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1. ping yahoo com check Internet connection traceroute yahoo com trace IP packets S ifconfig check host config route n check routing config dig dns server com host dom a mx any less check host dom DNS records by dns server com for a fa mx any record ipchains L n less check packet filter 2 2 kernel iptables L n less check packet filter 2 4 kernel netstat a find all open ports netstat 1 inet find listening ports netstat ln tcp find listening TCP ports numeric 8 6 30 Flush mail from local spool To flush mail from the local spool exim q flush waiting mail exim qf flush all mail exim qff flush even frozen mail qff may be better as an option in the etc ppp ip up d exim script For Sarge replace exim with exim4 8 6 31 Remove frozen mail from local spool To remove frozen mail from the local spool with a delivery error message exim Mg mailq grep frozen awk print 3 J For Sarge replace exim with exim4 8 6 32 Redeliver mbox contents You need to manually deliver mails to the sorted mailboxes in your home directory from var mail username if your home directory became full and procmail failed After making disk space in the home directory run Chapter 8 Debian tips 127 etc init d exim stop formail s procmail lt var mail username etc init d exim start For Sarge replace exim with exim
2. 109 Oe We nd oa ee Bene ee BR eG Be Ee ae Ole wo eee ee a eae 110 Oe os iG a ee ERE ERE EES e eS RS 110 SDA A 646 Cob SEH RSH Ge BS CHE Be aaar oe 110 Doel o 2 4 2 be 2 ace de RAN 111 cea a ko oad ale Ba RA ESE EE ESAS E OHSS 111 Differential backup and data synchronization o ooo o 111 8 4 1 Differential backup with rdiff lt lt os esse a 112 8 4 2 Daily backup with pdumpfS coc es eon ea oo ro coa w aoa aie E aa 112 8 4 3 Regular differential backup with RCS naaa as 112 Systemi Meez recovery oo aa taak Da k IA 112 Sl AQUA PICOS o mre moei ew eS Ce A A A eS 112 Boe AWSR oa i ye HORS ka e d e p A A it BS 113 Nifty litle commands t remember as soom a ra E 113 Od PIE e eel ee opi RIS OPES OEE OR EE Be E AUE ot eS 113 Othe o s 6 na eee bee ee Yb eed ee ee aE BO 113 SGo Sore BIOS ascii Esa BaD ee ee A OE ROS ee A 114 864 Set me NTP o bat ee bw ES bees Ed ees EEE SS 114 8 6 5 How to control console features such as the screensaver 115 8 6 6 Searchadministrative database ooo a aw ee ew ROS 115 8 67 Disable sound beep e ae ds we oe tbe pa anpa aiak eee A Rd 115 8 6 8 Error messages on the console screen 2 ee eee 115 Bho Del console lo Mie CONECTO cia ORR RSD EER HS 116 CONTENTS ix 8 6 10 Get the console back to a sane state o o ooo 116 6 611 Converta text file from DOS to Unix style a lt o 4444 6044 mires 116 8 6 12 Convert a text file with recodo
3. You need to provide your own main and yywrap or your program 1 should look like this to compile without a library yywrap is a macro Soption main turns on option noyywrap implicitly option main A Ae n ECHO ae 0 o Alternatively you may compile with the 1 1 linker option at the end of your cc command line like AT amp T Lex with 11 No option is needed in this case Chapter 13 Programming 234 13 7 4 Bison a better Yacc Several packages provide a Yacc compatible LALR parser generator in Debian e bison GNU LALR parser generator e byacc The Berkeley LALR parser generator e byyacc Backtracking parser generator based on byacc References for bison e info bison tutorial e bison 1 You need to provide your own main and yyerror main calls yyparse which calls yylex usually created with Flex A A oe oe 13 7 5 Autoconf autoconf is a tool for producing shell scripts that automatically configure software source code packages to adapt to many kinds of UNIX like systems using the entire GNU build sys tem autoconf produces the configuration script configure configure automatically creates a customized Makefile using the Makefile in template Compile and install a program Debian does not touch files in usr local see Supporting diversity on page 21 So if you compile a program from source install it into usr local so it will not inte
