and how to configure them Chapter 2 Basic Concepts This chapter is a short casual introduction to Subversion If you re new to version control this chapter is definitely for you We begin with a discussion of general version control concepts work our way into the specific ideas behind Subversion and show some simple examples of Subversion in use Even though the examples in this chapter show people sharing collections of program source code keep in mind that Subversion can manage any sort of file collection it s not limited to helping computer programmers The Repository Subversion is a centralized system for sharing information At its core is a repository which is a central store of data The repository stores information in the form of a filesystem tree a typical hierarchy of files and directories Any number of clients connect to the repository and then read or write to these files By writing data a client makes the information available to others by reading data the client receives information from others Figure 2 1 illustrates this Figure 2 1 A typical client server system Repository Hirie T Client Client So why is this interesting So far this sounds l
92. working copy removing locks resuming unfinished operations If you ever get a working copy locked error run this command to remove stale locks and get your working copy into a usable state again See Appendix B Troubleshooting If for some reason an svn update fails due to a problem running an external diff program e g user input or net work failure pass the diff 3 cmd to allow cleanup to complete any merging with your external diff program You can also specify any configuration directory with the config dir switch but you should need these switches extremely infrequently Alternate Names None Changes Working copy Accesses Repository Switches diff3 cmd CMD config dir DIR Examples Well there s not much to the examples here as svn cleanup generates no output If you pass no PATH is used svn cleanup svn cleanup path to working copy 155 Subversion Complete Reference Name svn commit Send changes from your working copy to the repository svn commit Synopsis svn commit PATH Description Send changes from your working copy to the repository If you do not supply a log message with your commit by using either the file or message switch svn will launch your editor for you to compose a commit message See the editor cmd section in Section Config Tip If you begin a commit and Subversion launches your editor to compose the commit messag
93. your Subversion repository See Servers and Permissions A Word of Warning 94 Server Configuration You will need to determine a permission system setup that satisfies Subversion s requirements without messing up any previously existing web page or script installations This might mean changing the permissions on your Subver sion repository to match those in use by other things that Apache serves for you or it could mean using the User and Group directives in httpd conf to specify that Apache should run as the user and group that owns your Sub version repository There is no single correct way to set up your permissions and each administrator will have dif ferent reasons for doing things a certain way Just be aware that permission related problems are perhaps the most common oversight when configuring a Subversion repository for use with Apache Authentication Options At this point if you configured httpd conf to contain something like lt Location svn gt DAV svn SVNParentPath usr local svn lt Location gt then your repository is anonymously accessible to the world Until you configure some authentication and au thorization policies the Subversion repositories you make available via the Location directive will be generally accessible to everyone In other words e anyone can use their Subversion client to checkout a working copy of a repository URL or any of its subdirecto ries e anyone can interact
94. your dumpfiles will create a valid repository but will preserve the paths exactly as they were in the original repository This means that even though you would have a repository solely for your calc project that repository would still have a top level directory named calc If you want your trunk tags and branches directories to live in the root of your repository you might wish to edit your dump files tweaking the Node path and Copyfrom path headers to no longer have that first calc path component Also you ll want to remove the section of dump data that creates the calc directory It will look something like Node path calc Node action add Node kind dir 70 Repository Administration Content length 0 All that remains now is to create your three new repositories and load each dumpfile into the right repository svnadmin create calc svnadmin load calc lt calc dumpfile lt lt lt Started new transaction based on original revision 1 adding path Makefile done adding path button c done lt lt lt Started new transaction based on original revision 1 adding path Makefile done svnadmin create calendar svnadmin load calendar lt cal dumpfile adding path cal c done svnadmin create spreadsheet svnadmin load spreadsheet lt ss dumpfile lt lt lt Started new transaction based on original revision 1 adding path Makefile done adding path ss c done
95. 00 Server Configuration calc branches calc bug 142 harry rw sally r In this first example the user harry has full read and write access on the branches calc bug 142 directory in the calc repository but the user sally has read only access Any other users are blocked from accessing this direc tory Of course permissions are inherited from parent to child directory That means that we can specify a subdirectory with a different access policy for Sally calc branches calc bug 142 harry rw sally r give sally write access only to the testing subdir calc branches calc bug 142 testing sally rw Now Sally can write to the testing subdirectory of the branch but can still only read other parts Harry mean while continues to have complete read write access to the whole branch It s also possible to explicitly deny permission to someone via inheritance rules by setting the username variable to nothing calc branches calc bug 142 harry rw sally r calc branches calc bug 142 secret harry In this example Harry has read write access to the entire bug 142 tree but has absolutely no access at all to the secret subdirectory within it By default nobody has any access to the repository at all That means that if you re starting with an empty file you ll probably want to give at least read permission to all users at the root of the repository You can do this by using the asterisk variable
96. 1 Merging a Whole Branch to Another oooccoccnnccnccnnccnnccnnccnnconnconnconnconncnnnconncnnncnnnrnnronaronicnnos 51 Undoing Changes Fun N aa iD dE ec Maden 53 Resurrecting Deleted Items escsi sccvcsteviesis vauescessepeegeas oot leds Ea E E E E SEESE RES 54 Switching a Working Copy evmecoooneccoonoteios riera ete rin nadia nde EEES ESEE EEEIEE EEEE REEE 55 A RO 56 Creating aSimple Ta coincida iden pubs asedets labs 56 Creating a Complex Tag cosita iia mistica lante eii entera 57 Branch Maldtendnce ss ssi ins A ETE EEA EEEE E de 58 Repository Layouts ii io E E E TEES 58 Dates sia ls A E a E E SERE 58 SUMA IS A AS A ds A a ad 59 Gi Po AAA phn sh ssh wetns sanwea Seis hi wonsss phewasy od ware E E ARN ERE SEEE Repository Basie A A A DA EE TEE 60 Understanding Transactions and Revisions oooooccoccnnconnconnccnncnnnconnconrononnnronnrnnncnnccnnccnnccnncos 60 Unversioned Properties iiis etsien EEE cues na caia ie adenda 61 Berkeley DB radiadores lira rin 61 Repository Creation and Configuration ooocooccnccnnccnnccnnconnconnconnconnconncnnncnnncnnnrnnronnrnnnrnnccnnccnnccnnioos 62 HOOK Scripts ssccesssseriieisp e e E E de neeghete ysaber el vaaaetde sea A E E 63 Berkeley DB Configuration 3 cccccsseccesces ones cee ceee seas USETE ISET desstavecusossaevedesttvensosteeecesstavecueeses 64 Repository Maintenance oi csccesse Eaa pess ra aane Eaa I oea GETER E SEE OEE pa ITERE EPOE sees 65 AnAdministrators Toolkit donen cateo ales e
97. 2 12 gt 17 branches 1 0 rc2 lt 1 1 10 gt 16 branches 1 0 rc2 lt 1 1 x gt 14 trunk lt 1 0 q gt 13 trunk lt 1 0 0 gt 14 trunk lt 1 0 k gt 9 trunk lt 1 0 g gt 8 trunk lt 1 0 e gt 7 trunk lt 1 0 b gt 6 trunk lt 1 0 9 gt 5 trunk lt 1 0 7 gt 4 trunk lt 1 0 6 gt 2 trunk lt 1 0 3 gt 1 trunk lt 1 0 2 gt 229 Subversion Complete Reference Name svnlook info Print the author datestamp log message size and log message svnlook info Synopsis svnlook info REPOS_PATH Description Print the author datestamp log message size and log message Switches revision 1 transaction t Examples This shows the info output for revision 40 in our sample repository svnlook info r 40 usr local svn repos sally 2003 02 22 17 44 49 0600 Sat 22 Feb 2003 15 Rearrange lunch 230 Subversion Complete Reference Name svnlook log Print the log message svnlook log Synopsis svnlook log REPOS_PATH Description Print the log message Switches revision 1 transaction t Examples This shows the log output for revision 40 in our sample repository svnlook log tmp repos Rearrange lunch 231 Subversion Complete Reference Name svnlook propget Print the raw value of a property on a path in the repository svnlook propget Synopsis svnlook propget REPOS_PATH PROPNAME PATH_IN_REPOS
98. 22 Basic Work Cyc lem ccs doveniete oir pri despe ie dba ppanenssphtvsa tsp or cpenseed dee bers diarias Beeb area dies y 24 Update Your Workin COPY ss cee E ata ee teins iia 25 Make Changes to Your Working Copy ooccocccnccnncnnncnnccnnccnnconnconnconnconnconncnnncnnncnnnrnnronarenicnnos 25 Examine Y our Changes inienn esie lead Quedoviluydessigueehsbs ievedasta EEES EE ETER S 26 Resolve Conflicts Merging Others Changes oooconoccnocnnccnnncnncnnncnnncnnconnconnconnccnnconnconnconinonoss 31 Commit Your Changes contorno iaa ese aeeess 34 Examining NN 35 O NN 36 NS 37 SVM Cat waa forse RR aca dowenbed gees has upeuens 38 SVMS e855 So Rab aoe A 39 AsFinal Word on HIStOr eese obs eect adveeseed seein es pee RES EE RE T pE E E AEE E EES toes wade 39 Version Control with Subversion Other Useful Commands ud A IE eee ee ee eis 39 O NN 39 SAID A o E 40 SUMIMALY A NN 40 4 Branching and Merging a ts A TO 41 PSA NO 41 Creating a Branch consi isidro ilatina TEOSES TENISERE ries 43 Working with Your Branch ocoooccnnccnnconoconocnncconorononnnrnnoronconnconnocnncrnncrnncrnncnnnrnnnrnnrnnnrnnns 45 The Key Concepts Behind Branches occooccnnconnconoconcconocnnnnnnonnncnnncnnconnconncrnncrnnccnnconnconaroniss 46 Copying Changes Between Branches spessi iea cece nec c eens E E aE Eea Eep s SERERE TENE 47 Copyime Specific Changes cicle ll tilda es da 47 Best Practices a AAA NO 49 Common Use Cases for MergIdg cti a erat 5
99. 8Note that the URL checked out in the example above ends not with svn but with a subdirectory thereof called trunk See our discussion of Subversion s branching and tagging model for the reasoning behind this 39While this may superficially appear as some sort of elitism this earn your commit privileges notion is about efficiency whether it costs more in time and effort to review and apply someone else s changes that are likely to be safe and useful versus the potential costs of undoing changes that are dangerous 40You might want to grab some popcorn Thorough in this instance translates to somewhere in the neighborhood of thirty minutes of non interactive machine churn 142 Developer Information sidered a success Ultimately the better the test suite the less time wasted on diagnosing potentially obscure regres sion bugs Donate Your Changes After making your modifications to the source code compose a clear and concise log message to describe those changes and the reasons for them Then send an email to the developers list containing your log message and the output of svn diff from the top of your Subversion working copy If the community members consider your changes acceptable someone who has commit privileges permission to make new revisions in the Subversion source repository will add your changes to the public source code tree Recall that permission to directly commit changes to the repository is grante
100. Check that the loop exited cleanly if apr_err return apr_err Yes it exited cleanly so close the dir apr_err apr_dir_close dir if apr_err return apr_err return APR_SUCCESS The previous example demonstrates effective pool usage in both looping and recursive situations Each recursion be gins by making a subpool of the pool passed to the function This subpool is used for the looping region and cleared with each iteration The result is memory usage is roughly proportional to the depth of the recursion not to total number of file and directories present as children of the top level directory When the first call to this recursive func tion finally finishes there is actually very little data stored in the pool that was passed to it Now imagine the extra complexity that would be present if this function had to alloc and free every single piece of data used Pools might not be ideal for every application but they are extremely useful in Subversion As a Subversion devel oper you ll need to grow comfortable with pools and how to wield them correctly Memory usage bugs and bloating can be difficult to diagnose and fix regardless of the API but the pool construct provided by APR has proven a tremendously convenient time saving bit of functionality Contributing to Subversion The official source of information about the Subversion project is of course the project s website at http subversion tigris
101. FAQ on Subversion s main website If you re still stuck then send mail to lt users subversion tigris org gt with a detailed description of the problem you re having 44 Problems Using Subversion Here are some of the most popular questions from Subversion s FAQ Every time I try to access my repository my Subversion client just hangs Your repository is not corrupt nor is your data lost If your process accesses the repository directly mod_dav_svn svnlook svnadmin or if you access a file URL then it s using Berkeley DB to access your data Berkeley DB is a journaling system meaning that it logs everything it is about to do before it does so If your process is inter rupted e g by a kill signal or segfault then a lockfile is left behind along with a logfile describing unfinished busi ness Any other process that attempts to access the database will just hang waiting for the lockfile to disappear To awaken your repository you need to ask Berkeley DB to either finish the work or rewind the database to a previous state that is known to be consistent Make sure you run this command as the user that owns and manages the database not as root or else it will leave root owned files in the db directory These files cannot be opened by the non root user that manages the database which is typically either you or your Apache process Also be sure to have the correct umask set when you run re cover since failing to do so will lock ou
102. In addition you can only move files within a single repository Subversion does not support cross repository moving WC gt WC Move and schedule a file or directory for addition with history URL gt URL Complete server side rename Alternate Names mv rename ren Changes Working copy repository if operating on a URL Accesses Repository Only if operating on a URL Switches message m TEXT file F FILE revision r REV quiet a force username USER password PASS 183 Subversion Complete Reference no auth cach non interactiv editor cmd EDITOR encoding ENC force log config dir DIR Examples Move a file in your working copy svn move foo c bar c A bar c D foo c Move a file in the repository an immediate commit so it requires a commit message S svn mov m Move a file http svn red bean com repos foo c http svn red bean com repos bar c Committed revision 27 184 Subversion Complete Reference Name svn propdel Remove a property from an item svn propdel Synopsis svn propdel PROPNAME PATH svn propdel PROPNAME revprop r REV URL Description This removes properties from files directories or revisions The first form removes versioned properties in your working copy while the second removes unversioned remote properties on a repository revision Alternate Names pdel pd
103. Is to write a program that uses Sub version and most importantly how to contribute to the development of Subversion Chapter 9 Subversion Complete Reference Explains in great detail every subcommand of svn svnadmin and svnlook with plenty of examples for the whole family Appendix A Subversion for CVS Users Covers the similarities and differences between Subversion and CVS with numerous suggestions on how to break all the bad habits you picked up from years of using CVS Included are descriptions of Subversion revi sion numbers versioned directories offline operations update vs status branches tags metadata conflict res olution and authentication Appendix B Troubleshooting Addresses common problems and difficulties using and building Subversion Appendix C WebDAV and Autoversioning Describes the details of WebDAV and DeltaV and how you can configure your Subversion repository to be mounted read write as a DAV share Appendix D Third Party Tools Discusses tools that support or use Subversion including alternative client programs repository browser tools XV This Preface and so on Book is Free This book started out as bits of documentation written by Subversion project developers which were then coalesced into a single work and rewritten As such it has always been under a free license See Appendix E Copyright In fact the book was written in the public eye as a part of Subversion This means
104. Mlimecomar Ss uses sel to 125961 Joe mocdears see o DOL To resolve property conflicts simply ensure that the conflicting properties contain the values that they should and then use the svn resolved command to alert Subversion that you have manually resolved the problem You might also have noticed the non standard way that Subversion currently displays property differences You can still run svn diff and redirect the output to create a usable patch file The patch program will ignore property patches as a rule it ignores any noise it can t understand This does unfortunately mean that to fully apply a patch generated by svn diff any property modifications will need to be applied by hand As you can see the presence of property modifications has no outstanding effect on the typical Subversion work flow Your general patterns of updating your working copy checking the status of your files and directories report ing on the modifications you have made and committing those modifications to the repository are completely im mune to the presence or absence of properties The svn program has some additional subcommands for actually making property changes but that is the only noticeable asymmetry Special Properties Subversion has no particular policy regarding properties you can use them for any purpose Subversion asks only that you not use property names that begin with the prefix svn That s the namespace that it sets aside for its
105. N Web nttp svn elixus org repos member clkao Perl based Subversion repository Web interface ViewCVS http viewcvs sourceforge net Python based CGI script for browsing CVS and Subversion repositories WebSVN http websvn tigris org PHP based Subversion repository browser Trac http projects edgewall com trac Minimalistic web based software project management and bug issue tracking system with version control inter faces and integrated Wiki support 256 Appendix E Copyright Copyright c 2002 2004 Ben Collins Sussman Brian W Fitzpatrick C Michael Pilato This work is licensed under the Creative Commons Attribution License To view a copy of this license visit http creativecommons org licenses by 2 0 or send a letter to Creative Commons 559 Nathan Abbott Way Stanford California 94305 USA A summary of the license is given below followed by the full legal text You are free to copy distribute display and perform the work to make derivative works to make commercial use of the work Under the following conditions Attribution You must give the original author credit For any reuse or distribution you must make clear to others the license terms of this work Any of these conditions can be waived if you get permission from the author Your fair use and other rights are in no way affected by the above The above is a summary of the full license below Creat
106. S has long been the tool of choice for version control And rightly so CVS itself is free software and its non restrictive modus operandi and support for networked operation which allow dozens of geographically dispersed programmers to share their work fits the collaborative nature of the open source world very well CVS and its semi chaotic development model have become cornerstones of open source culture But like many tools CVS is starting to show its age Subversion is a relatively new version control system designed to be the successor to CVS The designers set out to win the hearts of CVS users in two ways by creating an open source system with a design and look and feel similar to CVS and by attempting to fix most of CVS s noticeable flaws While the result isn t necessarily the next great evolution in version control design Subversion is very power ful very usable and very flexible This book is written to document the 1 0 series of the Subversion version control system We have made every at tempt to be thorough in our coverage However Subversion has a thriving and energetic development community so there are already a number of features and improvements planned for future versions of Subversion that may change some of the commands and specific notes in this book Audience This book is written for computer literate folk who want to use Subversion to manage their data While Subversion runs on a number of different op
107. Transmitting file data 169 Subversion Complete Reference Committed revision 16 This imports the local directory myproj into trunk vendors in your repository The directory trunk vendors need not exist before you import into it svn import will recursively create directories for you svn import m New import myproj http svn red bean com repos test trunk vendors myproj Adding myproj sample txt Transmitting file data Committed revision 19 170 Subversion Complete Reference Name svn info Print information about PATHs svn info Synopsis svn info PATH Description Print information about paths in your working copy including e Path e Name e URL e Revision e Node Kind e Last Changed Author e Last Changed Revision e Last Changed Date e Text Last Updated e Properties Last Updated e Checksum Alternate Names None Changes Nothing Accesses Repository No Switches 171 Subversion Complete Reference targets FILENAME recursiv R config dir DIR Examples svn info will show you all the useful information that it has for items in your working copy It will show information for files svn info foo c Path foo c ame foo c URL http svn red bean com repos test foo c Revision 4417 ode Kind file Schedule normal Last Changed Author sally Last Changed Rev 20 Last Changed Date 2003 01 13 16
108. V URL and it appears as a disk on the desktop just like any file server 47 Unfortunately this client refuses to work against an autoversioning mod_dav_svn because of its lack of LOCK sup port Mac OS X discovers the missing LOCK ability during the initial HTTP OPTIONS feature exchange and thus de cides to mount the Subversion repository as a read only share After that no write operations are possible at all In order to mount the repository as a read write share you must use the mod_dav_lock trick discussed previously Once locking seems to work the share behaves very nicely files can be opened directly in read write mode al though each save operation will cause the client to do a PUT to a temporary location a DELETE of original file and a MOVE of the temporary resource to the original filename That s three new Subversion revisions per save E One more word of warning OS X s WebDAV client can be overly sensitive to HTTP redirects If you re unable to mount the repository at all you may need to enable the BrowserMat ch directive in your httpd conf BrowserMatch WebDAVFS 1 012 redirect carefully Nautilus 2 Nautilus is the official file manager browser for the GNOME desktop Its main home page is at http www gnome org projects nautilus By simply typing a WebDAV URL into the Nautilus window the DAV share appears like a local filesystem In general Nautilus 2 works reasonably well against an autoversioni
109. Version Control with Subversion Revision 10061 by Ben Collins Sussman Brian W Fitzpatrick and C Michael Pilato Version Control with Subversion Revision 10061 by Ben Collins Sussman Brian W Fitzpatrick and C Michael Pilato Published TBA Copyright O 2002 2003 2004 Ben Collins SussmanBrian W FitzpatrickC Michael Pilato This work is licensed under the Creative Commons Attribution License To view a copy of this license visit http creativecommons org licenses by 2 0 or send a letter to Creative Commons 559 Nathan Abbott Way Stanford California 94305 USA Table of Contents Edi tds RN o A fd dcek tachi teie koa Bie baw Setatea ae Mok a hes ony beat a e e aeaa hea Mee aot erueo nat E shar tueens 13 Howto Read this BOOK coincide oak Sag aah Sowa eee eee oben edb us es 13 Conventions Usedin This BOOK cero fess ioeie ne causes pe ceawe Nr uses days ee O EATE 14 Typographie Conventions ay roroi ae sack A ok Mapes Sede scat posed Uae once RES 14 NCOMSras3 erase saGess wet ac cae tenens e e a Menge tae e ceed etn y adit ks 14 Organization OF This BOOK oi sc0ish 028 o eR a ee EG Rs E ee eB ed 15 This BOOK 1S Freeride i 16 Acknowledgments isens i iria odon dea dese ade 16 From Ben Collins SUSSMAO ito iris IEA a Retraso verve desfase 16 From Brian W Fitzpatric K oia ee 17 From Cy Michael Pilato dpi rondar esa AESA a niea 17 TEL UCA A A aonb bade veins ts What is Subversion AAA ON 1 SUDVErsiONn A ede aE EEEE sp swonu
110. _dav mod_dav_fs uses the ordinary filesystem to store files and directories and only understands vanilla WebDAV methods not DeltaV Subversion on the other hand uses mod_dav_svn as a provider for mod_dav mod_dav_svn understands all Web DAV methods except LOCK and understands a sizable subset of DeltaV methods It accesses data in the Subversion repository rather than in the real filesystem Subversion 1 0 doesn t support locking because it would actually be quite difficult to implement since Subversion uses the copy modify merge model 46 In Apache httpd 2 0 mod_dav supports the LOCK method by tracking locks in a private database assuming that the provider is willing to accept them In Apache httpd 2 1 or later however this locking support has been broken into an independent module mod_dav_lock It allows any mod_dav provider to take advantage of the lock database in cluding mod_dav_svn even though mod_dav_svn doesn t actually understand locking Confused yet In a nutshell you can use mod_dav_lock in Apache httpd 2 1 or later to create the illusion that mod_dav_svn is honoring LOCK requests Make sure mod_dav_lock is either compiled into httpd or being loaded in your httpd conf Then simply add the DAVGenericLockDB directive to your Location like so lt Location repos gt DAV svn SVNPath absolute path to repository SVNAutoversioning on DavGenericLockDB path to store locks lt Location gt This technique is a risky bu
111. _dav_svn for any filesystem re lated needs as opposed to the generic mod_dav_fs that comes with Apache So ultimately the client is communicat ing with mod_dav_svn which binds directly to the Subversion Repository Layer That was a simplified description of the actual exchanges taking place though For example the Subversion reposi tory might be protected by Apache s authorization directives This could result in initial attempts to communicate with the repository being rejected by Apache on authorization grounds At this point libsvn_ra_dav gets back the notice from Apache that insufficient identification was supplied and calls back into the Client Layer to get some up dated authentication data If the data is supplied correctly and the user has the permissions that Apache seeks lib svn_ra_dav s next automatic attempt at performing the original operation will be granted and all will be well If suf ficient authentication information cannot be supplied the request will ultimately fail and the client will report the failure to the user By using Neon and Apache Subversion gets free functionality in several other complex areas too For example if Neon finds the OpenSSL libraries it allows the Subversion client to attempt to use SSL encrypted communications with the Apache server whose own mod_ssl can speak the language Also both Neon itself and Apache s mod_deflate can understand the deflate algorithm the same one used by
112. a aa e a a E 65 Repository Cleaniip s mien ire di E ee Gee ANS S 73 EA A NN 75 Repository RecOVE mira il e a 76 Migrating a REpOSitory aena e e E R a a A a a e E Ea 77 Repository Backup ui ae Agee I lr Dass see 80 AddinS AN 81 Choosing a Repository Layout cece cece cece ence ence cece ce cene eee ceneeeeeeeeeeeeeeeseaeeeaeeea eee ecae esas 82 Creating the Layout and Importing Initial Data ooooccnnccnnconcconcconccnnoconocnncnnnronccnnccnnccnncinns 83 e NN 84 6 Server COMMSUTALONL cesiones yoo ugseesadese serena OVELVIE Waid sret seed tes iii Lestat E EEE dais oe 85 Network Model ocio A as eh ESE roda 85 Requests and Responses pyaar shaven st frisos iio aiii e 86 Chent Credentials Caching cti ic iia siii 86 SVNSELVES A CUSTOM SEEVER cociendo titan nati reine ii aiii 88 Invoking the Servei oi tido 88 Built in authentication and authorization oocooccnnccnnconnccnncnnncnnnconnconarnnnnnnronnrnnncnnccnnccnnccnnioos 89 SSH authentication and authorization 2 0 0 0 eee cece ee ce cece eeea seca eeeaeeseeeaeeeae een eeeeeeneeenes 91 httpd the Apache HTTP server neresen tenan pista deigetwansstoud cas toas rociado rales aereo ss piola 92 Prerequisites eiii diarrea 93 Basic Apache Configuration sssi osier ores Dri oia linde danna todoo OPERI eee 93 Authentication Options cabida ib se eta 95 Authorization Options sis cc sce ses vesiass orientan iaa EE T E verges rads aaa 98 Version Control with Subversion
113. a powerhouse server process and a network layer For users who simply wish to access the repositories on their local disk they may do so using file URLs and the functionality provided by libsvn_ra_local This RA module binds directly with the repository and filesystem li braries so no network communication is required at all Subversion requires that the server name included as part of the file URL be either localhost or empty and that there be no port specification In other words your URLs should look like either file localhost path to repos or file path to repos Also be aware that Subversion s file URLs cannot be used in a regular web browser the way typical file URLs can When you attempt to view a file URL in a regular web browser it reads and displays the contents of the file at that location by examining the filesystem directly However Subversion s resources exist in a virtual filesystem see Section Repository Layer and your browser will not understand how to read that filesystem Your RA Library Here For those who wish to access a Subversion repository using still another protocol that is precisely why the Reposi tory Access Layer is modularized Developers can simply write a new library that implements the RA interface on one side and communicates with the repository on the other Your new library can use existing network protocols or you can invent your own You could use inter process communication IPC call
114. a to store in your repository and finally how to make it avail able over a network The next chapter is all about networking 84 Chapter 6 Server Configuration A Subversion repository can be accessed simultaneously by clients running on the same machine on which the repository resides using the file method But the typical Subversion setup involves a single server machine being accessed from clients on computers all over the office or perhaps all over the world This section describes how to get your Subversion repository exposed outside its host machine for use by remote clients We will cover Subversion s currently available server mechanisms discussing the configuration and use of each After reading this section you should be able to decide which networking setup is right for your needs and understand how to enable such a setup on your host computer Overview Subversion was designed with an abstract network layer This means that a repository can be programmatically ac cessed by any sort of server process and the client repository access API allows programmers to write plugins that speak relevant network protocols In theory Subversion can sport an infinite number of network implementations In practice there are only two servers at the time of writing Apache is an extremely popular webserver using the mod_dav_svn module Apache can access a repository and make it available to clients via the WebDAV DeltaV p
115. a with a fresh clean history all its own Atomic commits A collection of modifications either goes into the repository completely or not at all This allows developers to construct and commit changes as logical chunks and prevents problems that can occur when only a portion of a set of changes is successfully sent to the repository Versioned metadata Each file and directory has a set of properties keys and their values associated with it You can create and store any arbitrary key value pairs you wish Properties are versioned over time just like file contents Choice of network layers Subversion has an abstracted notion of repository access making it easy for people to implement new network mechanisms Subversion can plug into the Apache HTTP Server as an extension module This gives Subversion a big advantage in stability and interoperability and instant access to existing features provided by that server authentication authorization wire compression and so on A more lightweight standalone Subversion server process is also available This server speaks a custom protocol which can be easily tunneled over SSH Consistent data handling Subversion expresses file differences using a binary differencing algorithm which works identically on both text human readable and binary human unreadable files Both types of files are stored equally compressed in the repository and differences are transmitted in both directions across the net
116. abNet offers a collaboration software suite called SourceCast of which one component is version control Although SourceCast used CVS as its initial version control system CVS s limitations were obvious from the begin ning and CollabNet knew it would eventually have to find something better Unfortunately CVS had become the de facto standard in the open source world largely because there wasn t anything better at least not under a free license So CollabNet determined to write a new version control system from scratch retaining the basic ideas of CVS but without the bugs and misfeatures In February 2000 they contacted Karl Fogel the author of Open Source Development with CVS Coriolis 1999 and asked if he d like to work on this new project Coincidentally at the time Karl was already discussing a design for a new version control system with his friend Jim Blandy In 1995 the two had started Cyclic Software a com pany providing CVS support contracts and although they later sold the business they still used CVS every day at their jobs Their frustration with CVS had led Jim to think carefully about better ways to manage versioned data and he d already come up with not only the name Subversion but also with the basic design of the Subversion reposi tory When CollabNet called Karl immediately agreed to work on the project and Jim got his employer RedHat Software to essentially donate him to the project for an indefinite period of t
117. able Runtime library This means Subversion should work on any operating system that the Apache httpd server runs on Windows Linux all flavors of BSD Mac OS X Netware and others Introduction The easiest way to get Subversion is to download a binary package built for your operating system Subversion s website http subversion tigris org often has these packages available for download posted by volun teers The site usually contains graphical installer packages for users of Microsoft operating systems If you run a Unix like operating system you can use your system s native package distribution system RPMs DEBs the ports tree etc to get Subversion Alternately you can build Subversion directly from source code From the Subversion website download the latest source code release After unpacking it follow the instructions in the INSTALL file to build it Note that a released source package contains everything you need to build a command line client capable of talking to a remote reposi tory in particular the apr apr util and neon libraries But optional portions of Subversion have many other depen dencies such as Berkeley DB and possibly Apache httpd If you want to do a complete build make sure you have all of the packages documented in the INSTALL file If you plan to work on Subversion itself you can use your client program to grab the latest bleeding edge source code This is documented in Section Get the So
118. ace to the repository The svnshell py Python script located in tools examples in the source tree uses Subversion s language bindings so you must have those properly compiled and installed in order for this script to work to connect to the repository and filesystem libraries Once started the program behaves similarly to a shell program allowing you to browse the various directories in your repository Initially you are positioned in the root directory of the HEAD revision of the repository and pre sented with a command prompt You can use the help command at any time to display a list of available commands and what they do svnshell py path to repos lt rev 2 gt help Available commands cat FILE dump the contents of FILE cd DIR change the current working directory to DIR exit exit the shell ls PATH list the contents of the current directory 1stxns list the transactions available for browsing setrev REV set the current revision to browse settxn TXN set the current transaction to browse youngest list the youngest browsable revision number lt rev 2 gt S Navigating the directory structure of your repository is done in the same way you would navigate a regular Unix or Windows shell using the cd command At all times the command prompt will show you what revision prefixed by rev or transaction prefixed by txn you are currently examining and at what path location in tha
119. ad Section Supporting Multiple Repository Access Methods Secondly when configuring svnserve Apache httpd or any other server process keep in mind that you might not want to launch the server process as the user root or as any other user with unlimited permissions Depending on the ownership and permissions of the repositories you re exporting it s often prudent to use a different perhaps custom user For example many administrators create a new user named svn grant that user exclusive ownership and rights to the exported Subversion repositories and only run their server processes as that user Once the svnserve program is running it makes every repository on your system available to the network A client needs to specify an absolute path in the repository URL For example if a repository is located at usr local repositories projectl then a client would reach 1t via svn host example com usr local repositories project1 To increase security you can pass the r option to svnserve which restricts it to exporting only repositories below that path svnserve d r usr local repositories Using the r option effectively modifies the location that the program treats as the root of the remote filesystem space Clients then use URLs that have that path portion removed from them leaving much shorter and much less revealing URLs svn checkout svn host example com projectl Built in authentication and authorization
120. ad configuration information from the specified directory instead of the default loca tion subversion in the user s home directory diff cmd CMD Specifies an external program to use to show differences between files When svn diff is invoked it uses Sub version s internal diff engine which provides unified diffs by default If you want to use an external diff pro gram use diff cmd You can pass switches to the diff program with the extensions switch more on that later in this section diff3 cmd CMD Specifies an external program to use to merge files dry run Goes through all the motions of running a command but makes no actual changes either on disk or in the repository editor cmd CMD Specifies an external program to use to edit a log message or a property value encoding ENC Tells Subversion that your commit message is encoded in the charset provided The default is your operating system s native locale and you should specify the encoding if your commit message is in any other encoding extensions x ARGS 41Yes yes you don t need a subcommand to use the version switch but we ll get to that in just a minute 144 Subversion Complete Reference Specifies an argument or arguments that Subversion should pass to an external diff command when providing differences between files If you wish to pass multiple arguments you must enclose all of them in quotes for example svn diff diff cmd usr
121. all the necessary adds and deletes and optionally performing moves too e It takes care of complicated series of operations between which Subversion requires an intermediate commit such as before renaming a file or directory twice e It will optionally tag the newly imported directory e Jt will optionally add arbitrary properties to files and directories that match a regular expression svn_load_dirs pl takes three mandatory arguments The first argument is the URL to the base Subversion directory to work in This argument is followed by the URL relative to the first argument into which the current vendor drop will be imported Finally the third argument is the local directory to import Using our previous example a typical run of svn_load_dirs pl might look like svn_load_dirs pl http svn example com repos vendor libcomplex current path to libcomplex 1 1 You can indicate that you d like svn_load_dirs pl to tag the new vendor drop by passing the t command line op tion and specifying a tag name This tag is another URL relative to the first program argument svn_load_dirs pl t libcomplex 1 1 http svn example com repos vendor libcomplex current path to libcomplex 1 1 When you run svn_load_dirs pl it examines the contents of your existing current vendor drop and compares them with the proposed new vendor drop In the trivial case there will be no files that are in one version and not the other
122. ally needed for Subver sion repositories has been duplicated in the svnadmin tool For example svnadmin list unused dblogs and svnad min list dblogs perform a subset of what is provided by Berkeley s db_archive command and svnadmin recover reflects the common use cases of the db_recover utility There are still a few Berkeley DB utilities that you might find useful The db_dump and db_load programs write and read respectively a custom file format which describes the keys and values in a Berkeley DB database Since Berkeley databases are not portable across machine architectures this format is a useful way to transfer those databases from machine to machine irrespective of architecture or operating system Also the db_stat utility can provide useful information about the status of your Berkeley DB environment including detailed statistics about the locking and storage subsystems Repository Cleanup Your Subversion repository will generally require very little attention once it is configured to your liking However there are times when some manual assistance from an administrator might be in order The svnadmin utility pro vides some helpful functionality to assist you in performing such tasks as e modifying commit log messages e removing dead transactions e recovering wedged repositories and e migrating repository contents to a different repository 73 Repository Administration Perhaps the most commonly used of
123. and for svn diff r N M old URL1 new URL2 If TARGET is a URL then revs N and M can be given either via the revision or by using notation as de scribed earlier If TARGET is a working copy path then the revision switch means revision N M The server compares TARGETO N and TARGETOM revision N The client compares TARGETO N against working copy no revision The client compares base and working copies of TARGET If the alternate syntax is used the server compares URL1 and URL2 at revisions N and M respectively If either N or M are omitted a value Of HEAD 1s assumed By default svn diff ignores the ancestry of files and merely compares the contents of the two files being compared If you use notice ancestry the ancestry of the paths in question will be taken into consideration when com paring revisions that is if you run svn diff on two files with identical contents but different ancestry you will see the entire contents of the file as having been removed and added again Alternate Names 163 Subversion Complete Reference di Changes Nothing Accesses Repository For obtaining differences against anything but BASE revision in your working copy Switches revision old OLD R r ARGE new NEW ARGE extensions x ARGS non recursiv diff cmd notice ances username password N CMD tr
124. ans 45 8 1 Files and directories in two dimensions cece cece cence cece cece ce cece cena cee ceeeeeeeceeeseeeeeeseaeseaeeeaeeaeeeges 128 8 2 Versioning time the third dimension oocooccnnccnnconnconnconnconncnnncnnncnnncnnrnnnrnnncnn cono sean E EE Tse 128 viii List of Tables 2 1 Repository Access URLs 6 1 Network Server Comparison coooconccnnccnnonononnnrnnn ron cece cece EEE TEE E OEE EEEE EEEE EE OEE 8 1 A Brief Inventory of the Subversion Libraries 2 0 0 0 00 ce eee csece cece ence ence neces ceeeseeeeaeeea esau sean scan eeaeeegs 1X List of Examples 5 1 Using svnshell to Navigate the Repository ocoooconoconoconccnnccnncnnnnonoconccnnconnccnnccnncrnnconncnnncnnncnnncnnrnnnss 72 5 2 txn info sh Reporting Outstanding Transactions 0c cee ceee cece neces ceeeeeeceeeeeeeseeeeaeeeaeeea eens seus eegs 75 6 1 A sample configuration for ANONYMOUS ACCESS 0 0 ee eee eee cence reece ee ea cece cena eeae eens ceneeeeeeeeeeeeeeeeeeaees 99 6 2 A sample configuration for authenticated access 1 0 0 0 eee ee cece cece eee cee ca eeca cena cena een eeneeeeeeeeeeeeeaereaees 99 6 3 A sample configuration for mixed authenticated anonyMous ACCESS occooccnnccnnconnconeconncnnnconccnnccnaranicnno 100 71 Sample Registration Entries Cres File 2iccc cheeses seerne chs egaws sieek tes den sdeescueddas due dase iaa 106 8 1 Using the Repository Layer ici iat oe OS di eae ph ee 129 8 2
125. apr_dir_open amp dir directory pool apr_err eturn apr_err Loop over the directory entries clearing the subpool at the top of each iteration apr_err apr_dir_read amp finfo flags dir apr_err APR_SUCCESS apr_err apr_dir_read amp finfo flags dir const char child_path Clear the per iteration SUBPOOL svn_pool_clear subpool Skip entries for this dir and its parent if finfo filetype APR_DIR if finfo name 0 amp amp finfo name 1 0 finfo name 1 amp amp finfo name 2 X0 continue Build CHILD _PATH from DIRECTORY and FINFO name ES child_path svn_path_join directory finfo name subpool Do some task to this encountered path do_some_task child_path subpool Handle subdirectories by recursing into them passing SUBPOOL as the pool for temporary allocations if finfo filetype APR_DIR apr_err crawl_dir files child_path subpool if apr_err return apro eref Handle files by adding their paths to the FILES array else if finfo filetype APR_REG Copy the file s path into the FILES array s pool child_path apr_pstrdup hash_pool child path Add the path to the array const char apr_array_ push files child path 140 Developer Information Destroy SUBPOOL svn_pool_destroy subpool
126. ares However it s important to note that RFC 2518 does not provide any sort of model for version control despite the V in DAV Basic WebDAV clients and servers assume only one version of each file or directory exists and can be repeatedly overwritten 45 Here are the new concepts and methods introduced in basic WebDAV New write methods Beyond the standard HTTP PuT method which creates or overwrites a web resource WebDAV defines new COPY and MOVE methods for duplicating or rearranging resources Collections This is simply the WebDAV term for a grouping of resources URIs In most cases it is analogous to a direc tory You can tell something is a collection if it ends with a trailing Whereas file resources can be written or created with a PUT method collection resources are created with the new MKCOL method Properties This is the same idea present in Subversion metadata attached to files and collections A client can list or re trieve properties attached to a resource with the new PROPFIND method and can change them with the PROP PATCH method Some properties are wholly created and controlled by users e g a property called color and others are wholly created and controlled by the WebDAV server e g a property that contains the last modifica tion time of a file The former kind are called dead properties and the latter kind are called live properties Locking A WebDAV server may de
127. arger tasks in stages instead of making huge sweeping modifications Your proposed changes will be easier to understand and therefore easier to review if you disturb the fewest lines of code possible to accomplish your task properly After making each set of proposed changes your Subversion tree should be in a state in which the software compiles with no warnings Subversion has a fairly thorough 40 regression test suite and your proposed changes are expected to not cause any of those tests to fail By running make check in Unix from the top of the source tree you can sanity check your changes The fastest way to get your code contributions rejected other than failing to supply a good log message is to submit changes that cause failure in the test suite In the best case scenario you will have actually added appropriate tests to that test suite which verify that your pro posed changes work as expected In fact sometimes the best contribution a person can make is solely the addition of new tests You can write regression tests for functionality that currently works in Subversion as a way to protect against future changes that might trigger failure in those areas Also you can write new tests that demonstrate known failures For this purpose the Subversion test suite allows you to specify that a given test is expected to fail called an XFAIL and so long as Subversion fails in the way that was expected a test result of XFAIL itself is con 3
128. articular revision tree and the second coordinate is a path within that tree So every version of your file or directory can be defined by a specific coordinate pair Subversion has no Attic directory like CVS does 10 so you need to use svn log to discover the exact coordinate pair you wish to resurrect A good strategy is to run svn log verbose in a directory which used to contain your deleted item The verbose option shows a list of all changed items in each revision all you need to do is find the revision in which you deleted the file or directory You can do this visually or by using another tool to examine the log output via grep or perhaps via an incremental search in an editor cd parent dir svn log verbose r808 joe 2003 12 26 14 29 40 0600 Fri 26 Dec 2003 3 lines Changed paths D calc trunk real c M calc trunk integer c Added fast fourier transform functions to integer c Removed real c because code now in double c In the example we re assuming that you re looking for a deleted file real c By looking through the logs of a par ent directory you ve spotted that this file was deleted in revision 808 Therefore the last version of the file to exist was in the revision right before that Conclusion you want to resurrect the path calc trunk real c from revi sion 807 That was the hard part the research Now that you know what you want to restore you have two different choices One option is to
129. ase back end uses a locking mechanism This mechanism en sures that portions of the database are not simultaneously modified by multiple database accessors and that each 76 Repository Administration process sees the data in the correct state when that data is being read from the database When a process needs to change something in the database it first checks for the existence of a lock on the target data If the data is not locked the process locks the data makes the change it wants to make and then unlocks the data Other processes are forced to wait until that lock is removed before they are permitted to continue accessing that section of the database In the course of using your Subversion repository fatal errors such as running out of disk space or available mem ory or interruptions can prevent a process from having the chance to remove the locks it has placed in the database The result is that the back end database system gets wedged When this happens any attempts to access the repos itory hang indefinitely since each new accessor is waiting for a lock to go away which isn t going to happen First if this happens to your repository don t panic Subversion s filesystem takes advantage of database transactions and checkpoints and pre write journaling to ensure that only the most catastrophic of events 15 can permanently de stroy a database environment A sufficiently paranoid repository administrator will be makin
130. at mylog UN Ut Ut Ur r14 r19 27 The incremental switch provides similar output control when using the xm1 switch Tip If you run svn log on a specific path and provide a specific revision and get no output at all svn log r 20 http svn red bean com untouched txt That just means that the path was not modified in that revision If you log from the top of the repository or 177 Subversion Complete Reference know the file that changed in that revision you can specify it explicitly svn log r 20 touched txt r20 sally 2003 01 17 22 56 19 0600 Fri 17 Jan 2003 1 line Made a change 178 Subversion Complete Reference Name svn merge Apply the differences between two sources to a working copy path svn merge Synopsis svn merge sourceURL1 N sourceURL2 M WCPATH svn merge r N M SOURCE PATH Description In the first form the source URLs are specified at revisions N and M These are the two sources to be compared The revisions default to HEAD if omitted In the second form SOURCE can be a URL or working copy item in which case the corresponding URL is used This URL at revisions N and Mm defines the two sources to be compared WCPATH is the working copy path that will receive the changes If WCPATH is omitted a default value of is as e sumed unless the sources have identical basenames that match a file w
131. ation repos gt DAV svn SVNParentPath usr local svn our access control policy AuthzSVNAccessFile path to access file try anonymous access first resort to real authentication if necessary Satisfy Any Require valid user how to authenticate a user AuthType Basic AuthName Subversion repository AuthUserFile path to users file lt Location gt Once your basic Location block is configured you can create an access file and define some authorization rules in it The syntax of the access file is the same familiar one used by svnserve conf and the runtime configuration files Lines that start with a hash are ignored In its simplest form each section names a repository and path within it and the authenticated usernames are the option names within each section The value of each option describes the user s level of access to the repository path either r read only or rw read write If the user is not mentioned at all no access is allowed To be more specific the value of the section names are either of the form repos name path or the form path If you re using the SVNParentPath directive then it s important to specify the repository names in your sections If you omit them then a section like some dir will match the path some dir in every repository If you re using the SVNPath directive however then it s fine to only define paths in your sections after all there s only one repository 1