4. iface eth0 inet static address 192 168 0 111 netmask 255 255 255 0 gateway 192 168 0 1 dns search somedomain org dns nameservers 195 238 2 21 195 238 2 22 fdown Chapter 10 Network configuration 190 The argument somedomain org of the dns search option corresponds to the argument of a search optionin resolv conf 5 The arguments 195 238 2 21and195 238 2 22 of the dns nameservers option correspond to the arguments of nameserver options Other recognized options are dns domain and dns sortlist See Managing nameserver infor mation resolvconf on page 187 10 6 2 Configuring an interface using DHCP To configure an interface using DHCP edit etc network interfaces so that it includes a stanza like this iface ethO inet dhcp In order for this to work you must have installed one of the DHCP clients mentioned in Con figuring network interfaces using DHCP on page 188 10 6 3 Configuring a Wi Fi interface The wireless tools package includes a hook script etc network if pre up d wireless tools which makes it possible to configure Wi Fi 802 11a b g hardware be fore the interface is brought up Configuration is done using the iwconfig program see iwconfig 8 For each possible command parameter of iwconfig you can include an op tion in etc network interfaces named like that parameter with a wireless prefix For example to set the ESSID of eth0 to myessid and the encryptio
5. 1 3 Example scripts Example scripts http www debian org doc manuals debian reference examples which accompany this document in the debian reference en package are available in usr share doc Debian reference examples The initial in the filenames of hidden files is converted to underscore _ An additional extension has been added to filenames when several alternatives are provided 1 4 Basic setup If the system is installed with the bare minimum of packages and you want to make the best use of this document then it is advisable to execute the following commands in order to install other packages containing useful documents Chapter 1 Preface 3 apt get install info man db doc base dhelp apt apt utils auto apt A dpkg less mc ssh nano tiny elvis tiny vim sash kernel package manpages manpages dev doc debian doc linux text debian policy developers reference maint guide apt howto harden doc install doc libpam doc glibc doc samba doc exim doc cvsbook gnupg doc apt get install debian reference for Sarge do this too For Woody add exim doc html to the above list For Sarge replace exim doc with exim4 doc html and exim4 doc info 1 5 Basics of the Debian distributions Debian maintains three different distributions simultaneously These are e stable Most useful for a production server since it is only updated with security fixes See The stable di
6. configuration options for etc X11 Xsession See Xsession options 5 for an explanation of the available options Default enabled allow failsafe de de HE H allow user resources allow user xsession use ssh agent Default disabled enable them by uncommenting do not use x session manager do not use x window manager Without the above mentioned modification to the system gnome session and kdebase are the packages containing these X session managers Removing them allows X window manager to be a default Yack any better idea On a system where etc X11 Xsession options contains a line allow user xsession without preceding characters any user who defines xsession or Xsession will be able to customize the action of etc X11 Xsession The last command in the xsession file should use form of exec some window session manager to start your favorite X window session manager A good example of an xsession scriptis given at usr share doc xfree86 common examples xsession gz I use this to set the window manager screen access and language support for each user ac count See Starting an X session for a user on the current page Getting root in X on page 153 and Example for a multilingual X window system on page 170 If you wish to have several X client programs started automatically see X clients on page 147 examples and invoke them from xsess