132. authorization against the repository It contains store auth creds This instructs Subversion to cache or not to cache authentication credentials that are supplied by the user in re sponse to server authentication challenges The default value is yes Set this to no to disable this on disk cre dential caching You can override this option for a single instance of the svn command using the no auth cache command line parameter for those subcommands that support it For more information see Section Client Credentials Caching The helpers section controls which external applications Subversion uses to accomplish its tasks Valid options in this section are editor cmd This specifies the program Subversion will use to query the user for a log message during a commit operation such as when using svn commit without either the message m or file F options This program is also used with the svn propedit command a temporary file is populated with the current value of the property the user wishes to edit and the edits take place right in the editor program see Section Properties This op tion s default value is empty If the option is not set Subversion will fall back to checking the environment vari ables SVN_EDITOR VISUAL and EDITOR in that order for an editor command diff cmd This specifies the absolute path of a differencing program used when Subversion generates diff output such as when
133. behind the scenes If you include a username in the URL for example svntrsh username host path the client will also include that in its command rsh username host svnserve t But you can define new tunneling schemes to be much more clever than that tunnels joessh JOESSH opt alternate ssh p 29934 This example demonstrates a couple of things First 1t shows how to make the Subversion client launch a very spe cific tunneling binary the one located at opt alternate ssh with specific options In this case accessing a svn joessh URL would invoke the particular SSH binary with p 29934 as arguments useful if you want the tunnel program to connect to a non standard port Second it shows how to define a custom environment variable that can override the name of the tunneling program Setting the SVN_SSH environment variable is a convenient way to override the default SSH tunnel agent But if you need to have several different overrides for different servers each perhaps contacting a different port or passing a different set of options you can use the mechanism demonstrated in this example Now if we were to set the JOESSH environment variable its value would override the entire value of the tunnel variable JOESSH would be executed instead of opt alternate ssh p 29934 httpd the Apache HTTP server The Apache HTTP Server is a heavy duty network server that Subversion can leverage Via a custom module httpd makes Su
134. bversion Complete Reference for more information and an example 56 Branching and Merging Once again svn copy comes to the rescue If you want to create a snapshot of calc trunk exactly as it looks in the HEAD revision then make a copy of it svn copy http svn example com repos calc trunk http svn example com repos calc tags release 1 0 m Tagging the 1 0 release of the calc project Committed revision 351 This example assumes that a calc tags directory already exists After the copy completes the new release 1 0 directory is forever a snapshot of how the project looked in the HEAD revision at the time you made the copy Of course you might want to be more precise about exactly which revision you copy in case somebody else may have committed changes to the project when you weren t looking So if you know that revision 350 of calc trunk is exactly the snapshot you want you can specify it by passing r 350 to the svn copy command But wait a moment isn t this tag creation procedure the same procedure we used to create a branch Yes in fact it is In Subversion there s no difference between a tag and a branch Both are just ordinary directories that are created by copying Just as with branches the only reason a copied directory is a tag 1s because humans have decided to treat it that way as long as nobody ever commits to the directory it forever remains a snapshot If people start com mit
135. bversion repositories available to clients via the WebDAV DeltaV protocol which is an extension to HTTP 1 1 see http www webdav org for more information This protocol takes the ubiquitous HTTP proto col that is the core of the World Wide Web and adds writing specifically versioned writing capabilities The re sult is a standardized robust system that is conveniently packaged as part of the Apache 2 0 software is supported by numerous operating systems and third party products and doesn t require network administrators to open up yet another custom port 22 While an Apache Subversion server has more features than svnserve it s also a bit more dif ficult to set up With flexibility often comes more complexity Much of the following discussion includes references to Apache configuration directives While some examples are given of the use of these directives describing them in full is outside the scope of this chapter The Apache team maintains excellent documentation publicly available on their website at http httpd apache org For exam ple a general reference for the configuration directives is located at http httpd apache org docs 2 0 mod directives html Also as you make changes to your Apache setup it is likely that somewhere along the way a mistake will be made If you are not already familiar with Apache s logging subsystem you should become aware of it In your httpd conf file are directives that specify the on disk l
136. ch item in the resultant output can then be used with svnlook and its transaction option to determine who created the transaction when it was created what types of changes were made in the transaction in other words whether or not the transaction is a safe candidate for removal If so the transaction s name can be passed to svnad min rmtxns which will perform the cleanup of the transaction In fact the rmtxns subcommand can take its input directly from the output of 1st xns svnadmin rmtxns myrepos svnadmin lstxns myrepos 74 Repository Administration If you use these two subcommands like this you should consider making your repository temporarily inaccessible to clients That way no one can begin a legitimate transaction before you start your cleanup The following is a little bit of shell scripting that can quickly generate information about each outstanding transaction in your repository Example 5 2 txn info sh Reporting Outstanding Transactions bin sh Generate informational output for all outstanding transactions in a Subversion repository SVNADMIN usr local bin svnadmin SVNLOOK usr local bin svnlook REPOS 1 if xSREPOS x then echo usage 0 REPOS_PATH exit fi for TXN in SVNADMIN lstxns S REPOS do echo Transaction TXN Ha x 8 S SVNLOOK info S REPOS transaction TXN done You can run the previous script using path
137. cide to offer a locking feature to clients this part of the specification is optional al though most WebDAV servers do offer the feature If present then clients can use the new LOCK and UNLOCK methods to mediate access to a resource In most cases these methods are used to create exclusive write locks as discussed in Section The Lock Modify Unlock Solution although shared write locks are also possible DeltaV Extensions Because RFC 2518 left out versioning concepts another capable group was left with the responsibility of writing 45For this reason some people jokingly refer to generic WebDAV clients as WebDA clients 249 WebDAV and Autoversioning RFC 3253 which adds versioning to WebDAV WebDAV DeltaV clients and servers are often called just DeltaV clients and servers since DeltaV implies the existence of basic WebDAV DeltaV introduces a whole slew of new acronyms but don t be intimidated The ideas are fairly straightforward Here are the new concepts and methods introduced in DeltaV Per resource versioning Like CVS and other version control systems DeltaV assumes that each resource has a potentially infinite num ber of states A client begins by placing a resource under version control using the new VERSION CONTROL method This creates a new Version Controlled Resource VCR Every time you change the VCR via PUT PROPPATCH etc a new state of the resource is created called a Version Resource
138. cidence rate for most people was implemented in revision 7598 On FreeBSD certain operations especially svnadmin create sometimes hang This is usually due to a lack of available entropy on the system Subversion asks APR to generate random numbers to create UUIDs from time to time and certain operating systems will block for high quality randomness You prob ably need to configure the system to gather entropy from sources such as hard disk and network interrupts Consult your system manpages specifically random 4 and rndcontrol 8 on how to effect this change Another workaround is to compile APR against dev urandom instead of dev random I can see my repository in a web browser but svn checkout gives me an error about 301 Moved Permanently It means your httpd conf is misconfigured Usually this error happens when you ve defined the Subversion virtual lo cation to exist within two different scopes at the same time For example if you ve exported a repository as lt Location www foo gt but you ve also set your DocumentRoot to be www then you re in trouble When the request comes in for www foo bar apache doesn t know whether to find a real file named foo bar within your DocumentRoot or whether to ask mod_dav_svn to fetch a file bar from the www foo repository Usually the former case wins and hence the Moved Permanently error The solution is to make sure your repository lt Location gt does not overlap or l
139. comes in for the URI www repos foo c Apache won t know whether to look for a file repos foo c in the Document Root or whether to delegate mod_dav_svn to return foo c from the Subversion repository Server Names and the COPY Request Subversion makes use of the COPY request type to perform server side copies of files and directories As part of the sanity checking done by the Apache modules the source of the copy is expected to be located on the same machine as the destination of the copy To satisfy this requirement you might need to tell mod_dav the name you use as the hostname of your server Generally you can use the ServerName directive in httpd conf to accomplish this ServerName svn example com If you are using Apache s virtual hosting support via the NameVirtualHost directive you may need to use the ServerAlias directive to specify additional names that your server is known by Again refer to the Apache docu mentation for full details At this stage you should strongly consider the question of permissions If you ve been running Apache for some time now as your regular web server you probably already have a collection of content web pages scripts and such These items have already been configured with a set of permissions that allows them to work with Apache or more appropriately that allows Apache to work with those files Apache when used as a Subversion server will also need the correct permissions to read and write to
140. commands and how property modifications affect your normal Subversion workflow Hopefully you ll be convinced that Subversion properties can enhance your version control experience Why Properties Properties can be very useful additions to your working copy In fact Subversion itself uses properties to house spe cial information and as a way to denote that certain special processing might be needed Likewise you can use properties for your own purposes Of course anything you can do with properties you could also do using regular versioned files but consider the following example of Subversion property use Say you wish to design a website that houses many digital photos and displays them with captions and a datestamp Now your set of photos is constantly changing so you d like to have as much of this site automated as possible These photos can be quite large so as is common with sites of this nature you want to provide smaller thumbnail images to your site visitors You can do this with traditional files That is you can have your image123 jpg and an image123 thumbnail jpg side by side in a directory Or if you want to keep the filenames the same you might have your thumbnails in a different directory like thumbnails image123 jpg You can also store your captions and datestamps in a similar fashion again separated from the original image file Soon your tree of files is a mess and grows in multiples with each new photo added to the
141. ction svn status The Limitations of Mixed Revisions As a general principle Subversion tries to be as flexible as possible One special kind of flexibility is the ability to have a working copy containing mixed revision numbers At first it may not be entirely clear why this sort of flexibility is considered a feature and not a liability After com pleting a commit to the repository the freshly committed files and directories are at a more recent working revision 18 Basic Concepts than the rest of the working copy It looks like a bit of a mess As demonstrated earlier the working copy can always be brought to a single working revision by running svn update Why would someone deliberately want a mixture of working revisions Assuming your project is sufficiently complex you ll discover that it s sometimes nice to forcibly backdate por tions of your working copy to an earlier revision you ll learn how to do that in Chapter 3 Perhaps you d like to test an earlier version of a sub module contained in a subdirectory or perhaps you d like to examine a number of previ ous versions of a file in the context of the latest tree However you make use of mixed revisions in your working copy there are limitations to this flexibility First you cannot commit the deletion of a file or directory which isn t fully up to date If a newer version of the item exists in the repository your attempt to delete will be rejected to
142. d If you distribute publicly display publicly perfo publicly digitally perform the Work or any Derivati Collective Works You must keep intact all copyrigh the Work and give the Original Author credit reason medium or means You are utilizing by conveying the pseudonym if applicable of the Original Author if title of the Work if supplied to the extent reason practicable the Uniform Resource Identifier if an Licensor specifies to be associated with the Work URI does not refer to the copyright notice or licen information for the Work and in the case of a Deri a credit identifying the use of the Work in the Der e terms of notice from emove from or the vative Work nt ference to rm or ve Works or t notices for able to the name or supplied the ably y that unless such sing vative Work ivative Work e g French translation of the Work by Original Author or Screenplay based on original Work by Original Auth credit may be implemented in any reasonable manner however that in the case of a Derivative Work or C Work at a minimum such credit will appear where an comparable authorship credit appears and in a manne prominent as such other comparable authorship credi UNLESS OTHERWISE MUTUALLY AGREED TO BY THE PARTIES IN WRI or Such provided ollective y other r at least as El TING LICENSOR OFFERS THE WORK AS IS AND MAKES NO REPRESENTATIONS OR
143. d Also quite often there are things that should be ignored in every working copy of a particular repository To force every user of that repository to add patterns for those resources to their run time configuration areas would be not just a burden but has the po tential to clash with the configuration needs of other working copies that the user has checked out The solution is to store ignore patterns that are unique to the resources likely to appear in a given directory with the directory itself Common examples of unversioned resources that are basically unique to a directory yet likely to ap pear there include output from program compilations Or to use an example more appropriate to this book the HTML PDF or PostScript files generated as the result of a conversion of some source DocBook XML files to a more legible output format 28The Windows filesystems use file extensions such as EXE BAT and COM to denote executable files 115 Advanced Topics Ignore Patterns for CVS Users The Subversion svn ignore property is very similar in syntax and function to the CVS cvsignore file In fact if you are migrating a CVS working copy to Subversion you can directly migrate the ignore patterns by using the cvsignore file as input file to the svn propset command svn propset svn ignore F cvsignore property svn ignore set on There are however some differences in the ways that CVS and Subversion handle ignore patte
144. d 3253 For a more thorough discussion of WebDAV how it works and how Subversion uses it see Appendix C WebDAV and Autoversioning Among other things that appendix discusses the degree to which Subversion adheres to the generic WebDAV specification and how that affects interoperability with generic WebDAV clients Programming with Memory Pools Almost every developer who has used the C programming language has at some point sighed at the daunting task of managing memory usage Allocating enough memory to use keeping track of those allocations freeing the memory when you no longer need it these tasks can be quite complex And of course failure to do those things properly can result in a program that crashes itself or worse crashes the computer Fortunately the APR library that Subver sion depends on for portability provides the apr_pool_t type which represents a pool from which the application may allocate memory A memory pool is an abstract representation of a chunk of memory allocated for use by a program Rather than re questing memory directly from the OS using the standard malloc and friends programs that link against APR can simply request that a pool of memory be created using the apr_pool_create function APR will allocate a moderately sized chunk of memory from the OS and that memory will be instantly available for use by the pro gram Any time the program needs some of the pool memory it uses one of the APR pool API
145. d on merit if you demonstrate comprehension of Subversion programming com petency and a team spirit you will likely be awarded that permission 143 Chapter 9 Subversion Complete Reference This chapter is intended to be a complete reference to using Subversion This includes the command line client svn and all its subcommands as well as the repository administration programs svnadmin and svnlook and their re spective subcommands The Subversion Command Line Client svn To use the command line client you type svn the subcommand you wish to use 41 and any switches or targets that you wish to operate on there is no specific order that the subcommand and the switches must appear in For example all of the following are valid ways to use svn status svn v status svn status v svn status v myfile You can find many more examples of how to use most client commands in Chapter 3 Guided Tour and commands for managing properties in Section Properties svn Switches While Subversion has different switches for its subcommands all switches are global that is each switch is guar anteed to mean the same thing regardless of the subcommand you use it with For example verbose v always means verbose output regardless of the subcommand you use it with auto props Enables auto props overriding the enable auto props directive in the config file config dir DIR Instructs Subversion to re
146. dav sends DeltaV requests to the server the Subversion client is not a general purpose DeltaV client In fact it expects some custom features from the server especially through custom REPORT requests Fur 250 WebDAV and Autoversioning ther mod_dav_svn is not a general purpose DeltaV server It only implements a strict subset of the DeltaV specifi cation A more general WebDAV or DeltaV client may very well be able to interoperate against it but only if that client operates within the narrow confines of those features that the server has implemented The Subversion devel opment team plans to address general WebDAV interoperability in a future release of Subversion Mapping Subversion to DeltaV Here is a very high level description of how various Subversion client operations use DeltaV In many cases these explanations are gross oversimplifications They should not be taken as a substitute for reading Subversion s source code or talking with its developers svn checkout list Perform a PROPFIND of depth 1 on the collection to get a list of immediate children Perform a GET and possi bly a PROPFIND on each child Recurse into collections and repeat svn commit Create an activity with MKACTIVITY and do a CHECKOUT of each changed item followed by a PUT of new data Finally a MERGE request causes an implicit CHECKIN of all working resources svn update switch status merge diff Send a custom REPORT
147. directories This allows you to recover older versions of your data or examine the history of how your data changed In this regard many people think of a version control system as a sort of time machine Subversion can access its repository across networks which allows it to be used by people on different computers At some level the ability for various people to modify and manage the same set of data from their respective loca tions fosters collaboration Progress can occur more quickly without a single conduit through which all modifica tions must occur And because the work is versioned you need not fear that quality is the trade off for losing that conduit if some incorrect change is made to the data just undo that change Some version control systems are also software configuration management SCM systems These systems are specifically tailored to manage trees of source code and have many features that are specific to software develop ment such as natively understanding programming languages or supplying tools for building software Subver sion however is not one of these systems It is a general system that can be used to manage any collection of files For you those files might be source code for others anything from grocery shopping lists to digital video mix downs and beyond Subversion s History In early 2000 CollabNet Inc http www collab net began seeking developers to write a replacement for CVS Coll
148. dmin create REPOS_PATH Description Create a new empty repository at the path provided If the provided directory does not exist it will be created for you 42 Switches bdb txn nosync bdb log keep Examples Creating a new repository is just this easy svnadmin create usr local svn repos 42Remember svnadmin works only with local paths not URLs 208 Subversion Complete Reference Name svnadmin deltify Deltify changed paths in a revision range svnadmin deltify Synopsis svnadmin deltify r LOWER UPPER REPOS_PATH Description svnadmin deltify only exists in 1 0 x due to historical reasons This command is deprecated and no longer needed It dates from a time when Subversion offered administrators greater control over compression strategies in the repository This turned out to be a lot of complexity for very little gain and this feature was deprecated Switches revision 1 quiet 209 Subversion Complete Reference Name svnadmin dump Dump the contents of filesystem to stdout svnadmin dump Synopsis svnadmin dump REPOS_PATH r LOWER UPPER incremental Description Dump the contents of filesystem to stdout in a dumpfile portable format sending feedback to stderr Dump revi sions LOWER rev through UPPER rev If no revisions are given dump all revision trees If only LOWER is given dump that one rev
149. e The output of the info subcommand is defined as 1 The author followed by a newline 2 The date followed by a newline 3 The number of characters in the log message followed by a newline 4 The log message itself followed by a newline This output is human readable meaning items like the datestamp are displayed using a textual representation instead of something more obscure such as the number of nanoseconds since the Tasty Freeze guy drove by But this out put is also machine parsable because the log message can contain multiple lines and be unbounded in length svn look provides the length of that message before the message itself This allows scripts and other wrappers around this command to make intelligent decisions about the log message such as how much memory to allocate for the message or at least how many bytes to skip in the event that this output is not the last bit of data in the stream Another common use of svnlook is to actually view the contents of a revision or transaction tree The svnlook tree command displays the directories and files in the requested tree If you supply the show ids option it will also show the filesystem node revision IDs for each of those paths which is generally of more use to developers than to users svnlook tree path to repos show ids lt 0 0 1 gt A lt 2 0 1 gt B lt 4 0 1 gt lambda lt 5 0 1 gt 66 Repository Administration E lt 6 0 1 gt al
150. e changes made in that transaction to your developer mailing list you need to use the libsvn_repos wrapped version 130 Developer Information of that function svn_repos_fs_commit_txn This function will actually first run the pre commit hook script if one exists then commit the transaction and finally will run a post commit hook script The hooks provide a special kind of reporting mechanism that does not really belong in the core filesystem library itself For more infor mation regarding Subversion s repository hooks see Section Hook Scripts The hook mechanism requirement is but one of the reasons for the abstraction of a separate repository library from the rest of the filesystem code The libsvn_repos API provides several other important utilities to Subversion These include the abilities to 1 create open destroy and perform recovery steps on a Subversion repository and the filesystem included in that repository 2 describe the differences between two filesystem trees 3 query for the commit log messages associated with all or some of the revisions in which a set of files was modified in the filesystem 4 generate a human readable dump of the filesystem a complete representation of the revisions in the filesys tem 5 parse that dump format loading the dumped revisions into a different Subversion repository As Subversion continues to evolve the repository library will grow with the filesy
151. e you can still abort without committing your changes If you want to cancel your commit just quit your editor without saving your commit message and Subversion will prompt you to either abort the commit continue with no message or edit the message again Alternate Names ci short for check in not co which is short for checkout Changes Working copy repository Accesses Repository Yes Switches message m TEXT file F FILE quiet a non recursiv N targets FILENAME force log username USER password PASS no auth cach non interactiv encoding ENC config dir DIR Examples 156 Subversion Complete Reference Commit a simple modification to a file with the commit message on the command line and an implicit target of your current directory svn commit m added howto section Sending a Transmitting file data Committed revision 3 Commit a modification to the file foo c explicitly specified on the command line with the commit message in a file named msg svn commit F msg foo c Sending foo c Transmitting file data Committed revision 5 If you want to use a file that s under version control for your commit message with file you need to pass the force log switch svn commit file file under_vc txt foo c svn The log message file is under version control svn Log message file is a versioned file use force log
152. e added to the repository at least the developers know that those new revisions are at least remotely related to everyone who uses that repository After deciding how to organize your projects with respect to repositories you ll probably want to think about direc tory hierarchies in the repositories themselves Because Subversion uses regular directory copies for branching and tagging see Chapter 4 Branching and Merging the Subversion community recommends that you choose a reposi tory location for each project root the top most directory which contains data related to that project and then create three subdirectories beneath that root trunk meaning the directory under which the main project develop ment occurs branches which is a directory in which to create various named branches of the main development line tags which is a directory of branches that are created and perhaps destroyed but never changed For example your repository might look like calc trunk tags branches calendar trunk tags branches spreadsheet trunk tags branches Note that it doesn t matter where in your repository each project root is If you have only one project per repository the logical place to put each project root is at the root of that project s respective repository If you have multiple projects you might want to arrange them in groups inside the repository perhaps putting projects with similar goals or shared c
153. e code must retain the above copyright notice this list of conditions and the recipe for Fitz s famous red beans and ric The last property related subcommand is propdel Since Subversion allows you to store properties with empty val ues you can t remove a property altogether using propedit or propset For example this command will not yield the desired effect svn propset license calc button c property license set on calc button c svn proplist verbose calc button c Properties on calc button c copyright c 2003 Red Bean Software 112 Advanced Topics license You need to use the propdel command to delete properties altogether The syntax is similar to the other property commands svn propdel license calc button c property license deleted from svn proplist verbose calc button c Properties on calc button c copyright c 2003 Red Bean Software Now that you are familiar with all of the property related svn subcommands let s see how property modifications affect the usual Subversion workflow As we mentioned earlier file and directory properties are versioned just like your file contents As a result Subversion provides the same opportunities for merging in cleanly or conflicting fashions someone else s modifications into your own Modifying Revision Properties Remember those unversioned revision properties You can modify those too with the svn program Simply add the
154. e file pwd home sally calc svn log verbose integer c r344 sally 2002 11 07 15 27 56 0600 Thu 07 Nov 2002 2 lines Changed paths M calc trunk integer c integer c fix a bunch of spelling errors r303 sally 2002 10 29 21 14 35 0600 Tue 29 Oct 2002 2 lines Changed paths M calc trunk integer c integer c Changed a docstring r98 sally 2002 02 22 15 35 29 0600 Fri 22 Feb 2002 2 lines Changed paths M calc trunk integer c integer c adding this file to the project Sally sees her own revision 344 change but not the change you made in revision 343 As far as Subversion is con cerned these two commits affected different files in different repository locations However Subversion does show that the two files share a common history Before the branch copy was made in revision 341 they used to be the same file That s why you and Sally both see the changes made in revisions 303 and 98 The Key Concepts Behind Branches There are two important lessons that you should remember from this section 1 Unlike many other version control systems Subversion s branches exist as normal filesystem directories in the repository not in an extra dimension These directories just happen to carry some extra historical information 46 Branching and Merging 2 Subversion has no internal concept of a branch only copies When you copy a directory the resulting direc tory i
155. e of speaking to clients over TCP IP using a custom stateful protocol Clients contact an svnserve server by using URLs that begin with the svn or svnt tssh schema This section will explain the different ways of running svnserve how clients authenticate themselves to the server and how to configure appropriate access control to your repositories Invoking the Server There a few different ways to invoke the svnserve program If invoked with no options you ll see nothing but a help message However if you re planning to have inetd launch the process then you can pass the i inetd option svnserve i success 1 2 ANONYMOUS edit pipeline When invoked with the inetd option svnserve attempts to speak with a Subversion client via stdin and stdout using a custom protocol This is the standard behavior for a program being run via inetd The IANA has reserved port 3690 for the Subversion protocol so on a Unix like system you can add lines to etc services like these if they don t already exist svn 3690 tcp Subversion svn 3690 udp Subversion And if your system is using a classic Unix like inetd daemon you can add this line to etc inetd conf svn stream tcp nowait svnowner usr local bin svnserve svnserv al Make sure svnowner is a user which has appropriate permissions to access your repositories Now when a client connection comes into your server on port 3690 inetd will spawn an svnserve proc
156. e repository if you run svn update show updates does not cause the status listing to re flect the repository s version of the item And finally the most information you can get out of the status subcommand svn status show updates verbose wc 201 Subversion Complete Reference M 965 938 sally wc bar c 7 965 922 harry wc foo c A 965 687 harry wc qax c 965 687 harry wc zig c Head revision 981 For many more examples of svn status see Section svn status 202 Subversion Complete Reference Name svn switch Update working copy to a different URL svn switch Synopsis svn switch URL PATH Description This subcommand updates your working copy to mirror a new URL usually a URL which shares a common ances tor with your working copy although not necessarily This is the Subversion way to move a working copy to a new branch See Section Switching a Working Copy for an in depth look at switching Alternate Names sw Changes Working copy Accesses Repository Yes Switches revision r REV non recursiv N quiet a diff3 cmd CMD relocate username USER password PASS no auth cach non interactiv config dir DIR Examples If you re currently inside the directory vendors which was branched to vendors with fix and you d like to switch your working copy to that branch svn switch http svn red bean com repos branches vendors
157. e root of the tree otherwise optionally showing node revision IDs Switches revision 1 transaction t show ids Examples This shows the tree output with node IDs for revision 40 in our sample repository svnlook tree r 40 usr local svn repos show ids lt 0 0 23 gt trunk lt p 0 23 gt vendors lt q 0 23 gt deli lt lg 0 23 gt egg txt lt li e 23 gt soda txt lt 1k 0 23 gt sandwich txt lt 13 0 23 gt 234 Subversion Complete Reference Name svnlook uuid Print the repository s UUID svnlook uuid Synopsis svnlook uuid REPOS_PATH Description Print the UUID for the repository the UUID is the repository s Universal Unique Dentifier The Subversion client uses this identifier to differentiate between one repository and another Examples svnlook uuid usr local svn repos 7fel1b91 8cd5 0310 98dd 2f12e793c5e8 235 Subversion Complete Reference Name svnlook youngest Print the youngest revision number svnlook youngest Synopsis svnlook youngest REPOS_PATH Description Print the youngest revision number of a repository Examples This shows the youngest revision of our sample repository svnlook youngest tmp repos 42 svnserve svnserve allows access to Subversion repositories using the svn network protocol You can run svnserve either as a standalone server process or you can have another process such as inetd xinetd or
158. e same file A within their copies Sally saves her changes to the repository first When Harry attempts to save his changes later the repository informs him that his file A is out of date In other words that file A in the repository has somehow changed since he last copied it So Harry asks his client to merge any new changes from the repository into his working copy of file A Chances are that Sally s changes don t overlap with his own so once he has both sets of changes integrated he saves his working copy back to the repository Figure 2 4 and Figure 2 5 show this process Figure 2 4 The copy modify merge solution Two users copy the some file They both begin to edit their copies Repository Repository A CA te a Harry Sally Harry Sally Sally publishes her version first Harry gets an out of date error Repository Repository Es ls E Write Write ye fa Harry Sally Harry Sally Figure 2 5 The copy modify merge solution continued 11 Basic Concepts Horry compares the latest version Anew merged version is created fo Ais own Repository Repository ar piv A A Harry Sally Harry Sally The menged version is published Now both users have each others changes Repository Repository Ds Read LS Lad Harry Sally Harry Sally But what if Sally s changes do overlap with Harry s changes What then This situation is called a conflict and it s usually not much of a
159. e use of the svnlook and svnad min tools which are provided with Subversion We ll address some common questions and mistakes and give some suggestions on how to arrange the data in the repository If you plan to access a Subversion repository only in the role of a user whose data is under version control that is via a Subversion client you can skip this chapter altogether However if you are or wish to become a Subversion repository administrator 12 you should definitely pay attention to this chapter Repository Basics Before jumping into the broader topic of repository administration let s further define what a repository is How does it look How does it feel Does it take its tea hot or iced sweetened and with lemon As an administrator you ll be expected to understand the composition of a repository both from a logical perspective dealing with how data is represented inside the repository and from a physical nuts and bolts perspective how a repository looks and acts with respect to non Subversion tools The following section covers some of these basic concepts at a very high level Understanding Transactions and Revisions Conceptually speaking a Subversion repository is a sequence of directory trees Each tree is a snapshot of how the files and directories versioned in your repository looked at some point in time These snapshots are created as a re sult of client operations and are called revisions Every revision be
160. e used to merge the contents of several different repositories into a single repository By 79 Repository Administration using the parent dir option of svnadmin load you can specify a new virtual root directory for the load pro cess That means if you have dumpfiles for three repositories say calc dumpfile cal dumpfile and ss dumpfile you can first create a new repository to hold them all svnadmin create path to projects Then make new directories in the repository which will encapsulate the contents of each of the three previous repos itories svn mkdir m Initial project roots file path to projects calc file path to projects calendar file path to projects spreadsheet Committed revision 1 Lastly load the individual dumpfiles into their respective locations in the new repository svnadmin load path to projects parent dir calc lt calc dumpfile svnadmin load path to projects parent dir calendar lt cal dumpfile svnadmin load path to projects parent dir spreadsheet lt ss dumpfile We ll mention one final way to use the Subversion repository dump format conversion from a different storage mechanism or version control system altogether Because the dump file format is for the most part human readable 16 it should be relatively easy to describe generic sets of changes each of which should be treated as a new revi sion using this file format In fac
161. e with the basics Developers Presumably you re already familiar with Subversion and now want to either extend it or build new software on top of its many APIs Chapter 8 is just for you The book ends with reference material chapter 9 is a reference guide for all Subversion commands and the appen dices cover a number of useful topics These are the chapters you re mostly likely to come back to after you ve fin ished the book Conventions Used in This Book This section covers the various conventions used in this book Typographic Conventions Constant width Used for commands command output and switches Constant width italic Used for replaceable items in code and text Italic Used for file and directory names Icons Note This icon designates a note relating to the surrounding text Tip This icon designates a helpful tip relating to the surrounding text Warning This icon designates a warning relating to the surrounding text Note that the source code examples are just that examples While they will compile with the proper compiler in cantations they are intended to illustrate the problem at hand not necessarily serve as examples of good program xiv Preface ming style Organization of This Book The chapters that follow and their contents are listed here Chapter 1 Introduction Covers the history of Subversion as well as its features architecture components and install methods Also in c
162. ecessary for designing a working Subversion client see Section Client Layer Repository Layer When referring to Subversion s Repository Layer we re generally talking about two libraries the repository library and the filesystem library These libraries provide the storage and reporting mechanisms for the various revisions of your version controlled data This layer is connected to the Client Layer via the Repository Access Layer and is from the perspective of the Subversion user the stuff at the other end of the line The Subversion Filesystem is accessed via the libsvn_fs API and is not a kernel level filesystem that one would in stall in an operating system like the Linux ext2 or NTFS but a virtual filesystem Rather than storing files and directories as real files and directories as in the kind you can navigate through using your favorite shell pro gram it uses a database system for its back end storage mechanism Currently the database system in use is Berke ley DB 33 However there has been considerable interest by the development community in giving future releases of Subversion the ability to use other back end database systems perhaps through a mechanism such as Open Database Connectivity ODBC The filesystem API exported by libsvn_fs contains the kinds of functionality you would expect from any other filesystem API you can create and remove files and directories copy and move them around mod
163. ed svn status u M 1047 foo c E 1045 faces html bloo png M 1050 bar baz c Status against revision 1066 In this case two new columns appear The second column contains an asterisk if the file or directory is out of date The third column shows the working copy s revision number of the item In the example above the asterisk indi cates that faces html would be patched if we updated and that bloo png is a newly added file in the repository The next to bloo png means that it doesn t yet exist in the working copy Lastly here s a quick summary of the most common status codes that you may see Resource is scheduled for Addition Resource is scheduled for Deletion Resource has local modifications Resource has conflicts changes have not been completely merged between the repository and working copy version Resource is external to this working copy comes from another repository See Section svn externals Resource is not under version control Resource is missing or incomplete removed by another tool than Subversion QkUP x lt Subversion has combined the CVS P and U codes into just U When a merge or conflict occurs Subversion simply prints G or C rather than a whole sentence about it gt For a more detailed discussion of svn status see Section svn status Branches and Tags Subversion doesn t distinguish between filesystem space and branch space branches and
164. ed from your working copy and the repository 2 svn copy foo bar Create a new item bar as a duplicate of foo bar is automatically scheduled for addition When bar is added to the repository on the next commit its copy history is recorded as having originally come from foo svn copy does not create intermediate directories svn move foo bar This command is exactly the same as running svn copy foo bar svn delete foo That is bar is scheduled for addition as a copy of foo and foo is scheduled for removal svn move does not create intermediate directories Changing the Repository Without a Working Copy Earlier in this chapter we said that you have to commit any changes that you make in order for the repository to re flect these changes That s not entirely true there are some use cases that immediately commit tree changes to the repository This only happens when a subcommand is operating directly on a URL rather than on a working copy path In particular specific uses of svn mkdir svn copy svn move and svn delete can work with URLs URL operations behave in this manner because commands that operate on a working copy can use the working copy as a sort of staging area to set up your changes before committing them to the repository Commands that operate on URLs don t have this luxury so when you operate directly on a URL any of the above actions represent an im mediate commit Examine Your Changes Once you ve finished mak
165. effort over the lifetime of the software incoming questions must be tracked responses monitored and all gathered into a coherent searchable whole that reflects the collective experi ence of users in the wild It calls for the patient observant attitude of a field naturalist No grand hypothesizing no visionary pronouncements here open eyes and accurate note taking are what s needed most What I love about this book is that it grew out of just such a process and shows it on every page It is the direct re sult of the authors encounters with users It began with Ben Collins Sussman s observation that people were asking the same basic questions over and over on the Subversion mailing lists What are the standard workflows to use with Subversion Do branches and tags work the same way as in other version control systems How can I find out who made a particular change Frustrated at seeing the same questions day after day Ben worked intensely over a month in the summer of 2002 to write The Subversion Handbook a sixty page manual that covered all the basics of using Subversion The manual made no pretense of being complete but it was distributed with Subversion and got users over that initial hump in the learning curve When O Reilly and Associates decided to publish a full length Subversion book the path of least resistance was obvious just expand the Subversion handbook The three co authors of the new book were thus presented with an unus
166. em directory Initially revision 0 also has a single revision property svn date set to the time at which the repository was created Warning Do not create your repository on a network share it cannot exist on a remote filesystem such as NES AFS or Windows SMB Berkeley DB requires that the underlying filesystem implement strict POSIX locking semantics and more importantly the ability to map files directly into process memory Almost no network filesystems provide these features If you attempt to use Berkeley DB on a network share the re sults are unpredictable you may see mysterious errors right away or it may be months before you dis cover that your repository database is subtly corrupted If you need multiple computers to access the repository you should set up a server process such as Apache or synserve store the repository on a local filesystem which the server can access and make the reposi tory available over a network Chapter 6 Server Configuration covers this process in detail You may have noticed that the path argument to svnadmin was just a regular filesystem path and not a URL like the svn client program uses when referring to repositories Both svnadmin and svnlook are considered server side utili ties they are used on the machine where the repository resides to examine or modify aspects of the repository and are in fact unable to perform tasks across a network A common mistake made by Subversion newcomers is t
167. emember though that while moving directories may be easy to do you need to be considerate of your users as well Your juggling can be disorienting to users with existing working copies If a user has a working copy of a par ticular repository directory your svn move operation might remove the path from the latest revision When the user next runs svn update they ll be told that their working copy represents a path that no longer exists and the user will be forced to svn switch to the new location Data Lifetimes Another nice feature of Subversion s model is that branches and tags can have finite lifetimes just like any other versioned item For example suppose you eventually finish all your work on your personal branch of the calc project After merging all of your changes back into calc trunk there s no need for your private branch direc tory to stick around anymore svn delete http svn example com repos calc branches my calc branch m Removing obsolete branch of calc project Committed revision 375 And now your branch is gone Of course it s not really gone the directory is simply missing from the HEAD revision 58 Branching and Merging no longer distracting anyone If you use svn checkout svn switch or svn list to examine an earlier revision you ll still be able to see your old branch If browsing your deleted directory isn t enough you can always bring it back Resurrecting data is very easy in Sub
168. ems 35 APR gives Subversion immediate access to many custom datatypes such as dynamic arrays and hash tables Subversion uses these types extensively throughout the codebase But perhaps the most pervasive APR datatype found in nearly every Subversion API prototype is the apr_pool_t the APR memory pool Subversion uses pools internally for all its memory allocation needs unless an external library requires a different memory management schema for data passed through its API 36 and while a person coding against the Subversion APIs is not required to do the same they are required to provide pools to the API functions that need them This means that users of the Subversion API must also link against APR must call apr_initialize to initialize the APR subsystem and then must acquire a pool for use with Subversion API calls See Section Programming with Memory Pools for more information URL and Path Requirements 35Subversion uses ANSI system calls and datatypes as much as possible 36Neon and Berkeley DB are examples of such libraries 134 Developer Information With remote version control operation as the whole point of Subversion s existence it makes sense that some atten tion has been paid to internationalization 118n support After all while remote might mean across the office it could just as well mean across the globe To facilitate this all of Subversion s public interfaces that accept path ar g
169. ents will be created The per user configuration area also contains a cache of authentication data The auth directory holds a set of sub directories that contain pieces of cached information used by Subversion s various supported authentication meth ods This directory is created in such a way that only the user herself has permission to read its contents Configuration and the Windows Registry In addition to the usual INI based configuration area Subversion clients running on Windows platforms may also use the Windows registry to hold the configuration data The option names and their values are the same as in the INI files The file section hierarchy is preserved as well though addressed in a slightly different fashion in this schema files and sections are just levels in the registry key tree Subversion looks for system wide configuration values under the HKEY_LOCAL_MACHINE Software Tigris org Subversion key For example the global ignores option which is in the miscellany section of the config file would be found at HKEY_LOCAL_MACHINE Software Tigris org Subversion Config Miscellany global ignores Per user configuration values should be stored under HKEY_CURRENT_USER Software Tigris org Subversion Registry based configuration options are parsed before their file based counterparts so are overridden by values found in the configuration files In other words configuration priorit
170. epository will reject your commit for being out of date More on this subject later svn diff Another way to examine your changes is with the svn diff command You can find out exactly how you ve modified things by running svn diff with no arguments which prints out file changes in unified diff format 3 svn diff Index bar c bar c revision 3 bar c working copy 1 7 1 12 include lt sys types h gt include lt sys stat h gt include lt unistd h gt include lt stdio h gt int main void printf Sixty four slices of American Cheese n printf Sixty five slices of American Cheese n return 0 Index README README revision 3 README working copy 193 3 193 4 Qe Note to self pick up laundry Index stuff fish c stuff fish c revision 1 stuff fish c working copy 3Subversion uses its internal diff engine which produces unified diff format by default If you want diff output in a different format specify an external diff program using diff cmd and pass any flags you d like to it using the extensions switch For example to see local differ ences in file foo c in context output format while ignoring whitespace changes you might run svn diff diff cmd usr bin diff extensions be foo c 29 Guided Tour Welcome to the file known as fish Informat
171. eral ways e Rebuild db4 for the kernel you re using e Use a RedHat 9 kernel e Apply the NPTL patches to the kernel you re using e Use a recent 2 5 x kernel with the NPTL support included e Check if environment variable LD_ASSUME_KERNEL is set to 2 2 5 and if so unset it before starting Subversion Apache You usually would set this variable to run Wine or Winex on RedHat 9 Why does log say no author for files committed or imported via Apache ra_dav If you allow anonymous write access to the repository via Apache the Apache server never challenges the client for a username and instead permits the write operation without authentication Since Subversion has no idea who did the operation this results in a log like this svn log rev 24 no author 2003 07 29 19 28 35 0200 Tue 29 Jul 2003 Read about adding authentication in Chapter 6 Server Configuration I m getting occasional Access Denied errors on Windows They seem to happen at random These appear to be due to the various Windows services that monitor the filesystem for changes anti virus software 246 Troubleshooting indexing services the COM Event Notification Service This is not really a bug in Subversion which makes it dif ficult for to fix A summary of the current state of the investigation is available at http www contactor se dast svn archive 2003 10 0136 shtml A workaround that should reduce the in