7. Change the contents of etc pam d login as follows if you want insecure but passwordless console terminals at your own risk auth required pam_unix so nullok auth required pam_permit so Chapter 9 Tuning a Debian system 136 Similar tricks can be applied for xdm gdm for passwordless console X On the other hand install crack1ib2 and set etc pam d passwd as follows if you want to enforce a good password policy password required pam_cracklib so retry 3 minlen 6 difok 3 A one time login password for account activation may also help For this use the passwd command with the e option See passwd 1 The maximum number of processes can be set with ulimit u 1000 in a Bash shell or with settings in etc security limits conf from PAM Other parameters such as core can be set similarly The initial value of PATH can be set by etc login defs before the shell startup script The documentation for PAM is packaged in the 1ibpam doc package The Linux PAM System Administrator s Guide covers configuring PAM what modules are available etc The documen tation also includes The Linux PAM Application Developers Guide and The Linux PAM Module Writers Guide 9 2 2 Why GNU su does not support the wheel group This is the famous phrase at the bottom of the old info su page by Richard M Stallman Not to worry the current su in Debian uses PAM so that one can restrict the ability to use su to any group using pam_wheel
8. Compact disc drive access optimization setcd x 2toslow down to 2x speed See setca 1 e setserial Collection of tools for serial port management e scsitools Collection of tools for SCSI hardware management e memtest86 Collection of tools for memory hardware management e hwtools Collection of tools for low level hardware management x irgtune changes the IRQ priority of devices to allow devices that require high priority and fast service e g serial ports modems to have it 3x speedup of serial modem throughput is possible x scanport scans I O space from 0x100 to 0x3ff looking for installed ISA de vices x inb a quick little hack that reads an I O port and dumps the value in hex and binary e schedutils Linux scheduler utilities taskset irqset 1srt and rt are included Together with nice and renice not included they allow full control of process scheduling parameters Chapter 9 Tuning a Debian system 135 Mounting a filesystem with the noatime option is also very effective in speeding up read access to the file See fstab 5 and mount 8 Some hardware can be tuned directly by the Linux kernel itself through the proc filesystem See Tuning the kernel through the proc filesystem on page 103 There are many hardware specific configuration utilities in Debian Many of them address needs specific to the laptop PC Here are some interesting packages available in Debian
9. Conflicts status is often combined with Replaces e Package A Replaces Package B when files installed by B are removed or overwritten by files in A e Package A Provides Package B when all of the files and functionality of B are incorpo rated into A More detailed information on the use of each these terms can be found in the Packaging Manual and the Policy Manual Chapter 2 Debian fundamentals 16 Note that dselect has more fine grained control over packages specified by Recommends and Suggests than apt get which simply pulls all the packages specified by Depends and leaves all the packages specified by Recommends and Suggests Both programs in modern form use APT as their back end 2 2 9 The meaning of Pre Depends dpkg always configures a package upon which another package Depends before it configures the package that Depends on it However dpkg normally unpacks archive files in arbitrary order independently of dependencies Unpacking consists of extracting files from the archive file and putting them in the right place If however a package Pre Depends on another then the other package is unpacked and configured before the one that Pre Depends is even unpacked The use of this dependency is kept to a minimum 2 2 10 Package status Package status can be unknown install remove purge or hold These want flags indicate what the user wanted to do with a package eithe
10. S dmesg less apt get install cdrecord cdrecord scanbus Per Warren Dodge Sometimes there may be conflicts between ide scsi and ide cd if there are both CD ROM and CD R RW on the system Try adding the following line to your etc modutils aliases running update modules and rebooting pre install ide scsi modprobe ide cd This causes the IDE driver to load before ide scsi The IDE driver ide cd takes control of the ATAPI CD ROM anything that it hasn t been told to ignore That leaves just the ignored devices for ide scsi to control 9 3 5 CD image file bootable To create a CD image of files under target directory as cd image raw bootable Joliet TRANS TBL enabled format if not bootable take out b and c options insert a boot floppy in the first floppy drive and dd if dev fd0 target directory boot img mkisofs r V volume_id b boot img c bootcatalog J T o cd image raw target_directory One funny hack is to make a bootable DOS CD ROM If an ordinary DOS boot floppy disk image is in the above boot img the CD ROM will boot as if a DOS floppy were in the first floppy drive A Doing this with freeDOS may be more interesting This CD image file can be inspected by mounting it on the loop device Chapter 9 Tuning a Debian system 141 mount t iso9660 o ro loop cd image raw cdrom cd cdrom mc umount cdrom Se e e SHE 9 3 6 Write to the CD writer R RW First test with assuming doub
11. SIGNALS JOB CON TROL and SHELL BUILTIN COMMANDS 7 commandl command2 The standard output of command1 is fed to the standard input of command2 Both commands may be running concurrently This is called pipeline commandl command2 The command1 and command2 are executed sequentially commandl amp amp command2 The command1 is executed If successful command2 is also executed sequentially Return success if both command1 and command2 are successful commandl1 command2 The command is executed If not successful command2 is also executed sequentially Return success if command1 or command2 are successful command gt foo Redirect standard output of command to a file foo overwrite command gt gt foo Redirect standard output of command to a file foo append command gt foo 2 gt amp 1 Redirect both standard output and standard error of command to a file foo The Debian system is a multi tasking system Chapter 4 Debian tutorials 60 command lt foo Redirect standard input of command to a file foo Try lt etc motd pager ai the greetings pager lt etc motd a the greetings pager etc motd the greetings cat etc motd pager the greetings Although all 4 syntaxes display the same thing the last example runs extra cat command and wastes resources with no reason 4 3 11 Command alias You can set an alias for the frequently used comman
12. There are a few web browser packages with graphical display capabilities as of the Woody release e mozilla The Mozilla browser new e galeon Mozilla based browser with a Gnome UI new e konqueror KDE browser e dillo GTK browser e amaya gtk W3C reference browser e amaya lesstif W3C reference browser e netscape many old e communicator many old The version of mozilla must match the version that galeon requires Although they differ in UI these two programs share the Gecko HTML rendering engine Plug ins for browsers such as mozilla and galeon can be enabled by installing so man ually in the plug in directory and restarting the browsers Plug in resources 11 don t have any xftl stuff on my machine anymore so I m not sure if you need to restart X or not before this change will take effect I seem to remember that xftcache would update the Xftl cache but it d be good if someone could confirm that for me 5Fontconfig does not exist in Woody Chapter 9 Tuning a Debian system 158 e Java plug in install binary J2SE from http java sun com e Flash plug in install binary Macromedia Flash Player 5 from http www macromedia com software flashplayer e freewrl VRML browser and Netscape plug in 9 5 SSH SSH Secure SHell is the secure way to connect over the Internet A free version of SSH called OpenSSH is available as the ssh package in Debian 9 5 1 Basics
13. sun echo run at 04 05 every sunday run at 03 40 on the first Monday of each month 40 3 1 7 date a Mon amp amp command args Run the at command to schedule a one time job echo command args at 3 40 monday 8 6 28 Console switching with screen The screen program allows you to run multiple virtual terminals each with its own interac tive shell on a single physical terminal or terminal emulation window Even if you use Linux virtual consoles or multiple xterm windows it is worth exploring screen for its rich feature set which includes e scrollback history e copy and paste e output logging e digraph entry and e the ability to detach an entire screen session from your terminal and reattach it later Remote access scenario If you frequently log on to a Linux machine from a remote terminal or using a VT100 terminal program screen will make your life much easier with the detach feature Chapter 8 Debian tips 125 1 You are logged in via a dialup connection and are running a complex screen session with editors and other programs open in several windows 2 Suddenly you need to leave your terminal but you don t want to lose your work by hanging up 3 Simply type A d to detach the session then log out Or even quicker type A DD to have screen detach and log you out itself 4 When you log on again later enter the command screen r and screen will magi cally reattach all the wi