172. erating systems its primary user interface is command line based It is that com mand line tool svn which is discussed and used in this book For consistency the examples in this book assume the reader is using a Unix like operating system and is relatively comfortable with Unix and command line inter faces That said the svn program also runs on non Unix platforms like Microsoft Windows With a few minor exceptions such as the use of backward slashes instead of forward slashes for path separators the input to and output from this tool when run on Windows are identical to its Unix counterpart However Windows users may find more success by running the examples inside the Cygwin Unix emulation environment Most readers are probably programmers or sysadmins who need to track changes to source code This is the most common use for Subversion and therefore it is the scenario underlying all of the book s examples But Subversion can be used to manage changes to any sort of information images music databases documentation and so on To Subversion all data is just data While this book is written with the assumption that the reader has never used version control we ve also tried to make it easy for users of CVS to make a painless leap into Subversion Special sidebars may discuss CVS from time to time and a special appendix summarizes most of the differences between CVS and Subversion How to Read this Book This book aims to be u
173. eration in subversion the program tries to dynamically load a plugin based on the URL scheme A file URL will try to load ra_local and an http URL will try to load ra_dav The error you are seeing means that the dynamic linker loader can t find the plugins to load This normally happens when you build subversion with shared libraries then attempt to run it without first running make install Another possible cause is that you ran make install but the libraries were installed in a location that the dynamic linker loader doesn t recognize Under Linux you can allow the linker loader to find the libraries by adding the library di rectory to etc 1d so conf and running Idconfig If you don t wish to do this or you don t have root access you can also specify the library directory in the LD_LIBRARY_PATH environment variable Why does the svn revert command require an explicit target Why is it not recursive by default This behavior differs from almost all the other sub commands The short answer it s for your own good Subversion places a very high priority on protecting your data and not just your versioned data Modifications that you make to already versioned files and new files scheduled for addition to the version control system must be treated with care Making the svn revert command require an explicit target even if that target is just is one way of accomplish ing that This requirement as well as requiring you
174. eresting To enable customization of these directory displays Subversion provides an XML index feature A single SVNIndexXSLT directive in your repository s Location block of httpd conf will instruct mod_dav_svn to generate XML output when displaying a directory listing and to reference the XSLT stylesheet of your choice lt Location svn gt DAV svn SVNParentPath usr local svn SVNIndexXSLT svnindex xsl lt Location gt Using the SVNIndexXSLT directive and a creative XSLT stylesheet you can make your directory listings match the color schemes and imagery used in other parts of your website Or if you d prefer you can use the sample stylesheets provided in the Subversion source distribution s tools xsit directory Keep in mind that the path pro vided to the SVNIndexXSLT directory is actually a URL path browsers need to be able to read your stylesheets in order to make use of them Can I view older revisions With an ordinary web browser In one word nope At least not with mod_dav_svn as your only tool 102 Server Configuration Your web browser only speaks ordinary HTTP That means it only knows how to GET public URLs which repre sent the latest versions of files and directories According to the WebDAV DeltaV spec each server defines a pri vate URL syntax for older versions of resources and that syntax is opaque to clients To find an older version of a file a client must follow a specific procedure to di
175. erify that the transaction is in fact in a zombie state Managing Disk Space 75 Repository Administration While the cost of storage has dropped incredibly in the past few years disk usage is still a valid concern for adminis trators seeking to version large amounts of data Every additional byte consumed by the live repository is a byte that needs to be backed up offsite perhaps multiple times as part of rotating backup schedules Since the primary storage mechanism of a Subversion repository is a complex database system 1t is useful to know what pieces of data need to remain on the live site which need to be backed up and which can be safely removed Until recently the largest offender of disk space usage with respect to Subversion repositories was the logfiles to which Berkeley DB performs its pre writes before modifying the actual database files These files capture all the ac tions taken along the route of changing the database from one state to another while the database files reflect at any given time some state the logfiles contain all the many changes along the way between states As such they can start to accumulate quite rapidly Fortunately beginning with the 4 2 release of Berkeley DB the database environment has the ability to remove its own unused logfiles without any external procedures Any repositories created using an svnadmin which is com piled against Berkeley DB version 4 2 or greater will be configured f
176. ermine what special processing to perform on the file so that the file s line ending style isn t flip flopping with every commit that comes from a different operating system The valid values are native This causes the file to contain the EOL markers that are native to the operating system on which Subversion was run In other words if a user on a Windows machine checks out a working copy that contains a file with an svn eol style property set to native that file will contain CRLF EOL markers A unix user checking out a working copy which contains the same file will see LF EOL markers in his copy of the file Note that Subversion will actually store the file in the repository using normalized Lr EOL markers regardless of the operating system This is basically transparent to the user though CRLF This causes the file to contain CRLF sequences for EOL markers regardless of the operating system in use LF This causes the file to contain LF characters for EOL markers regardless of the operating system in use CR This causes the file to contain CR characters for EOL markers regardless of the operating system in use This line ending style is not very common It was used on older Macintosh platforms on which Subversion doesn t even run 119 Advanced Topics svn externals The svn externals property contains instructions for Subversion to populate a versioned directory with one or more other checked out Subversion working copies
177. ermission from the Licensor to exercise rights under this License despite a previous violation Fair Use Rights Nothing in this license is intended to reduce limit or restrict any rights arising from fair use first sale or other limitations on the exclusive rights of the copyright owner under copyright law or other applicable laws License Grant Subject to the terms and conditions of this License Licensor hereby grants You a worldwide royalty free non exclusive perpetual for the duration of the applicable copyright license to exercise the rights in the Work as stated below a to reproduce the Work to incorporate the Work into one or more Collective Works and to reproduce the Work as incorporated in the Collective Works to create and reproduce Derivative Works to distribute copies or phonorecords of display publicly perform publicly and perform publicly by means of a digital audio transmission the Work including as incorporated in Collective Works to distribute copies or phonorecords of display publicly perform publicly and perform publicly by means of a digital audio transmission Derivative Works For the avoidance of doubt where the work is a musical composition i Performance Royalties Under Blanket Licenses Licensor waives the exclusive right to collect whether individually or via a performance rights society e g ASCAP BMI SESAC royalties for the public performance
178. ernal notion of whether a file is text or binary data but this notion is only extant in the working copy During an svn update Subversion will perform contextual merges on locally modified text files but will not attempt to do so for binary files To determine whether a contextual merge is possible Subversion examines the svn mime type property If the file has no svn mime type property or has a mime type that is textual e g text Subversion assumes it is text Oth erwise Subversion assumes the file is binary Subversion also helps users by running a binary detection algorithm in the svn import and svn add commands These commands will make a good guess and then possibly set a binary svn mime type property on the file being added If Subversion guesses wrong the user can always remove or hand edit the property Versioned Modules Unlike CVS a Subversion working copy is aware that it has checked out a module That means that if somebody changes the definition of a module then a call to svn update will update the working copy appropriately Subversion defines modules as a list of directories within a directory property see Section Externals Definitions 241 Subversion for CVS Users Authentication With CVS s pserver you are required to login to the server before any read or write operation you even have to login for anonymous operations With a Subversion repository using Apache HTTPD as the s
179. ers like files Or more properly it s correct to talk about directory foo in revision 5 Let s talk more about that last point Directory versioning is a hard problem because we want to allow mixed revi sion working copies there are some limitations on how far we can abuse this model From a theoretical point of view we define revision 5 of directory foo to mean a specific collection of directory en tries and properties Now suppose we start adding and removing files from foo and then commit It would be a lie to say that we still have revision 5 of foo However if we bumped foo s revision number after the commit that would be a lie too there may be other changes to foo we haven t yet received because we haven t updated yet Subversion deals with this problem by quietly tracking committed adds and deletes in the svn area When you eventually run svn update all accounts are settled with the repository and the directory s new revision number is set correctly Therefore only after an update is it truly safe to say that you have a perfect revision of a directory Most of the time your working copy will contain imperfect directory revisions 238 Subversion for CVS Users Similarly a problem arises if you attempt to commit property changes on a directory Normally the commit would bump the working directory s local revision number But again that would be a lie because there may be adds or deletes that
180. ersion s modular design covered in Section Layered Library Design and the availability of language bind ings as described in Section Using Languages Other than C and C make it a likely candidate for use as an extension or backend to other pieces of software In this appendix we ll briefly introduce you to some of the many third party tools that are using Subversion functionality under the hood For a more recently updated version of this information check out the Links page on the Subversion website http subversion tigris org project_links html Clients and Plugins AnkhSVN http ankhsvn tigris org Subversion add in for Microsoft Visual Studio NET JSVN http jsvn alternatecomputing com Java Subversion Client including a plugin for IDEA psvn el nttp xsteve nit at prg vc_svn Subversion interface for emacs RapidSVN http rapidsvn tigris org Cross platform Subversion GUI based on the WxPython libraries Subclipse nttp subclipse tigris org Subversion plugin for the Eclipse environment Subway http nidaros homedns org subway Microsoft SCC provider for Subversion sourcecross org http www sourcecross org Microsoft SCC provider for Subversion Supervision nttp supervision tigris org Java Swing visual client for Subversion Sven http www nikwest de Software SvenOverview Native GUI for Subversion using the Mac OS X Cocoa framework Svn4Eclipse http svnteclip
181. ersion supplies and most of its code uses the wrapper functions svn_pool_create svn_pool_clear and svn_pool_destroy While pools are helpful for basic memory management the pool construct really shines in looping and recursive scenarios Since loops are often unbounded in their iterations and recursions in their depth memory consumption in these areas of the code can become unpredictable Fortunately using nested memory pools can be a great way to easily manage these potentially hairy situations The following example demonstrates the basic use of nested pools in a situation that is fairly common recursively crawling a directory tree doing some task to each thing in the tree 139 Developer Information Example 8 5 Effective Pool Usage Recursively crawl over DIRECTORY adding the paths of all its file children to the FILES array and doing some task to each path ncountered Use POOL for the all temporary allocations and store the hash paths in the same pool as the hash itself is allocated in static apr_status_t crawl_dir apr_array_header_t files apr apr apr apr apr apr apr if r for const char directory apr_pool_t pool _pool_t hash_pool files gt pool array pool _pool_t subpool svn_pool_create pool iteration pool _dir_t dir finfo t finto status_t apr_err _int32_t flags APR_FINFO_TYPE APR_FINFO_NAMI pl _err
182. erver you don t pro vide any authentication credentials at the outset 1f an operation that you perform requires authentication the server will challenge you for your credentials whether those credentials are username and password a client certificate or even both So if your repository is world readable you will not be required to authenticate at all for read operations As with CVS Subversion still caches your credentials on disk in your subversion auth directory unless you tell it not to by using the no auth cache switch Converting a Repository from CVS to Subversion Perhaps the most important way to familiarize CVS users with Subversion is to let them continue to work on their projects using the new system And while that can be somewhat accomplished using a flat import into a Subversion repository of an exported CVS repository the more thorough solution involves transferring not just the latest snap shot of their data but all the history behind it as well from one system to another This is an extremely difficult problem to solve that involves deducing changesets in the absence of atomicity and translating between the systems completely orthogonal branching policies among other complications Still there are a handful of tools claiming to at least partially support the ability to convert existing CVS repositories into Subversion ones One such tool is cvs2svn http cvs2svn tigris org a Python script originally created
183. es on calc button c Name copyright c 2003 Red Bean Software Notice how the status subcommand displays M in the second column instead of the first That is because we have modified the properties on calc button c but not modified its textual contents Had we changed both we would have seen M in the first column too see Section svn status 27Fixing spelling errors grammatical gotchas and just plain wrongness in commit log messages is perhaps the most common use case for the revprop option 113 Advanced Topics Property Conflicts As with file contents local property modifications can conflict with changes committed by someone else If you up date your working copy directory and receive property changes on a versioned resource that clash with your own Subversion will report that the resource is in a conflicted state svn update calc M calc Makefile in Cucalie bhutronne Updated to revision 143 Subversion will also create in the same directory as the conflicted resource a file with a prej extension which contains the details of the conflict You should examine the contents of this file so you can decide how to resolve the conflict Until the conflict is resolved you will see a C in the second column of svn status output for that resource and attempts to commit your local modifications will fail S svn status calle E calc button c 7 callo Acto Core Scale calle Mowe ton aa aos
184. ess to service it A second option is to run svnserve as a standalone daemon process Use the a option for this svnserve d svnserve is now running listening on port 3690 When running svnserve in daemon mode you can use the 1isten port and listen host options to cus tomize the exact port and hostname to bind to There s still a third way to invoke svnserve and that s in tunnel mode with the t option This mode assumes that a remote service program such as RSH or SSH has successfully authenticated a user and is now invoking a private 88 Server Configuration svnserve process as that user The svnserve program behaves normally communicating via stdin and stdout and assumes that the traffic is being automatically redirected over some sort of tunnel back to the client When svnserve 1s invoked by a tunnel agent like this be sure that the authenticated user has full read and write access to the reposi tory database files See Servers and Permissions A Word of Warning It s essentially the same as a local user ac cessing the repository via file URLs Servers and Permissions A Word of Warning First remember that a Subversion repository is a collection of BerkeleyDB database files any process which ac cesses the repository directly needs to have proper read and write permissions on the entire repository If you re not careful this can lead to a number of headaches Be sure to re
185. example we could have done svn propset copyright c 2002 Red Bean Software calc property copyright set on calc Makefile property copyright set on calc button c property copyright set on calc integer c All of this property adding and editing isn t really very useful if you can t easily get the stored property value So the svn program supplies two subcommands for displaying the names and values of properties stored on files and direc tories The svn proplist command will list the names of properties that exist on a path Once you know the names of the properties on the node you can request their values individually using svn propget This command will given a path or set of paths and a property name print the value of the property to the standard output stream svn proplist calc button c Properties on calc button c copyright license svn propget copyright calc button c c 2003 Red Bean Software There s even a variation of the proplist command that will list both the name and value of all of the properties Sim ply supply the verbose v option svn proplist verbose calc button c Properties on calc button c copyright c 2003 Red Bean Software license Copyright c 2003 Red Bean Software All rights reserved Redistribution and use in source and binary forms with or without modification are permitted provided that the following conditions are met 1 Redistributions of sourc
186. expected the examples honed from genuine use cases and most of all the sensitivity to the user s needs and the user s point of view Of course no one can promise that this book will answer every question you have about Subversion Sometimes the precision with which it anticipates your questions will seem eerily telepathic yet occasionally you will stumble into a hole in the community s knowledge and come away empty handed When this happens the best thing you can do is email lt users subversion tigris org gt and present your problem The authors are still there still watching and they include not just the three listed on the cover but many others who contributed corrections and original ma xi Foreword terial From the community s point of view solving your problem is merely a pleasant side effect of a much larger project namely slowly adjusting this book and ultimately Subversion itself to more closely match the way people actually use it They are eager to hear from you not merely because they can help you but because you can help them With Subversion as with all active free software projects you are not alone Let this book be your first companion Karl Fogel Chicago 14 March 2004 xii Preface If C gives you enough rope to hang yourself think of Subversion as a sort of rope storage facil ity Brian W Fitzpatrick In the world of open source software the Concurrent Versions System CV
187. f fic to pass through sysadmins typically don t even have to change their firewall configurations to allow Subversion to work Subversion uses HTTP and WebDAV with DeltaV to communicate with an Apache server You can read more about this in the WebDAV section of this chapter but in short WebDAV and DeltaV are extensions to the standard HTTP 1 1 protocol that enable sharing and versioning of files over the web Apache 2 0 comes with mod_dav an Apache module that understands the DAV extensions to HTTP Subversion itself supplies mod_dav_svn though which is another Apache module that works in conjunction with really as a back end to mod_dav to provide Sub version s specific implementations of WebDAV and DeltaV When communicating with a repository over HTTP the RA loader library chooses libsvn_ra_dav as the proper ac cess module The Subversion client makes calls into the generic RA interface and libsvn_ra_dav maps those calls which embody rather large scale Subversion actions to a set of HTTP WebDAV requests Using the Neon library libsvn_ra_dav transmits those requests to the Apache server Apache receives these requests exactly as it does generic HTTP requests that your web browser might make notices that the requests are directed at a URL that is configured as a DAV location using the Location directive in httpd conf and hands the request off to its own mod_dav module When properly configured mod_dav knows to use Subversion s mod
188. f FILE This is similar to using svn propset revprop to set the svn 1og property on a revision except that you can also use the option bypass hooks to avoid running any pre or post commit hooks which is useful if the modifica tion of revision properties has not been enabled in the pre revprop change hook Warning Revision properties are not under version control so this command will permanently overwrite the previous log message Switches revision r ARG bypass hooks Examples Set the log message for revision 19 to the contents of the file msg svnadmin setlog usr local svn repos r 19 msg 219 Subversion Complete Reference Name svnadmin verify Verify the data stored in the repository svnadmin verify Synopsis svnadmin verify REPOS_PATH Description Run this command if you wish to verify the integrity of your repository This basically iterates through all revisions in the repository by internally dumping all revisions and discarding the output Examples Verify a hung repository svnadmin verify usr local svn repos Verified revision 1729 svnlook svnlook is a command line utility for examining different aspects of a Subversion repository It does not make any changes to the repository it s just used for peeking svnlook is typically used by the repository hooks but a repository administrator might find it useful for diagnostic purposes Since svnlook w
189. fails In the case of an error or bug it s possible that a transac tion can be accidentally left lying around in the repository not really affecting anything but still taking up space In theory someday whole workflow applications might revolve around more fine grained control of transaction life time It is feasible to imagine a system whereby each transaction slated to become a revision is left in stasis well af 12This may sound really prestigious and lofty but we re just talking about anyone who is interested in that mysterious realm beyond the working copy where everyone s data hangs out 60 Repository Administration ter the client finishes describing its changes to repository This would enable each new commit to be reviewed by someone else perhaps a manager or engineering QA team who can choose to promote the transaction into a revi sion or abort it Unversioned Properties Transactions and revisions in the Subversion repository can have properties attached to them These properties are generic key to value mappings and are generally used to store information about the tree to which they are attached The names and values of these properties are stored in the repository s filesystem along with the rest of your tree data Revision and transaction properties are useful for associating information with a tree that is not strictly related to the files and directories in that tree the kind of information that isn t ma
190. ferent operating systems For example consider a source code file and developers that edit this file on both Windows and Unix sys tems If all the developers always use tools which preserve the line ending style of the file no problems occur But in practice many common tools either fail to properly read a file with foreign EOL markers or they convert the file s line endings to the native style when the file is saved If the former is true for a developer he has to use an ex ternal conversion utility such as dos2unix or its companion unix2dos to prepare the file for editing The latter case requires no extra preparation But both cases result in a file that differs from the original quite literally on every line Prior to committing his changes the user has two choices Either he can use a conversion utility to restore the modified file to the same line ending style that it was in before his edits were made Or he can simply commit the file new EOL markers and all The result of scenarios like these include wasted time and unnecessary modifications to committed files Wasted time is painful enough But when commits change every line in a file this complicates the job of determining which of those lines were changed in a non trivial way Where was that bug really fixed On what line was a syntax error introduced The solution to this problem is the svn eo1 style property When this property is set to a valid value Subversion uses it to det
191. fined values Subversion will force its value to when setting this property Fi nally this property is valid only on files not on directories svn mime type The svn mime type property serves many purposes in Subversion Besides being a general purpose storage loca tion for a file s Multipurpose Internet Mail Extensions MIME classification the value of this property determines some behavioral characteristics of Subversion itself For example if a file s svn mime type property is set to a non text MIME type generally something that doesn t begin with text though there are exceptions Subversion will assume that the file contains binary that is not human readable data One of the benefits that Subversion typically provides is contextual line based merging of changes received from the server during an update into your working file But for files believed to contain binary data there is no concept of a line So for those files Subversion does not attempt to perform contextual merges during updates Instead any time you have locally modified a binary working copy file that is also being updated your file is renamed with a orig extension and then Subversion stores a new working copy file that contains the changes received during the update but not your own local modifications at the original filename This behavior is really for the protection of the user against failed attempts at performing contextual merges on files that s
192. fo grep URL URL http svn example com repos calc branches my calc branch After switching to the branch your working copy is no different than what you would get from doing a fresh checkout of the directory And it s usually more efficient to use this command because often branches only differ by a small degree The server sends only the minimal set of changes necessary to make your working copy reflect the branch directory The svn switch command also takes a revision r option so you need not always move your working copy to the tip of the branch Of course most projects are more complicated than our calc example containing multiple subdirectories Subver sion users often follow a specific algorithm when using branches 1 Copy the project s entire trunk to a new branch directory 2 Switch only part of the trunk working copy to mirror the branch 55 Branching and Merging In other words if a user knows that the branch work only needs to happen on a specific subdirectory they use svn switch to move only that subdirectory to the branch Or sometimes users will switch just a single working file to the branch That way they can continue to receive normal trunk updates to most of their working copy but the switched portions will remain immune unless someone commits a change to their branch This feature adds a whole new dimension to the concept of a mixed working copy not only can wo
193. foo c 99 is an an 50 Branching and Merging cestor of foo cf100 On the other hand suppose you commit the deletion of foo c in revision 101 and then add a new file by the same name in revision 102 In this case foo c 99 and foo c 102 may appear to be related they have the same path but in fact are completely different objects in the repository They share no history or ancestry The reason for bringing this up is to point out an important difference between svn diff and svn merge The former command ignores ancestry while the latter command is quite sensitive to it For example if you asked svn diff to compare revisions 99 and 102 of foo c you would see line based diffs the diff command is blindly comparing two paths But if you asked svn merge to compare the same two objects it would notice that they re unrelated and first attempt to delete the old file then add the new file you would see a D foo c followed by aA foo c Most merges involve comparing trees that are ancestrally related to one another and therefore svn merge defaults to this behavior Occasionally however you may want the merge command to compare two unrelated trees For exam ple you may have imported two source code trees representing different vendor releases of a software project see Section Vendor branches If you asked svn merge to compare the two trees you d see the entire first tree being deleted followed by an add of the entire seco
194. fter all svn status foo foo nw svn add foo A foo svn revert foo Reverted foo svn status foo 2 foo Note svn revert ITEM has exactly the same effect as deleting ITEM from your working copy and then running svn update r BASE ITEM However if you re reverting a file svn revert has one very noticeable differ ence it doesn t have to communicate with the repository to restore your file Or perhaps you mistakenly removed a file from version control svn status README 30 Guided Tour README svn delete README D README svn revert README Reverted README svn status README README Look Ma No Network All three of these commands svn status svn diff and svn revert can be used without any network access This makes it easy to manage your changes in progress when you are somewhere without a network connection such as traveling on an airplane riding a commuter train or hacking on the beach Subversion does this by keeping private caches of pristine versions of each versioned file inside of the svn admin istrative areas This allows Subversion to report and revert local modifications to those files without network ac cess This cache called the text base also allows Subversion to send the user s local modifications during a com mit to the server as a compressed delta or difference against t
195. functions like apr_palloc which returns a generic memory location from the pool The program can keep requesting bits and pieces of memory from the pool and APR will keep granting the requests Pools will automatically grow in size to accommodate programs that request more memory than the original pool contained until of course there is no more memory available on the system Now if this were the end of the pool story it would hardly have merited special attention Fortunately that s not the case Pools can not only be created they can also be cleared and destroyed using apr_pool_clear and apr_pool_destroy respectively This gives developers the flexibility to allocate several or several thousand things from the pool and then clean up all of that memory with a single function call Further pools have hierarchy You can make subpools of any previously created pool When you clear a pool all of its subpools are destroyed if you destroy a pool it and its subpools are destroyed Before we go further developers should be aware that they probably will not find many calls to the APR pool func tions we just mentioned in the Subversion source code APR pools offer some extensibility mechanisms like the ability to have custom user data attached to the pool and mechanisms for registering cleanup functions that get called when the pool is destroyed Subversion makes use of these extensions in a somewhat non trivial way So Subv
196. g off site backups of the repository data in some fashion but don t call your system administrator to restore a backup tape just yet Secondly use the following recipe to attempt to unwedge your repository 1 Make sure that there are no processes accessing or attempting to access the repository For networked reposi tories this means shutting down the Apache HTTP Server too 2 Become the user who owns and manages the repository This is important as recovering a repository while run ning as the wrong user can tweak the permissions of the repository s files in such a way that your repository will still be inaccessible even after it is unwedged 3 Run the command svnadmin recover path to repos You should see output like this Please wait recovering the repository may take some time Recovery completed The latest repos revision is 19 This command may take many minutes to complete 4 Restart the Subversion server This procedure fixes almost every case of repository lock up Make sure that you run this command as the user that owns and manages the database not just as root Part of the recovery process might involve recreating from scratch various database files shared memory regions for example Recovering as root will create those files such that they are owned by root which means that even after you restore connectivity to your repository regular users will be unable to access it If the previous p
197. ged Print the directories that were themselves changed svnlook dirs changed Synopsis svnlook dirs changed REPOS_PATH Description Print the directories that were themselves changed property edits or whose file children were changed revision 1 transaction t Examples This shows the directories that changed in revision 40 in our sample repository svnlook dirs changed r 40 usr local svn repos trunk vendors deli 227 Subversion Complete Reference Name svnlook help svnlook help Synopsis Also svnlook h and svnlook Description Displays the help message for svnlook This command like its brother svn help is also your friend even though you never call it anymore and forgot to invite it to your last party Alternate Names h 228 Subversion Complete Reference Name svnlook history Print information about the history of a path in the repository or the root directory if no path is supplied svnlook history Synopsis svnlook history REPOS_PATH PATH_IN_REPOS Description Print information about the history of a path in the repository or the root directory 1f no path is supplied revision 1 show ids Examples This shows the history output for the path tags 1 0 as of revision 20 in our sample repository svnlook history r 20 usr local svn repos tags 1 0 show ids REVISION PATH lt ID gt 19 tags 1 0 lt 1
198. gins life as a transaction tree When doing a commit a client builds a Subversion transaction that mirrors their local changes plus any additional changes that might have been made to the repository since the begin ning of the client s commit process and then instructs the repository to store that tree as the next snapshot in the se quence If the commit succeeds the transaction is effectively promoted into a new revision tree and is assigned a new revision number If the commit fails for some reason the transaction is destroyed and the client is informed of the failure Updates work in a similar way The client builds a temporary transaction tree that mirrors the state of the working copy The repository then compares that transaction tree with the revision tree at the requested revision usually the most recent or youngest tree and sends back information that informs the client about what changes are needed to transform their working copy into a replica of that revision tree After the update completes the temporary trans action is deleted The use of transaction trees is the only way to make permanent changes to a repository s versioned filesystem How ever it s important to understand that the lifetime of a transaction is completely flexible In the case of updates transactions are temporary trees that are immediately destroyed In the case of commits transactions are transformed into permanent revisions or removed if the commit
199. h the same URL you can use the URL svn log http svn red bean com repos test foo c bar c PATH syntax r32 sally 2003 01 13 16 43 13 0600 Mon 13 Jan Added defines 2003 1 line r31 harry 2003 01 10 12 25 08 0600 Fri 10 Jan Added new file bar c 1 line r28 sally 2003 01 07 21 48 33 0600 Tue 07 Jan That is the same as explicitly placing both URLs on the command line svn log http svn red bean com repos test foo c http svn red bean com repos test bar c 3 lines 176 Subversion Complete Reference When you re concatenating the results of multiple calls to the log command you may want to use the incremental switch svn log normally prints out a dashed line at the beginning of a log message after each sub sequent log message and following the final log message If you ran svn log on a range of two revisions you would get this svn log r 14 15 r14 PES However if you wanted to gather 2 non sequential log messages into a file you might do something like this svn log r 14 gt mylog svn log r 19 gt gt mylog svn log r 27 gt gt mylog cat mylog UN Ut Ut Ur r14 19 AAN You can avoid the clutter of the double dashed lines in your output by using the incremental switch svn log incremental r 14 gt mylog svn log incremental r 19 gt gt mylog svn log incremental r 27 gt gt mylog c
200. he this directory entry from its own svn entries file However a reference to the subdirec tory is kept in its parent s entries file with enough information to permit basic versioning operations in the event that the subdirectory itself is actually missing from disk Pristine Copies and Property Files As mentioned before the svn directory also holds the pristine text base versions of files Those can be found in svn text base The benefits of these pristine copies are multiple network free checks for local modifications and difference reporting network free reversion of modified or missing files smaller transmission of changes to the server but comes at the cost of having each versioned file stored at least twice on disk These days this seems to be a negligible penalty for most files However the situation gets uglier as the size of your versioned files grows Some attention is being given to making the presence of the text base an option Ironically though it is as your versioned files sizes get larger that the existence of the text base becomes more crucial who wants to transmit a huge file across a network just because they want to commit a tiny change to it Similar in purpose to the text base files are the property files and their pristine prop base copies located in svn props and svn prop base respectively Since directories can have properties too there are also svn dir props and svn
201. he pristine version Having this cache is a tremen dous benefit even if you have a fast net connection it s much faster to send only a file s changes rather than the whole file to the server At first glance this might not seem that important but imagine the repercussions if you try to commit a one line change to a 400MB file and have to send the whole file to the server Resolve Conflicts Merging Others Changes We ve already seen how svn status u can predict conflicts Suppose you run svn update and some interesting things occur svn update U INSTALL G README bar c Updated to revision 46 The U and G codes are no cause for concern those files cleanly absorbed changes from the repository The files marked with U contained no local changes but were Updated with changes from the repository The G stands for merGed which means that the file had local changes to begin with but the changes coming from the repository didn t overlap in any way But the c stands for conflict This means that the changes from the server overlapped with your own and now you have to manually choose between them Whenever a conflict occurs three things occur to assist you in noticing and resolving that conflict e Subversion prints a C during the update and remembers that the file is in a state of conflict e Subversion places conflict markers special strings of text which delimit the sides of the conflict into the file t
202. he svn client For exam ple instead of running svn diff r 1000 2000 http host repos branches mybranch foo c svn Filesystem has no item svn branches mybranch foo c not found in the repository at revision 1000 247 Troubleshooting you would instead run svn diff r1000 2000 http host repos trunk foo c 248 Appendix C WebDAV and Autoversioning WebDAV is an extension to HTTP and is growing more and more popular as a standard for file sharing Today s Operating systems are becoming extremely Web aware and many have now built in support for mounting shares exported by WebDAV servers If you use Apache mod_dav_svn as your Subversion network server then to some extent you are also running a WebDAV server This appendix gives some background on the nature of this protocol how Subversion uses it and how well Subversion interoperates with other software that is WebDAV aware Basic WebDAV Concepts This section provides a very brief very general overview to the ideas behind WebDAV It should lay the foundation for understanding WebDAV compatibility issues between clients and servers Just Plain WebDAV RFC 2518 defines a set of concepts and accompanying extension methods to HTTP 1 1 that make the web into a more universal read write medium The basic idea is that a WebDAV compliant web server can act like a generic file server clients can mount WebDAV shares that behave much like NFS or SMB sh
203. hell understands the notions of relative and absolute paths and will properly handle the and special path components The youngest command displays the youngest revision This is useful for determining the range of valid revisions you can use as arguments to the set rev command you are allowed to browse all the revisions recalling that they are named with integers between O and the youngest inclusively Determining the valid browsable transactions isn t quite as pretty Use the Istxms command to list the transactions that you are able to browse The list of browsable transactions is the same list that svnadmin Istxns returns and the same list that is valid for use with svnlook s transaction option Once you ve finished using the shell you can exit cleanly by using the exit command Alternatively you can supply an end of file character Control D though some Win32 Python distributions use the Windows Control Z conven tion instead Berkeley DB Utilities All of your versioned filesystem s structure and data live in a set of Berkeley DB database tables within the db sub directory of your repository This subdirectory is a regular Berkeley DB environment directory and can therefore be used in conjunction with any of Berkeley s database tools you can see the documentation for these tools at Sleepy Cat s website http www sleepycat com For day to day Subversion use these tools are unnecessary Most of the functionality typic
204. hen you tell them it s a computer book sort of glaze over Thanks to all my close friends who make me a rich rich man Don t look at me that way you know who you are 10h and thanks Karl for being too overworked to write this book yourself xvi From From Preface Brian W Fitzpatrick Huge thanks to my wife Marie for being incredibly understanding supportive and most of all patient Thank you to my brother Eric who first introduced me to UNIX programming way back when Thanks to my Mom and Grand mother for all their support not to mention enduring a Christmas holiday where I came home and promptly buried my head in my laptop to work on the book To Mike and Ben It was a pleasure working with you on the book Heck 1t s a pleasure working with you at work To everyone in the Subversion community and the Apache Software Foundation thanks for having me Not a day goes by where I don t learn something from at least one of you Lastly thanks to my Grandfather who always told me that freedom equals responsibility I couldn t agree more C Michael Pilato Special thanks to my wife Amy for her love and patient support for putting up with late nights and for even re viewing entire sections of this book you always go the extra mile and do so with incredible grace Gavin when you re old enough to read I hope you re as proud of your Daddy as he is of you Mom and Dad and the rest of the family thanks f
205. hing and Merging may have made many other changes in the repository that are difficult to incorporate into your working espe copy cially if you run svn update after weeks of isolation The better solution is to create your own branch or line of development in the repository This allows you to save your half broken work frequently without interfering with others yet you can still selectively share information with your collaborators You ll see exactly how this works later on Creating a Branch Creating a branch is very simple you make a copy of the project in the repository using the svn copy command Subversion is not only able to copy single files but whole directories as well In this case you want to make a copy of the calc trunk directory Where should the new copy live Wherever you wish it s a matter of project pol icy Let s say that your team has a policy of creating branches in the calc branches area of the repository and you want to name your branch my calc branch You ll want to create a new directory calc branches my calc branch which begins its life as a copy of calc trunk There are two different ways to make a copy We ll demonstrate the messy way first just to make the concept clear To begin check out a working copy of the project s root directory calc svn checkout http svn example com repos calc bigwc A bigwc trunk A bigwc trunk Makefile A bigwc trunk integer c A bigwc trunk button c A b
206. hose binary is usually named tethereal 244 Troubleshooting e Pull down the Capture menu and choose Start e Type port 80 for Filter and turn off promiscuous mode e Run your Subversion client e Hit Stop Now you have a capture It looks like a huge list of lines e Click on the Protocol column to sort Then click on the first relevant TCP line to select it e Right click and choose Follow TCP Stream You ll be presented with the request response pairs of the Subver sion client s HTTP conversion Alternatively you may set a parameter in your client s servers run time configuration file to cause neon s debug ging output to appear The numeric value of neon debug is a combination of the NE_DBG_ values in the header file ne_utils h Setting the neon debug mask variable to 130 i e NE_DBG_HTTP NE_DBG_HTTPBODY will cause the HTTP data to be shown You may well want to disable compression when doing a network trace by tweaking the http compression pa rameter in the same file I just built the distribution binary and when I try to check out Subversion get an error about an Unrecognized URL scheme Subversion uses a plugin system to allow access to repositories Currently there are three of these plugins ra_local allows access to a local repository ra_dav allows access to a repository via WebDAV and ra_svn allows local or re mote access via the svnserve server When you attempt to perform an op
207. hout specifying a time of day for example 2002 11 27 you may think that Subversion should give you the last revision that took place on the 27th of November Instead you ll get back a revision from the 26th or even earlier Remember that Subversion will find the most recent revision of the repository as of the date you give If you give a date without a timestamp like 2002 11 27 Subversion assumes a time of 00 00 00 so looking for the most recent revision won t return anything on the day of the 27th If you want to include the 27th in your search you can either specify the 27th with the time 2002 11 27 23 59 or just specify the next day 2002 11 28 You can also use a range of dates Subversion will find all revisions between both dates inclusive svn log revision 2002 11 20 2002 11 29 As we pointed out you can also mix dates and revisions svn log revision 2002 11 20 4040 Users should be aware of a subtlety that can become quite a stumblingblock when dealing with dates in Subversion Since the timestamp of a revision is stored as a property of the revision an unversioned modifiable re property vision timestamps can be changed to represent complete falsifications of true chronology or even re moved altogether This will wreak havoc on the internal date to revision conversion that Subversion performs Initial Checkout Most of the time you will start using a Subversion repository by doing a checkout
208. ic svn_error_t make_new_directory const char repos_path const char new_directory apr_pool_t pool svn_error_t err 129 Developer Information svn_repos_t repos svn ES G Es svn_revnum_t youngest_rev svn_fs_txn_t txn svn_fs_root_t txn_root const char conflict_str Open the repository located at REPOS_PATH SVN_ERR svn_repos_open amp repos repos_path pool Get a pointer to the filesystem object that is stored in REPOS fs svn_repos_fs repos Ask the filesystem to tell us the youngest revision that currently exists SVN_ERR svn_fs_youngest_rev amp youngest_rev fs pool Begin a new transaction that is based on YOUNGEST_REV We are less likely to have our later commit rejected as conflicting if we always try to make our changes against a copy of the latest snapshot of the filesystem tree SVN_ERR svn_fs_begin_txn amp txn fs youngest_rev pool Now that we have started a new Subversion transaction get a root object that represents that transaction SVN_ERR svn_fs_txn_root amp txn_root txn pool Create our new directory under the transaction root at the path NEW_DIRECTORY SVN_ERR svn_fs_make_dir txn_root new_directory pool Commit the transaction creating a new revision of the filesystem which includes our added directory
209. id out according to the structure of your project tree In Subversion the repository looks like a single filesystem Each commit results in an entirely new filesystem tree in essence the repository is an array of trees Each of these trees is labeled with a single revision number When someone talks about revision 54 they re talking about a particular tree and indirectly the way the filesystem looked after the 54th commit Technically it s not valid to talk about revision 5 of foo c Instead one would say foo c as it appears in revi sion 5 Also be careful when making assumptions about the evolution of a file In CVS revisions 5 and 6 of foo c are always different In Subversion it s most likely that foo c did not change between revisions 5 and 6 For more details on this topic see Section Revisions Directory Versions Subversion tracks tree structures not just file contents It s one of the biggest reasons Subversion was written to re place CVS Here s what this means to you as a former CVS user e The svn add and svn delete commands work on directories now just as they work on files So do svn copy and svn move However these commands do not cause any kind of immediate change in the repository Instead the working items are simply scheduled for addition or deletion No repository changes happen until you run svn commit e Directories aren t dumb containers anymore they have revision numb
210. ides the auto props feature which allows you to create mappings of filename patterns to prop erty names and values These mappings are made in your runtime configuration area They again affect adds and im ports and not only can override any default MIME type decision made by Subversion during those operations they can also set additional Subversion or custom properties too For example you might create a mapping that says that any time you add JPEG files ones that match the pattern jpg Subversion should automatically set the svn mime type property on those files to image jpeg Or perhaps any files that match cpp should have svn eol style set to native and svn keywords set to Id Auto prop support is perhaps the handiest property related tool in the Subversion toolbox See Section Config for more about configuring that support Externals Definitions Sometimes it is useful to construct a working copy that is made out of a number of different checkouts For example you may want different subdirectories to come from different locations in a repository or perhaps from different repositories altogether You could certainly setup such a scenario by hand using svn checkout to create the sort of nested working copy structure you are trying to achieve But if this layout is important for everyone who uses your repository every other user will need to perform the same checkout operations that you did Fortunately Subversion provides sup
211. ies can be accessed through many different methods on local disk or through various network protocols A repository location however is always a URL Table 2 1 describes how different URL schemas map to the available access methods 14 Basic Concepts Table 2 1 Repository Access URLs Schema Access Method tiles direct repository access on local disk ecos access via WebDAV protocol to Subversion aware Apache server https same as http but with SSL encryption svn access via custom protocol to an svnserve server svn ssh same as svn but through an SSH tunnel For the most part Subversion s URLs use the standard syntax allowing for server names and port numbers to be specified as part of the URL Remember that the file access method is valid only for locations on the same server as the client in fact in accordance with convention the server name portion of the URL is required to be either ab sent or localhost svn checkout file path to repos svn checkout file localhost path to repos Also users of the file scheme on Windows platforms will need to use an unofficially standard syntax for ac cessing repositories that are on the same machine but on a different drive than the client s current working drive Ei ther of the two following URL path syntaxes will work where x is the drive on which the repository resides C gt svn checkout fi
212. ify file contents and so on It also has features that are not quite as common such as the ability to add modify and remove metadata properties on each file or directory Furthermore the Subversion Filesystem is a versioning filesystem which means that as you make changes to your directory tree Subversion remembers what your tree looked like before those changes And before the previous changes And the previous ones And so on all the way back through ver sioning time to and just beyond the moment you first started adding things to the filesystem All the modifications you make to your tree are done within the context of a Subversion transaction The following is a simplified general routine for modifying your filesystem 1 Begin a Subversion transaction 2 Make your changes adds deletes property modifications etc 3 Commit your transaction Once you have committed your transaction your filesystem modifications are permanently stored as historical arti facts Each of these cycles generates a single new revision of your tree and each revision is forever accessible as an immutable snapshot of the way things were The Transaction Distraction The notion of a Subversion transaction especially given its close proximity to the database code in libsvn_fs can become easily confused with the transaction support provided by the underlying database itself Both types of trans action exist to provide atomicity and iso