14. 1 46 646s bb eb a eae ewes 117 8 6 13 Regular Expressi n substitution ai esas een ea es ae gene ews 118 8 614 Edita tile in place using aSctipr eos obs OER A udusse 118 8 6 15 Extract differences and merge updates for source files 118 6 6 16 Converta large file mio small files gt o s ss oo so c awu anes Ee eH 119 8 6 17 Extract data from text file table nunaa 119 8 6 18 Script snippets for piping commands saosa a 120 8 6 19 Script snippets for looping over each file conoci ei es devs es 121 8 6 20 Perl shortseript madness c sasara eee ime denh 122 8 6 21 Get text or a mailing list archive from a web page 122 8 6 22 Preity printa WED Pags o s cii See datha eee eee Ae Re kia 122 8 623 Preity pimamanual page e s ocs sarsa ostes o maas kop WA OE ee g 123 8 6 24 Merge two PostScriptor PDE files 20 o maa naie aga ros 123 6625 Dmeaconmand seca sega s ere A e ew Rd a ee ae 123 86 20 nice command isa A Rd dd a ad aS 123 8 027 Scheduleac vity Crom at cs e o A 4S PERS 124 8 6 28 Console switching with screen co bs cise be ee td ane daa eda 124 8 6 29 IWelwork testing basics lt lt s ncssa ea ma Oe aE PE ae eee ODO 126 S600 Flush mail inom local spool sc ses ee es bee ee ee we ede me 126 8 6 31 Remove frozen mail from local spool 2 ede rs 126 8 6 32 Redeliver mbox contents ee 126 8 6 33 Clear file contents ee 127 e Dumy Mesi a OEE SRS SSS D pA aii E Ree EES i OR
15. 22 2 3 2 4 2 5 2 6 2 7 The Debian package management system ooo a 11 22 1 Overview of Debian packages oo eso 27552 aa i 11 222 Debian package IOMAT e a A AR AA AAA A a 12 2 2 3 Naming conventions for Debian package filenames 12 224 Preservation of local configuration 54504504 e608 08 6604s 13 220 JJiebian maintenance Sci ico HES ERD EMER ERS A a 13 226 ERRORES a ne Ge ead oS REE RSS HEROS eS 14 227 a ae ee ak ee OSES Bae ON a ane ed ae eS 15 228 Packaged pendencies 34 data AAA 15 229 Tie meaning of Pre Depends rr AAA AA 16 SU PARES SIS yodo e A a o e e a ed 16 2 2 11 Holding back packages from an upgrade es eee ewes 16 2212 OMe POSTES so ea ds A ARS ATA ie 17 2 2 13 Building binary packages from a source package o o 17 2 2 14 Creating new Debian Packages o o siso sasasi se wediei a dai 18 Upgrading a Debian SyStem 1 cerrara a a GaS 18 LAIL OA sd A a lea rd 18 Pee APs spe ETA 19 Dod MESSI sss fds Bass Ooi Se Seah u RD Be Doha Bae BS 19 234 Uperadinga running system 6 26 48 o cores 19 2 3 5 Downloaded and cached deb archive files 19 2 3 6 Record keeping for upgrades os s sc sa socos caca Oe a we 20 The Debian Oe so sa sopane tiee aa ei bate ORK Ree a ea CS 20 2l td AI 20 es E A IN 20 24 9 Cu st izin g Ennleveala oscar A A KEREES 21 a oa ee ee ed oS be EES amp DRE we we ia 21 Ie y or e ae AA A ee g 22 Debian and Te Reel 2 ew e
16. ABORT ERROR OK AT OK ATDT 0676012321 CONNECT d c EOF cat gt etc chatscripts Planet DenHaag lt lt EOF ABORT BUSY ABORT NO CARRIER ABORT VOICE ABORT NO DIALTONE ABORT NO DIAL TONE ABORT NO ANSWER ABORT ERROR OK AT OK ATDT 0676002505 CONNECT d c EOF To be able to connect to these ISPs you need client names and passwords that pppd can supply to the peer on demand This information is stored either in etc ppp pap secrets if the PAP protocol is used or in etc ppp chap secrets if the CHAP protocol is used Although CHAP is more secure PAP is still more widely used Because these files contain secrets group and world should not have permission to read or write them The format of these files is explained in pppd 8 A secret third field is looked up in the file by finding the client name first field and or the server name second field When connecting to an ISP one generally doesn t know the server name so one supplies a client name instead this was done on the user lines in peers KPN and peers Planet above client name server name secret Chapter 10 Network configuration 185 kpn ES kpn user3579 planet nl myfavoritepet See usr share doc ppp README Debian gz for more information Configuring pppd using pppconfig A quick way to configure pppd is to use the pppconfig program which comes in the package of the same name pppco
17. Alternative commands on page 94 e make kpkg can accommodate many boot loaders See make kpkg 1 and Debian standard method on page 97 Any files under usr 1local belong to the system administrator and Debian will not touch them Most files under etc are conffiles and Debian will not overwrite them upon upgrade unless the system administrator requests so explicitly 2 6 Internationalization The Debian system is internationalized and provides support for character display and entry in many languages both within the console and under X Many documents manual pages and system messages have been translated into a growing number of languages During in stallation Debian prompts the user to choose an installation language and sometimes a local language variant If your installed system does not support all the language features you need or if you need to change languages or install a different keyboard to support your language see Localization on page 165 2 7 Debian and the kernel See The Linux kernel under Debian on page 97 2 7 1 Compiling a kernel from non Debian source One has to understand the Debian policy with respect to headers The Debian C libraries are built with the most recent stable releases of the kernel headers For example the Debian 1 2 release used version 5 4 13 of the headers This practice con trasts with the Linux kernel source packages distributed at all Linux FTP archive s
18. Display a file location of command commandname which commandname does the same type commandname Display information on command commandname apropos key word Find commands related to key word man k key word does the same whatis commandname Display one line explanation on command commandname man a commandname Display explanation on command commandname Unix style info commandname Display rather long explanation on command commandname GNU style In the X Window environment the mouse functions in the same way with the Xterm program Here I use Unix in its generic sense Any Unix clone OSs usually offer the equivalent commands The Debian system is no exception Do not worry if some commands do not work as you wish now These examples are not meant to be executed in this order Tf alias is used in the shell their outputs are different Chapter 4 Debian tutorials 53 els List contents of directory non dot files and directories 20 eis a List contents of directory all files and directories els A List contents of directory almost all files and directories i e skip and e ls la List all contents of directory with detail information See The filesystem concept in Debian on page 64 e ls d List all directories under the current directory e lsof foo List open status of file foo e mkdir foo Make a new directory foo in the current di
19. Official release notes for upgrading are located at http www debian org releases stable releasenotes and http www debian org releases testing releasenotes work in progress Upgrading a system to the stable testing or unstable distribution may require several steps which must be in the following order e Upgrade to Woody if your system is earlier than Woody e Upgrade to stable e Upgrade to testing e Upgrade to unstable Debian does not support upgrades that skip intermediate releases 5 1 Upgrading from Potato to Woody This procedure is described separately because Potato s APT did not have all the features de scribed in the current apt_preferences 5 manpage After including only Woody sources in etc apt sources list upgrade APT and re quired core packages to Woody versions by doing the following apt get update apt get install libc6 perl libdb2 debconf apt get install apt apt utils dselect dpkg Chapter 5 Upgrading a distribution to stable testing or unstable 74 Then upgrade the rest of the system to Woody apt get upgrade apt get dist upgrade 5 2 Preparing for upgrade You can upgrade from one distribution to another by fetching packages over the network This can be done as follows Get a clean list of repositories for stable cd etc apt cp f sources list sources list old gt sources list apt setup noprobe If you want to upgrade to test ing then