213. igwc branches Checked out revision 340 Making a copy is now simply a matter of passing two working copy paths to the svn copy command cd bigwc svn copy trunk branches my calc branch svn status A branches my calc branch In this case the svn copy command recursively copies the trunk working directory to a new working directory branches my calc branch As you can see from the svn status command the new directory is now scheduled for addition to the repository But also notice the sign next to the letter A This indicates that the scheduled addi tion is a copy of something not something new When you commit your changes Subversion will create calc branches my calc branch in the repository by copying calc trunk rather than resending all of the working copy data over the network svn commit m Creating a private branch of calc trunk Adding branches my calc branch Committed revision 341 And now the easier method of creating a branch which we should have told you about in the first place svn copy is able to operate directly on two URLs svn copy http svn example com repos calc trunk http svn example com repos calc branches my calc branch m Creating a private branch of calc trunk Committed revision 341 There s really no difference between these two methods Both procedures create a new directory in revision 341 and the new directory is a copy of calc trunk This is shown in Figure 4
214. ike the definition of a typical file server And indeed the repository is a kind of file server but it s not your usual breed What makes the Subversion repository special is that it remembers every change ever written to it every change to every file and even changes to the directory tree itself such as the addition deletion and rearrangement of files and directories When a client reads data from the repository it normally sees only the latest version of the filesystem tree But the client also has the ability to view previous states of the filesystem For example a client can ask historical questions like What did this directory contain last Wednesday or Who was the last person to change this file and what changes did they make These are the sorts of questions that are at the heart of any version control system systems that are designed to record and track changes to data over time Versioning Models The core mission of a version control system is to enable collaborative editing and sharing of data But different sys tems use different strategies to achieve this Basic Concepts The Problem of File Sharing All version control systems have to solve the same fundamental problem how will the system allow users to share information but prevent them from accidentally stepping on each other s feet It s all too easy for users to acciden tally overwrite each other s changes in the repository Consider the scenario
215. ile editing the conflicted file you can always consult the three files that Sub version creates for you in your working copy including your file as it was before you updated You can even use a third party interactive merging tool to examine those three files Copying a File Onto Your Working File If you get a conflict and decide that you want to throw out your changes you can merely copy one of the temporary files created by Subversion over the file in your working copy svn update C sandwich txt Updated to revision 2 ls sandwich sandwich txt sandwich txt mine sandwich txt r2 sandwich txt rl S cp sandwich txt r2 sandwich txt svn resolved sandwich txt Punting Using svn revert If you get a conflict and upon examination decide that you want to throw out your changes and start your edits again just revert your changes svn revert sandwich txt Reverted sandwich txt ls sandwich sandwich txt Note that when you revert a conflicted file you don t have to run svn resolved Now you re ready to check in your changes Note that svn resolved unlike most of the other commands we ve dealt with in this chapter requires an argument In any case you want to be careful and only run svn resolved when you re certain that you ve fixed the conflict in your file once the temporary files are removed Subversion will let you commit the file even if it still contains conflict markers Commit Your Changes Finally Your ed
216. ile should probably live in a more public place The repositories sharing the users file should also be configured to have the same realm since the list of users essentially defines an authentication realm Wherever the file lives be sure to set the file s read and write permissions appropriately If you know which user s svnserve will run as restrict read access to the user file as necessary Set access controls There are two more variables to set in the svnserve conf file they determine what unauthenticated anonymous and authenticated users are allowed to do The variables anon access and auth access can be set to the values none read or write Setting the value to none restricts all access of any kind read allows read only access to the repository and write allows complete read write access to the repository For example general password db userfil realm example realm anonymous users can only read the repository anon access read 21See RFC 2195 90 Server Configuration authenticated users can both read and write auth access writ The example settings are in fact the default values of the variables should you forget to define them If you want to be even more conservative you can block anonymous access completely general password db userfil realm example realm anonymous users aren t allowed anon access non authenticated users can both read and write auth acce
217. ime CollabNet hired Karl and Ben Collins Sussman and detailed design work began in May With the help of some well placed prods from Brian Behlendorf and Jason Robbins of CollabNet and Greg Stein at the time an independent developer active in the WebDAV DeltaV specification process Subversion quickly attracted a community of active developers It turned out that many people had had the same frustrating experiences with CVS and welcomed the chance to finally do something about it Introduction The original design team settled on some simple goals They didn t want to break new ground in version control methodology they just wanted to fix CVS They decided that Subversion would match CVS s features and preserve the same development model but not duplicate CVS s most obvious flaws And although it did not need to be a drop in replacement for CVS it should be similar enough that any CVS user could make the switch with little effort After fourteen months of coding Subversion became self hosting on August 31 2001 That is Subversion devel opers stopped using CVS to manage Subversion s own source code and started using Subversion instead While CollabNet started the project and still funds a large chunk of the work it pays the salaries of a few full time Subversion developers Subversion is run like most open source projects governed by a loose transparent set of rules that encourage meritocracy CollabNet s copyright license
218. imply can not be contextually merged Also if the svn mime type property is set then the Subversion Apache module will use its value to populate the Content type HTTP header when responding to GET requests This gives a crucial clue about how to display a file when perusing your repository with a web browser svn ignore The svn ignore property contains a list of file patterns which certain Subversion operations will ignore Perhaps the most commonly used special property it works in conjunction with the global ignores run time configura tion option see Section Config to filter unversioned files and directories out of commands like svn status svn add and svn import The rationale behind the svn ignore property is easily explained Subversion does not assume that every file or subdirectory in a working copy directory is intended for version control Resources must be explicitly placed under Subversion s management using the svn add or svn import commands As a result there are often many resources in a working copy that are not versioned Now the svn status command displays as part of its output every unversioned file or subdirectory in a working copy that is not already filtered out by the global ignores option or its built in default value This is done so that users can see if perhaps they ve forgotten to add a resource to version control But Subversion cannot possibly guess the names of every resource that should be ignore
219. in revi sion 32 and the same path as it exists in revision 98 Figure 8 2 shows revision history as an added dimension to the Subversion filesystem universe Figure 8 2 Versioning time the third dimension 34We understand that this may come as a shock to sci fi fans who have long been under the impression that Time was actually the fourth dimen sion and we apologize for any emotional trauma induced by our assertion of a different theory 128 Developer Information As we mentioned earlier the libsvn_fs API looks and feels like any other filesystem except that it has this wonder ful versioning capability It was designed to be usable by any program interested in a versioning filesystem Not co incidentally Subversion itself is interested in that functionality But while the filesystem API should be sufficient for basic file and directory versioning support Subversion wants more and that is where libsvn_repos comes in The Subversion repository library libsvn_repos is basically a wrapper library around the filesystem functionality This library is responsible for creating the repository layout making sure that the underlying filesystem is initial ized and so on Libsvn_repos also implements a set of hooks scripts that are executed by the repository code when certain actions take place These scripts are useful for notification authorization or whatever purposes the reposi tory administrator desires This type of functi
220. ing to the database Fortunately Sleepycat s Berkeley DB documents describe a certain order in which database files can be copied that will guarantee a valid backup copy And better still you don t have to implement that algorithm yourself because the Subversion development team has already done so The hot backup py script is found in the tools backup directory of the Subversion source distribution Given a repository path and a backup location 16The Subversion repository dump format resembles an RFC 822 format the same type of format used for most email 80 Repository Administration which is really just a more intelligent wrapper around the svnadmin hotcopy command will perform the necessary steps for backing up your live repository without requiring that you bar public repository access at all and then will clean out the dead Berkeley log files from your live repository Even if you also have an incremental backup you might want to run this program on a regular basis For example you might consider adding hot backup py to a program scheduler such as crond on Unix systems Or if you pre fer fine grained backup solutions you could have your post commit hook script call hot backup py see Section Hook Scripts which will then cause a new backup of your repository to occur with every new revision created Simply add the following to the hooks post commit script in your live repository directory cd path to ho
221. ing changes you need to commit them to the repository but before you do so it s usually a good idea to take a look at exactly what you ve changed By examining your changes before you commit you can make a more accurate log message You may also discover that you ve inadvertently changed a file and this gives you a chance to revert those changes before committing Additionally this is a good opportunity to review and scru tinize changes before publishing them You can see exactly what changes you ve made by using svn status svn diff and svn revert You will usually use the first two commands to find out what files have changed in your working copy and then perhaps the third to revert some or all of those changes Subversion has been optimized to help you with this task and is able to do many things without communicating 20f course nothing is ever totally deleted from the repository just from the HEAD of the repository You can get back anything you delete by checking out or updating your working copy a revision earlier than the one in which you deleted it 26 Guided Tour with the repository In particular your working copy contains a secret cached pristine copy of each version con trolled file within the svn area Because of this Subversion can quickly show you how your working files have changed or even allow you to undo your changes without contacting the repository svn status You ll probably use the svn stat
222. ing the changes were properly merged together There s no need for them to take turns in this situation Locking may create a false sense of security Pretend that Harry locks and edits file A while Sally simultane ously locks and edits file B But suppose that A and B depend on one another and the changes made to each are semantically incompatible Suddenly A and B don t work together anymore The locking system was powerless to prevent the problem yet it somehow provided a false sense of security It s easy for Harry and Sally to imag ine that by locking files each is beginning a safe insulated task and thus inhibits them from discussing their in 10 Basic Concepts compatible changes early on The Copy Modify Merge Solution Subversion CVS and other version control systems use a copy modify merge model as an alternative to locking In this model each user s client contacts the project repository and creates a personal working copy a local reflection of the repository s files and directories Users then work in parallel modifying their private copies Finally the pri vate copies are merged together into a new final version The version control system often assists with the merging but ultimately a human being is responsible for making it happen correctly Here s an example Say that Harry and Sally each create working copies of the same project copied from the reposi tory They work concurrently and make changes to th
223. ing those changes You ll also see how to bring changes made by others into your working copy examine them and work through any conflicts that might arise Note that this chapter is not meant to be an exhaustive list of all Subversion s commands rather it s a conversa tional introduction to the most common Subversion tasks you ll encounter This chapter assumes that you ve read and understood Chapter 2 Basic Concepts and are familiar with the general model of Subversion For a complete reference of all commands see Chapter 9 Subversion Complete Reference Help Before reading on here is the most important command you ll ever need when using Subversion svn help The Sub version command line client is self documenting at any time a quick svn help lt subcommand gt will describe the syntax switches and behavior of the subcommand Import You use svn import to import a new project into a Subversion repository While this is most likely the very first thing you will do when you set up your Subversion server it s not something that happens very often For a detailed description of import see Section svn import later in this chapter Revisions Numbers Keywords and Dates Oh My Before we go on you should know a bit about how to identify a particular revision in your repository As you learned in Section Revisions a revision is a snapshot of the repository at a particular moment in time As you continue to c
224. inimize the size of the actual transmission In cases where network bandwidth is in short supply this kind of compression can greatly increase the speed at which communications between server and client can be sent In extreme cases this minimized network transmission could be the difference between an operation timing out or completing successfully Less interesting but equally useful are other features of the Apache and Subversion relationship such as the ability to specify a custom port instead of the default HTTP port 80 or a virtual domain name by which the Subversion repository should be accessed or the ability to access the repository through a proxy These things are all supported by Neon so Subversion gets that support for free Finally because mod_dav_svn is speaking a semi complete dialect of WebDAV DeltaV it s possible to access the repository via third party DAV clients Most modern operating systems Win32 OS X and Linux have the built in ability to mount a DAV server as a standard network share This is a complicated topic for details read Appendix C WebDAV and Autoversioning Supporting Multiple Repository Access Methods You ve seen how a repository can be accessed in many different ways But is it possible or safe for your reposi tory to be accessed by multiple methods simultaneously The answer is yes provided you use a bit of foresight At any given time these processes may require read and write acce
225. inting informa tion about the tree itself or how it differs from the previous revision of the repository You use the revision and transaction options to specify which revision or transaction respectively to examine Note that while revision 65 Repository Administration numbers appear as natural numbers transaction names are alphanumeric strings Keep in mind that the filesystem only allows browsing of uncommitted transactions transactions that have not resulted in a new revision Most repositories will have no such transactions because transactions are usually either committed which disqualifies them from viewing or aborted and removed In the absence of both the revision and transaction options svnlook will examine the youngest or HEAD revision in the repository So the following two commands do exactly the same thing when 19 is the youngest revision in the repository located at path to repos svnlook info path to repos svnlook info path to repos revision 19 The only exception to these rules about subcommands is the svnlook youngest subcommand which takes no op tions and simply prints out the HEAD revision number svnlook youngest path to repos 19 Output from svnlook is designed to be both human and machine parsable Take as an example the output of the info subcommand svnlook info path to repos sally 2002 11 04 09 29 13 0600 Mon 04 Nov 2002 201 Added the usual Greek tre
226. ion svn checkout http svn example com repos calc A calc A calc Makefile A calc integer c A calc button c hecked out revision 148 Fetching external item into calc third party sounds calc third party sounds ding ogg calc third party sounds dong ogg calc third party sounds clang ogg DDD A calc third party sounds bang ogg A calc third party sounds twang ogg Checked out revision 14 Fetching external item into calc third party skins If you need to change the externals definition you can do so using the regular property modification subcommands When you commit a change to the svn externals property Subversion will synchronize the checked out items against the changed externals definition when you next run svn update The same thing will happen when others up date their working copies and receive your changes to the externals definition The svn status command also recognizes externals definitions displaying a status code of x for the disjoint subdi rectories into which externals are checked out and then recursing into those subdirectories to display the status of the external items themselves The support that exists for externals definitions in Subversion today can be a little misleading though The working copies created via the externals definition support are still disconnected from the primary working copy on whose versioned directories the svn externals property was actually set And Subversion still on
227. ion on fish will be here soon Index stuff things bloo h stuff things bloo h revision 8 stuff things bloo h working copy Here is a new file to describ things about bloo The svn diff command produces this output by comparing your working files against the cached pristine copies within the svn area Files scheduled for addition are displayed as all added text and files scheduled for deletion are displayed as all deleted text Output is displayed in unified diff format That is removed lines are prefaced with a and added lines are prefaced with a svn diff also prints filename and offset information useful to the patch program so you can generate patches by redirecting the diff output to a file svn diff gt patchfile You could for example email the patchfile to another developer for review or testing prior to commit svn revert Now suppose you see the above diff output and realize that your changes to README are a mistake perhaps you ac cidentally typed that text into the wrong file in your editor This is a perfect opportunity to use svn revert S svn revert README Reverted README Subversion reverts the file to its pre modified state by overwriting it with the cached pristine copy from the svn area But also note that svn revert can undo any scheduled operations for example you might decide that you don t want to add a new file a
228. ion repository In general you shouldn t tamper with your repository by hand The svnadmin tool should be sufficient for any changes necessary to your repository or you can look to third party tools such as Berkeley DB s tool suite for tweaking relevant subsections of the repository Some exceptions exist though and we ll cover those here Scripts A hook is a program triggered by some repository event such as the creation of a new revision or the modification of an unversioned property Each hook is handed enough information to tell what that event is what target s it s op erating on and the username of the person who triggered the event Depending on the hook s output or return status the hook program may continue the action stop it or suspend it in some way The hooks subdirectory is by default filled with templates for various repository hooks ls repos hooks post commit tmpl pre revprop change tmpl post revprop change tmpl start commit tmpl pre commit tmpl There is one template for each hook that the Subversion repository implements and by examining the contents of those template scripts you can see what triggers each such script to run and what data is passed to that script Also present in many of these templates are examples of how one might use that script in conjunction with other Subver sion supplied programs to perform common useful tasks To actually install a working hook you need only place so
229. irst time simply svn revert the changes and try again It s possible however that your working copy might already have local modifications The changes applied by a merge will be mixed with your pre existing ones and running svn revert is no longer an option The two sets of changes may be impossible to separate In cases like this people take comfort in being able to predict or examine merges before they happen One simple way to do that is to run svn diff with the same arguments you plan to pass to svn merge as we already showed in our first example of merging Another method of previewing is to pass the dry run option to the merge com mand svn merg dry run r 343 344 http svn example com repos calc trunk U integer c svn status nothing printed working copy is still unchanged The dry run option doesn t actually apply any local changes to the working copy It only shows status codes that would be printed in a real merge It s useful for getting a high level preview of the potential merge for those times when running svn diff gives too much detail Subversion and Changesets Everyone seems to have a slightly different definition of changeset or a least a different expectation of what it means for a version control system to have changeset features For our purpose let s say that a changeset is just a collection of changes with a unique name The changes might include textual edits to file contents
230. is fully compliant with the Debian Free Software Guidelines In other words anyone is free to download modify and redistribute Subversion as he pleases no per mission from CollabNet or anyone else is required Subversion s Features When discussing the features that Subversion brings to the version control table it is often helpful to speak of them in terms of how they improve upon CVS s design If you re not familiar with CVS you may not understand all of these features And if you re not familiar with version control at all your eyes may glaze over unless you first read Chapter 2 Basic Concepts in which we provide a gentle introduction to version control in general Subversion provides Directory versioning CVS only tracks the history of individual files but Subversion implements a virtual versioned filesystem that tracks changes to whole directory trees over time Files and directories are versioned True version history Since CVS is limited to file versioning operations such as copies and renames which might happen to files but which are really changes to the contents of some containing directory aren t supported in CVS Addition ally in CVS you cannot replace a versioned file with some new thing of the same name without the new item inheriting the history of the old perhaps completely unrelated file With Subversion you can add delete copy and rename both files and directories And every newly added file begins
231. ision numbers separated by a colon are passed via revision r then the two revisions are directly compared svn diff revision 2 3 rules txt Index rules txt rules txt revision 2 rules txt revision 3 1 4 1 4 Be kind to others Freedom Chocolate Ice Cream Freedom Responsibility Everything in moderation Chew with your mouth closed O Not only can you use svn diff to compare files in your working copy to the repository but if you supply a URL ar gument you can examine the differences between items in the repository without even having a working copy This is especially useful if you wish to inspect changes in a file when you don t have a working copy on your local ma chine svn diff revision 4 5 http svn red bean com repos example trunk text rules txt svn cat If you want to examine an earlier version of a file and not necessarily the differences between two files you can use svn cat svn cat revision 2 rules txt Be kind to others Freedom Chocolate Ice Cream Everything in moderation Chew with your mouth closed You can also redirect the output directly into a file svn cat revision 2 rules txt gt rules txt v2 You re probably wondering why we don t just use svn update revision to update the file to the older revision There are a few reasons why we might prefer to use svn cat First you may want to see the differences between two rev
232. ision tree See Section Migrating a Repository for a practical use Switches revision 1 incremental quiet Examples Dump your whole repository svnadmin dump usr local svn repos SVN fs dump format version 1 Revision number 0 Dumped revision 0 Prop content length 56 Content length 56 Incrementally dump a single transaction from your repository svnadmin dump usr local svn repos r 21 incremental Dumped revision 21 SVN fs dump format version 1 Revision number 21 Prop content length 101 Content length 101 210 Subversion Complete Reference Name svnadmin help svnadmin help Synopsis svnadmin help SUBCOMMAND Description This subcommand is useful when you re trapped on a desert island with neither a net connection nor a copy of this book Alternate Names h 211 Subversion Complete Reference Name svnadmin hotcopy Make a hot copy of a repository svnadmin hotcopy Synopsis svnadmin hotcopy OLD_REPOS_PATH NEW_REPOS_PATH Description This subcommand makes a full hot backup of your repository including all hooks configuration files and of course database files If you pass the clean logs switch svnadmin will perform a hotcopy of your repository and then remove unused Berkeley DB logs from the original repository You can run this command at any time and make a safe copy of the repositor
233. isions of a file using an external diff program perhaps a 38 Guided Tour graphical one or perhaps your file is in such a format that the output of unified diff is nonsensical In this case you ll need to grab a copy of the old revision redirect it to a file and pass both that and the file in your working copy to your external diff program Sometimes it s easier to look at an older version of a file in its entirety as opposed to just the differences between it and another revision svn list The svn list command shows you what files are in a repository directory without actually downloading the files to your local machine svn list http svn collab net repos svn README branches clients tags trunk If you want a more detailed listing pass the verbose v flag to get output like this svn list verbose http svn collab net repos svn 2755 harry 1331 Jul 28 02 07 README 2173 sally Jul 29 15 07 branches 2769 sally Jul 29 12 07 clients 2698 harry Jul 24 18 07 tags 2785 sally Jul 29 19 07 trunk The columns tell you the revision at which the file or directory was last modified the user who modified it the size if it is a file the date it was last modified and the item s name A Final Word on History In addition to all of the above commands you can use svn update and svn checkout with the revision switch to take an entire working copy back in time 6 svn checkout
234. isplay unless they are versioned The default value is o lo la rej rej 26Anyone for potluck dinner 109 Advanced Topics You can override this option for a single instance of the svn status command by using the no ignore com mand line flag For information on more fine grained control of ignored items see Section svn ignore enable auto props This instructs Subversion to automatically set properties on newly added or imported files The default value is no So Set this to yes to enable Auto props The auto props section controls the Subversion client s ability to automatically set properties on files when they are added or imported It contains any number of key value pairs in the format PATTERN PROP NAME PROPVALUE where PATTERN is a file pattern that matches a set of filenames and the rest of the line is the property and its value Multiple matches on a file will result in multiple propsets for that file however there is no guarantee that auto props will be applied in the order in which they are listed in the config file so you can t have one rule override another You can find several examples of auto props usage in the config file Lastly don t forget to set enable auto props to yes if you want to enable auto props log encoding This variable sets the default character set encoding for commit log messages It s a permanent form of the encoding option see Section s
235. ith the directory path itself paths directory Loop over the entries names entries keys for name in names Calculate the entry s full path full_path os path join basepath name If the entry is a directory recurse The recursion will return a list with the entry and all its children which we will add to 135 Developer Information our running list of paths if fs is_dir fsroot full_path pool subpaths crawl_filesystem_dir root full_path pool paths extend subpaths Else it is a file so add the entry s full path to the FILES list else paths append full_path return paths An implementation in C of the previous example would stretch on quite a bit longer The same routine in C would need to pay close attention to memory usage and need to use custom datatypes for representing the hash of entries and the list of paths Python has hashes and lists called dictionaries and sequences respectively as built in datatypes and provides a wonderful selection of methods for operating on those types And since Python uses refer ence counting and garbage collection users of the language don t have to bother themselves with allocating and free ing memory In the previous section of this chapter we mentioned the 1ibsvn_client interface and how it exists for the sole purpose of simplifying the process of writing a Subversion client The following is a brief example of how tha
236. ithin in Which case the differences will be applied to that file Unlike svn diff the merge command takes the ancestry of a file into consideration when performing a merge opera tion This is very important when you re merging changes from one branch into another and you ve renamed a file on one branch but not the other Alternate Names None Changes Working copy Accesses Repository Only if working with URLs Switches revision r REV non recursiv N quiet a force dry run diff3 cmd CMD ignore ancestry username USER password PASS no auth cach non interactiv 179 Subversion Complete Reference config dir DIR Examples Merge a branch back into the trunk assuming that you have a working copy of the trunk and that the branch was created in revision 250 svn merge r 250 HEAD http svn red bean com repos branches my branch U myproJ tiny txt U myproj thhgttg txt U U myproj win txt myproj flo txt If you branched at revision 23 and you want to merge changes on trunk into your branch you could do this from in side the working copy of your branch svn merge r 23 30 file tmp repos trunk vendors U myproj thhgttg txt To merge changes to a single file cd myproj svn merge r 30 31 thhgttg txt Uo thhgttg txt 180 Subversion Complete Reference Name svn mkdir Create a new directory under version control svn mkdir
237. itory For detailed information see Section svnadmin Since svnadmin works via direct repository access and thus can only be used on the machine that holds the reposi tory it refers to the repository with a path not a URL svnadmin Switches bdb log keep Berkeley DB specific Disable automatic log removal of database log files bdb txn nosync Berkeley DB specific Disables fsync when committing database transactions bypass hooks Bypass the repository hook system 206 Subversion Complete Reference clean logs Removes unused Berkeley DB logs force uuid By default when loading data into repository that already contains revisions svnadmin will ignore the UUID from the dump stream This switch will cause the repository s UUID to be set to the UUID from the stream ignore uuid By default when loading an empty repository svnadmin will use the UUID from the dump stream This switch will cause that UUID to be ignored incremental Dump a revision only as a diff against the previous revision instead of the usual fulltext parent dir DIR When loading a dumpfile root paths at DIR instead of revision r ARG Specify a particular revision to operate on quiet Do not show normal progress show only errors svnadmin Subcommands 207 Subversion Complete Reference Name svnadmin create Create a new empty repository svnadmin create Synopsis svna
238. itory In most cases the repository is being accessed via Apache HTTP server and mod_dav_svn so this user is the same user that Apache runs as The hooks themselves will need to be configured with OS level permissions that allow that user to execute them Also this means that any file or programs including the Subversion repository it self accessed directly or indirectly by the hook will be accessed as the same user In other words be alert to poten tial permission related problems that could prevent the hook from performing the tasks you ve written it to perform Berkeley DB Configuration 64 Repository Administration A Berkeley DB environment is an encapsulation of one or more databases log files region files and configuration files The Berkeley DB environment has it own set of default configuration values for things like the number of locks allowed to be taken out at any given time or the maximum size of the journaling log files etc Subversion s filesystem code additionally chooses default values for some of the Berkeley DB configuration options However sometimes your particular repository with its unique collection of data and access patterns might require a different set of configuration option values The folks at Sleepycat the producers of Berkeley DB understand that different databases have different require ments and so they have provided a mechanism for overriding at runtime many of the configuration values for the
239. itory access RA modules are available ra_dav Module for accessing a repository via WebDAV DeltaV protocol handles http schema handles https schema ra_local Module for accessing a repository on local disk handles file schema ra_svn Module for accessing a repository using the svn network protocol handles svn schema RA DAV Repository Access Using HTTP DAV 131 Developer Information The libsvn_ra_dav library is designed for use by clients that are being run on different machines than the servers with which they communicating specifically machines reached using URLs that contain the http or https pro tocol portions To understand how this module works we should first mention a couple of other key components in this particular configuration of the Repository Access Layer the powerful Apache HTTP Server and the Neon HTTP WebDAV client library Subversion s primary network server is the Apache HTTP Server Apache is a time tested extensible open source server process that is ready for serious use It can sustain a high network load and runs on many platforms The Apache server supports a number of different standard authentication protocols and can be extended through the use of modules to support many others It also supports optimizations like network pipelining and caching By using Apache as a server Subversion gets all of these features for free And since most firewalls already allow HTTP tra
240. its are finished you ve merged all changes from the server and you re ready to commit your changes to the repository The svn commit command sends all of your changes to the repository When you commit a change you need to supply a log message describing your change Your log message will be attached to the new revision you create If your log message is brief you may wish to supply it on the command line using the message or m option svn commit message Corrected number of cheese slices Sending sandwich txt Transmitting file data Committed revision 3 However if you ve been composing your log message as you work you may want to tell Subversion to get the mes sage from a file by passing the filename with the fi1le switch svn commit file logmsg Sending sandwich Transmitting file data 34 Guided Tour Committed revision 4 If you fail to specify either the message or file switch then Subversion will automatically launch your fa vorite editor as defined in the environment variable EDITOR for composing a log message Tip If you re in your editor writing a commit message and decide that you want to cancel your commit you can just quit your editor without saving changes If you ve already saved your commit message simply delete the text and save again svn commit Waiting for Emacs Done Log message unchanged or not specified a bort c ontinue e dit a The reposit
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242. ive within any areas already exported as normal web shares I m trying to look at an old version of my file but svn says something about path not found A nice feature of Subversion is that the repository understands copies and renames and preserves the historical con nections For example if you copy trunk to branches mybranch then the repository understands that every file in the branch has a predecessor in the trunk Running svn log verbose will show you the historical copy so you can see the rename r7932 joe 2003 12 03 17 54 02 0600 Wed 03 Dec 2003 1 line Changed paths A branches mybranch from trunk 7931 Unfortunately while the repository is aware of copies and renames almost all the svn client subcommands in ver sion 1 0 are not aware Commands like svn diff svn merge and svn cat ought to understand and follow renames but don t yet do this It s scheduled as a post 1 0 feature For example if you ask swn diff to compare two earlier ver sions of branches mybranch foo c the command will not automatically understand that the task actually re quires comparing two versions of trunk foo c due to the rename Instead you ll see an error about how the branch path doesn t exist in the earlier revisions The workaround for all problems of this sort is to do the legwork yourself That is you need to be aware of any re named paths discover them yourself using svn log v and then provide them explicitly to t
243. ively browse the repository s latest revision simply by pointing their web browser to the repository URL and e anyone can commit to the repository Basic HTTP Authentication The easiest way to authenticate a client is via the HTTP Basic authentication mechanism which simply uses a user name and password to verify that a user is who she says she is Apache provides an htpasswd utility for managing the list of acceptable usernames and passwords those to whom you wish to grant special access to your Subversion repository Let s grant commit access to Sally and Harry First we need to add them to the password file First time use c to create the file S Use m to use MD5 encryption of the password which is more secure htpasswd cm etc svn auth file harry New password x xxx Re type new password Adding password for user harry htpasswd etc svn auth fil m sally New password x Re type new password x x Adding password for user sally Next you need to add some more httpd conf directives inside your Location block to tell Apache what to do with your new password file The AuthType directive specifies the type of authentication system to use In this case we want to specify the Basic authentication system AuthName is an arbitrary name that you give for the au thentication domain Most browsers will display this name in the pop up dialog box when the browser is querying the user for his name a
244. ization policies The file has the same format as other configuration files see Section Runtime Configuration Area section names are marked by square brackets and comments begin with hashes and each section contains specific variables that can be set variable value Let s walk through this file and learn how to use them Create a users file and realm For now the general section of the svnserve conf has all the variables you need Begin by defining a file which contains usernames and passwords and an authentication realm general password db userfil realm example realm The realm is a name that you define It tells clients which sort of authentication namespace they re connecting to the Subversion client displays it in the authentication prompt and uses it as a key along with the server s hostname and port for caching credentials on disk see Section Client Credentials Caching The password db variable points to a separate file that contains a list of usernames and passwords using the same familiar format For exam ple users harry foopassword sally barpassword The value of password db can be an absolute or relative path to the users file For many admins it s easy to keep the file right in the con area of the repository alongside svnserve conf On the other hand it s possible you may want to have two or more repositories share the same users file in that case the f
245. klist It can be quite tricky to get a bunch of users with existing SSH accounts to share a repository without permissions problems If you re confused about all the things that you as an administrator need to do on a Unix like system here s a quick checklist that resummarizes some of things discussed in this section e All of your SSH users need to be able to read and write to the repository Put all the SSH users into a single group Make the repository wholly owned by that group and set the group permissions to read write Your users need to use a sane umask when accessing the repository Make sure that svnserve usr local bin svnserve or wherever it lives in PATH is actually a wrapper script which sets umask 002 and executes the real svnserve binary e When BerkeleyDB creates new logfiles they need to be owned by the group as well so make sure you run chmod g s on the repository s db directory 104 Chapter 7 Advanced Topics If you ve been reading this book chapter by chapter from start to finish you should by now have acquired enough knowledge to use the Subversion client to perform the most common version control operations You understand how to checkout a working copy from a Subversion repository You are comfortable with submitting and receiving changes using the svn commit and svn update functions You ve probably even developed a reflex which causes you to run the svn status command almost unconsciously For all i
246. ks out a version of the calc project between revisions 303 and 349 they ll still see the bad change right Yes that s true When we talk about removing a change we re really talking about removing it from HEAD The original change still exists in the repository s history For most situations this is good enough Most people are only interested in tracking the HEAD of a project anyway There are special cases however where you really might want to destroy all evidence of the commit Perhaps somebody accidentally committed a confidential document This isn t so easy it turns out because Subversion was deliberately designed to never lose information Revisions are im mutable trees which build upon one another Removing a revision from history would cause a domino effect creat ing chaos in all subsequent revisions and possibly invalidating all working copies 9 Resurrecting Deleted Items The great thing about version control systems is that information is never lost Even when you delete a file or direc tory it may be gone from the HEAD revision but the object still exists in earlier revisions One of the most common questions new users ask is How do I get my old file or directory back The first step is to define exactly which item you re trying to resurrect Here s a useful metaphor you can think of every object in the repository as existing in a sort of two dimensional coordinate system The first coordinate is a p
247. lation In other words transactions give you the ability to perform a set of actions in an all or nothing fashion either all the actions in the set complete with success or they all get treated as if none of them ever happened and in a way that does not interfere with other processes acting on the data 33The choice of Berkeley DB brought several automatic features that Subversion needed such as data integrity atomic writes recoverability and hot backups 127 Developer Information Database transactions generally encompass small operations related specifically to the modification of data in the database itself such as changing the contents of a table row Subversion transactions are larger in scope encom passing higher level operations like making modifications to a set of files and directories which are intended to be stored as the next revision of the filesystem tree If that isn t confusing enough consider this Subversion uses a database transaction during the creation of a Subversion transaction so that if the creation of Subversion transaction fails the database will look as if we had never attempted that creation in the first place Fortunately for users of the filesystem API the transaction support provided by the database system itself is hidden almost entirely from view as should be expected from a properly modularized library scheme It is only when you start digging into the implementation of the filesy
248. le X path to repos C gt svn checkout file X path to repos In the second syntax you need to quote the URL so that the vertical bar character is not interpreted as a pipe Note that a URL uses ordinary slashes even though the native non URL form of a path on Windows uses back slashes Suppose you make changes to button c Since the svn directory remembers the file s modification date and orig inal contents Subversion can tell that you ve changed the file However Subversion does not make your changes public until you explicitly tell it to The act of publishing your changes is more commonly known as committing or checking in changes to the repository To publish your changes to others you can use Subversion s commit command svn commit button c Sending button c Transmitting file data Committed revision 57 Now your changes to button c have been committed to the repository if another user checks out a working copy of calc they will see your changes in the latest version of the file Suppose you have a collaborator Sally who checked out a working copy of calc at the same time you did When 15 Basic Concepts you commit your change to button c Sally s working copy is left unchanged Subversion only modifies working copies at the user s request To bring her project up to date Sally can ask Subversion to update her working copy by using the Subversion up date command This will incorporate yo
249. list is most useful if you want to see what files a repository has without downloading a working copy S svn list http svn red bean com repos test support README txt INSTALL examples Like UNIX Is you can also pass the verbose switch for additional information svn list verbose file tmp repos 16 sally 28361 Jan 16 23 18 README txt 27 sally 0 Jan 18 15 27 INSTALL 24 harry Jan 18 11 27 examples For further details see Section svn list 174 Subversion Complete Reference Name svn log Display commit log messages svn log Synopsis svn log PATH svn log URL PATH Description The default target is the path of your current directory If no arguments are supplied svn log shows the log messages for all files and directories inside of and including the current working directory of your working copy You can refine the results by specifying a path one or more revisions or any combination of the two The default revision range for a local path is BASE 1 If you specify a URL alone then it prints log messages for everything that the URL contains If you add paths past the URL only messages for those paths under that URL will be printed The default revision range for a URL is H EAD 1 With verbose svn log will also print all affected paths with each log message With quiet svn log will not print the log message body itself this is compatible
250. locked the item in the svn working area You will see an L if you run svn status in a directory where an svn commit is in progress perhaps when you are editing the log message If Subversion is not running then presumably Subversion was interrupted and the lock needs to be cleaned up by running svn cleanup more about that later in this chapter The fourth column will only show whitespace or a which means that the file or directory is scheduled to be added or modified with additional attached history This typically happens when you svn move or svn copy a file or direc tory If you see A this means the item is scheduled for addition with history It could be a file or the root of a copied directory means the item is part of a subtree scheduled for addition with history i e some parent got copied and it s just coming along for the ride M means the item is part of a subtree scheduled for addition with history and it has local modifications When you commit first the parent will be added with history copied which means this file will automatically exist in the copy Then the local modifications will be uploaded into the copy The fifth column will only show whitespace or an s This signifies that the file or directory has been switched from the path of the rest of the working copy using svn switch to a branch If you pass a specific path to svn status it gives you information about that item alone svn status stuff fish c
251. ludes a commit email pl script located in the tools hook scripts direc tory of the Subversion source tree that can be used to send email with and or append to a log file a description of a given commit This mail contains a list of the paths that were changed the log message attached to the commit the author and date of the commit as well as a GNU diff style display of the changes made to the vari ous versioned files as part of the commit Another useful tool provided by Subversion is the hot backup py script located in the too1s backup direc tory of the Subversion source tree This script performs hot backups of your Subversion repository a feature supported by the Berkeley DB database back end and can be used to make a per commit snapshot of your repository for archival or emergency recovery purposes pre revprop chang Because Subversion s revision properties are not versioned making modifications to such a property for exam ple the svn log commit message property will overwrite the previous value of that property forever Since data can be potentially lost here Subversion supplies this hook and its counterpart post revprop change so that repository administrators can keep records of changes to these items using some external means if they so desire As a precaution against losing unversioned property data Subversion clients will not be allowed to re motely modify revision properties at all unless this hook is implemented f
252. ludes a quick start guide Chapter 2 Basic Concepts Explains the basics of version control and different versioning models along with Subversion s repository working copies and revisions Chapter 3 Guided Tour Walks you through a day in the life of a Subversion user It demonstrates how to use Subversion to obtain mod 1fy and commit data Chapter 4 Branching and Merging Discusses branches merges and tagging including best practices for branching and merging common use cases how to undo changes and how to easily swing from one branch to the next Chapter 5 Repository Administration Describes the basics of the Subversion repository how to create configure and maintain a repository and the tools you can use to do all of this Chapter 6 Server Configuration Explains how to configure your Subversion server and the three ways to access your repository HTTP the svn protocol and local access It also covers the details of authentication authorization and anonymous access Chapter 7 Advanced Topics Explores the Subversion client configuration files file and directory properties how to ignore files in your working copy how to include external trees in your working copy and lastly how to handle vendor branches Chapter 8 Developer Information Describes the internals of Subversion the Subversion filesystem and the working copy administrative areas from a programmer s point of view Demonstrates how to use the public AP
253. ly offers credentials logs in to the server before ever making a request In Subversion the server pulls credentials by challenging the client at the appropriate mo ment rather than the client pushing them This makes certain operations more elegant For example if a server is configured to allow anyone in the world to read a repository then the server will never issue an authentication chal lenge when a client attempts to svn checkout If the client s network request writes new data to the repository e g svn commit then a new revision tree is cre ated If the client s request was authenticated then the authenticated user s name is stored as the value of the svn author property on the new revision see Section Unversioned Properties If the client was not authenti cated in other words the server never issued an authentication challenge then the revision s svn author property is empty 19 Client Credentials Caching Many servers are configured to require authentication on every request This can become a big annoyance to users who are forced to type their passwords over and over again Happily the Subversion client has a remedy for this a built in system for caching authentication credentials on disk By default whenever the commandline client successfully authenticates itself to a server it saves the credentials in the user s private runtime configuration area in subversion auth on Unix like syste