20. When using this trick to su to a non root user make sure Xauthority is group readable by this non root user To automate this command sequence create a file xsession from the user s account con taining the following lines This makes X work when I su to the root account if z SXAUTHORITY then XAUTHORITY SHOME Xauthority export XAUTHORITY fi unset XSTARTUP If a particular window session manager is desired uncomment the following and edit it to fit your needs XSTARTUP usr bin blackbox This starts x window session manager program if z SXSTARTUP then if x usr bin x session manager then XSTARTUP x session manager elif x usr bin x window manager then XSTARTUP x window manager elif x usr bin x terminal emulator then XSTARTUP x terminal emulator Ed fi execute auto selected X window session manager exec SXSTARTUP Then run su not su in an xterm window of the user Now GUI programs started from this xterm can display output on this user s X window while running with root privilege This trick works as long as the default etc X11 Xsession is executed If a user set up his customization using xinitrc or xsession the above mentioned environment variable XAUTHORITY needs to be set similarly in those scripts Alternatively sudo can be used to automate the command sequence sudo xterm or sudo H s Chapter 9 Tuning a Debian system 155 Here root ba
21. de e 3 mkinitrd o boot initrd img 2 4 17 686 smp 1ib modules 2 4 17 686 smp lilo tune2fs j i 0 dev hdal tune2fs j i 0 dev hda2 for all EXT2 FS s converted to EXT3 shutdown r now Now EXT3 journaling is enabled If etc mkinitrd modules was not set when mkinitrd was run and you would like to add some modules at boot time s de E OH at initrd prompt to gain shell 5 sec type RETURN insmod jbd insmod ext3 modprobe ext3 may take care of everything insmod ext2 AD continue booting At the system boot screen dmesg cramfs wrong magic may appear but this is known to be harmless This issue has been resolved in Sarge 2002 10 See http bugs debian org 135537 and the EXT3 File System mini HOWTO http www zip com au akpm linux ext3 ext3 usage html or usr share doc HOWTO en txt mini extra ext3 mini HOWTO gz for more information Some systems are reported to experience severe kernel lockup if EXT3 is enabled but I had no problem as of 2 4 17 Chapter 7 The Linux kernel under Debian 103 7 2 5 Realtek RTL 8139 support in 2 4 For whatever reason the RTL 8139 support module is no longer called rtl8139 it s now called 8139too Just edit your etc modules to reflect this change when upgrading a 2 2 kernel to a 2 4 kernel 7 2 6 Parallel port support For kernel image 2 4 parallel port support is provided as a module Enable it by modprobe lp ech
22. postinst This script typically completes any required configuration of a package once it has been unpacked from its Debian archive deb file Often postinst scripts ask the user for input and or warn the user that if he accepts default values he should remember to go back and reconfigure the package as the situation warrants Many postinst scripts then execute any commands necessary to start or restart a service once a new package has been installed or upgraded prerm This script typically stops any daemons which are associated with a package It is executed before the removal of files associated with the package postrm This script typically modifies links or other files associated with a package and or removes files created by it Also see Virtual packages on page 15 Chapter 2 Debian fundamentals 14 Currently all of the control files can be found in the directory var lib dpkg info The files relevant to package foo begin with the name foo and have file extensions of preinst postinst etc as appropriate The file foo 1list in that directory lists all of the files that were installed with the package foo Note that the location of these files is a dpkg internal and may be subject to change 2 2 6 Package priorities Each Debian package is assigned a priority by the distribution maintainers as an aid to the package management system The priorities are Required packages are necessa