254. ly truly operates on non disjoint working copies So for example if you want to commit changes that you ve made in one or more of those external working copies you must run svn commit explicitly on those working copies committing on the primary working copy will not recurse into any external ones Also since the definitions themselves use absolute URLs moving or copying a directory to which they are attached will not affect what gets checked out as an external though the relative local target subdirectory will of course move with renamed directory This can be confusing even frustrating in certain situations For example if you use externals definitions on a directory in your trunk development line which point to other areas of that same line and then you use svn copy to branch that line to some new location branches my branch the externals definitions on items in your new branch will still refer to versioned resources in trunk Also be aware that if you need to re parent your working copy using svn switch relocate externals definitions will not also be re parented Vendor branches As is especially the case when developing software the data that you maintain under version control is often closely related to or perhaps dependent upon someone else s data Generally the needs of your project will dictate that you stay as up to date as possible with the data provided by that external entity without sacrificing the stability of yo
255. me executable program or script into the repos hooks directory which can be executed as the name like start commit or post commit of the hook On Unix platforms this means supplying a script or program which could be a shell script a Python program a compiled C binary or any number of other things named exactly like the name of the hook Of course the template files are present for more than just informational purposes the easiest way to install a hook on Unix platforms is to simply copy the appropriate template file to a new file that lacks the tmp1 extension customize the hook s con tents and ensure that the script is executable Windows however uses file extensions to determine whether or not a program is executable so you would need to supply a program whose basename is the name of the hook and whose extension is one of the special extensions recognized by Windows for executable programs such as exe or com for programs and bat for batch files Currently there are five hooks implemented by the Subversion repository start commit This is run before the commit transaction is even created It is typically used to decide if the user has commit privileges at all The repository passes two arguments to this program the path to the repository and username which is attempting the commit If the program returns a non zero exit value the commit is stopped before the transaction is even created pre commit This is run when the tran
256. me question you ve probably seen coming from your web browser which is just another HTTP client like Subversion If you choose the p ermanent option the server cer tificate will be cached in your private run time auth area in just the same way your username and password are cached see Section Client Credentials Caching If cached Subversion will automatically remember to trust this certificate in future negotiations Your run time servers file also gives you the ability to make your Subversion client automatically trust specific CAs either globally or on a per host basis Simply set the ss1 authority files variable to a semicolon sepa rated list of PEM encoded CA certificates global ssl authority files path to CAcertl pem path to CAcert2 pem Many OpenSSL installations also have a pre defined set of default CAs that are nearly universally trusted To make the Subversion client automatically trust these standard authorities set the ss1 trust default ca variable to true When talking to Apache a Subversion client might also receive a challenge for a client certificate Apache is asking the client to identify itself is the client really who it says it is If all goes correctly the Subversion client sends back a private certificate signed by a CA that Apache trusts A client certificate is usually stored on disk in encrypted for mat protected by a local password When Subversion receives this challenge it will ask
257. message about the last time you merged from the branch S cd calc trunk svn log r406 user 2004 02 08 11 17 26 0600 Sun 08 Feb 2004 1 line Merged my calc branch changes r341 405 into the trunk 52 EAD revision is now 480 and you re ready to do an Branching and Merging Aha Since all branch changes that happened between revisions 341 and 405 were previously merged to the trunk as revision 406 you now know that you want to merge only the branch changes after that by comparing revisions 406 and HEAD cd calc trunk svn update At revision 480 We notice that HEAD is currently 480 so we use it to do the merge svn merge r 406 480 http svn example com repos calc branches my calc branch U integer c U button c U Makefile svn commit m Merged my calc branch changes r406 480 into the trunk Sending integer c Sending button c Sending Makefile Transmitting file data Committed revision 481 Now the trunk contains the complete second wave of changes made to the branch At this point you can either delete your branch we ll discuss this later on or continue working on your branch and repeat this procedure for subsequent merges Undoing Changes Another common use for svn merge is to roll back a change that has already been committed Suppose you re work ing away happily on a working copy of calc trunk and you discover that the change made way back in revision
258. module for mapping WebDAV operations to Subversion ones The fact that the word miscellaneous only appears once in Table 8 1 is a good sign The Subversion development team is serious about making sure that functionality lives in the right layer and libraries Perhaps the greatest advan tage of the modular design is its lack of complexity from a developer s point of view As a developer you can quickly formulate that kind of big picture that allows you to pinpoint the location of certain pieces of functionality with relative ease Another benefit of modularity is the ability to replace a given module with a whole new library that implements the same API without affecting the rest of the code base In some sense this happens within Subversion already The 126 Developer Information libsvn_ra_dav libsvn_ra_local and libsvn_ra_svn all implement the same interface And all three communicate with the Repository Layer libsvn_ra_dav and libsvn_ra_svn do so across a network and libsvn_ra_local connects to it directly The client itself also highlights modularity in the Subversion design While Subversion currently comes with only a command line client program there are already a few other programs being developed by third parties to act as GUIs for Subversion Again these GUIs use the same APIs that the stock command line client does Subversion s libsvn_client library is the one stop shop for most of the functionality n
259. modules subdirectory of the Apache install location often usr local apache2 The LoadModule directive has a simple syntax mapping a named module to the location of a shared library on disk LoadModule dav_svn_module modules mod_dav_svn so Note that if mod_dav was compiled as a shared object instead of statically linked directly to the httpd binary you ll need a similar LoadModule statement for it too Be sure that it comes before the mod_dav_svn line LoadModule dav_module modules mod_dav so LoadModule dav_svn_module modules mod_dav_svn so At a later location in your configuration file you now need to tell Apache where you keep your Subversion reposi tory or repositories The Location directive has an XML like notation starting with an opening tag and ending with a closing tag with various other configuration directives in the middle The purpose of the Location directive is to instruct Apache to do something special when handling requests that are directed at a given URL or one of its 93 Server Configuration children In the case of Subversion you want Apache to simply hand off support for URLs that point at versioned resources to the DAV layer You can instruct Apache to delegate the handling of all URLs whose path portions the part of the URL that follows the server s name and the optional port number begin with repos to a DAV provider whose repository is located at absolute path to repository using the following
260. more information non recursive N Stops a subcommand from recursing into subdirectories Most subcommands recurse by default but some sub commands usually those that have the potential to remove or undo your local modifications do not notice ancestry Pay attention to ancestry when calculating differences old ARG Uses ARG as the older target password PASS Indicates that you are providing your password for authentication on the command line otherwise if it is needed Subversion will prompt you for it quiet q Requests that the client print only essential information while performing an operation recursive R Makes a subcommand recurse into subdirectories Most subcommands recurse by default relocate FROM TO PATH Used with the svn switch subcommand changes the location of the repository that your working copy refer ences This is useful if the location of your repository changes and you have an existing working copy that you d like to continue to use See svn switch for an example revision r REV Indicates that you re going to supply a revision or range of revisions for a particular operation You can pro vide revision numbers revision keywords or dates in curly braces as arguments to the revision switch If you wish to provide a range of revisions you can provide two revisions separated by a colon For example svn Log sr 1729 svn log r 1729 HEAD svn log r 1729 1744
261. ms or SAPPDATA Subversion auth on Windows The runtime area is covered in more detail in Section Runtime Configuration Area Successful credentials are cached on disk keyed on a combination of hostname port and au thentication realm When the client receives an authentication challenge it first looks for the appropriate credentials in the disk cache if not present or if the cached credentials fail to authenticate then the client simply prompts the user for the informa tion The security paranoid people may be thinking to themselves Caching passwords on disk That s terrible You should never do that But please remain calm First the auth caching area is permission protected so that only the user owner can read data from it not the world at large If that s still not safe enough for you you can disable credential caching To disable caching for a single command pass the no auth cache option svn commit F log_msg txt no auth cach Authentication realm lt svn host example com 3690 gt example realm Username joe Password for joe Adding newfile Transmitting file data Committed revision 2324 19This problem is actually a FAQ resulting from a misconfigured server setup 86 Server Configuration password was not cached so a second commit still prompts us svn rm newfile svn commit F new_msg txt Authentication realm lt svn host example com 3690 gt example realm Username
262. n our access control policy AuthzSVNAccessFile path to access file lt Location gt On the opposite end of the paranoia scale you can configure your block to demand authentication from everyone All clients must supply credentials to identify themselves Your block unconditionally requires authentication via the Require valid user directive and defines a means to authenticate Example 6 2 A sample configuration for authenticated access 99 Server Configuration lt Location repos gt DAV svn SVNParentPath usr local svn our access control policy AuthzSVNAccessFile path to access file only authenticated users may access the repository Require valid user how to authenticate a user AuthType Basic AuthName Subversion repository AuthUserFile path to users file lt Location gt A third very popular pattern is to allow a combination of authenticated and anonymous access For example many administrators want to allow anonymous users to read certain repository directories but want only authenticated users to read or write more sensitive areas In this setup all users start out accessing the repository anonymously If your access control policy demands a real username at any point Apache will demand authentication from the client To do this you use both the Satisfy Any and Require valid user directives together Example 6 3 A sample configuration for mixed authenticated anonymous access lt Loc
263. n But there are a few other nice features that Apache provides Repository Browsing One of the most useful benefits of an Apache WebDAV configuration for your Subversion repository is that the youngest revisions of your versioned files and directories are immediately available for viewing via a regular web browser Since Subversion uses URLs to identify versioned resources those URLs used for HTTP based repository access can be typed directly into a Web browser Your browser will issue a GET request for that URL and based on whether that URL represents a versioned directory or file mod_dav_svn will respond with a directory listing or with file contents Since the URLs do not contain any information about which version of the resource you wish to see mod_dav_svn will always answer with the youngest version This functionality has the wonderful side effect that you can pass around Subversion URLs to your peers as references to documents and those URLs will always point at the latest manifestation of that document Of course you can even use the URLs as hyperlinks from other web sites too You generally will get more use out of URLs to versioned files after all that s where the interesting content tends to lie But you might have occasion to browse a Subversion directory listing where you ll quickly note that the gen erated HTML used to display that listing is very basic and certainly not intended to be aesthetically pleasing or even int
264. n in depth look at resolving conflicts Alternate Names None Changes Working copy Accesses Repository No Switches targets FILENAME recursiv R quiet a config dir DIR Examples If you get a conflict on an update your working copy will sprout three new files svn update C s 00uC Updated to revision 31 S ls foo c foo c mine foo c r30 foo c r31 Once you ve resolved the conflict and foo c is ready to be committed run svn resolved to let your working copy 195 Subversion Complete Reference know you ve taken care of everything Warning You can just remove the conflict files and commit but svn resolved fixes up some bookkeeping data in the working copy administrative area in addition to removing the conflict files so we recommend that you use this command 196 Subversion Complete Reference Name svn revert Undo all local edits svn revert Synopsis svn revert PATH Description Reverts any local changes to a file or directory and resolves any conflicted states svn revert will not only revert the contents of an item in your working copy but also any property changes Finally you can use it to undo any scheduling operations that you may have done e g files scheduled for addition or deletion can be unscheduled Alternate Names None Changes Working copy Accesses Repository No Switches targets FILENAME
265. n log Shows you broad information log messages attached to revisions and which paths changed in each revision svn diff Shows you the specific details of how a file changed over time svn cat This is used to retrieve any file as it existed in a particular revision number and display it on your screen svn list Displays the files in a directory for any given revision 35 Guided Tour svn log To find out information about the history of a file or directory use the svn log command svn log will provide you with a record of who made changes to a file or directory at what revision it changed the time and date of that revi sion and if it was provided the log message that accompanied the commit svn log r3 sally on 15 Jul 2002 18 03 46 0500 1 line Added include lines and corrected of cheese slices 2 harry on 15 Jul 2002 17 47 57 0500 1 line Added main methods rl sally on 15 Jul 2002 17 40 08 0500 1 line Initial import Note that the log messages are printed in reverse chronological order by default If you wish to see a different range of revisions in a particular order or just a single revision pass the revision r switch svn log revision 5 19 shows logs 5 through 19 in chronological order svn log r 19 5 shows logs 5 through 19 in reverse order svn log r 8 shows log for revision 8 You can also examine the log history of a single file
266. n the repository and looks something like SLastChangedDate 2002 07 22 21 42 37 0700 Mon 22 Jul 2002 It may be abbreviated as Date LastChangedRevision This keyword describes the last known revision in which this file changed in the repository and looks some thing like LastChangedRevision 144 It may be abbreviated as Rev LastChangedBy This keyword describes the last known user to change this file in the repository and looks something like LastChangedBy harry It may be abbreviated as Author HeadURL This keyword describes the full URL to the latest version of the file in the repository and looks something like HeadURL http svn collab net repos trunk README It may be abbreviated as URL Id This keyword is a compressed combination of the other keywords Its substitution looks something like Id calc c 148 2002 07 28 21 30 43Z sally and is interpreted to mean that the file calc c was last changed in revision 148 on the evening of July 28 2002 by the user sally 117 Advanced Topics Simply adding keyword anchor text to your file does nothing special Subversion will never attempt to perform tex tual substitutions on your file contents unless explicitly asked to do so After all you might be writing a document 31 about how to use keywords and you don t want Subversion to substitute your beautiful examples of un substituted keyword anchors To tell Subversion whether or not to substitute ke
267. naged by client working copies For example when a new commit transaction is created in the repository Subversion adds a property to that transaction named svn date a datestamp representing the time that the transaction was created By the time the commit process is finished and the transaction is promoted to a permanent revision the tree has also been given a property to store the username of the revision s author svn author and a property to store the log message attached to that revision svn log Revision and transaction properties are unversioned properties as they are modified their previous values are per manently discarded Also while revision trees themselves are immutable the properties attached to those trees are not You can add remove and modify revision properties at any time in the future If you commit a new revision and later realize that you had some misinformation or spelling error in your log message you can simply replace the value of the svn 1og property with a new corrected log message Berkeley DB The data housed within Subversion repositories actually lives inside a database specifically a Berkeley DB Data Store When the initial design phase of Subversion was in progress the developers decided to use Berkeley DB for a variety of reasons including its open source license transaction support reliability performance API simplicity thread safety support for cursors and so on Berkeley DB provides
268. nd log message log Print the tree s log message propget Print the value of a property on a path in the tree proplist Print the names and values of properties set on paths in the tree tree Print the tree listing optionally revealing the filesystem node revision IDs associated with each path 67 Repository Administration uuid Print the tree s unique user ID UUID youngest Print the youngest revision number svnadmin The svnadmin program is the repository administrator s best friend Besides providing the ability to create Subver sion repositories this program allows you to perform several maintenance operations on those repositories The syn tax of svnadmin is similar to that of svnlook svnadmin help general usage svnadmin SUBCOMMAND REPOS_PATH ARGS amp OPTIONS Type svnadmin help lt subcommand gt for help on a specific subcommand Available subcommands create deltify dump help h We ve already mentioned svnadmin s create subcommand see Section Repository Creation and Configuration Most of the others we will cover in more detail later in this chapter For now let s just take a quick glance at what each of the available subcommands offers create Create a new Subversion repository deltify Run over a specified revision range performing predecessor deltification on the paths changed in those revi sions If no revisions are specified this command will sim
269. nd password Finally use the AuthUserFile directive to specify the location of the pass word file you created using htpasswd 95 Server Configuration After adding these three directives your lt Location gt block should look something like this lt Location svn gt DAV svn SVNParentPath usr local svn AuthType Basic AuthName Subversion repository AuthUserFile etc svn auth fil lt Location gt This lt Location gt block is not yet complete and will not do anything useful It s merely telling Apache that when ever authorization is required Apache should harvest a username and password from the Subversion client What s missing here however are directives that tell Apache which sorts of client requests require authorization Wherever authorization is required Apache will demand authentication as well The simplest thing to do is protect all requests Adding Require valid user tells Apache that all requests require an authenticated user lt Location svn gt DAV svn SVNParentPath usr local svn AuthType Basic AuthName Subversion repository AuthUserFile etc svn auth fil Require valid user lt Location gt Be sure to read the next section Section Authorization Options for more detail on the Require directive and other ways to set authorization policies One word of warning HTTP Basic Auth passwords pass in very nearly plain text over the network and thus are ex tremely insecure If you
270. nd tree In these situations you ll want svn merge to do a path based comparison only ignoring any relations between files and directories Add the ignore ancestry option to your merge command and it will behave just like svn diff And conversely the notice ancestry option will cause svn diff to behave like the merge command Common Use Cases for Merging There are many different uses for svn merge and this section describes the most common ones you re likely to run into Merging a Whole Branch to Another To complete our running example we ll move forward in time Suppose several days have passed and many changes have happened on both the trunk and your private branch Suppose that you ve finished working on your private branch the feature or bugfix is finally complete and now you want to merge all of your branch changes back into the trunk for others to enjoy So how do we use svn merge in this scenario Remember that this command compares two trees and applies the differences to a working copy So to receive the changes you need to have a working copy of the trunk We ll as sume that either you still have your original one lying around fully updated or that you recently checked out a fresh working copy of calc trunk But which two trees should be compared At first glance the answer may seem obvious just compare the latest trunk tree with your latest branch tree But beware this assumption is wrong and has burned many
271. ndumpfilter include and svndumpfilter exclude and if they don t you shouldn t Further if your dumpfile has an inconsistent usage of leading slashes for some reason 14 you should probably normalize those paths so they all have or lack leading slashes Also copied paths can give you some trouble Subversion supports copy operations in the repository where a new path is created by copying some already existing path It is possible that at some point in the lifetime of your reposi tory you might have copied a file or directory from some location that svndumpfilter is excluding to a location that it is including In order to make the dump data self sufficient svrndumpfilter needs to still show the addition of 14While svnadmin dump has a consistent leading slash policy to not include them other programs which generate dump data might not be so consistent 71 Repository Administration the new path including the contents of any files created by the copy and not represent that addition as a copy from a source that won t exist in your filtered dump data stream But because the Subversion repository dump format only shows what was changed in each revision the contents of the copy source might not be readily available If you suspect that you have any copies of this sort in your repository you might want to rethink your set of included ex cluded paths svnshell py The Subversion source tree also comes with a shell like interf
272. ne it dis plays the general client help text ignore ancestry Tells Subversion to ignore ancestry when calculating differences rely on path contents alone incremental Prints output in a format suitable for concatenation message m MESSAGE Indicates that you will specify a commit message on the command line following this switch For example svn commit m They don t make Sunday new ARG Uses ARG as the newer target no auth cach Prevents caching of authentication information e g username and password in the Subversion administrative directories no auto props Disables auto props overriding the enable auto props directive in the config file no diff deleted Prevents Subversion from printing differences for deleted files The default behavior when you remove a file is for svn diff to print the same differences that you would see if you had left the file but removed all the content no ignore Shows files in the status listing that would normally be omitted since they match a pattern in the svn ignore property See Section Config for more information non interactiv In the case of an authentication failure or insufficient credentials prevents prompting for credentials e g user 145 Subversion Complete Reference name or password This is useful if you re running Subversion inside of an automated script and it s more ap propriate to have Subversion fail than to prompt for
273. ne b Checked out revision 2 Ts mine 153 Subversion Complete Reference Check out 2 different directories into two separate working copies svn checkout file tmp repos test file tmp repos quiz A test a A test b Checked out revision 2 A quiz l A quiz m Checked out revision 2 S ls quiz test Check out 2 different directories into two separate working copies but place both into a directory called working copies svn checkout file tmp repos test file tmp repos quiz working copies A working copies test a A working copies test b Checked out revision 2 A working copies quiz 1 A working copies quiz m Checked out revision 2 ls working copies If you interrupt a checkout or something else interrupts your checkout like loss of connectivity etc you can restart 1t either by issuing the identical checkout command again or by updating the incomplete working copy svn checkout file tmp repos test test A test a A test b AC svn The operation was interrupted svn caught SIGINT svn checkout file tmp repos test test A test c A test d e svn The operation was interrupted svn Caught SIGINT cd test svn update A test e A test f Updated to revision 3 154 Subversion Complete Reference Name svn cleanup Recursively clean up the working copy svn cleanup Synopsis svn cleanup PATH Description Recursively clean up the
274. ng copy up to date U foo File foo was Updated received changes from the server A foo File or directory foo was Added to your working copy D foo File or directory foo was Deleted from your working copy R foo File or directory foo was Replaced in your working copy that is foo was deleted and a new item with the same name was added While they may have the same name the repository considers them to be distinct objects with distinct histories G foo File foo received new changes from the repository but your local copy of the file had your modifications The changes did not intersect however so Subversion has merGed the repository s changes into the file without a problem C foo File foo received Conflicting changes from the server The changes from the server directly overlap your own changes to the file No need to panic though This overlap needs to be resolved by a human you we discuss this situation later in this chapter Make Changes to Your Working Copy Now you can get to work and make changes in your working copy It s usually most convenient to decide on a par ticular change or set of changes to make such as writing a new feature fixing a bug etc The Subversion com mands that you will use here are svn add svn delete svn copy and svn move However if you are merely editing files that are already in Subversion you may not need to use any of these commands until you commit Changes you can make to your wo
275. ng copy is a hodgepodge of repository locations from different revisions But after testing you know it s the precise combination of data you need Time to make a snapshot Copying one URL to another won t work here In this case you want to make a snapshot of your exact working copy arrangement and store it in the repository Luckily svn copy actually has four different uses which you can read about in Chapter 9 including the ability to copy a working copy tree to the repository ls my working copy svn copy my working copy http svn example com repos calc tags mytag Committed revision 352 Now there is a new directory in the repository calc tags mytag which is an exact snapshot of your working copy mixed revisions urls and all Other users have found interesting uses for this feature Sometimes there are situations where you have a bunch of local changes made to your working copy and you d like a collaborator to see them Instead of running svn diff and sending a patchfile which won t capture tree changes you can instead use svn copy to upload your working copy 57 Branching and Merging to a private area of the repository Your collaborator can then either checkout a verbatim copy of your working copy or use svn merge to receive your exact changes Branch Maintenance You may have noticed by now that Subversion is extremely flexible Because it implements branches and tags with the same underlying
276. ng mod_dav_svn with the following caveats e Any files opened directly from the share are treated as read only Even the mod_dav_lock trick seems to have no effect It seems that Nautilus never issues the LOCK method at all The copy locally edit copy back trick does work however Unfortunately Nautilus overwrites the old file by issuing a DELETE first which creates an extra revision e When overwriting or creating a file Nautilus first does a PUT of an empty file then overwrites it with a second 47Unix users can also run mount t webdav URL mountpoint 253 WebDAV and Autoversioning PUT This creates two Subversion filesystem revisions rather than one e When deleting a collection it issues an HTTP DELETE on each individual child instead of on the collection it self This creates a whole bunch of new revisions Linux davfs2 Linux davfs2 is a filesystem module for the Linux kernel whose development is located at http dav sourceforge net Once installed a WebDAV network share can be mounted with the usual Linux mount command The word on the street is that this DAV client doesn t work at all with mod_dav_svn s autoversioning Every single attempt to write to the server is preceded by a LOCK request which mod_dav_svn doesn t support At this time there is no data indicating whether the use of mod_dav_lock resolves this problem 254 Appendix D Third Party Tools Subv
277. ng the svn ignore property on the parent directory For more information on ignored files see Section svn ignore file or dir The file or directory file_or_dir is under version control but is missing or somehow incomplete The item can be missing if it s removed using a non Subversion command In the case of a directory it can be incomplete if you happened to interrupt a checkout or update A quick svn update will refetch the file or directory from the repository or svn revert file will restore a missing file file_or_dir The file or directory file_or_dir is in the repository as one kind of object but what s actually in your work ing copy is some other kind For example Subversion might have a file in the repository but you removed the file and created a directory in its place without using the svn delete or svn add commands I file_or_dir Subversion is ignoring the file or directory file_or_dir probably because you told it to For more informa tion on ignored files see Section svn ignore Note that this symbol only shows up if you pass the no ignore option to svn status The second column tells the status of a file or directory s properties see Section Properties for more information on properties If an M appears in the second column then the properties have been modified otherwise a whitespace will be printed The third column will only show whitespace or an L which means that Subversion has
278. nges In the previous section we mentioned that both you and Sally made changes to integer c on different branches If you look at Sally s log message for revision 344 you can see that she fixed some spelling errors No doubt your copy of the same file still has the same spelling errors It s likely that your future changes to this file will be affecting the same areas that have the spelling errors so you re in for some potential conflicts when you merge your branch someday It s better then to receive Sally s change now before you start working too heavily in the same places It s time to use the svn merge command This command it turns out is a very close cousin to the svn diff command which you read about in Chapter 3 Both commands are able to compare any two objects in the repository and de scribe the differences For example you can ask svn diff to show you the exact change made by Sally in revision 344 S svn diff r 343 344 http svn example com repos calc trunk Index integer c integer c revision 343 integer c revision 344 147 7 147 7 QQ case 6 sprintf info gt operating_system HPFS OS 2 or NT break case 7 sprintf info gt operating_system Macintosh break case 8 sprintf info gt operating_system Z System break case 9 sprintf info gt operating_system CPM break case 9 sprintf info gt operating_system CP M break case 10 sprintf info gt operating_sy
279. nlook date Synopsis svnlook date REPOS_PATH Description Print the datestamp of a revision or transaction in a repository Switches revision 1 transaction t Examples This shows the date of revision 40 of a test repository svnlook date r 40 tmp repos 2003 02 22 17 44 49 0600 Sat 22 Feb 2003 225 Subversion Complete Reference Name svnlook diff Print differences of changed files and properties svnlook diff Synopsis svnlook diff REPOS_PATH Description Print GNU style differences of changed files and properties in a repository Switches revision 1 transaction t no diff deleted Examples This shows a newly added empty file a deleted file and a copied file svnlook diff r 40 usr local svn repos Copied egg txt from rev 39 trunk vendors deli pickle txt Added trunk vendors deli soda txt Modified trunk vendors deli sandwich txt trunk vendors deli sandwich txt original trunk vendors deli sandwich txt 2003 02 22 17 45 04 000000000 0600 0 0 1 ee Don t forget the mayo Modified trunk vendors deli logo jpg Binary files differ Deleted trunk vendors deli chips txt Deleted trunk vendors deli pickle txt If a file has a non textual svn mime type property then the differences are not explicitly shown 226 Subversion Complete Reference Name svnlook dirs chan
280. ns DeltaV allows you define flexible collections of VCRs called configurations which don t necessarily respond to particular directories Each VCR s contents can be made to point to a specific VR using the UPDATE method Once the configuration is perfect the client can create a snapshot of the whole configuration called a base line Clients use the CHECKOUT and CHECKIN methods to capture specific states of configurations much like they use these methods to create specific VR states of VCRs Extensibility DeltaV defines a new method REPORT which allows the client and server to perform customized data ex changes The client sends a REPORT request with a properly labeled XML body full of custom data assuming the server understands the specific report type 1t responds with an equally custom XML body This technique is very similar to XML RPC Autoversioning For many this is the killer feature of DeltaV If the DeltaV server supports this feature then basic WebDAV clients i e those unaware of versioning can still write to the server and the server will silently perform ver sioning anyway In the simplest example an ignorant PUT from a basic WebDAV client might be translated by the server as a CHECKOUT PUT CHECKIN Subversion and DeltaV So how compatible is Subversion with other DeltaV software In two words not very At least not yet not in Sub version 1 0 While libsvn_ra_
281. ntents and purposes you are ready to use Subver sion in a typical environment But the Subversion feature set doesn t stop at common version control operations This chapter highlights some of Subversion s features that aren t quite so regularly used In it we will discuss Sub version s property or metadata support and how to modify Subversion s default behaviors by tweaking its run time configuration area We will describe how you can use externals definitions to instruct Subversion to pull data from multiple repositories We ll cover in detail some of the additional client and server side tools that are part of the Subversion distribution Before reading this chapter you should be familiar with the basic file and directory versioning capabilities of Sub version If you haven t already read about those or if you need a refresher we recommend that you check out Chap ter 2 Basic Concepts and Chapter 3 Guided Tour Once you ve mastered the basics and consumed this chapter you ll be a Subversion power user Runtime Configuration Area Subversion provides many optional behaviors that can be controlled by the user Many of these options are of the kind that a user would wish to apply to all Subversion operations So rather than forcing users to remember com mand line arguments for specifying these options and to use them for each and every operation they perform Sub version uses configuration files segregated into a Subve
282. o visibly demonstrate the overlapping areas e For every conflicted file Subversion places three extra files in your working copy filename mine This is your file as it existed in your working copy before you updated your working copy that is without 31 Guided Tour conflict markers This file has your latest changes in it and nothing else filename rOLDREV This is the file that was the BASE revision before you updated your working copy That is the file that you checked out before you made your latest edits filename rNEWREV This is the file that your Subversion client just received from the server when you updated your working copy This file corresponds to the HEAD revision of the repository Here OLDREV is the revision number of the file in your svn directory and NEWREV is the revision number of the repository HEAD For example Sally makes changes to the file sandwich txt in the repository Harry has just changed the file in his working copy and checked it in Sally updates her working copy before checking in and she gets a conflict svn update C sandwich txt Updated to revision 2 ls 1 sandwich txt sandwich txt mine sandwich txt rl sandwich txt r2 At this point Subversion will not allow you to commit the file sandwich txt until the three temporary files are re moved svn commit message Add a few more things svn Commit failed details follow svn Abor
283. oblem here is that you don t want to interfere with Sally who is in the process of fixing small bugs here and there She s depending on the fact that the latest version of the project in calc trunk is always usable If you start committing your changes bit by bit you ll surely break things for Sally One strategy is to crawl into a hole you and Sally can stop sharing information for a week or two That is start gut ting and reorganizing all the files in your working copy but don t commit or update until you re completely finished with the task There are a number of problems with this though First it s not very safe Most people like to save their work to the repository frequently should something bad accidentally happen to their working copy Second it s not very flexible If you do your work on different computers perhaps you have a working copy of calc trunk on two different machines you ll need to manually copy your changes back and forth or just do all the work on a single computer By that same token it s difficult to share your changes in progress with anyone else A common software development best practice is to allow your peers to review your work as you go If nobody sees your in termediate commits you lose potential feedback Finally when you re finished with all your changes you might find it very difficult to re merge your final work with the rest of the company s main body of code Sally or others 42 Branc
284. ocations of the access and error logs generated by Apache the CustomLog and ErrorLog directives respectively Subversion s mod_dav_svn uses Apache s error logging interface as well You can always browse the contents of those files for information that might reveal the source of a problem that is not clearly noticeable otherwise Why Apache 2 If you re a system administrator it s very likely that you re already running the Apache web server and have some prior experience with it At the time of writing Apache 1 3 is by far the most popular version of Apache The world has been somewhat slow to upgrade to the Apache 2 X series for various reasons some people fear change espe 22They really hate doing that 92 Server Configuration cially changing something as critical as a web server Other people depend on plug in modules that only work against the Apache 1 3 API and are waiting for a 2 X port Whatever the reason many people begin to worry when they first discover that Subversion s Apache module is written specifically for the Apache 2 API The proper response to this problem is don t worry about it It s easy to run Apache 1 3 and Apache 2 side by side simply install them to separate places and use Apache 2 as a dedicated Subversion server that runs on a port other than 80 Clients can access the repository by placing the port number into the URL svn checkout http host example com 7382 repos project Prere
285. ode in the same subdirectory or maybe just grouping them alphabetically Such an arrangement might 82 Repository Administration look like f utils calc trunk tags branches calendar trunk tags branches office spreadsheet trunk tags branches Lay out your repository in whatever way you see fit Subversion does not expect or enforce a layout schema in its eyes a directory is a directory is a directory Ultimately you should choose the repository arrangement that meets the needs of the people who work on the projects that live there Creating the Layout and Importing Initial Data After deciding how to arrange the projects in your repository you ll probably want to actually populate the reposi tory with that layout and with initial project data There are a couple of ways to do this in Subversion You could use the svn mkdir command see Chapter 9 Subversion Complete Reference to create each directory in your skeletal repository layout one by one A quicker way to accomplish the same task is to use the svn import command see Section svn import By first creating the layout in a temporary location on your drive you can import the whole layout tree into the repository in a single commit mkdir tmpdir cd tmpdir mkdir projectA mkdir projectA trunk mkdir projectA branches mkdir projectA tags mkdir projectB mkdir projectB trunk mkdir projectB branches mkdir projectB tags UN Ut UI I Y Y
286. of changes to a branch It should auto matically remember which changes a branch has already received and be able to list them for you It should use this information to help automate merges as much as possible Unfortunately Subversion is not such a system Like CVS Subversion 1 0 does not yet record any information about merge operations When you commit local modifications the repository has no idea whether those changes came from running svn merge or from just hand editing the files What does this mean to you the user It means that until the day Subversion grows this feature you ll have to track merge information yourself The best place to do this is in the commit log message As demonstrated in the earlier 8In the future the Subversion project plans to use or invent an expanded patch format that describes tree changes 49 Branching and Merging example it s recommended that your log message mention a specific revision number or range of revisions that are being merged into your branch Later on you can run svn log to review which changes your branch already con tains This will allow you to carefully construct a subsequent svn merge command that won t be redundant with pre viously ported changes In the next section we ll show some examples of this technique in action Previewing Merges Because merging only results in local modifications it s not usually a high risk operation If you get the merge wrong the f
287. of the first vendor drop We ll call our vendor branch directory 1ibcomplex and our code drops will go into a subdirectory of our vendor branch called current And since svn import creates all the intermediate parent directories it needs we can actually accomplish both of these steps with a single command svn import path to libcomplex 1 0 http svn example com repos vendor libcomplex current m importing initial 1 0 vendor drop We now have the current version of the libcomplex source code in vendor 1libcomplex current Now we tag that version see Section Tags and then copy it into the main development branch Our copy will create a new directory called 1ibcomplex in our existing calc project directory It is in this copied version of the vendor data that we will make our customizations 122 Advanced Topics svn copy http svn example com repos vendor libcomplex current http svn example com repos vendor libcomplex 1 0 m tagging libcomplex 1 0 svn copy http svn example com repos vendor libcomplex 1 0 http svn example com repos calc libcomplex m bringing libcomplex 1 0 into the main branch We check out our project s main branch which now includes a copy of the first vendor drop and we get to work customizing the libcomplex code Before we know it our modified version of libcomplex is now completely inte grated into our calculator program 32 A few weeks later
288. of the svn 1og commit log message property on a given revision in the repository with a new value verify Verify the contents of the repository This includes among other things checksum comparisons of the ver sioned data stored in the repository svndumpfilter Since Subversion stores everything in an opaque database system attempting manual tweaks is unwise if not quite difficult And once data has been stored in your repository Subversion generally doesn t provide an easy way to re move that data 13 But inevitably there will be times when you would like to manipulate the history of your reposi tory You might need to strip out all instances of a file that was accidentally added to the repository and shouldn t be there for whatever reason Or perhaps you have multiple projects sharing a single repository and you decide to split them up into their own repositories To accomplish tasks like this administrators need a more manageable and malleable representation of the data in their repositories the Subversion repository dump format The Subversion repository dump format is a human readable representation of the changes that you ve made to your versioned data over time You use the svnadmin dump command to generate the dump data and svnadmin load to populate a new repository with it see Section Migrating a Repository The great thing about the human readability aspect of the dump format is that if you aren t careless abou
289. ok scripts hot backup py REPOS path to backups amp The resulting backup is a fully functional Subversion repository able to be dropped in as a replacement for your live repository should something go horribly wrong There are benefits to both types of backup methods The easiest is by far the full backup which will always result in a perfect working replica of your repository This again means that should something bad happen to your live reposi tory you can restore from the backup with a simple recursive directory copy Unfortunately if you are maintaining multiple backups of your repository these full copies will each eat up just as much disk space as your live reposi tory Incremental backups using the repository dump format are excellent to have on hand if the database schema changes between successive versions of Subversion itself Since a full repository dump and load are generally required to up grade your repository to the new schema it s very convenient to already have half of that process the dump part finished Unfortunately the creation of and restoration from incremental backups takes longer as each commit is effectively replayed into either the dumpfile or the repository In either backup scenario repository administrators need to be aware of how modifications to unversioned revision properties affect their backups Since these changes do not themselves generate new revisions they will not trigger post commi
290. ommit and grow your repository you need a mechanism for identifying these snapshots You specify these revisions by using the revision r switch plus the revision you want svn revision REV or you can specify a range by separating two revisions with a colon svn revision REV1 REV2 And Subversion lets you refer to these revisions by number keyword or date Revision Numbers When you create a new Subversion repository it begins its life at revision zero and each successive commit in creases the revision number by one After your commit completes the Subversion client informs you of the new re vision number svn commit message Corrected number of cheese slices Sending sandwich txt Transmitting file data Committed revision 3 If at any point in the future you want to refer to that revision we ll see how and why we might want to do that later in this chapter you can refer to it as 3 Revision Keywords The Subversion client understands a number of revision keywords These keywords can be used instead of integer arguments to the revision switch and are resolved into specific revision numbers by Subversion 20 Guided Tour Note Each directory in your working copy contains an administrative subdirectory called svn For every file in a directory Subversion keeps a copy of each file in the administrative area This copy is an unmodified no keyword expansion no end of line translation no nothing
291. on Complete Reference Name svnlook cat Print the contents of a file svnlook cat Synopsis svnlook cat REPOS_PATH PATH_IN_REPOS Description Print the contents of a file Switches revision 1 transaction t Examples This shows the contents of a file in transaction ax8 located at trunk README svnlook cat t ax8 usr local svn repos trunk README Subversion a version control system SLastChangedDate 2003 07 17 10 45 25 0500 Thu 17 Jul 2003 Contents I A FEW POINTERS II DOCUMENTATION III PARTICIPATING IN THE SUBVERSION COMMUNITY 223 Subversion Complete Reference Name svnlook changed Print the paths that were changed svnlook changed Synopsis svnlook changed REPOS_PATH Description Print the paths that were changed in a particular revision or transaction as well as an svn update style status letter in the first column A for added D for deleted and U for updated modified Switches revision 1 transaction t Examples This shows a list of all the changed files in revision 39 of a test repository svnlook changed r 39 usr local svn repos trunk vendors deli trunk vendors deli chips txt trunk vendors deli sandwich txt trunk vendors deli pickle txt PPP Pw 224 Subversion Complete Reference Name svnlook date Print the datestamp sv
292. on foo c foo c s working revision is decreased These keywords allow you to perform many common and helpful operations without having to look up specific re vision numbers or remember the exact revision of your working copy Revision Dates Anywhere that you specify a revision number or revision keyword you can also specify a date by specifying the date inside curly braces You can even access a range of changes in the repository using both dates and revi sions together 21 Guided Tour Here are examples of the date formats that Subversion accepts Remember to use quotes around any date that con tains spaces svn checkout revision 2002 02 17 svn checkout revision 15 30 svn checkout revision 15 30 00 200000 svn checkout revision 2002 02 17 15 30 svn checkout revision 2002 02 17 15 30 0230 svn checkout revision 2002 02 17T15 30 svn checkout revision 2002 02 17T15 302 svn checkout revision 2002 02 17T15 30 04 00 svn checkout revision 20020217T1530 svn checkout revision 20020217T1530Z svn checkout revision 20020217T1530 0500 When you specify a date as a revision Subversion finds the most recent revision of the repository as of that date svn log revision 2002 11 28 r12 ira 2002 11 27 12 31 51 0600 Wed 27 Nov 2002 6 lines Is Subversion a Day Early If you specify a single date as a revision wit
293. onality and other utility provided by the repository library is not strictly related to implementing a versioning filesystem which is why it was placed into its own library Developers who wish to use the libsvn_repos API will find that it is not a complete wrapper around the filesystem interface That is only certain major events in the general cycle of filesystem activity are wrapped by the repository interface Some of these include the creation and commit of Subversion transactions and the modification of revi sion properties These particular events are wrapped by the repository layer because they have hooks associated with them In the future other events may be wrapped by the repository API All of the remaining filesystem interaction will continue to occur directly via the libsvn_fs API though For example here is a code segment that illustrates the use of both the repository and filesystem interfaces to create a new revision of the filesystem in which a directory is added Note that in this example and all others throughout this book the SVN_ERR macro simply checks for a non successful error return from the function it wraps and re turns that error if it exists Example 8 1 Using the Repository Layer Create a new directory at the path NEW_DIRECTORY in the Subversion repository located at REPOS_PATH Perform all memory allocation in POOL This function will create a new revision for the addition of NEW_DIRECTORY stat
294. ont an abbreviation for cont inue then matching will continue with the next line of the configuration file Any whitespace in the regular expression property name or property value must be surrounded by either single or double quote characters You can escape quote characters that are not used for wrapping whitespace by preceding them with a backslash 1 character The backslash escapes only quotes when parsing the configuration file so do not protect any other characters beyond what is necessary for the regular expression 125 Chapter 8 Developer Information Subversion is an open source software project developed under an Apache style software license The project is fi nancially backed by CollabNet Inc a California based software development company The community that has formed around the development of Subversion always welcomes new members who can donate their time and atten tion to the project Volunteers are encouraged to assist in any way they can whether that means finding and diagnos ing bugs refining existing source code or fleshing out whole new features This chapter is for those who wish to assist in the continued evolution of Subversion by actually getting their hands dirty with the source code We will cover some of the software s more intimate details the kind of technical nitty gritty that those developing Subversion itself or writing entirely new tools based on the Subversion libraries should be aware
295. oper ties as a remote client is the pre and post revprop change hooks are still triggered and therefore must be setup to accept changes of this nature But an administrator can get around these protections by passing the bypass hooks option to the svnadmin setlog command Warning Remember though that by bypassing the hooks you are likely avoiding such things as email notifications of property changes backup systems which track unversioned property changes and so on In other words be very careful about what you are changing and how you change it Another common use of svnadmin is to query the repository for outstanding possibly dead Subversion transac tions In the event that a commit should fail the transaction is usually cleaned up That is the transaction itself is re moved from the repository and any data associated with and only with that transaction is removed as well Occa sionally though a failure occurs in such a way that the cleanup of the transaction never happens This could happen for several reasons perhaps the client operation was inelegantly terminated by the user or a network failure might have occurred in the middle of an operation etc Regardless of the reason these dead transactions serve only to clut ter the repository and consume resources You can use svnadmin s 1st xns command to list the names of the currently outstanding transactions svnadmin lstxns myrepos 19 3al a45 Ea
296. or directory For example svn log foo c svn log http foo com svn trunk code foo c These will display log messages only for those revisions in which the working file or URL changed If you want even more information about a file or directory svn log also takes a verbose v switch Because Subversion allows you to move and copy files and directories it is important to be able to track path changes in the filesystem so in verbose mode svn log will include a list of changed paths in a revision in its output svn log r 8 v r8 sally 2002 07 14 08 15 29 0500 1 line Changed paths U trunk code foo c U trunk code bar h A trunk code doc README Frozzled the sub space winch Why Does svn log Give Me an Empty Response After working with Subversion for a bit most users will come across something like this Guided Tour S eya los r 2 At first glance this seems like an error But recall that while revisions are repository wide svn log operates on a path in the repository If you supply no path Subversion uses the current working directory as the default target As a result if you re operating in a subdirectory of your working copy and attempt to log a revision in which neither that directory nor any of its children was changed Subversion will give you an empty log If you want to see what changed in that revision try pointing svn log directly at the top most URL of your
297. or this automatic log file removal If you don t want this feature enabled simply pass the bdb 1og keep option to the svnadmin create command If you for get to do this or change your mind at a later time simple edit the DB_CONFIG file found in your repository s db di rectory comment out the line which contains the set_flags DB_LOG_AUTOREMOVE directive and then run svnad min recover on your repository to force the configuration changes to take effect See Section Berkeley DB Con figuration for more information about database configuration Without some sort of automatic log file removal in place log files will accumulate as you use your repository This is actually somewhat of a feature of the database system you should be able to recreate your entire database using nothing but the log files so these files can be useful for catastrophic database recovery But typically you ll want to archive the log files that are no longer in use by Berkeley DB and then remove them from disk to conserve space Use the svnadmin list unused dblogs command to list the unused logfiles svnadmin list unused dblogs path to repos path to repos log 0000000031 path to repos log 0000000032 path to repos log 0000000033 svnadmin list unused dblogs path to repos xargs rm disk space reclaimed To keep the size of the repository as small as possible Subversion uses deltification or deltified storage within the repositor
298. or your constant support and enthusiasm Hats off to Shep Kendall through whom the world of computers was first opened to me Ben Collins Sussman my tour guide through the open source world Karl Fogel you are my emacs Greg Stein for oozing practical pro gramming know how Brian Fitzpatrick for sharing this writing experience with me To the many folks from whom I am constantly picking up new knowledge keep dropping it Finally to the One who perfectly demonstrates creative excellence thank you xvii Chapter 1 Introduction Version control is the art of managing changes to information It has long been a critical tool for programmers who typically spend their time making small changes to software and then undoing those changes the next day But the usefulness of version control software extends far beyond the bounds of the software development world Anywhere you can find people using computers to manage information that changes often there is room for version control And that s where Subversion comes into play This chapter contains a high level introduction to Subversion what it is what it does how to get it What is Subversion Subversion is a free open source version control system That is Subversion manages files and directories over time A tree of files is placed into a central repository The repository is much like an ordinary file server except that it remembers every change ever made to your files and
299. or your repository This hook runs just before such a modification is made to the repository The repository passes four arguments to this hook the path to the repository the revision on which the to be modified property exists the authenti cated username of the person making the change and the name of the property itself post revprop chang As mentioned earlier this hook is the counterpart of the pre revprop change hook In fact for the sake of paranoia this script will not run unless the pre revprop change hook exists When both of these hooks are present the post revprop change hook runs just after a revision property has been changed and is typically used to send an email containing the new value of the changed property The repository passes four arguments to this hook the path to the repository the revision on which the property exists the authenticated username of the person making the change and the name of the property itself The Subversion distribution includes a propchange email pl script located in the tools hook scripts di rectory of the Subversion source tree that can be used to send email with and or append to a log file the de tails of a revision property change This mail contains the revision and name of the changed property the user who made the change and the new property value Subversion will attempt to execute hooks as the same user who owns the process which is accessing the Subversion repos
300. org There you can find information about getting access to the source code and participating on the discussion lists The Subversion community always welcomes new members If you are inter ested in participating in this community by contributing changes to the source code here are some hints on how to get started Join the Community The first step in community participation is to find a way to stay on top of the latest happenings To do this most ef fectively you will want to subscribe to the main developer discussion list lt dev subversion tigris org gt and commit mail list lt svn subversion tigris org gt By following these lists even loosely you will have access to important design discussions be able to see actual changes to Subversion source code as they occur and be able to witness peer reviews of those changes and proposed changes These email based discussion lists are the primary communication media for Subversion development See the Mailing Lists section of the website for other Subver sion related lists you might be interested in But how do you know what needs to be done It is quite common for a programmer to have the greatest intentions of helping out with the development yet be unable to find a good starting point After all not many folks come to the community having already decided on a particular itch they would like to scratch But by watching the developer discussion lists you might see mentions of existing bugs o
301. orks via direct repository access and thus can only be used on the machine that holds the reposi tory it refers to the repository with a path not a URL If no revision or transaction is specified svnlook defaults to the youngest most recent revision of the repository svnlook Switches Switches in svnlook are global just like in svn and svnadmin however most switches only apply to one subcom mand since the functionality of svnlook is intentionally limited in scope no diff deleted Prevents svnlook from printing differences for deleted files The default behavior when a file is deleted in a transaction revision is to print the same differences that you would see if you had left the file but removed all the content revision r Specify a particular revision number that you wish to examine transaction t Specify a particular transaction ID that you wish to examine show ids Show the filesystem node revision IDs for each path in the filesystem tree 220 Subversion Complete Reference svnlook 221 Subversion Complete Reference Name svnlook author Print the author svnlook author Synopsis svnlook author REPOS_PATH Description Print the author of a revision or transaction in the repository Switches revision 1 transaction t Examples svnlook author is handy but not very exciting svnlook author r 40 usr local svn repos sally 222 Subversi
302. ort or via via 3rd party tools such as ViewCVS 3rd party tools such as ViewCVS Speed somewhat slower somewhat faster Initial setup somewhat complex fairly simple Network Model 85 Server Configuration This section is a general discussion of how a Subversion client and server interact with one another regardless of the network implementation you re using After reading you ll have a good understanding of how a server can behave and the different ways in which a client can be configured to respond Requests and Responses The Subversion client spends most of its time managing working copies When it needs information from a reposi tory however it makes a network request and the server responds with an appropriate answer The details of the network protocol are hidden from the user the client attempts to access a URL and depending on the URL schema a particular protocol is used to contact the server see Repository URLs Users can run svn version to see which URL schemas and protocols the client knows how to use When the server process receives a client request it typically demands that the client identify itself It issues an au thentication challenge to the client and the client responds by providing credentials back to the server Once authen tication is complete the server responds with the original information the client asked for Notice that this system is different from systems like CVS where the client pre emptive
303. orts bugfixes over to the stable branch Even after the stable branch has shipped you ll probably continue to maintain the branch for a long time that is as long as you continue to support that release for customers Summary We ve covered a lot of ground in this chapter We ve discussed the concepts of tags and branches and demonstrated how Subversion implements these concepts by copying directories with the svn copy command We ve shown how to use svn merge to copy changes from one branch to another or roll back bad changes We ve gone over the use of svn switch to create mixed location working copies And we ve talked about how one might manage the organiza tion and lifetimes of branches in a repository Remember the Subversion mantra branches and tags are cheap So use them liberally 59 Chapter 5 Repository Administration The Subversion repository is the central storehouse of versioned data for any number of projects As such it be comes an obvious candidate for all the love and attention an administrator can offer While the repository is gener ally a low maintenance item it is important to understand how to properly configure and care for it so that potential problems are avoided and actual problems are safely resolved In this chapter we ll discuss how to create and configure a Subversion repository and how to expose that repository for network accessibility We ll also talk about repository maintenance including th
304. ory doesn t know or care 1f your changes make any sense as a whole it only checks to make sure that no body else has changed any of the same files that you did when you weren t looking If somebody has done that the entire commit will fail with a message informing you that one or more of your files is out of date svn commit message Add another rule Sending rules txt svn Commit failed details follow svn Out of date rules txt in transaction g At this point you need to run svn update deal with any merges or conflicts that result and attempt your commit again That covers the basic work cycle for using Subversion There are many other features in Subversion that you can use to manage your repository and working copy but you can get by quite easily using only the commands that we ve discussed so far in this chapter Examining History As we mentioned earlier the repository is like a time machine It keeps a record of every change ever committed and allows you to explore this history by examining previous versions of files and directories as well as the metadata that accompanies them With a single Subversion command you can check out the repository or restore an existing working copy exactly as it was at any date or revision number in the past However sometimes you just want to peer into the past instead of going into the past There are several commands that can provide you with historical data from the repository sv
305. ous revision in the repository the same way it treats every other revision that gets dumped It will then output the first revision exactly as it does the rest of the revisions in the dump range mentioning only the changes that occurred in that revision The benefit of this is that you can create several small dump files that can be loaded in succession instead of one large one like so svnadmin dump myrepos revision 0 1000 gt dumpfilel svnadmin dump myrepos revision 1001 2000 incremental gt dumpfile2 svnadmin dump myrepos revision 2001 3000 incremental gt dumpfile3 These dump files could be loaded into a new repository with the following command sequence svnadmin load newrepos lt dumpfilel svnadmin load newrepos lt dumpfile2 svnadmin load newrepos lt dumpfile3 Another neat trick you can perform with this incremental option involves appending to an existing dump file a new range of dumped revisions For example you might have a post commit hook that simply appends the reposi tory dump of the single revision that triggered the hook Or you might have a script that runs nightly to append dump file data for all the revisions that were added to the repository since the last time the script ran Used like this svnadmin s dump and load commands can be a valuable means by which to backup changes to your repository over time in case of a system crash or some other catastrophic event The dump format can also b
306. own working copy directory see Section Externals Definitions But sometimes you want to maintain custom modifications to third party data in your own version control system Returning to the software development example programmers might need to make modifications to that third party library for their own purposes These modifications might include new functionality or bug fixes maintained inter nally only until they become part of an official release of the third party library Or the changes might never be re layed back to the library maintainers existing solely as custom tweaks to make the library further suit the needs of the software developers Now you face an interesting situation Your project could house its custom modifications to the third party data in some disjointed fashion such as using patch files or full fledged alternate versions of files and directories But these quickly become maintenance headaches requiring some mechanism by which to apply your custom changes to the third party data and necessitating regeneration of those changes with each successive version of the third party data that you track The solution to this problem is to use vendor branches A vendor branch is a directory tree in your own version con trol system that contains information provided by a third party entity or vendor Each version of the vendor s data that you decide to absorb into your project is called a vendor drop Vendor branches pro
307. pass the show updates switch The item in your working copy is up to date A newer revision of the item exists on the server The remaining fields are variable width and delimited by spaces The working revision is the next field if the show updates or verbose switches are passed If the verbose switch is passed the last committed revision and last committed author are displayed next The working copy path is always the final field so 1t can include spaces 200 Subversion Complete Reference Alternate Names stat st Changes Nothing Accesses Repository Only if using show updates Switches show updates u verbose v non recursiv N quiet a no ignore username USER password PASS no auth cach non interactiv config dir Examples This is the easiest way to find out what changes you have made to your working copy S svn status wc M wc bar c A wc qax c If you want to find out what files in your working copy are out of date pass the show updates switch this will not make any changes to your working copy Here you can see that wc foo c has changed in the repository since we last updated our working copy svn status show updates wc M 965 wc bar c iS 965 wc foo c A 965 we qax c Status against revision 981 Note show updates only places an asterisk next to items that are out of date that is items that will be up dated from th
308. path err svn_repos_fs_commit_txn amp conflict_str repos gyoungest_rev txn pool 1f err No error Excellent Print a brief report of our success printf Directory s was successfully added as new revision 1 SVN_REVNUM_T_FMT n new_directory youngest_rev lse if err gt apr_err SVN_ERR_FS_CONFLICT Uh oh Our commit failed as the result of a conflict someone else seems to have made changes to the same area of the filesystem that we tried to modify Print an error message printf A conflict occurred at path s while attempting to add directory Ss to the repository at s n conflict_str new_directory repos_path else Some other error has occurred Print an error message printf An error occurred while attempting to add directory to the repository at s n new_directory repos_path Sst Return the result of the attempted commit to our caller return err In the previous code segment calls were made to both the repository and filesystem interfaces We could just as eas ily have committed the transaction using svn_fs_commit_txn But the filesystem API knows nothing about the repository library s hook mechanism If you want your Subversion repository to automatically perform some set of non Subversion tasks every time you commit a transaction like for example sending an email that describes all th
309. per user config uration area override those in the system wide one and command line arguments supplied to the svn program have the final word on behavior On Unix like platforms the system wide configuration area is expected to be the etc subversion directory on Windows machines it looks for a Subversion directory inside the common Ap plication Data location again as specified by the Windows Registry Unlike the per user case the svn program does not attempt to create the system wide configuration area 25The APPDATA environment variable points to the Application Data area so you can always refer to this folder as SAPPDATA Subversion 105 Advanced Topics The configuration area currently contains three files two configuration files config and servers and a README txt file which describes the INI format At the time of their creation the files contain default values for each of the supported Subversion options mostly commented out and grouped with textual descriptions about how the values for the key affect Subversion s behavior To change a certain behavior you need only to load the appro priate configuration file into a text editor and modify the desired option s value If at any time you wish to have the default configuration settings restored you can simply remove or rename your configuration directory and then run some innocuous svn command such as svn version A new configuration directory with the default cont
310. pha lt 7 0 1 gt beta lt 8 0 1 gt F lt 9 0 1 gt mu lt 3 0 1 gt C lt a 0 1 gt D lt b 0 1 gt gamma lt c 0 1 gt G lt d 0 1 gt pi lt e 0 1 gt rho lt f 0 1 gt tau lt g 0 1 gt H lt h 0 1 gt chi lt i 0 1 gt omega lt k 0 1 gt psi JO L gt iota lt 1 0 1 gt Once you ve seen the layout of directories and files in your tree you can use commands like svnlook cat svnlook propget and svnlook proplist to dig into the details of those files and directories svnlook can perform a variety of other queries displaying subsets of bits of information we ve mentioned previ ously reporting which paths were modified in a given revision or transaction showing textual and property differ ences made to files and directories and so on The following is a brief description of the current list of subcom mands accepted by svnlook and the output of those subcommands author Print the tree s author cat Print the contents of a file in the tree changed List all files and directories that changed in the tree date Print the tree s datestamp diff Print unified diffs of changed files dirs changed List the directories in the tree that were themselves changed or whose file children were changed history Display interesting points in the history of a versioned path places where modifications or copies occurred info Print the tree s author datestamp log message character count a
311. plish tasks such as repository migrations upgrades backups and cleanups An Administrator s Toolkit Subversion provides a handful of utilities useful for creating inspecting modifying and repairing your repository Let s look more closely at each of those tools Afterward we ll briefly examine some of the utilities included in the Berkeley DB distribution that provide functionality specific to your repository s database backend not otherwise pro vided by Subversion s own tools svnlook svnlook is a tool provided by Subversion for examining the various revisions and transactions in a repository No part of this program attempts to change the repository it s a read only tool svnlook is typically used by the repository hooks for reporting the changes that are about to be committed in the case of the pre commit hook or that were just committed in the case of the post commit hook to the repository A repository administrator may use this tool for diagnostic purposes svnlook has a straightforward syntax svnlook help general usage svnlook SUBCOMMAND REPOS_PATH ARGS amp OPTIONS Note any subcommand which takes the revision and transaction options will if invoked without one of those options act on the repository s youngest revision Type svnlook help lt subcommand gt for help on a specific subcommand Nearly every one of svnlook s subcommands can operate on either a revision or a transaction tree pr
312. ply deltify the HEAD revision dump Dump the contents of the repository bounded by a given set of revisions using a portable dump format hotcopy Make a hot copy of a repository You can run this command at any time and make a safe copy of the repository regardless if other processes are using the repository list dblogs List the paths of Berkeley DB log files associated with the repository This list includes all log files those still in use by Subversion as well as those no longer in use list unused dblogs List the paths of Berkeley DB log files associated with but no longer used by the repository You may safely remove these log files from the repository layout possibly archiving them for use in the event that you ever need to perform a catastrophic recovery of the repository load Load a set of revisions into a repository from a stream of data that uses the same portable dump format gener ated by the dump subcommand lstxns List the names of uncommitted Subversion transactions that currently exist in the repository 68 Repository Administration recover Perform recovery steps on a repository that is in need of such generally after a fatal error has occurred that pre vented a process from cleanly shutting down its communication with the repository rmtxns Cleanly remove Subversion transactions from the repository conveniently fed by output from the 1stxns sub command setlog Replace the current value
313. port for externals definitions An externals definition is a mapping of a local di rectory to the URL and possibly a particular revision of a versioned resource In Subversion you declare exter nals definitions in groups using the svn externals property You can create or modify this property using svn propset or svn propedit see Section Why Properties It can be set on any versioned directory and its value is a multi line table of subdirectories relative to the versioned directory on which the property is set and fully quali fied absolute Subversion repository URLs svn propget svn externals calc third party sounds http sounds red bean com repos third party skins http skins red bean com repositories skinproj third party skins toolkit r21 http svn red bean com repos skin maker The convenience of the svn externals property is that once it is set on a versioned directory everyone who checks out a working copy with that directory also gets the benefit of the externals definition In other words once one person has made the effort to define those nested working copy checkouts no one else has to Subver bother sion will upon checkout of the original working copy also checkout the external working copies 120 Advanced Topics Note the previous externals definition example When someone checks out a working copy of the calc directory Subversion also continues to checkout the items found in its externals definit
314. previously that svnadmin dump outputs a range of revisions Use the revision option to specify a single revision to dump or a range of revisions If you omit this option all the existing repository revisions will be dumped svnadmin dump myrepos revision 23 gt rev 23 dumpfile svnadmin dump myrepos revision 100 200 gt revs 100 200 dumpfile As Subversion dumps each new revision it outputs only enough information to allow a future loader to re create that revision based on the previous one In other words for any given revision in the dump file only the items that were changed in that revision will appear in the dump The only exception to this rule is the first revision that is dumped with the current synadmin dump command By default Subversion will not express the first dumped revision as merely differences to be applied to the previous revision For one thing there is no previous revision in the dump file And secondly Subversion cannot know the state of the repository into which the dump data will be loaded if it ever in fact occurs To ensure that the output of each execution of svnadmin dump is self sufficient the first dumped revision is by default a full representation of every directory file and property in that revision of the repository However you can change this default behavior If you add the incremental option when you dump your repos itory svnadmin will compare the first dumped revision against the previ
315. problem When Harry asks his client to merge the latest repository changes into his working copy his copy of file A is somehow flagged as being in a state of conflict he ll be able to see both sets of conflicting changes and manually choose between them Note that software can t automatically resolve conflicts only humans are capable of understanding and making the necessary intelligent choices Once Harry has manually resolved the overlapping changes perhaps after a discussion with Sally he can safely save the merged file back to the reposi tory The copy modify merge model may sound a bit chaotic but in practice it runs extremely smoothly Users can work in parallel never waiting for one another When they work on the same files it turns out that most of their concur rent changes don t overlap at all conflicts are infrequent And the amount of time it takes to resolve conflicts is far less than the time lost by a locking system In the end it all comes down to one critical factor user communication When users communicate poorly both syn tactic and semantic conflicts increase No system can force users to communicate perfectly and no system can de tect semantic conflicts So there s no point in being lulled into a false promise that a locking system will somehow prevent conflicts in practice locking seems to inhibit productivity more than anything else Subversion in Action It s time to move from the abstract to the concrete In
316. put This type of translation can be lossy That is the program may not display all of the information harvested from the API or may combine bits of information for compact representation If you wrap such a command line program with yet another program the second program has access only to al ready interpreted and as we mentioned likely incomplete information which it must again translate into its repre sentation format With each layer of wrapping the integrity of the original data is potentially tainted more and more much like the result of making a copy of a copy of a copy of a favorite audio or video cassette Using the APIs Developing applications against the Subversion library APIs is fairly straightforward All of the public header files live in the subversion include directory of the source tree These headers are copied into your system locations when you build and install Subversion itself from source These headers represent the entirety of the functions and types meant to be accessible by users of the Subversion libraries The first thing you might notice is that Subversion s datatypes and functions are namespace protected Every public Subversion symbol name begins with svn_ followed by a short code for the library in which the symbol is defined such as wc client fs etc followed by a single underscore _ and then the rest of the symbol name Semi public functions used among source files of a given library but
317. py in a directory named subv instead of a directory named trunk as we did previ ously Basic Work Cycle Subversion has numerous features options bells and whistles but on a day to day basis odds are that you will only use a few of them In this section we ll run through the most common things that you might find yourself doing with Subversion in the course of a day s work The typical work cycle looks like this e Update your working copy e svn update e Make changes e svnadd e svn delete e svn copy e svn move Examine your changes e svn status e svn diff e svn revert e Merge others changes svn merge e svn resolved e Commit your changes e svn commit 24 Guided Tour Update Your Working Copy When working on a project with a team you ll want to update your working copy to receive any changes made since your last update by other developers on the project Use svn update to bring your working copy into sync with the latest revision in the repository svn update U foosce U bar c Updated to revision 2 In this case someone else checked in modifications to both foo c and bar c since the last time you updated and Subversion has updated your working copy to include those changes Let s examine the output of svn update a bit more When the server sends changes to your working copy a letter code is displayed next to each item to let you know what actions Subversion performed to bring your worki
318. quisites To network your repository over HTTP you basically need four components available in two packages You ll need Apache httpd 2 0 the mod_dav DAV module that comes with it Subversion and the mod_dav_svn filesystem provider module distributed with Subversion Once you have all of those components the process of networking your repository is as simple as e getting httpd 2 0 up and running with the mod_dav module e installing the mod_dav_svn plugin to mod_dav which uses Subversion s libraries to access the repository and e configuring your httpd conf file to export or expose the repository You can accomplish the first two items either by compiling httpd and Subversion from source code or by installing pre built binary packages of them on your system For the most up to date information on how to compile Subver sion for use with the Apache HTTP Server as well as how to compile and configure Apache itself for this purpose see the INSTALL file in the top level of the Subversion source code tree Basic Apache Configuration Once you have all the necessary components installed on your system all that remains is the configuration of Apache via its httpd conf file Instruct Apache to load the mod_dav_svn module using the LoadModule direc tive This directive must precede any other Subversion related configuration items If your Apache was installed us ing the default layout your mod_dav_svn module should have been installed in the
319. r feature requests fly by that particularly interest you Also a great place to look for outstanding unclaimed tasks is the Issue Tracking database on the Subversion web site There you will find the current list of known bugs and feature requests If you want to start with something small look for issues marked as bite sized Get the Source Code To edit the code you need to have the code This means you need to check out a working copy from the public Sub version source repository As straightforward as that might sound the task can be slightly tricky Because Subver 141 Developer Information sion s source code is versioned using Subversion itself you actually need to bootstrap by getting a working Sub version client via some other method The most common methods include downloading the latest binary distribution 1f such is available for your platform or downloading the latest source tarball and building your own Subversion client If you build from source make sure to read the INSTALL file in the top level of the source tree for instruc tions After you have a working Subversion client you are now poised to checkout a working copy of the Subversion source repository from http svn collab net repos svn trunk 38 svn checkout http svn collab net repos svn trunk subversion A HACKING A INSTALL A README A A autogen sh build conf The above command will checkout the bleeding edge late
320. rane Cibej John R Daily Peter Davis Olivier Davy Robert P J Day Mo DeJong Brian Denny Joe Drew Nick Duf fek Ben Elliston Justin Erenkrantz Shlomi Fish Julian Foad Chris Foote Martin Furter Dave Gilbert Eric Gille spie Matthew Gregan Art Haas Greg Hudson Alexis Huxley Jens B Jorgensen Tez Kamihira David Kimdon Mark Benedetto King Andreas J Koenig Nuutti Kotivuori Matt Kraai Scott Lamb Vincent Lefevre Morten Lud vigsen Paul Lussier Bruce A Mah Philip Martin Feliciano Matias Patrick Mayweg Gareth McCaughan Jon Middleton Tim Moloney Mats Nilsson Joe Orton Amy Lyn Pilato Kevin Pilch Bisson Dmitriy Popkov Michael Price Mark Proctor Steffen Prohaska Daniel Rall Tobias Ringstrom Garrett Rooney Joel Rosdahl Christian Sauer Larry Shatzer Russell Steicke Sander Striker Erik Sjoelund Johan Sundstroem John Szakmeister Mason Thomas Eric Wadsworth Colin Watson Alex Waugh Chad Whitacre Josef Wolf Blair Zajac and the entire Sub version community Ben Collins Sussman Thanks to my wife Frances who for many months got to hear But honey I m still working on the book rather than the usual But honey I m still doing email I don t know where she gets all that patience She s my perfect counterbalance Thanks to my extended family for their sincere encouragement despite having no actual interest in the subject You know the ones who say Ooh you re writing a book and then w
321. re prop erty calculator debug_log After you ve added this property you will now have a local property modification on the calc directory But notice what else is different about your svn status output svn status calc calc button c calc data c 25 Now all the cruft is missing from the output Of course those files are still in your working copy Subversion is simply not reminding you that they are present and unversioned And now with all the trivial noise removed from the display you are left with more interesting items such as that source code file that you probably forgot to add to version control 29The patterns are strictly for that directory they do not carry recursively into subdirectories 30Isn t that the whole point of a build system 116 Advanced Topics If you want to see the ignored files you can pass the no ignore option to subversion svn status no ignore M calc button c calc calculator calc data c calc debug_log calc debug_log 1 calc debug_log 2 gz calc debug_log 3 gz HHHHWH The list of patterns to ignore is also used by svn add and svn import Both of these operations involve asking Sub version to begin managing some set of files and directories Rather than force the user to pick and choose which files in a tree she wishes to start versioning Subversion uses the ignore patterns to determine which files should not be swept into the version control system as part of a larger
322. real transaction support perhaps its most powerful feature Multiple processes accessing your Subversion repositories don t have to worry about accidentally clobbering each other s data The isolation pro vided by the transaction system is such that for any given operation the Subversion repository code sees a static view of the database not a database that is constantly changing at the hand of some other process and can make decisions based on that view If the decision made happens to conflict with what another process is doing the entire operation is rolled back as if it never happened and Subversion gracefully retries the operation against a new up dated and yet still static view of the database Another great feature of Berkeley DB is hot backups the ability to backup the database environment without tak ing it offline We ll discuss how to backup your repository in Section Repository Backup but the benefits of being able to make fully functional copies of your repositories without any downtime should be obvious Berkeley DB is also a very reliable database system Subversion uses Berkeley DB s logging facilities which means that the database first writes to on disk logfiles a description of any modifications it is about to make and then makes the modification itself This is to ensure that if anything goes wrong the database system can back up to a previous checkpoint a location in the logfiles known not to be corrup
323. recursiv R quiet a config dir DIR Examples Discard changes to a file svn revert foo c Reverted foo c If you want to revert a whole directory of files use the recursive flag S svn revert recursiv Reverted newdir afile Reverted foo c Reverted bar txt 197 Subversion Complete Reference Lastly you can undo any scheduling operations svn add mistake txt whoops A A A mistake txt whoops whoops oopsie c svn revert mistake txt whoops Reverted mistake txt Reverted whoops svn status mistake txt whoops Note If you provide no targets to svn revert it will do nothing to protect you from accidentally losing changes in your working copy svn revert requires you to provide at least one target 198 Subversion Complete Reference Name svn status Print the status of working copy files and directories svn status Synopsis svn status PATH Description Print the status of working copy files and directories With no arguments it prints only locally modified items no repository access With show updates add working revision and server out of date information With verbose print full revision information on every item The first five columns in the output are each one character wide and each column gives you information about dif ferent aspects of each working copy item The first column indicates that an item was added dele
324. recursive addition or import operation svn keywords Subversion has the ability to substitute keywords pieces of useful dynamic information about a versioned file into the contents of the file itself Keywords generally describe information about the last time the file was known to be modified Because this information changes each time the file changes and more importantly just after the file changes it is a hassle for any process except the version control system to keep the data completely up to date Left to human authors the information would inevitably grow stale For example say you have a document in which you would like to display the last date on which it was modified You could burden every author of that document to just before committing their changes also tweak the part of the document that describes when it was last changed But sooner or later someone would forget to do that Instead sim ply ask Subversion to perform keyword substitution on the LastChangedDate keyword You control where the keyword is inserted into your document by placing a keyword anchor at the desired location in the file This anchor is just a string of text formatted as KeywordName Subversion defines the list of keywords available for substitution That list contains the following five keywords some of which have shorter aliases that you can also use LastChangedDate This keyword describes the last time the file was known to have been changed i
325. ree things the working copy directory itself called the this directory entry and noted as having an empty value for its name at tribute a file in that working copy directory noted by having its kind attribute set to file or a subdirectory in that working copy kind here is set to dir The files and subdirectories whose entries are stored in this file are either already under version control or as in the case of the file named zeta above are scheduled to be added to version control when the user next commits this working copy directory s changes Each entry has a unique name and each entry has a node kind Developers should be aware of some special rules that Subversion uses when reading and writing its entries files While each entry has a revision and URL associated with it note that not every ent ry tag in the sample file has ex plicit revision or url attributes attached to it Subversion allows entries to not explicitly store those two attributes when their values are the same as in the revision case or trivially calculable from 37 in the ur1 case the data stored in the this directory entry Note also that for subdirectory entries Subversion stores only the crucial at tributes name kind url revision and schedule In an effort to reduce duplicated information Subversion dictates that the method for determining the full set of information about a subdirectory is to traverse down into that subdi rectory and read t
326. repos svn trunk COMMITTERS README HACKING If you have a working copy you can obtain the differences without typing in the long URLs svn diff r 3000 3500 COMMITTERS Index COMMITTERS COMMITTERS revision 3000 COMMITTERS revision 3500 Use diff cmd CMD x to pass arguments directly to the external diff program svn diff diff cmd usr bin diff x i b COMMITTERS Index COMMITTERS Dal 2 gt This is a test gt 165 Subversion Complete Reference Name svn export Export a clean directory tree svn export Synopsis svn export r REV URL PATH svn export PATH1 PATH2 Description The first form exports a clean directory tree from the repository specified by URL at revision REV if it is given oth erwise at HEAD into PATH If PATH is omitted the last component of the URL is used for the local directory name The second form exports a clean directory tree from the working copy specified by PATA1 into PATH2 All local changes will be preserved but files not under version control will not be copied Alternate Names None Changes Local disk Accesses Repository Only if exporting from a URL Switches revision r REV quiet q force username USER password PASS no auth cach non interactiv config dir DIR Examples Export from your working copy doesn t print every file and directory
327. rking copies contain a mixture of working revisions but a mixture of repository locations as well If your working copy contains a number of switched subtrees from different repository locations it continues to function as normal When you update you ll receive patches to each subtree as appropriate When you commit your local changes will still be applied as a single atomic change to the repository Note that while it s okay for your working copy to reflect a mixture of repository locations these locations must all be within the same repository Subversion repositories aren t yet able to communicate with one another that s a fea ture planned beyond Subversion 1 0 11 Switches and Updates Have you noticed that the output of svn switch and svn update look the same The switch command is actually a superset of the update command When you run svn update you re asking the repository to compare two trees The repository does so and then sends a description of the differences back to the client The only difference between svn switch and svn update is that the update command always compares two identical paths That is if your working copy is a mirror of calc trunk then svn update will automatically compare your work ing copy of calc trunk to calc trunk in the HEAD revision If you re switching your working copy to a branch then svn switch will compare your working copy of calc trunk to some other branch directory in the HEAD revision
328. rking copy File changes This is the simplest sort of change You don t need to tell Subversion that you intend to change a file just make your changes Subversion will be able to automatically detect which files have been changed Tree changes 25 Guided Tour You can ask Subversion to mark files and directories for scheduled removal addition copying or moving While these changes may take place immediately in your working copy no additions or removals will happen in the repository until you commit them To make file changes use your text editor word processor graphics program or whatever tool you would normally use Subversion handles binary files just as easily as it handles text files and just as efficiently too Here is an overview of the four Subversion subcommands that you ll use most often to make tree changes we ll cover svn import and svn mkdir later svn add foo Schedule foo to be added to the repository When you next commit foo will become a child of its parent direc tory Note that if foo is a directory everything underneath foo will be scheduled for addition If you only want to schedule foo itself pass the non recursive N switch svn delete foo Schedule foo to be deleted from the repository If foo is a file it is immediately deleted from your working copy If foo is a directory it is not deleted but Subversion schedules it for deletion When you commit your changes foo will be remov
329. rns The two systems use the ignore patterns at some different times and there are slight discrepancies in what the ignore patterns apply to Also Subversion does not recognize the use of the pattern as a reset back to having no ignore patterns at all For this purpose the svn ignore property is the solution Its value is a multi line collection of file patterns one pattern per line The property is set on the directory in which you wish the patterns to be applied 29 For example say you have the following output from svn status svn status calc M calc button c calc calculator calc data c calc debug_log calc debug_log 1 calc debug_log 2 gz calc debug_log 3 gz IV VV VV In this example you have made some property modifications to button c but in your working copy you also have some unversioned files the latest calculator program that you ve compiled from your source code a source file named data c and a set of debugging output log files Now you know that your build system always results in the calculator program being generated 30 And you know that your test suite always leaves those debugging log files lying around These facts are true for all working copies not just your own And you know that you aren t inter ested in seeing those things every time you run svn status So you use svn propedit svn ignore calc to add some ignore patterns to the calc directory For example you might add this as the new value of the svn igno
330. rocedure for some reason does not successfully unwedge your repository you should do two things First move your broken repository out of the way and restore your latest backup of it Then send an email to the Subversion user list at lt users subversion tigris org gt describing your problem in detail Data integrity is an extremely high priority to the Subversion developers Migrating a Repository A Subversion filesystem has its data spread throughout various database tables in a fashion generally understood by and of interest to only the Subversion developers themselves However circumstances may arise that call for all or some subset of that data to be collected into a single portable flat file format Subversion provides such a mech anism implemented in a pair of synadmin subcommands dump and load The most common reason to dump and load a Subversion repository is due to changes in Subversion itself As Sub 15E g hard drive huge electromagnet disaster 77 Repository Administration version matures there are times when certain changes made to the back end database schema cause Subversion to be incompatible with previous versions of the repository The recommended course of action when you are upgrad ing across one of those compatibility boundaries is a relatively simple process 1 Using your current version of svnadmin dump your repositories to dump files 2 Upgrade to the new version of Subversion 3 Mo
331. rotocol which is an extension of HTTP In the other corner is svnserve a small standalone server program that speaks a custom protocol with clients Table 6 1 presents a com parison of the two servers Note that Subversion as an open source project does not officially endorse any server as primary or official Neither network implementation is treated as a second class citizen each server has distinct advantages and disad vantages In fact it s possible for different servers to run in parallel each accessing your repositories in its own way and each without hindering the other see Section Supporting Multiple Repository Access Methods Here s a brief overview and comparison of the two available Subversion servers as an administrator it s up to you to choose whatever works best for you and your users Table 6 1 Network Server Comparison Feature Apache mod_dav_svn svnserve Authentication options HTTP S basic auth X 509 certifi CRAM MD5 or SSH cates LDAP NTLM or any other mechanism available to Apache httpd User account options private users file private users file or existing system SSH accounts Authorization options blanket read write access or per blanket read write access directory access control Encryption via optional SSL via optional SSH tunnel Interoperability partially usable by other WebDAV not interoperable clients Web viewing limited built in supp
332. rsion oocoooccnccnnccnncnnoconoconccnnconnconnconnconncnnncnnncnnncnnncnnss 242 B Troubleshooting mrenea os econ A A wap E ads Common Problems sson NN 243 Problems Using Subversion cnino renoir oi ar EEEN seaeeeagresa sense cectegeresteceees 243 C WebDAV and Autoversioning sssri itera snie e sos eine stent ral die gta sab ORO Aide Breda Basic WebDAV Concepts c siccieis ig ueties eb ceeds Suda EEEE veen sus EEEE dape od dee Dona 249 Just Plain WebDAV romeri nresep eea ootan dase AE SEEE og feesnaeh nesbieagsesseeuss sebipagheesnies geebtees 249 Delta V EXtensions eroe t e n eere Giese E S ale teea ds os lisa 249 Subversion and Delta Wisconsin daa Mtro aaberes dacaseag ssa bat EET eats 250 Mapping Subversionto Delt Ve nanan soa oeutvess eettes veneration NA TERESE RES 251 AULOVETSIONING SUPPORL ii II A A ad 251 The mod_dav_lock Alternative cc cece cccececeeccee cece eeeeaeceesceeeeeeeaeseeseeeeeeeeueeseseeeeeeeaeess 252 Autoversioning Interoperability suave da a Dee ee sah ded teint deh ee 252 Win32 WebFolderS s oeeo lovey sudesseeteduter OE A VEEE E seeders pysmeeoneante EEEE 253 ET ORD CEA E A A E A E lars 253 Unix Nautilus De ciconia eae e ap EE Ea E A E AE apa 253 Tinuk davfs2 orion rie diners pega 254 D Third Party Toole reon ine a eaan a vied E Aa PA E EE TEATRE TSE EAE SREDE Clients anid Plugins siss ero erea E ESE E E EEEE E E E EE E E E EEES debeey 255 Language Bd PS cp n E E E EEE E E EEEE EE EE ESEE 255 Reposi
333. rsion configuration area The Subversion configuration area is a two tiered hierarchy of option names and their values Usually this boils down to a special directory that contains configuration files the first tier which are just text files in standard INI format with sections providing the second tier These files can be easily edited using your favorite text editor such as Emacs or vi and contain directives read by the client to determine which of several optional behaviors the user prefers Configuration Area Layout The first time that the svn command line client is executed it creates a per user configuration area On Unix like systems this area appears as a directory named subversion in the user s home directory On Win32 systems Subversion creates a folder named Subversion typically inside the Application Data area of the user s profile directory which by the way is usually a hidden directory However on this platform the exact location differs from system to system and is dictated by the Windows registry 25 We will refer to the per user configuration area using its Unix name subversion In addition to the per user configuration area Subversion also recognizes the existence of a system wide configura tion area This gives system administrators the ability to establish defaults for all users on a given machine Note that the system wide configuration area does not alone dictate mandatory policy the settings in the
334. rying to pass URLs even local file ones to these two programs So after you ve run the svnadmin create command you have a shiny new Subversion repository in its own direc tory Let s take a peek at what is actually created inside that subdirectory ls repos conf dav db format hooks locks README txt With the exception of the README txt and format files the repository directory is a collection of subdirectories As in other areas of the Subversion design modularity is given high regard and hierarchical organization is pre ferred to cluttered chaos Here is a brief description of all of the items you see in your new repository directory conf A directory containing repository configuration files dav A directory provided to Apache and mod_dav_svn for their private housekeeping data db The main Berkeley DB environment full of DB tables that comprise the data store for Subversion s filesystem where all of your versioned data resides format A file whose contents are a single integer value that dictates the version number of the repository layout hooks A directory full of hook script templates and hook scripts themselves once you ve installed some 62 Hook Repository Administration locks A directory for Subversion s repository locking data used for tracking accessors to the repository README txt A file which merely informs its readers that they are looking at a Subvers
335. s This is a semicolon delimited list of paths to files containing certificates of the certificate authorities or CAs that are accepted by the Subversion client when accessing the repository over HTTPS ssl trust default ca Set this variable to yes if you want Subversion to automatically trust the set of default CAs that ship with OpenSSL ssl client cert fil If a host or set of hosts requires an SSL client certificate you ll normally be prompted for a path to your cer tificate By setting this variable to that same path Subversion will be able to find your client certificate automat ically without prompting you There s no standard place to store your certificate on disk Subversion will grab it from any path you specify ssl client cert password If your SSL client certificate file is encrypted by a passphrase Subversion will prompt you for the passphrase whenever the certificate is used If you find this annoying and don t mind storing the password in the servers file then you can set this variable to the certificate s passphrase You won t be prompted anymore 108 Config Advanced Topics The config file contains the rest of the currently available Subversion run time options those not related to net working There are only a few options in use at this time but they are again grouped into sections in expectation of future additions The auth section contains settings related to Subversion s authentication and
336. s or let s get crazy shall we you could even implement an email based protocol Subversion supplies the APIs you supply the creativity Client Layer On the client side the Subversion working copy is where all the action takes place The bulk of functionality imple mented by the client side libraries exists for the sole purpose of managing working copies directories full of files and other subdirectories which serve as a sort of local editable reflection of one or more repository locations and propagating changes to and from the Repository Access layer Subversion s working copy library libsvn_wc is directly responsible for managing the data in the working copies To accomplish this the library stores administrative information about each working copy directory within a special subdirectory This subdirectory named svn is present in each working copy directory and contains various other files and directories which record state and provide a private workspace for administrative action For those familiar with CVS this svn subdirectory is similar in purpose to the CVs administrative directories found in CVS working copies For more information about the svn administrative area see Section Inside the Working Copy Adminis tration Area in this chapter The Subversion client library libsvn_client has the broadest responsibility its job is to mingle the functionality of the working copy library with that of the Reposi
337. s an internal MKACTIVITY CHECKOUT PUT and CHECKIN A generic log message is auto generated and a new filesystem revi sion is created Because so many operating systems already have integrated WebDAV abilities the use case for this feature borders on fantastical imagine an office of ordinary users running Microsoft Windows or Mac OS Each computer mounts the Subversion repository which appears to be an ordinary network share They use the server as they always do open files from the server edit them and save them back to the server But in this fantasy the server is automati cally versioning everything Later on a sysadmin can use a Subversion client to search and retrieve all older ver sions 251 WebDAV and Autoversioning Is this fantasy real Not quite The main snag is that Subversion 1 0 has no support whatsoever for the WebDAV LOCK or UNLOCK methods Most operating system DAV clients attempt to LOCK a resource opened directly from a DAV mounted network share For now users may have to copy a file from the DAV share to local disk edit the file then copy it back again Not ideal autoversioning but still doable The mod_dav_lock Alternative The mod_dav Apache module is a complex beast it understands and parses all of the WebDAV and DeltaV meth ods yet it depends on a back end provider to access the resources themselves In its simplest incarnation a user can use mod_dav_fs as a provider for mod
338. s are out of date with respect to others work A typical Subversion repository often holds the files or source code for several projects usually each project is a subdirectory in the repository s filesystem tree In this arrangement a user s working copy will usually correspond to a particular subtree of the repository For example suppose you have a repository that contains two software projects paint and calc Each project lives in its own top level subdirectory as shown in Figure 2 6 Figure 2 6 The repository s filesystem 13 Basic Concepts EN 7 Makefile i integer c button c paint i Makefile Canvas 7 brush c To get a working copy you must check out some subtree of the repository The term check out may sound like it has something to do with locking or reserving resources but it doesn t it simply creates a private copy of the project for you For example if you check out calc you will get a working copy like this svn checkout http svn example com repos calc calc calc Makefile calc integer c calc button c PPP PH ls A calc Makefile integer c button c svn The list of letter A s indicates that Subversion is adding a number of items to your working copy You now have a personal copy of the repository s calc directory with one additional entry svn which holds the extra infor mation needed by Subversion as mentioned earlier Repository URLs Subversion repositor
339. s only a branch because you attach that meaning to it You may think of the directory differently or treat it differently but to Subversion it s just an ordinary directory that happens to have been created by copy ing Copying Changes Between Branches Now you and Sally are working on parallel branches of the project you re working on a private branch and Sally is working on the trunk or main line of development For projects that have a large number of contributors it s common for most people to have working copies of the trunk Whenever someone needs to make a long running change that is likely to disrupt the trunk a standard proce dure is to create a private branch and commit changes there until all the work is complete So the good news is that you and Sally aren t interfering with each other The bad news is that it s very easy to drift too far apart Remember that one of the problems with the crawl in a hole strategy is that by the time you re fin ished with your branch it may be near impossible to merge your changes back into the trunk without a huge number of conflicts Instead you and Sally might continue to share changes as you work It s up to you to decide which changes are worth sharing Subversion gives you the ability to selectively copy changes between branches And when you re completely finished with your branch your entire set of branch changes can be copied back into the trunk Copying Specific Cha
340. s opaque URLs passing from client to server asks mod_dav_svn to decode them and then possibly vetoes requests based on access policies defined in a configuration file If you ve built Subversion from source code mod_authz_svn is automatically built and installed alongside mod_dav_svn Many binary distributions install it automatically as well To verify that it s installed correctly make sure it comes right after mod_dav_svn s LoadModule directive in httpd conf LoadModule dav_module modules mod_dav so LoadModule dav_svn_module modules mod_dav_svn so LoadModule authz_svn_module modules mod_authz_svn so To activate this module you need to configure your Location block to use the AuthzSVNAccessFile directive which specifies a file containing the permissions policy for paths within your repositories In a moment we ll dis cuss the format of that file Apache is flexible so you have the option to configure your block in one of three general patterns To begin choose one of these basic configuration patterns The examples below are very simple look at Apache s own documenta tion for much more detail on Apache authentication and authorization options The simplest block is to allow open access to everyone In this scenario Apache never sends authentication chal lenges so all users are treated as anonymous Example 6 1 A sample configuration for anonymous access lt Location repos gt DAV svn SVNParentPath usr local sv
341. s to that file have been committed to the reposi tory since its working revision A svn commit of the file will do nothing and an svn update of the file will do nothing Locally changed and current The file has been changed in the working directory and no changes to that file have been committed to the repository since its base revision There are local changes that have not been committed to the repository thus an svn commit of the file will succeed in publishing your changes and an svn update of the file will do noth ing Unchanged and out of date The file has not been changed in the working directory but it has been changed in the repository The file should eventually be updated to make it current with the public revision An svn commit of the file will do nothing and an svn update of the file will fold the latest changes into your working copy Locally changed and out of date The file has been changed both in the working directory and in the repository An svn commit of the file will fail with an out of date error The file should be updated first an svn update command will attempt to merge the public changes with the local changes If Subversion can t complete the merge in a plausible way automati cally it leaves it to the user to resolve the conflict This may sound like a lot to keep track of but the svn status command will show you the state of any item in your working copy For more information on that command see Se
342. saction is complete but before it is committed Typically this hook is used to protect against commits that are disallowed due to content or location for example your site might require that all commits to a certain branch include a ticket number from the bug tracker or that the incoming log message is non empty The repository passes two arguments to this program the path to the repository and the name of the transaction being committed If the program returns a non zero exit value the commit is aborted and the transaction is removed 63 Repository Administration The Subversion distribution includes some access control scripts located in the too1s hook scripts direc tory of the Subversion source tree that can be called from pre commit to implement fine grained access con trol At this time this is the only method by which administrators can implement finer grained access control beyond what Apache s httpd conf offers In a future version of Subversion we plan to implement access con trol lists ACLs directly in the filesystem post commit This is run after the transaction is committed and a new revision is created Most people use this hook to send out descriptive emails about the commit or to make a backup of the repository The repository passes two argu ments to this program the path to the repository and the new revision number that was created The exit code of the program is ignored The Subversion distribution inc
343. scape this root tunnel t Causes svnserve to run in tunnel mode which is just like the inetd mode of operation serve one connection over stdin stdout except that the connection is considered to be pre authenticated with the username of the cur rent uid This flag is selected by the client when running over a tunnel agent such as ssh threads T When running in daemon mode causes svnserve to spawn a thread instead of a process for each connection The svnserve process still backgrounds itself at startup time listen once X Causes svnserve to accept one connection on the svn port serve it and exit This option is mainly useful for de bugging 237 Appendix A Subversion for CVS Users This appendix is a guide for CVS users new to Subversion It s essentially a list of differences between the two sys tems as viewed from 10 000 feet For each section we provide backreferences to relevant chapters when possible Although the goal of Subversion is to take over the current and future CVS user base some new features and design changes were required to fix certain broken behaviors that CVS had This means that as a CVS user you may need to break habits ones that you forgot were odd to begin with Revision Numbers Are Different Now In CVS revision numbers are per file This is because CVS uses RCS as a backend each file has a corresponding RCS file in the repository and the repository is roughly la
344. scover the proper URL the procedure involves issuing a series of WebDAV PROPFIND requests and understanding DeltaV concepts This is something your web browser simply can t do So to answer the question one obvious way to see older revisions of files and directories is by passing the revision argument to the svn list and svn cat commands To browse old revisions with your web browser how ever you can use third party software A good example of this is ViewCVS http viewcvs sourceforge net ViewCVS was originally written to display CVS repositories through the web and the latest bleeding edge versions at the time of writing are able to understand Subversion repositories as well Other Features Several of the features already provided by Apache in its role as a robust Web server can be leveraged for increased functionality or security in Subversion as well Subversion communicates with Apache using Neon which is a generic HTTP WebDAV library with support for such mechanisms as SSL the Secure Socket Layer discussed ear lier and Deflate compression the same algorithm used by the gzip and PKZIP programs to shrink files into smaller chunks of data You need only to compile support for the features you desire into Subversion and Apache and properly configure the programs to use those features Deflate compression places a small burden on the client and server to compress and decompress network transmis sions as a way to m
345. se tigris org Subversion plugin for the Eclipse IDE Svn Up http svnup tigris org Java based GUI for Subversion and plugin for the IDEA IDE TortoiseSVN http tortoisesvn tigris org Subversion client implemented as a Microsoft Windows shell extension WorkBench http pysvn tigris org Cross platform Python based software development GUI built on Subversion Language Bindings 255 Third Party Tools PySVN http pysvn tigris org Object oriented Python bindings for the Subversion client API Subversion http subversion tigris org Python Perl and Java bindings to Subversion API mirroring the core C API SVNCPP http rapidsvn tigris org C object oriented bindings for the Subversion client API Repository Converters cvs2svn http cvs2svn tigris org CVS to Subversion conversion Subversion VCP Plugin http svn clkao org revml branches svn perl VCP plugin for CVS to Subversion Higher Level Tools Kwiki http www kwiki org Wiki with a Subversion backup backend Subissue http subissue tigris org Track issues directly in your Subversion repository Subwiki nttp subwiki tigris org Wiki that uses Subversion for its data repository svk http svk elixus org Decentralized version control system based on Subversion submaster http www rocklinux org submaster html System for distributed software development based on Subversion Repository Browsing Tools SV
346. seful to people of widely different backgrounds from people with no previous experience in version control to experienced sysadmins Depending on your own background certain chapters may be more or less important to you The following can be considered a recommended reading list for various types of readers Experienced sysadmins The assumption here is that you ve probably used CVS before and are dying to get a Subversion server up and running ASAP Chapters 5 and 6 will show you how to create your first repository and make it available over xiii Preface the network After that s done chapter 3 and appendix A are the fastest routes to learning the Subversion client while drawing on your CVS experience New users Your administrator has probably set up Subversion already and you need to learn how to use the client If you ve never used a version control system like CVS then chapters 2 and 3 are a vital introduction If you re already an old hand at CVS chapter 3 and appendix A are the best place to start Advanced users Whether you re a user or administrator eventually your project will grow larger You re going to want to learn how to do more advanced things with Subversion such as how to use branches and perform merges chapter 4 how to use Subversion s property support how to configure runtime options chapter 7 and other things Chap ters 4 and 7 aren t vital at first but be sure to read them once you re comfortabl
347. shown in Figure 2 2 Suppose we have two co workers Harry and Sally They each decide to edit the same repository file at the same time If Harry saves his changes to the repository first then it s possible that a few moments later Sally could accidentally overwrite them with her own new version of the file While Harry s version of the file won t be lost forever because the system remembers every change any changes Harry made won t be present in Sally s newer version of the file because she never saw Harry s changes to begin with Harry s work is still effectively lost or at least missing from the latest version of the file and probably by accident This is definitely a situation we want to avoid Figure 2 2 The problem to avoid lwo users read the same file They both begin to edit their copies Repository Repository Es A Read Read Es E is a i Harry Sally Harry Sally Horry publishes his version first Sally accidentally overwrites Horry3 version Repository Repository T i Sally Harry The Lock Modify Unlock Solution Many version control systems use a lock modify unlock model to address this problem In such a system the reposi tory allows only one person to change a file at a time First Harry must lock the file before he can begin making changes to it Locking a file is a lot like borrowing a book from the library if Harry has locked a file then Sally can not make any changes to it If she tries to
348. siness in some sense the mod_dav_svn is now lying to the WebDAV client It claims to accept the LOCK request but in reality the lock isn t being enforced at all levels If a second WebDAV client at tempts to LOCK the same resource then mod_dav_lock will notice and correctly deny the request But there s abso lutely nothing preventing an ordinary Subversion client from changing the file via a normal svn commit If you use this technique you re giving users the opportunity to stomp on each others changes In particular a WebDAV client might accidentally overwrite a change committed by regular svn client On the other hand if you set up your environment very carefully you may mitigate the risk For example if all of your users are working though basic WebDAV clients rather than svn clients then things should be fine Autoversioning Interoperability In this section we ll describe the most common generic WebDAV clients at the time of writing and how well they operate against a mod_dav_svn server using the SVNAutoversioning directive RFC 2518 is a bit large and per haps a bit too flexible Every WebDAV client behaves slightly differently and creates slightly different problems 46Subversion may someday develop a reserved checkout locking model that can live peaceably with copy modify merge but it probably won t happen soon 252 WebDAV and Autoversioning Win32 WebFolders Windows 98 2000 and XP have an integrated WebDAV
349. sion between the cvs status and cvs update commands The cvs status command has two purposes first to show the user any local modifications in the working copy and second to show the user which files are out of date Unfortunately because of CVS s hard to read status output many CVS users don t take advantage of this command at all Instead they ve developed a habit of running cvs up or Cvs up n to quickly see their mods If users forget to use the n option this has the side effect of merging reposi tory changes they may not be ready to deal with With Subversion we ve tried to remove this muddle by making the output of svn status easy to read for both hu mans and parsers Also svn update only prints information about files that are updated not local modifications svn status prints all files that have local modifications By default the repository is not contacted While this sub command accepts a fair number of options the following are the most commonly used ones t Contact the repository to determine and then display out of dateness information Vi Show all entries under version control 239 Subversion for CVS Users N Run non recursively do not descend into subdirectories The status command has two output formats In the default short format local modifications look like this svn status M foo c M bar baz c If you specify the show updates u switch a longer output format is us
350. sk space reclaimed 214 Subversion Complete Reference Name svnadmin load Read a dumpfile formatted stream from stdin svnadmin load Synopsis svnadmin load REPOS_PATH Description Read a dumpfile formatted stream from stdin committing new revisions into the repository s filesystem Send progress feedback to stdout Switches quiet sq ignore uuid force uuid parent dir Example This shows the beginning of loading a repository from a backup file made of course with svn dump svnadmin load usr local svn restored lt repos backup lt lt lt Started new txn based on original revision 1 adding path test done adding path test a done Or if you want to load into a subdirectory svnadmin load parent dir new subdir for project usr local svn restored lt repos backup lt lt lt Started new txn based on original revision 1 adding path test done adding path test a done 215 Subversion Complete Reference Name svnadmin Istxns Print the names of all uncommitted transactions svnadmin Istxns Synopsis svnadmin lstxns REPOS_PATH Description Print the names of all uncommitted transactions See Section Repository Cleanup for information on how un committed transactions are created and what you should do with them Examples List all outstanding transactions in a repository svnadmin lst
351. ss writ Notice that svnserve only understands blanket access control A user either has universal read write access uni versal read access or no access There is no detailed control over access to specific paths within the repository For many projects and sites this level of access control is more than adequate However if you need per directory ac cess control you ll need to use Apache instead of svnserve as your server process SSH authentication and authorization svnserve s built in authentication can be very handy because it avoids the need to create real system accounts On the other hand some administrators already have well established SSH authentication frameworks in place In these situations all of the project s users already have system accounts and the ability to SSH into the server machine It s easy to use SSH in conjunction with svnserve The client simply uses the svn ssh URL schema to connect whoami harry svn list svn ssh host example com repos project harry host example com s password foo bar baz What s happening here is that the Subversion client is invoking a local ssh process connecting to host example com authenticating as the user harry then spawning a private svnserve process on the remote machine running as the user harry The svnserve command is being invoked in tunnel mode t and all network protocol is being tunneled over the encrypted connection by ssh
352. ss ESEE pe ven EKAR op vennincs ATS EE EE ENDRE ESEE 1 SUDVErSIO SFeat tes sson ie ae i E ET E a PERT E ERE A TEN E E e R E a 2 Subversion s Archena ri than E e a eo ea ue Rab eg A E dabas 3 Installine SUDversiO tia ls CE ee Bk ne A EE S nade ees 4 Subversion COMPONEN S ssi erne gosh e eE EER ER sop E ASA EEE EE N EEE 5 A Quick SE A A A it SA 5 2 Basic CONCEP tS esis rito praia irte osa The Repository ccoo aii er E Ai ered ss Un ee 8 Versioning Models ccoo scscd snails sotet ass ri isos EEI GESE tros adas 8 The Problem of File Sharing cennin a ae e EE EEE EE E a 9 The Lock Modify Unlock Solution ooccocccoccnnccnnconnccnnccnnconoconoconncnnnrnnnrnnronnrnnncnnccnncinninnn 9 The Copy Modify Merge Solution prsne eian eona ee ea E EE eE EErEE ENEE EREE Y 11 Subversion in A COM Srei aoon nia 12 Working COPIES viscosa oiis 13 REVISIONS senenn ce deh Mag ETS ede o SEA Saws Dag toes bbs 16 How Working Copies Track the Repository 2 2 0 0 cece cece cece nec c eee e cen eeneceeeeeeeeeeeeeeeaeseaeeeges 18 The Limitations of Mixed Revisions oocooccoconccnconccnconcnnconconcnnconcnnconcnnroncrnroncnnroncnnroncnnroncnns 18 SUMMALY O NS 19 IEC ecos Heliconia ree aaa EAS 20 PO cities ele 20 Revisions Numbers Keywords and Dates Oh My cee ceceeeceec nec eenece cetera eeeeeaeeeeraeeeeaeeeeaeenes 20 Revision NUMDBETS ie 20 REVISION KEY WOLdS Siria a ri ici 20 Revision Dates nl ta ti 21 Initial Checkout its Pa Siete bees E E E N ias
353. ss to your repository e regular system users using a Subversion client as themselves to access the repository directly via file URLs e regular system users connecting to SSH spawned private svnserve processes running as themselves which ac cess the repository e an svnserve process either a daemon or one launched by inetd running as a particular fixed user 103 Server Configuration e an Apache httpd process running as a particular fixed user The most common problem administrators run into is repository ownership and permissions Does every process or user in the previous list have the rights to read and write the Berkeley DB files Assuming you have a Unix like op erating system a straightforward approach might be to place every potential repository user into a new svn group and make the repository wholly owned by that group But even that s not enough because a process may write to the database files using an unfriendly umask one that prevents access by other users So the next step beyond setting up a common group for repository users is to force every repository accessing pro cess to use a sane umask For users accessing the repository directly you can make the svn program into a wrapper script that first sets umask 002 and then runs the real svn client program You can write a similar wrapper script for the svnserve program and add a umask 002 command to Apache s own startup script apachect 1 For example
354. st version of the Subversion source code into a subdirec tory named subversion in your current working directory Obviously you can adjust that last argument as you see fit Regardless of what you call the new working copy directory though after this operation completes you will now have the Subversion source code Of course you will still need to fetch a few helper libraries apr apr util etc see the INSTALL file in the top level of the working copy for details Become Familiar with Community Policies Make Now that you have a working copy containing the latest Subversion source code you will most certainly want to take a cruise through the HACKING file in that working copy s top level directory The HACKING file contains general instructions for contributing to Subversion including how to properly format your source code for consistency with the rest of the codebase how to describe your proposed changes with an effective change log message how to test your changes and so on Commit privileges on the Subversion source repository are earned a government by meri tocracy 39 The HACKING file is an invaluable resource when it comes to making sure that your proposed changes earn the praises they deserve without being rejected on technicalities and Test Your Changes With the code and community policy understanding in hand you are ready to make your changes It is best to try to make smaller but related sets of changes even tackling l
355. stem TOPS 20 break case 11 sprintf info gt operating_system NTFS Windows NT break case 12 sprintf info gt operating_system QDOS break 164 7 164 7 QR low unsigned short read_byte gzfile read LSB high unsigned short read_byte gzfile read MSB high high lt lt 8 interpret MSB correctly total low high add them togethe for correct total total low high add them together for correct total info gt extra_header unsigned char my_malloc total 47 Branching and Merging fread info gt extra_header total 1 gzfile 241 7 241 7 Store the offset with ftell if info gt data_offset ftell gzfile 1 printf error ftell retturned 1 n printf error ftell returned 1 n exit 1 249 7 249 7 QA printf I believe start of compressed data is u n info gt data_offset tendif Set postion eight bytes from the end of the file Set position eight bytes from the end of the file if fseek gzfile 8 SEEK_END printf error fseek returned non zero n The svn merge is almost exactly the same Instead of printing the differences to your terminal however it applies them directly to your working copy as local modifications svn merge r 343 344 http svn example com repos calc trunk U integer c svn status M integer c The
356. stem itself that such things become visible or interesting Most of the functionality provided by the filesystem interface comes as an action that occurs on a filesystem path That is from outside of the filesystem the primary mechanism for describing and accessing the individual revisions of files and directories comes through the use of path strings like foo bar just as if you were addressing files and directories through your favorite shell program You add new files and directories by passing their paths to be to the right API functions You query for information about them by the same mechanism Unlike most filesystems though a path alone is not enough information to identify a file or directory in Subversion Think of a directory tree as a two dimensional system where a node s siblings represent a sort of left and right mo tion and descending into subdirectories a downward motion Figure 8 1 shows a typical representation of a tree as exactly that Figure 8 1 Files and directories in two dimensions Of course the Subversion filesystem has a nifty third dimension that most filesystems do not have Time 34 In the filesystem interface nearly every function that has a path argument also expects a root argument This svn_fs_root_t argument describes either a revision or a Subversion transaction which is usually just a revision to be and provides that third dimensional context needed to understand the difference between foo bar
357. stem library to offer increased functionality and configurable option support Repository Access Layer If the Subversion Repository Layer is at the other end of the line the Repository Access Layer is the line itself Charged with marshalling data between the client libraries and the repository this layer includes the libsvn_ra mod ule loader library the RA modules themselves which currently includes libsvn_ra_dav libsvn_ra_local and lib svn_ra_svn and any additional libraries needed by one or more of those RA modules such as the mod_dav_svn Apache module with which libsvn_ra_dav communicates or libsvn_ra_svn s server svnserve Since Subversion uses URLs to identify its repository resources the protocol portion of the URL schema usually file http https or svn is used to determine which RA module will handle the communications Each module registers a list of the protocols it knows how to speak so that the RA loader can at runtime determine which module to use for the task at hand You can determine which RA modules are available to the Subversion command line client and what protocols they claim to support by running svn version svn version svn version 1 0 1 r9023 compiled Mar 17 2004 09 31 13 Copyright C 2000 2004 CollabNet Subversion is open source software see http subversion tigris org This product includes software developed by CollabNet http www Collab Net The following repos
358. subcommand in the pair svnadmin load parses the standard input stream as a Subversion repository dump file and effectively replays those dumped revisions into the target repository for that operation It also gives informative feedback this time using the standard output stream svnadmin load newrepos lt dumpfile lt lt lt Started new txn based on original revision 1 adding path A done adding path A B done SS gt Committed new rev 1 loaded from original rev 1 gt gt gt lt lt lt Started new txn based on original revision 2 editing path A mu done editing path A D G rho done 2 3 Committed new rev 2 loaded from original rev 2 gt gt gt lt lt lt Started new txn based on original revision 25 editing path A D gamma done A aaa a Committed new rev 25 loaded from original rev 25 gt gt gt lt lt lt Started new txn based on original revision 26 78 Repository Administration adding path A Z zeta done editing path A mu done AAA Committed new rev 26 loaded from original rev 26 gt gt gt Note that because svnadmin uses standard input and output streams for the repository dump and load process peo ple who are feeling especially saucy can try things like this perhaps even using different versions of svnadmin on each side of the pipe svnadmin create newrepos svnadmin dump myrepos svnadmin load newrepos We mentioned
359. svn propget svn log revprop r 20 Began journal 190 Subversion Complete Reference Name svn proplist List all properties svn proplist Synopsis svn proplist PATH svn proplist revprop r REV URL Description List all properties on files directories or revisions The first form lists versioned properties in your working copy while the second lists unversioned remote properties on a repository revision Alternate Names plist pl Changes Working copy repository only if operating on a URL Accesses Repository Only if operating on a URL Switches verbose v recursiv R revisi n r REV quiet a revprop username USER password PASS no auth cach non interactiv config dir DIR Examples You can use proplist to see the properties on an item in your working copy svn proplist foo c Properties on foo c svn mime type svn keywords owner 191 Subversion Complete Reference But with the verbose flag svn proplist is extremely handy as it also shows you the values for the properties svn proplist verbose foo c Properties on foo c svn mime type text plain svn keywords Author Date Rev owner sally 192 Subversion Complete Reference Name svn propset Set PROPNAME to PROPVAL on files directories or revisions svn propset Synopsis svn propset PROPNAME PROPVAL F VALFILE PATH
360. t and replay transactions until the data is re stored to a usable state See Section Managing Disk Space for more about Berkeley DB logfiles But every rose has its thorn and so we must note some known limitations of Berkeley DB First Berkeley DB envi ronments are not portable You cannot simply copy a Subversion repository that was created on a Unix system onto a Windows system and expect it to work While much of the Berkeley DB database format is architecture indepen dent there are other aspects of the environment that are not Secondly Subversion uses Berkeley DB in a way that will not operate on Windows 95 98 systems if you need to house a repository on a Windows machine stick with Windows 2000 or Windows XP Finally you should never keep a Subversion repository on a network share While Berkeley DB promises to behave correctly on network shares that meet a particular set of specifications almost no known shares actually meet all those specifications 61 Repository Administration Repository Creation and Configuration Creating a Subversion repository is an incredibly simple task The svnadmin utility provided with Subversion has a subcommand for doing just that To create a new repository just run svnadmin create path to repos This creates a new repository in the directory path to repos This new repository begins life at revision 0 which is defined to consist of nothing but the top level root filesyst
361. t the evs2svn py utility see Section Converting a Repository from CVS to Subversion uses the dump format to represent the contents of a CVS repository so that those contents can be moved in a Subversion repository Repository Backup Despite numerous advances in technology since the birth of the modern computer one thing unfortunately rings true with crystalline clarity sometimes things go very very awry Power outages network connectivity dropouts cor rupt RAM and crashed hard drives are but a taste of the evil that Fate is poised to unleash on even the most consci entious administrator And so we arrive at a very important topic how to make backup copies of your repository data There are generally two types of backup methods available for Subversion repository administrators incremental and full We discussed in an earlier section of this chapter how to use svnadmin dump incremental to perform an incremental backup see Section Migrating a Repository Essentially the idea is to only backup at a given time the changes to the repository since the last time you made a backup A full backup of the repository is quite literally a duplication of the entire repository directory which includes the Berkeley database environment Now unless you temporarily disable all other access to your repository simply do ing a recursive directory copy runs the risk of generating a faulty backup since someone might be currently writ
362. t hcogentane 144 SvnSuUbCOMMANS es A HU eee aes 147 SVMAGMIN osito odio oie ren dassG ne uses eeths sev edadesnstemeadessaseaseshotasoseedeaawessriaa gas 206 Svnadmin S Witches cucuta ico inde E ceases tse HOS Govee Sods E EEE EEEE R See 206 svnadminSubcommadds sisses niero e inae oe EE pte sete E eT sek ratita E EEEa 207 O A EE E A A E 220 SVMOOK Switches irrin esre asen eon airin eSEE PIPERS TESA ETE ERE O ERa E E EPPS E ASOTIR EEE EES E 220 O AEE E E E E E EE E E E E ton cose 221 A A A E AE A EA EAEI N A 236 SVISELVE OWIICHES eucpora tirita pones i E R EEE EAE RE AEE SEER E S 236 A Subversion Tor CV S Users iia E EE di E a qa backed r E ES Revision Numbers Are Different NOW oooccooccnnconnconoconoconoconononoroncnnnrnnnrnnccnnccnncrnnconnconncrnncnnanonnss 238 Directory Vers1ons aa A A ds 238 More Disconnected Operations ecosport testeo des spuwanes roce wom eran canicas NEE SE REEE SEER 239 Distinction Between Status and Update oocoooccnnconcconoconoconoconocnnocnnconncnnncnnccnnccnnccnnccnnconnconncnnciniss 239 Branches and Tags siste te plebe dro tried 240 Metadata Properties ii A is 241 Conflict Resolution 5 o c siis ies oir roer DESE PE web otahess AE REET Manges 241 Binary Eilles and Translations 2 28200 siveassase CI bee cae eii 241 Versioned Modules seiscientos abia oracion 241 vi Version Control with Subversion Authentic ds a ain od acetal ed Ost eel ols at vag 242 Converting a Repository from CVS to Subve
363. t hooks and may not even trigger the pre revprop change and post revprop change hooks 17 And since you can change revision properties without respect to chronological order you can change any revision s properties at any time an incremental backup of the latest few revisions might not catch a property modification to a revision that was included as part of a previous backup Generally speaking only the truly paranoid would need to backup their entire repository say every time a commit occurred However assuming that a given repository has some other redundancy mechanism in place with relatively fine granularity like per commit emails a hot backup of the database might be something that a repository admin istrator would want to include as part of a system wide nightly backup For most repositories archived commit emails alone provide sufficient redundancy as restoration sources at least for the most recent few commits But it s your data protect it as much as you d like Often the best approach to repository backups is a diversified one You can leverage combinations of full and incre mental backups plus archives of commit emails The Subversion developers for example back up the Subversion source code repository after every new revision is created and keep an archive of all the commit and property change notification emails Your solution might be similar but should be catered to your needs and that delicate bal ance of convenience
364. t it you can manually inspect and modify it Of course the downside is that if you have two years worth of repository activity encapsulated in what is likely to be a very large dumpfile it could take you a long long time to manually inspect and modify it While it won t be the most commonly used tool at the administrator s disposal svndumpfilter provides a very par ticular brand of useful functionality the ability to quickly and easily modify that dumpfile data by acting as a path based filter Simply give it either a list of paths you wish to keep or a list of paths you wish to not keep then pipe your repository dump data through this filter The result will be a modified stream of dump data that contains only the versioned paths you explicitly or implicitly requested The syntax of svndumpfilter is as follows svndumpfilter help general usage svndumpfilter SUBCOMMAND ARGS amp OPTIONS Type svndumpfilter help lt subcommand gt for help on a specific subcommand Available subcommands exclude include help h There are only two interesting subcommands They allow you to make the choice between explicit or implicit inclu sion of paths in the stream exclude Filter out a set of paths from the dump data stream 13That by the way is a feature not a bug 69 Repository Administration include Allow only the requested set of paths to pass through the dump data stream Let s look a realistic example
365. t li brary can be accessed via the SWIG bindings In just a few lines of Python you can check out a fully functional Subversion working copy Example 8 3 A Simple Script to Check Out a Working Copy usr bin env python import sys from svn import util _util _client def usage print Usage sys argv 0 URL PATH n sys exit 0 def run url path Initialize APR and get a POOL _util apr_initialize pool util svn_pool_create None Checkout the HEAD of URL into PATH silently _client svn_client_checkout None None url path 1 1 None pool Cleanup our POOL and shut down APR util svn_pool_destroy pool _util apr_terminate VE name _ main_ if len sys argv 3 usage run sys argv 1 sys argv 2 Subversion s language bindings unfortunately tend to lack the level of attention given to the core Subversion mod ules However there have been significant efforts towards creating functional bindings for Python Perl and Java Once you have the SWIG interface files properly configured generation of the specific wrappers for all the sup ported SWIG languages which currently includes versions of CH Guile Java Mzscheme OCaml Perl PHP Python Ruby and Tcl should theoretically be trivial Still some extra programming is required to compensate for complex APIs that SWIG needs some help generalizing For more information on SWIG itself see the project s website at http www s
366. t markers are even present and then accidentally commit files containing conflict markers Subversion solves this problem by making conflicts more tangible It remembers that a file is in a state of conflict and won t allow you to commit your changes until you run svn resolved See Section Resolve Conflicts Merging Others Changes for more details Binary Files and Translation In the most general sense Subversion handles binary files more gracefully than CVS does Because CVS uses RCS it can only store successive full copies of a changing binary file But internally Subversion expresses differences be tween files using a binary differencing algorithm regardless of whether they contain textual or binary data That means that all files are stored differentially compressed in the repository and small differences are always sent over the network CVS users have to mark binary files with kb flags to prevent data from being garbled due to keyword expansion and line ending translations They sometimes forget to do this Subversion takes the more paranoid route first it never performs any kind of keyword or line ending translation un less you explicitly ask it do so see Section svn keywords and Section svn eol style for more details By de fault Subversion treats all file data as literal byte strings and files are always stored in the repository in an untrans lated state Second Subversion maintains an int
367. t revision or transaction You can change your current revision or transaction with the setrev and settxn commands re spectively As in a Unix shell you can use the 1s command to display the contents of the current directory and you can use the cat command to display the contents of a file Example 5 1 Using svnshell to Navigate the Repository lt rev 2 gt ls REV AUTHOR NODE REV ID SIZE DATE NAME 1 sally lt 2 0 1 gt Nov 15 11 50 A 2 harry lt 1 0 2 gt 56 Nov 19 08 19 iota lt rev 2 gt S cd A lt rev 2 A gt ls REV AUTHOR NODE REV ID SIZE DATE NAME 1 sally lt 4 0 1 gt Nov 15 11 50 B T sally lt a 0 1 gt Nov 15 11 50 C 1 sally lt b 0 1 gt Nov 15 11 50 D dl sally lt 3 O41 23 Nov 15 11 50 mu lt rev 2 A gt cd D G lt rev 2 A D G gt S ls REV AUTHOR NODE REV ID SIZE DATE NAME 1 sally lt e 0 1 gt 23 Nov 15 11 50 pi 1 sally lt 0 1 gt 24 Nov 15 11 50 rho 1 sally lt g 0 1 gt 24 Nov 15 11 50 tau lt rev 2 A gt cd lt rev 2 gt cat iota 72 Repository Administration This is the file iota Added this text in revision 2 lt rev 2 gt setrev 1 cat iota This is the file iota lt rev 1 gt exit As you can see in the previous example multiple commands may be specified at a single command prompt sepa rated by a semicolon Also the s
368. t the copies are related to one another It also helps you dupli cate changes from one branch to another Finally it can make portions of your working copy reflect different branches so that you can mix and match different lines of development in your daily work Using Branches At this point you should understand how each commit creates an entire new filesystem tree called a revision in the repository If not go back and read about revisions in Section Revisions 41 Branching and Merging For this chapter we ll go back to the same example from Chapter 2 Remember that you and your collaborator Sally are sharing a repository that contains two projects paint and calc Notice that in Figure 4 2 however each project directory now contains subdirectories named trunk and branches The reason for this will soon become clear Figure 4 2 Starting repository layout E DLL I E im H As before assume that Sally and you both have working copies of the calc project Specifically you each have a working copy of calc trunk All the files for the project are in this subdirectory rather than in calc itself be cause your team has decided that calc trunk is where the main line of development is going to take place Let s say that you ve been given the task of performing a radical reorganization of the project It will take a long time to write and will affect all the files in the project The pr
369. t users that are in the group allowed to access the repository Simply run svnadmin recover path to repos Once the command has completed check the permissions in the db directory of the repository Every time I try to run svn it says my working copy is locked Subversion s working copy just like Berkeley DB uses a journaling mechanism to perform all actions That is it logs everything it is about to do before it does so If svn is interrupted while performing an action then one or more lockfiles are left behind along with log files describing the unfinished actions svn status will show an L next to locked directories Any other process that attempts to access the working copy will fail when it sees the locks To awaken your working copy you need to tell the client to finish the work To fix this run this command from the top of your working copy svn cleanup 44Remember that the amount of detail you provide about your setup and your problem is directly proportional to the likelihood of getting an an swer from the mailing list You re encouraged to include everything short of what you had for breakfast and your mother s maiden name 243 Troubleshooting I m getting errors finding or opening a repository but know my repository URL is correct See Section Every time I try to access my repository my Subversion client just hangs You might also have a permissions problem opening the repository See Sec
370. tags are ordinary directo ries within the filesystem This is probably the single biggest mental hurdle a CVS user will need to climb Read all about it in Chapter 4 Branching and Merging Warning Since Subversion treats branches and tags as ordinary directories always remember to check out the trunk http svn example com repos calc trunk of your project and not the project itself http svn example com repos calc If you make the mistake of checking out the project itself you ll wind up with a working copy that contains a copy of your project for every branch and tag you have 43 43That is providing you don t run out of disk space before your checkout finishes 240 Subversion for CVS Users Metadata Properties A new feature of Subversion is that you can attach arbitrary metadata or properties to files and directories Prop erties are arbitrary name value pairs associated with files and directories in your working copy To set or get a property name use the svn propset and svn propget subcommands To list all properties on an ob ject use svn proplist For more information see Section Properties Conflict Resolution CVS marks conflicts with in line conflict markers and prints a C during an update Historically this has caused problems because CVS isn t doing enough Many users forget about or don t see the C after it whizzes by on their terminal They often forget that the conflic
371. ted or otherwise changed No modifications A Item is scheduled for Addition D Item is scheduled for Deletion M Item has been modified C Item is in conflict with updates received from the repository Item is related to an externals definition T Item is being ignored e g with the svn ignore property Item is not under version control sy Item is missing e g you moved or deleted it without using svn This also indicates that a directory is incom plete a checkout or update was interrupted Item is versioned as a directory but has been replaced by a file or vice versa The second column tells the status of a file s or directory s properties 199 Subversion Complete Reference No modifications M Properties for this item have been modified C Properties for this item are in conflict with property updates received from the repository The third column is populated only if the working copy directory is locked Item is not locked T Ttem is locked The fourth column is populated only if the item is scheduled for addition with history No history scheduled with commit History scheduled with commit The fifth column is populated only if the item is switched relative to its parent see Section Switching a Working Copy Item is a child of its parent directory IS Ttem is switched The out of date information appears in the eighth column only if you
372. that translate the datatypes native to your scripting language into the datatypes needed by Subversion s C libraries There is an obvious benefit to accessing the Subversion APIs via a language binding simplicity Generally speak ing languages such as Python and Perl are much more flexible and easy to use than C or C The sort of high level datatypes and context driven type checking provided by these languages are often better at handling information that comes from users As you know humans are proficient at botching up input to a program and scripting languages tend to handle that misinformation more gracefully Of course often that flexibility comes at the cost of perfor mance That is why using a tightly optimized C based interface and library suite combined with a powerful flexi ble binding language is so appealing Let s look at an example that uses Subversion s Python SWIG bindings Our example will do the same thing as our last example Note the difference in size and complexity of the function this time Example 8 2 Using the Repository Layer with Python from svn import fs import os path def crawl_filesystem_dir root directory pool Recursively crawl DIRECTORY under ROOT in the filesystem and return a list of all the paths at or below DIRECTORY Use POOL for all allocations Get the directory entries for DIRECTORY entries fs dir_entries root directory pool Initialize our returned list w
373. the developers of libcomplex release a new version of their library version 1 1 which contains some features and functionality that we really want We d like to upgrade to this new version but without losing the customizations we made to the existing version What we essentially would like to do is to replace our current base line version of libcomplex 1 0 with a copy of libcomplex 1 1 and then re apply the custom modifications we previ ously made to that library to the new version But we actually approach the problem from the other direction apply ing the changes made to libcomplex between versions 1 0 and 1 1 to our modified copy of it To perform this upgrade we checkout a copy of our vendor branch and replace the code in the current directory with the new libcomplex 1 1 source code We quite literally copy new files on top of existing files perhaps explod ing the libcomplex 1 1 release tarball atop our existing files and directories The goal here is to make our current directory contain only the libcomplex 1 1 code and to ensure that all that code is under version control Oh and we want to do this with as little version control history disturbance as possible After replacing the 1 0 code with 1 1 code svn status will show files with local modifications as well as perhaps some unversioned or missing files If we did what we were supposed to do the unversioned files are only those new files introduced in the 1 1 release of libcomplex
374. the directory doesn t yet have because no update has happened Therefore you are not allowed to com mit property changes on a directory unless the directory is up to date For more discussion about the limitations of directory versioning see Section The Limitations of Mixed Revisions More Disconnected Operations In recent years disk space has become outrageously cheap and abundant but network bandwidth has not Therefore the Subversion working copy has been optimized around the scarcer resource The svn administrative directory serves the same purpose as the cvs directory except that it also stores read only pristine copies of your files This allows you to do many things off line svn status Shows you any local changes you ve made see Section svn status svn diff Shows you the details of your changes see Section svn diff svn revert Removes your local changes see Section svn revert Also the cached pristine files allow the Subversion client to send differences when committing which CVS cannot do The last subcommand in the list is new it will not only remove local mods but it will un schedule operations such as adds and deletes It s the preferred way to revert a file running rm file svn update will still work but it blurs the purpose of updating And while we re on this subject Distinction Between Status and Update In Subversion we ve tried to erase a lot of the confu
375. ting commit home sally svn work sandwich txt remains in conflict If you get a conflict you need to do one of three things e Merge the conflicted text by hand by examining and editing the conflict markers within the file e Copy one of the temporary files on top of your working file e Run svn revert lt filename gt to throw away all of your local changes Once you ve resolved the conflict you need to let Subversion know by running svn resolved This removes the three temporary files and Subversion no longer considers the file to be in a state of conflict 4 svn resolved sandwich txt Resolved conflicted state of sandwich txt Merging Conflicts by Hand Merging conflicts by hand can be quite intimidating the first time you attempt it but with a little practice it can be come as easy as falling off a bike 4You can always remove the temporary files yourself but would you really want to do that when Subversion can do it for you We didn t think so 32 Guided Tour Here s an example Due to a miscommunication you and Sally your collaborator both edit the file sandwich txt at the same time Sally commits her changes and when you go to update your working copy you get a conflict and we re going to have to edit sandwich txt to resolve the conflicts First let s take a look at the file cat sandwich txt Top piece of bread Mayonnaise Lettuce Tomato Provolone lt lt lt lt lt lt lt mine Salami
376. ting to it 1t becomes a branch If you are administering a repository there are two approaches you can take to managing tags The first approach is hands off as a matter of project policy decide where your tags will live and make sure all users know how to treat the directories they copy in there That is make sure they know not to commit to them The second approach is more paranoid you can use one of the access control scripts provided with Subversion to prevent anyone from doing anything but creating new copies in the tags area See Chapter 6 Server Configuration The paranoid ap proach however isn t usually necessary If a user accidentally commits a change to a tag directory you can simply undo the change as discussed in the previous section This is version control after all Creating a Complex Tag Sometimes you may want your snapshot to be more complicated than a single directory at a single revision For example pretend your project is much larger than our calc example suppose it contains a number of subdirec tories and many more files In the course of your work you may decide that you need to create a working copy that is designed to have specific features and bugfixes You can accomplish this by selectively backdating files or direc tories to particular revisions using svn update r liberally or by switching files and directories to particular branches making use of svn switch When you re done your worki
377. tion Supporting Multiple Repository Access Methods How can I specify a Windows drive letter in a file URL See Repository URLs I m having trouble doing write operations to a Subversion repository over a network If import works fine over local access mkdir test touch test testfile svn import test file var svn test m Initial import Adding test testfile Transmitting file data Committed revision 1 But not from a remote host svn import test http svn red bean com test m Initial import harry s password XXXXXXX svn_error The specified activity does not exist We ve seen this when the REPOS dav directory is not writable by the httpd process Check the permissions to en sure that Apache httpd can write to the dav directory and to the corresponding db directory of course Under Windows XP the Subversion server sometimes seems to send out corrupted data You need to install Windows XP Service Pack 1 to fix a TCP IP stack bug in the operating system You can get all sorts of information about that Service Pack at http support microsoft com default aspx scid kb EN US q317949 What is the best method of doing a network trace of the conversation be tween a Subversion client and Apache server Use Ethereal to eavesdrop on the conversation Note The following instructions are specific to the graphical version of Ethereal and may not apply to the com mand line version w
378. to override svn commit force log file file under_vc txt foo c Sending foo c Transmitting file data Committed revision 6 To commit a file scheduled for deletion S svn commit m removed fil Ela Deleting c Committed revision 7 157 Subversion Complete Reference Name svn copy Copy a file or directory in a working copy or in the repository svn copy Synopsis svn copy SRC DST Description Copy a file in a working copy or in the repository SRC and DST can each be either a working copy WC path or URL WC gt WC Copy and schedule an item for addition with history WC gt URL Immediately commit a copy of WC to URL URL gt WC Check out URL into WC and schedule it for addition URL gt URL Complete server side copy This is usually used to branch and tag Note You can only copy files within a single repository Subversion does not support cross repository copying Alternate Names cp Changes Repository if destination is a URL Working copy 1f destination is a WC path Accesses Repository If source or destination is in the repository or if needed to look up the source revision number Switches message m TEXT file F FILE revision r REV 158 Subversion Complete Reference quiet a username USER password PASS no auth cach non interactiv force log editor cmd EDITOR encoding ENC config dir DIR
379. ton c and commit that change Assuming no other commits have taken place your commit will create revision 5 of the repository and your working copy will now look like this calc Makefile 4 integer c 4 button a Suppose that at this point Sally commits a change to integer c creating revision 6 If you use svn update to bring your working copy up to date then it will look like this 17 Basic Concepts calc Makefile 6 integer c 6 button c 6 Sally s changes to integer c will appear in your working copy and your change will still be present in button c In this example the text of Makefile is identical in revisions 4 5 and 6 but Subversion will mark your working copy Of Makefile with revision 6 to indicate that it is still current So after you do a clean update at the top of your working copy 1t will generally correspond to exactly one revision in the repository How Working Copies Track the Repository For each file in a working directory Subversion records two essential pieces of information in the svn adminis trative area e what revision your working file is based on this is called the file s working revision and e atimestamp recording when the local copy was last updated by the repository Given this information by talking to the repository Subversion can tell which of the following four states a working file is in Unchanged and current The file is unchanged in the working directory and no change
380. tory Access Layer and then to provide the highest level API to any application that wishes to perform general revision control actions For example the function svn_client_checkout takes a URL as an argument It passes this URL to the RA layer and opens an authenti cated session with a particular repository It then asks the repository for a certain tree and sends this tree into the working copy library which then writes a full working copy to disk svn directories and all The client library is designed to be used by any application While the Subversion source code includes a standard command line client it should be very easy to write any number of GUI clients on top of the client library New GUIs or any new client really for Subversion need not be clunky wrappers around the included command line client they have full access via the libsvn_client API to same functionality data and callback mechanisms that the command line client uses 133 Developer Information Binding Directly A Word About Correctness Why should your GUI program bind directly with a libsvn_client instead of acting as a wrapper around a command line program Besides simply being more efficient this can address potential correctness issues as well A com mand line program like the one supplied with Subversion that binds to the client library needs to effectively trans late feedback and requested data bits from C types to some form of human readable out
381. tory Converters esiste tanes EE EE o EREE A EE E EEE AEE EEEE EE 256 Higher evel Tool ee O a E EN ye E E Tues S 256 Repository Browsing TOONS scc4 cssaccseeacdsesh a dca E a sewed a E denia 256 E Oop e des A Ra A ES A vii List of Figures 1 1 Subversion s Architectute ev isscce sees rar e aE EEEE savas caps cia os PEISE SS CEES EPIRA ETER ase sebeee 3 2 1 A typical client server system coro isois a caves e Ee EE VREE E EAE EEEE E EESE AT RIERS 8 2 2 Fhe problem to ayoldi eanna ee e aa aa va E a E aaa EEE ride 9 2 3 The lock modify unlock solution ooocooccnccnnccnnccnnccnnccnnccnnccnnconnconnconncnnnrnnnrnnrrnnrnnnrnnncnnccnncconccnnions 10 2 4 The copy modify merge solution coocooccocnccnoconcnoconcnononcnorononoroncnoroncnnroncrnroncrnroncnnroncnnroncnnronenarones 11 2 5 The copy modify merge solution continued coocccccnnncnnccnnconnccnnccnnccnncnnnconncnnncnnrnnnrnnncnnccnncinnccnnions 11 2 6 The Teposttory s filesystem csi a ak a Naeem 13 2h THETEPOSILOLY NO 16 4 1 Branches of development cceceeceecceeeecceeceeeeeeeeeecserecaeeeeeaeeeeaseeeeasereeeereeeereeeseeeeeereseereees 41 4 2 Starting TEPOSitOLry layout spot ltda ratio das 42 4 3 Repository with NeW COPY 0 cc 2ccssereccns sgrsedoag vee EEE NEES susan secusag uves EENE TEER ES EIRE SE O eveveebeeees 44 4 4 The branching of one file s history svsicisceessccseck esaera sisar res Esson gasborsssneedebedesbecesdevvscnsspssovtesseedo
382. tory changes into your current working directory 2 You want to merge the changes in a specific file into a file by the same name which exists in your current working directory If you are merging a directory and haven t specified a target path svn merge assumes the first case above and tries to apply the changes into your current directory If you are merging a file and that file or a file by the same name exists in your current working directory svn merge assumes the second case and tries to apply the changes to a lo cal file with the same name If you want changes applied somewhere else you ll need to say so For example if you re sitting in the parent direc tory of your working copy you ll have to specify the target directory to receive the changes S svn merge r 343 344 http svn example com repos calc trunk my calc branch U my calc branch integer c Best Practices for Merging Tracking Merges Manually Merging changes sounds simple enough but in practice it can become a headache The problem is that if you repeat edly merge changes from one branch to another you might accidentally merge the same change twice When this happens sometimes things will work fine When patching a file Subversion typically notices if the file already has the change and does nothing But if the already existing change has been modified in any way you ll get a conflict Ideally your version control system should prevent the double application
383. u for it verbose v Requests that the client print out as much information as it can while running any subcommand This may result in Subversion printing out additional fields detailed information about every file or additional information re garding its actions version Prints the client version info This information not only includes the version number of the client but also a list ing of all repository access modules that the client can use to access a Subversion repository xml Prints output in XML format svn Subcommands 147 Subversion Complete Reference Name svn add Add files and directories svn add Synopsis svn add PATH Description Add files and directories to your working copy and schedule them for addition to the repository They will be up loaded and added to the repository on your next commit If you add something and change your mind before com mitting you can unschedule the addition using svn revert Alternate Names None Changes Working Copy Switches targets FILENAME non recursiv N quiet a config dir DIR auto props no auto props Examples To add a file to your working copy svn add foo c A foo c When adding a directory the default behavior of svn add is to recurse svn add testdir A testdir A testdir a A testdir b A testdir c A testdir d You can add a directory without adding its contents 148 S
384. u want to view readme txt in your repository without checking it out svn cat http svn red bean com repos test readme txt This is a README file You should read this Tip If your working copy is out of date or you have local modifications and you want to see the H1 EAD revision of a file in your working copy svn cat will automatically fetch the HEAD revision when you give it a path cat foo c 151 Subversion Complete Reference This file is in my local working copy and has changes that I ve made svn cat foo c Latest revision fresh from the repository 152 Subversion Complete Reference Name svn checkout Check out a working copy from a repository svn checkout Synopsis svn checkout URL PATH Description Check out a working copy from a repository If PATH is omitted the basename of the URL will be used as the desti nation If multiple URLs are given each will be checked out into a subdirectory of PATH with the name of the sub directory being the basename of the URL Alternate Names co Changes Creates a working copy Accesses Repository Yes Switches revision r REV quiet q non recursiv N username USER password PASS no auth cach non interactiv config dir DIR Examples Check out a working copy into a directory called mine svn checkout file tmp repos test min A mine a A mi
385. ual opportunity Officially their task was to write a book top down starting from a table of contents and an initial draft But they also had access to a steady stream indeed an uncontrollable geyser of bottom up source material Subversion was already in the hands of thousands of early adopters and those users were giving tons of feedback not only about Subversion but about its existing documentation During the entire time they wrote this book Ben Mike and Brian haunted the Subversion mailing lists and chat rooms incessantly carefully noting the problems users were having in real life situations Monitoring such feedback is part of their job descriptions at CollabNet anyway and it gave them a huge advantage when they set out to docu ment Subversion The book they produced is grounded firmly in the bedrock of experience not in the shifting sands of wishful thinking it combines the best aspects of user manual and FAQ sheet This duality might not be noticeable on a first reading Taken in order front to back the book is simply a straightforward description of a piece of soft ware There s the overview the obligatory guided tour the chapter on administrative configuration some advanced topics and of course a command reference and troubleshooting guide Only when you come back to it later seeking the solution to some specific problem does its authenticity shine out the telling details that can only result from en counters with the un
386. ubversion Complete Reference svn add non recursive otherdir A otherdir 149 Subversion Complete Reference Name svn blame Show author and revision information in line for the specified files or URLs svn blame Synopsis svn blame TARGET Description Show author and revision information in line for the specified files or URLs Each line of text is annotated at the be ginning with the author username and the revision number for the last change to that line Alternate Names praise annotate ann Changes Nothing Accesses Repository Yes Switches revision r REV username USER password PASS no auth cach non interactiv config dir DIR Examples If you want to see blame annotated source for readme txt in your test repository svn blame http svn red bean com repos test readme txt 3 sally This is a README file 5 harry You should read this 150 Subversion Complete Reference Name svn cat Output the contents of the specified files or URLs svn cat Synopsis svn cat TARGET Description Output the contents of the specified files or URLs For listing the contents of directories see svn list Alternate Names None Changes Nothing Accesses Repository Yes Switches revision r REV username USER password PASS no auth cach non interactiv config dir DIR Examples If yo
387. uirements meii renne aer ninio a linia oasbihewebous des diia 134 Using Languages Other than C and C o oo ccc cecc cece nce eeceeceeeceeeeeeeeeeesaeseaeeeu sean sean scans 135 Inside the Working Copy Administration Area ooocooccnnccnnconoconeconcnnncnnnnnnconoronccnnconnccnnccnnconnconicnnnss 137 The Entries Piles csv tiv tal ietec betes thctinelt E A react E Uys cdegabaeucdinny estoi edit 137 Pristine Coples and Property Files cu cotesniicta tebe agente vhs eea adams sna tace ds buaden desea toageueadeusduedans syuecs 138 WebDAV oirr nr aran dd 138 Programming with Memory Pools i s rpii resser rade ponte serio dins toser PaE PE Sr SEERE E PISOS ESERE ESPOR ERETTE 139 Contributing to Subversion c ccoociciconntocinin err aes ra EEES E ETEK SDE SS E EEE SIE EE Esi 141 J in the COMMUNITY bemol a E E a 141 Get the Source Codes c2 sisseccsshaweeeseistece snuse EE EENES EEEE ER vous conserved EPEE E EEEIEE EES ERINO ESSEKS EEE 141 Become Familiar with Community Policies oooconocnnccnnccnnnnnncnnncnnocnnconnconnconnccnncnnncnnncnnncnnnos 142 Make and Test Y our Changes sisanra e e E E EEEa a des EE S 142 Donat Your Chan ges 233 sete veces LO iD taa 143 9 Subversion Complete Reference yey ern ssnges davon ireren rece EE ua doo EEEE PEE OEE EEE Weeden pacien The Subversion Command Line Client svn 0 cee c cence ence eeceeeceeecaeeea seca cena eeue een eeneeeeeeees 144 SVN S Witches wise sah hoes sodawn sy eth sa lios iria tii il abe
388. uments expect those paths to be canonicalized and encoded in UTF 8 This means for example that any new client binary that drives the libsvn_client interface needs to first convert paths from the locale specific encoding to UTF 8 before passing those paths to the Subversion libraries and then re convert any resultant output paths from Subversion back into the locale s encoding before using those paths for non Subversion purposes Fortunately Sub version provides a suite of functions see subversion include svn_utf h that can be used by any program to do these conversions Also Subversion APIs require all URL parameters to be properly URl encoded So instead of passing file home username My File txt as the URL of a file named My File txt you need to pass file home username My 20File txt Again Subversion supplies helper functions that your application can use svn_path_uri_encode and svn_path_uri_decode for URI encoding and decoding respectively Using Languages Other than C and C If you are interested in using the Subversion libraries in conjunction with something other than a C program say a Python script or Java application Subversion has some initial support for this via the Simplified Wrapper and In terface Generator SWIG The SWIG bindings for Subversion are located in subversion bindings swig and are slowly maturing into a usable state These bindings allow you to call Subversion API functions indirectly using wrappers
389. ur own project This scenario plays itself out all the time anywhere that the information generated by one group of people has a direct effect on that which is generated by another group For example software developers might be working on an application which makes use of a third party library Sub version has just such a relationship with the Apache Portable Runtime library see Section The Apache Portable Runtime Library The Subversion source code depends on the APR library for all its portability needs In earlier stages of Subversion s development the project closely tracked APR s changing API always sticking to the bleed ing edge of the library s code churn Now that both APR and Subversion have matured Subversion attempts to 121 Advanced Topics synchronize with APR s library API only at well tested stable release points Now if your project depends on someone else s information there are several ways that you could attempt to syn chronize that information with your own Most painfully you could issue oral or written instructions to all the con tributors of your project telling them to make sure that they have the specific versions of that third party informa tion that your project needs If the third party information is maintained in a Subversion repository you could also use Subversion s externals definitions to effectively pin down specific versions of that information to some loca tion in your
390. ur changes into her working copy as well as any others that have been com mitted since she checked it out pwd home sally calc ls A svn Makefile integer c button c svn update U button c The output from the svn update command indicates that Subversion updated the contents of button c Note that Sally didn t need to specify which files to update Subversion uses the information in the svn directory and further information in the repository to decide which files need to be brought up to date Revisions An svn commit operation can publish changes to any number of files and directories as a single atomic transaction In your working copy you can change files contents create delete rename and copy files and directories and then commit the complete set of changes as a unit In the repository each commit is treated as an atomic transaction either all the commit s changes take place or none of them take place Subversion tries to retain this atomicity in the face of program crashes system crashes network problems and other users actions Each time the repository accepts a commit this creates a new state of the filesystem tree called a revision Each re vision is assigned a unique natural number one greater than the number of the previous revision The initial revision of a freshly created repository is numbered zero and consists of nothing but an empty root directory Figure 2 7 illustrates a nice way to visuali
391. urce Code Subversion s Components Subversion once installed has a number of different pieces The following is a quick overview of what you get Don t be alarmed if the brief descriptions leave you scratching your head there are plenty more pages in this book devoted to alleviating that confusion svn The command line client program svnversion A program for reporting the state in terms of revisions of the items present of a working copy svnlook A tool for inspecting a Subversion repository svnadmin A tool for creating tweaking or repairing a Subversion repository svndumpfilter A program for filtering Subversion repository dumpfile format streams mod_dav_svn A plug in module for the Apache HTTP Server used to make your repository available to others over a net work svnserve A custom standalone server program runnable as a daemon process or invokable by SSH another way to make your repository available to others over a network Assuming you have Subversion installed correctly you should be ready to start The next two chapters will walk you through the use of svn Subversion s command line client program A Quick Start Some people have trouble absorbing a new technology by reading the sort of top down approach provided by this book This section is a very short introduction to Subversion and is designed to give bottom up learners a fighting chance If you re one of those folks who prefers to learn by e
392. us command more than any other Subversion command CVS Users Hold That Update You re probably used to using cvs update to see what changes you ve made to your working copy svn status will give you all the information you need regarding what has changed in your working copy without accessing the repository or potentially incorporating new changes published by other users In Subversion update does just that it updates your working copy with any changes committed to the repository since the last time you ve updated your working copy You ll have to break the habit of using the update command to see what local modifications you ve made If you run svn status at the top of your working copy with no arguments it will detect all file and tree changes you ve made This example is designed to show all the different status codes that svn status can return Note that the text following in the following example is not actually printed by svn status svn status L abc c svn has a lock in its svn directory for abc c M bar c the content in bar c has local modifications M baz c baz c has property but no content modifications X 3rd_party this dir is part of an externals definition foo o svn doesn t manage foo o l some_dir svn manages this but it s either missing or incomplete qux versioned as dir but is file or vice versa I screenrc this file is ignored Ain moved_dir added with history of where it came from M
393. use svn merge to apply revision 808 in reverse We ve already discussed how to undo changes see Section Undoing Changes This would have the effect of re adding real c as a local modification The file would be scheduled for addition and after a commit the file would again exist in HEAD In this particular example however this is probably not the best strategy Reverse applying revision 808 would not only schedule real c for addition but the log message indicates that it would also undo certain changes to inte ger c which you don t want Certainly you could reverse merge revision 808 and then svn revert the local modi 9The Subversion project has plans however to someday implement an svnadmin obliterate command that would accomplish the task of perma nently deleting information In the meantime see Section svndumpfilter for a possible workaround 10Because CVS doesn t version trees it creates an Att ic area within each repository directory as a way of remembering deleted files 54 Branching and Merging fications to integer c but this technique doesn t scale well What if there were 90 files changed in revision 808 A second more targeted strategy is not to use svn merge at all but rather the svn copy command Simply copy the exact revision and path coordinate pair from the repository to your working copy svn copy revision 807 http svn example com repos calc trunk real c real c
394. using the svn diff command By default Subversion uses an internal differencing library setting this option will cause it to perform this task using an external program diff3 cmd This specifies the absolute path of a three way differencing program Subversion uses this program to merge changes made by the user with those received from the repository By default Subversion uses an internal differ encing library setting this option will cause it to perform this task using an external program diff3 has program arg This flag should be set to true if the program specified by the dif 3 cmd option accepts a diff program command line parameter The tunnels section allows you to define new tunnel schemes for use with svnserve and svn client connec tions For more details see Section SSH authentication and authorization The miscellany section is where everything that doesn t belong elsewhere winds up 26 In this section you can find global ignores When running the svn status command Subversion lists unversioned files and directories along with the ver sioned ones annotating them with a character see Section svn status Sometimes it can be annoying to see uninteresting unversioned items for example object files that result from a program s compilation in this display The global ignores option is a list of whitespace delimited globs which describe the names of files and directories that Subversion should not d
395. ve two different types of information e a server certificate e ademand for a client certificate 23While self signed server certificates are still vulnerable to a man in the middle attack such an attack is still much more difficult for a casual observer to pull off compared to sniffing unprotected passwords 96 Server Configuration If the client receives a server certificate it needs to verify that it trusts the certificate is the server really who it claims to be The OpenSSL library does this by examining the signer of the server certificate or certifying authority CA If OpenSSL is unable to automatically trust the CA or if some other problem occurs such as an expired cer tificate or hostname mismatch the Subversion commandline client will ask you whether you want to trust the server certificate anyway S svn list https host example com repos project Error validating server certificate for https home example com 443 The certificate is not issued by a trusted authority Use the fingerprint to validate the certificate manually Certificate information Hostname host example com Valid from Jan 30 19 23 56 2004 GMT until Jan 30 19 23 56 2006 GMT Issuer CA example com Sometown California US Fingerprint d el a9 34 33 39 ba 6a e9 a5 c4 22 98 7b 76 5c 92 a0 9c 7b R eject accept t emporarily or accept p ermanently This dialogue should look familiar it s essentially the sa
396. ve your old repositories out of the way and create new empty ones in their place using your new svnadmin 4 Again using your new svnadmin load your dump files into their respective just created repositories 5 Finally be sure to copy any customizations from your old repositories to the new ones including DB_CONFIG files and hook scripts You ll want to pay attention to the release notes for the new release of Subversion to see if any changes since your last upgrade affect those hooks or configuration options svnadmin dump will output a range of repository revisions that are formatted using Subversion s custom filesystem dump format The dump format is printed to the standard output stream while informative messages are printed to the standard error stream This allows you to redirect the output stream to a file while watching the status output in your terminal window For example svnlook youngest myrepos 26 svnadmin dump myrepos gt dumpfile Dumped revision 0 Dumped revision 1 Dumped revision 2 E Dumped revision 25 Dumped revision 26 At the end of the process you will have a single file dumpfile in the previous example that contains all the data stored in your repository in the requested range of revisions Note that svnadmin dump is reading revision trees from the repository just like any other reader process would svn checkout for example So it s safe to run this command at any time The other
397. vide two key benefits First by storing the currently supported vendor drop in your own version control system the members of your project never need to question whether they have the right version of the ven dor s data They simply receive that correct version as part of their regular working copy updates Secondly because the data lives in your own Subversion repository you can store your custom changes to it in place you have no more need of an automated or worse manual method for swapping in your customizations General Vendor Branch Management Procedure Managing vendor branches generally works like this You create a top level directory such as vendor to hold the vendor branches Then you import the third party code into a subdirectory of that top level directory You then copy that subdirectory into your main development branch for example trunx at the appropriate location You always make your local changes in the main development branch With each new release of the code you are tracking you bring it into the vendor branch and merge the changes into trunk resolving whatever conflicts occur between your local changes and the upstream changes Perhaps an example will help to clarify this algorithm We ll use a scenario where your development team is creating a calculator program that links against a third party complex number arithmetic library libcomplex We ll begin with the initial creation of the vendor branch and the import
398. vision given by the For each updated item a line will start with a character reporting the action taken These characters have the follow ing meaning A Added D Deleted U Updated C Conflict G Merged A character in the first column signifies an update to the actual file while updates to the file s properties are shown in the second column Alternate Names up Changes Working copy Accesses Repository Yes Switches 205 Subversion Complete Reference revision r non recursi quiet a diff3 cmd C username US password PA vV D ER SS no auth cac n REV N non interactiv config dir DIR Examples Pick up repository changes that have happened since your last update svn update newdir toggle c newdir lau ne N C newdir READM A A newdir disclose c A D U pdated to revision 32 You can also update your working copy to an older revision Subversion doesn t have the concept of sticky files like CVS does see Appendix A Subversion for CVS Users svn update r30 newdir READM newdir toggle c newdir lau foo c ne A D D newdir disclose c D U U N C pdated to revision 30 Tip If you want to examine an older revision of a single file you may want to use svn cat svnadmin svnadmin is the administrative tool for monitoring and repairing your Subversion repos
399. vn Switches The Subversion repository stores log messages in UTF8 and assumes that your log message is written using your operating system s native locale You should specify a dif ferent encoding if your commit messages are written in any other encoding use commit times Normally your working copy files have timestamps that reflect the last time they were touched by any process whether that be your own editor or by some svn subcommand This is generally convenient for people develop ing software because build systems often look at timestamps as a way of deciding which files need to be re compiled In other situations however it s sometimes nice for the working copy files to have timestamps that reflect the last time they were changed in the repository The svn export command always places these last commit timestamps on trees that it produces By setting this config variable to yes the svn checkout svn update svn switch and svn revert commands will also set last commit timestamps on files that they touch Properties We ve already covered in detail how Subversion stores and retrieves various versions of files and directories in its repository Whole chapters have been devoted to this most fundamental piece of functionality provided by the tool And if the versioning support stopped there Subversion would still be complete from a version control perspective But it doesn t stop there In addition to versioning your directories
400. wig org 136 Developer Information Inside the Working Copy Administration Area As we mentioned earlier each directory of a Subversion working copy contains a special subdirectory called svn which houses administrative data about that working copy directory Subversion uses the information in svn to keep track of things like e Which repository location s are represented by the files and subdirectories in the working copy directory e What revision of each of those files and directories are currently present in the working copy e Any user defined properties that might be attached to those files and directories e Pristine un edited copies of the working copy files While there are several other bits of data stored in the svn directory we will examine only a couple of the most important items The Entries File Perhaps the single most important file in the svn directory is the entries file The entries file is an XML docu ment which contains the bulk of the administrative information about a versioned resource in a working copy direc tory It is this one file which tracks the repository URLs pristine revision file checksums pristine text and property timestamps scheduling and conflict state information last known commit information author revision timestamp local copy history practically everything that a Subversion client is interested in knowing about a versioned or to be versioned resource Comparing
401. with verbose Each log message is printed just once even if more than one of the affected paths for that revision were explicitly requested Logs follow copy history by default Use stop on copy to disable this behavior which can be useful for determining branch points Alternate Names None Changes Nothing Accesses Repository Yes Switches revision r REV quiet q verbose v targets FILENAME stop on Ccopy incremental xml username USER 175 Subversion Complete Reference password PASS no auth cach non interactiv config dir DIR Examples You can see the log messages for all the paths that changed in your working copy by running svn log from the top svn log r20 harry 2003 01 17 22 56 19 0600 Fri 17 Jan 2003 1 line Tweak r17 sally 2003 01 16 23 21 19 0600 Thu 16 Jan 2003 2 lines Examine all log messages for a particular file in your working copy svn log foo c r32 sally 2003 01 13 16 43 13 0600 Mon 13 Jan 2003 1 line Added defines r28 sally 2003 01 07 21 48 33 0600 Tue 07 Jan 2003 3 lines If you don t have a working copy handy you can log a URL S svn log http svn red bean com repos test foo c r32 sally 2003 01 13 16 43 13 0600 Mon 13 Jan 2003 1 line Added defines 2003 3 lines r28 sally 2003 01 07 21 48 33 0600 Tue 07 Jan If you want several distinct paths underneat
402. with paranoia And while all of this might not save your hardware from the iron fist of Fate 18 it should certainly help you recover from those trying times Adding Projects Once your repository is created and configured all that remains is to begin using it If you have a collection of exist ing data that is ready to be placed under version control you will more than likely want to use the svn client pro gram s import subcommand to accomplish that Before doing this though you should carefully consider your long term plans for the repository In this section we will offer some advice on how to plan the layout of your 17svnadmin setlog can be called in a way that bypasses the hook interface altogether 18You know the collective term for all of her fickle fingers 81 Repository Administration repository and how to get your data arranged in that layout Choosing a Repository Layout While Subversion allows you to move around versioned files and directories without any loss of information doing so can still disrupt the workflow of those who access the repository often and come to expect things to be at certain locations Try to peer into the future a bit plan ahead before placing your data under version control By laying out the contents of your repositories in an effective manner the first time you can prevent a load of future headaches There are a few things to consider when setting up Subversion repositories
403. work Introduction Efficient branching and tagging The cost of branching and tagging need not be proportional to the project size Subversion creates branches and tags by simply copying the project using a mechanism similar to a hard link Thus these operations take only a very small constant amount of time Hackability Subversion has no historical baggage it is implemented as a collection of shared C libraries with well defined APIs This makes Subversion extremely maintainable and usable by other applications and languages Subversion s Architecture Figure 1 1 illustrates what one might call a mile high view of Subversion s design Figure 1 1 Subversion s Architecture Introduction Client interface oO EB A A A A A A A Re Working copy management Client library library Repository access Subversion repository On one end is a Subversion repository that holds all of your versioned data On the other end is your Subversion client program which manages local reflections of portions of that versioned data called working copies Be tween these extremes are multiple routes through various Repository Access RA layers Some of these routes go across computer networks and through network servers which then access the repository Others bypass the network altogether and access the repository directly Installing Subversion Subversion is built on a portability layer called APR the Apache Port
404. xns usr local svn repos 1w 1x 216 Subversion Complete Reference Name svnadmin recover Recover any lost state in a repository svnadmin recover Synopsis svnadmin recover REPOS_PATH Description Run this command if you get an error indicating that your repository needs to be recovered Examples Recover a hung repository svnadmin recover usr local svn repos Acquiring exclusive lock on repository db Recovery is running please stand by Recovery completed The latest repos revision is 34 217 Subversion Complete Reference Name svnadmin rmtxns Delete transactions from a repository svnadmin rmtxns Synopsis svnadmin rmtxns REPOS_PATH TXN_NAME Description Delete outstanding transactions from a repository This is covered in detail in Section Repository Cleanup quiet q Examples Remove named transactions svnadmin rmtxns usr local svn repos lw 1x Fortunately the output of svn Istxns works great as the input for rmtxns svnadmin rmtxns usr local svn repos svnadmin lstxns usr local svn repos Which will remove all uncommitted transactions from your repository 218 Subversion Complete Reference Name svnadmin setlog Set the log message on a revision svnadmin setlog Synopsis svnadmin setlog REPOS_PATH r REVISION FILE Description Set the log message on revision REVISION to the contents o
405. xperimentation the following demonstration will get you up and running Along the way we give links to the relevant chapters of this book If you re new to the entire concept of version control or to the copy modify merge model used by both CVS and Subversion then you should read Chapter 2 Basic Concepts before going any further 5 Introduction Note The following example assumes that you have svn the Subversion commandline client and svnadmin the administrative tool ready to go It also assumes that your svn client has been compiled against Berkeley DB To verify this run svn version and make sure the ra_local module is available Without this mod ule the client cannot access file URLs Subversion stores all versioned data in a central repository To begin create a new repository svnadmin create path to repos ls path to repos conf dav db format hooks locks README txt This command creates a new directory path to repos which contains a Subversion repository Make sure that this directory lives on a local disk not a network share This new directory mainly contains a collection of Berkeley DB database files You won t see your versioned files if you peek inside For more information about repository cre ation and maintenance see Chapter 5 Repository Administration Next create a tree of files and directories to import into the repository For reasons that will be clear later on see
406. y USER PASS no auth cac nN non interac no diff del tiv ted config dir DIR Examples Compare BAS E and your working copy one of the most popular uses of svn diff svn diff COMMITTERS Index COMMITTERS COMMITTERS revision 4404 COMMITTERS working copy See how your working copy s modifications compare against an older revision svn diff r 3900 COMMITTERS Index COMMITTERS COMMITTERS revision 3900 COMMITTERS working copy Compare revision 3000 to revision 3500 using syntax svn diff http svn collab net repos svn trunk COMMITTERS 3000 http svn collab net repos svn tru Index COMMITTERS COMMITTERS revision 3000 COMMITTERS revision 3500 Compare revision 3000 to revision 3500 using range notation you only pass the one URL in this case 164 Subversion Complete Reference svn diff r 3000 3500 http svn collab net repos svn trunk COMMITTERS Index COMMITTERS COMMITTERS revision 3000 COMMITTERS revision 3500 Compare revision 3000 to revision 3500 of all files in trunk using range notation svn diff r 3000 3500 http svn collab net repos svn trunk Compare revision 3000 to revision 3500 of only three files in t runk using range notation svn diff r 3000 3500 old http svn collab net
407. y property value you probably do not want to supply that value on the com mand line So the propset subcommand takes a file F option for specifying the name of a file which contains the new property value svn propset license F path to LICENSE calc button c property license set on calc button c In addition to the propset command the svn program supplies the propedit command This command uses the con figured editor program see Section Config to add or modify properties When you run the command svn in vokes your editor program on a temporary file that contains the current value of the property or which is empty 1f you are adding a new property Then you just modify that value in your editor program until it represents the new 111 Advanced Topics value you wish to store for the property save the temporary file and then exit the editor program If Subversion de tects that you ve actually changed the existing value of the property it will accept that as the new property value If you exit your editor without making any changes no property modification will occur svn propedit copyright calc button c exit the editor without changes No changes to property copyright on calc button c We should note that as with other svn subcommands those related to properties can act on multiple paths at once This enables you to modify properties on whole sets of files with a single command For
408. y regardless of whether other processes are using the repository Switches clean logs 212 Subversion Complete Reference Name svnadmin list dblogs Ask Berkeley DB which log files exist for a given svn repository svnadmin list dblogs Synopsis svnadmin list dblogs REPOS_PATH Description Berkeley DB creates logs of all changes to the repository which allow it to recover in the face of catastrophe Un less you enable DB_LOGS_AUTOREMOVE the log files accumulate although most are no longer used and can be deleted to reclaim disk space See Section Managing Disk Space for more information 213 Subversion Complete Reference Name svnadmin list unused dblogs Ask Berkeley DB which log files can be safely deleted svnadmin list unused dblogs Synopsis svnadmin list unused dblogs REPOS_PATH Description Berkeley DB creates logs of all changes to the repository which allow it to recover in the face of catastrophe Un less you enable DB_LOGS_AUTOREMOVE the log files accumulate although most are no longer used and can be deleted to reclaim disk space See Section Managing Disk Space for more information Examples Remove all unused log files from a repository svnadmin list unused dblogs path to repos path to repos log 0000000031 path to repos log 0000000032 path to repos log 0000000033 svnadmin list unused dblogs path to repos xargs rm di
409. y is granted in the following order on a Win dows system 1 Command line options 2 The per user INI files 3 The per user Registry values 4 The system wide INI files 5 The system wide Registry values Also the Windows Registry doesn t really support the notion of something being commented out However Sub version will ignore any option key whose name begins with a hash character This allows you to effectively com ment out a Subversion option without deleting the entire key from the Registry obviously simplifying the process of restoring that option The svn command line client never attempts to write to the Windows Registry and will not attempt to create a de fault configuration area there You can create the keys you need using the REGEDIT program Alternatively you can create a reg file and then double click on that file from the Explorer shell which will cause the data to be merged into your registry Example 7 1 Sample Registration Entries reg File REGEDIT4 106 Advanced Topics HKEY_LOCA EY_LOCA MACHINE Software Tigris org Subversion Servers groups MACHINE Software Tigris org Subversion Servers global ttp proxy host ttp proxy port PPV VDVVA ttp proxy username ttp proxy password ttp proxy exceptions ttp timeout 0 http compression yes neon debug mas ssl authority files k
410. y itself Deltification involves encoding the representation of a chunk of data as a collection of differ ences against some other chunk of data If the two pieces of data are very similar this deltification results in storage savings for the deltified chunk rather than taking up space equal to the size of the original data it only takes up enough space to say I look just like this other piece of data over here except for the following couple of changes Specifically each time a new version of a file is committed to the repository Subversion encodes the previous ver sion actually several previous versions as a delta against the new version The result is that most of the repository data that tends to be sizable namely the contents of versioned files is stored at a much smaller size than the orig inal fulltext representation of that data Note Because all of the Subversion repository data that is subject to deltification is stored in a single Berkeley DB database file reducing the size of the stored values will not necessarily reduce the size of the database file itself Berkeley DB will however keep internal records of unused areas of the database file and use those areas first before growing the size of the database file So while deltification doesn t produce immedi ate space savings it can drastically slow future growth of the database Repository Recovery In order to protect the data in your repository the datab
411. you for both a path to the certificate and the password which protects it S svn list https host example com repos project Authentication realm https host example com 443 Client certificate filename path to my cert p12 Passphrase for path to my cert pl2 Notice that the client certificate is a p12 file To use a client certificate with Subversion it must be in PKCS 12 format which is a portable standard Most web browsers are already able to import and export certificates in that format Another option is to use the OpenSSL commandline tools to convert existing certificates into PKCS 12 Again the runtime servers file allows you to automate this challenge on a per host basis Either or both pieces of information can be described in runtime variables groups 97 Server Configuration xamplehost host example com examplehost ssl client cert fil path to my cert p12 ssl1 client cert password somepassword Once you ve set the ss1 client cert file and ss1 client cert password variables the Subversion client can automatically respond to a client certificate challenge without prompting you 24 Authorization Options At this point you ve configured authentication but not authorization Apache is able to challenge clients and con firm identities but it has not been told how to allow or restrict access to the clients bearing those identities This sec tion describes two strategies for
412. you re already familiar with Subver sion s basic concepts Chapter 2 Basic Concepts What s a Branch Suppose it s your job to maintain a document for a division in your company a handbook of some sort One day a different division asks you for the same handbook but with a few parts tweaked for them since they do things slightly differently What do you do in this situation You do the obvious thing you make a second copy of your document and begin maintaining the two copies separately As each department asks you to make small changes you incorporate them into one copy or the other You often want to make the same change to both copies For example if you discover a typo in the first copy it s very likely that the same typo exists in the second copy The two documents are almost the same after all they only differ in small specific ways This is the basic concept of a branch namely a line of development that exists independently of another line yet still shares a common history if you look far enough back in time A branch always begins life as a copy of some thing and moves on from there generating its own history see Figure 4 1 Figure 4 1 Branches of development 3rd branch 1st branch Original line of development nd branch time Subversion has commands to help you maintain parallel branches of your files and directories It allows you to cre ate branches by copying your data and remembers tha
413. yourfile Committed revision 15 Here s an example of how to force deletion of a file that has local mods svn delete over ther svn Attempting restricted operation for modified resource svn Us force to override this restriction svn over there has local modifications svn delet force over ther D over there 162 Subversion Complete Reference Name svn diff Display the differences between two paths svn diff Synopsis svn diff r N M old OLD TGT new NEW TGT PATH svn diff r N M URL svn diff r N M URL1 N URL2 M Description Display the differences between two paths The three different ways you can use svn diff are svn diff r N M old OLD TGT new NEW TGT PATH displays the differences between OLD TGT and NEW TGT If PATHs are given they are treated as relative to OLD TGT and NEW TGT and the output is restricted to differences in only those paths OLD TGT and NEW TGT may be working copy paths or URL REV OLD TGT de faults to the current working directory and NEW TGT defaults to OLD TGT N defaults to BASE or if OLD TGT is a URL to HEAD M defaults to the current working version or if NEW TGT is a URL to HEAD svn diff r N sets the re vision of OLD TGT to N svn diff r N M also sets the revision of NEW TGT to M svn diff r N M URL is shorthand for svn diff r N M old URL new URL svn diff r N M URL1 N URL2 EM is shorth
414. ywords on a particular file we again turn to the property related subcommands The svn keywords property when set on a versioned file controls which keywords will be substi tuted on that file The value is a space delimited list of the keyword names or aliases found in the previous table For example say you have a versioned file named weather txt that looks like this Here is the latest report from the front lines SLastChangedDate SRevS Cumulus clouds are appearing more frequently as summer approaches With no svn keywords property set on that file Subversion will do nothing special Now let s enable substitution of the LastChangedDate keyword svn propset svn keywords LastChangedDate Author weather txt property svn keywords set on weather txt Now you have made a local property modification on the weather txt file You will see no changes to the file s contents unless you made some of your own prior to setting the property Notice that the file contained a keyword anchor for the Rev keyword yet we did not include that keyword in the property value we set Subversion will hap pily ignore requests to substitute keywords that are not present in the file and will not substitute keywords that are not present in the svn keywords property value Keywords and Spurious Differences The user visible result of keyword substitution might lead you to think that every version of a file with that feature in use differs from the
415. ze the repository Imagine an array of revision numbers starting at 0 stretching from left to right Each revision number has a filesystem tree hanging below it and each tree is a snap shot of the way the repository looked after each commit Figure 2 7 The repository 16 Basic Concepts Global Revision Numbers Unlike those of many other version control systems Subversion s revision numbers apply to entire trees not indi vidual files Each revision number selects an entire tree a particular state of the repository after some committed change Another way to think about it is that revision N represents the state of the repository filesystem after the Nth commit When a Subversion user talks about revision 5 of foo c they really mean foo c as it appears in revi sion 5 Notice that in general revisions N and M of a file do not necessarily differ Because CVS uses per file revi sions numbers CVS users might want to see Appendix A Subversion for CVS Users for more details It s important to note that working copies do not always correspond to any single revision in the repository they may contain files from several different revisions For example suppose you check out a working copy from a repository whose most recent revision is 4 calc Makefile 4 integer c 4 button c 4 At the moment this working directory corresponds exactly to revision 4 in the repository However suppose you make a change to but

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