23. q Get back command mode C g lt esc gt Backward left E b h Forward right C a Next down C n J Previous up C p k stArt of line C a 0 End of line C e mUltiple commands C u nnn cmd nnn cmd Multiple commands M digitkey cmd save File Cx CS w file beginning of buffer M lt 16 end of buffer M gt G scroll forward 1 screen C v AF scroll forward 1 2 screen D scroll forward 1 line E scroll backward 1 screen M v B scroll backward 1 2 screen sy scroll backward 1 line PY scroll the other window M C v delete under cursor C q x delete from cursor to eol C k D iSearch forward C 5 isearch Reverse C E Search forward C s enter search Reverse C r enter 2 isearch regexp M C s isearch backward regexp M C r search regexp M C s enter search backward regexp M C r enter Help C h C h help Help Apropos C h a Help key Bindings C h b help key Help Info Gah ca Help Major mode C h m Help tutorial C h E help howto Undo E u Redo Goer R Mark cursor position C Q m a zA Z eXchange Mark and position C CX goto mark in current file a z goto mark in any file A Z copy region M w visual y kill region C w visual d Chapter 11 Editors 210 Yank and keep buffer C y Yank from kill buffer M y p convert region to Upper C x C u visual U convert region to Lower C x C visual u Insert special char C q octalnum keystroke V dec
24. smbmount server share mnt smb o username myname uid my_uid gid my_gid smbclient L 192 168 1 2 list the shares on a computer Samba neighbors can be checked from Linux using smbclient N L ip_address_of_your_PC less nmblookup T 8 6 39 Utilities for foreign filesystems Many foreign filesystems have Linux kernel support and can thus be accessed simply by mounting the devices containing the filesystems For certain filesystems there are also a few specialized tools to access the filesystems without mounting the devices This is accomplished with user space programs so that kernel filesystem support is not needed e mtools for MSDOS filesystem MS DOS Windows e cpmtools for CP M filesystem e hfsutils for HFS filesystem native Macintosh e hfsplus for HFS filesystem modern Macintosh In order to create and check an MS DOS FAT filesystem dosfstool1s is useful 8 7 Typical mistakes to be noted Here are few examples of dangerous actions The negative impacts will be enhanced if you are using privileged account root 8 7 1 rm rf In rm rf expands to include and and if you happen to have privileges to write to the parent directory then you ll end up removing all directories next to your current directory as well Chapter 8 Debian tips 131 removes everything under current directory and current directory itself removes every non dot
25. 6 3 6 Install a package into an unbootable system 85 6 3 7 What to do if the dpkg command is broken 86 64 Debian nirvanacommands c ood eee Se aa RE OE e a 86 6 4 1 Information on afile 2 2 cs SS BREE EES EEA ee Ee SS 86 64 2 IniormiaOn GNA Package dio br SPHERE Oe Ra EHS 87 6 4 3 Unattended installation with APT 6 266 weed ee ew ee we eS 88 644 Reconfigure installed packages gt lt ees cee eee en ees 88 64 5 Remove and p rge packages os oso saca paros OEE OE we Se Es 89 64 6 Holding older packages o o BES SPREE RE RE a KS 89 6 4 7 Mixed stable testing unstablesystem 89 C40 Prmecacisd package files o coos curs a Babee ran He eS 90 6 4 9 Record copy system configuration 6 6 eek die eee eee es 90 6 4 10 Porta package to the stable system o ooo ooo 90 SLI Local package archive isc isaac KS 91 CONTENTS vii 6 4 12 Convert or install an alien binary package o o 6 4 13 6 4 14 6 4 15 6 5 Other Debian peculiarities 6 5 1 6 5 2 6 53 6 5 4 GD Automatically install command Verify installed package files Optimized sources list The dpkg divert command The equivs package Alternative commands Runlevel usage 2 6s kee Disabled daemon services 7 The Linux kernel under Debian 7 1 Kernel AL FAA ZAS 7 2 The modularized 2 4 kernel recompile se ra see
26. T ron FontPath usr share fonts truetype FontPath usr lib X11 fonts CID t t FontPath usr lib X11 fonts Speedo E t t t FontPath usr lib X11 fonts misc FontPath usr lib X11 fonts cyrillic F Path usr lib X11 fonts 100dpi unscaled FontPath usr lib X11 fonts 75dpi unscaled FontPath usr lib X11 fonts Typel EndSection The first line will setup XFree86 to use any TrueType fonts you install from Debian pack ages Typel font entry is moved down since XFree86 does a rather poor job of rendering Typel fonts The unscaled trick for bitmap fonts should not be needed for new XF4 ron mr Path var lib defoma x ttcidfont conf d dirs TrueType Chapter 9 Tuning a Debian system 156 anymore but I included it here just be sure In order to preserve manual changes of etc X11 XF86Config 4 follow instructions in Configuring the X server manually on page 146 Then install DFSG font packages e Western TrueType fonts ttf bitstream vera A set of high quality TrueType fonts created by Bitstream Inc ttf freefont A set of free high quality TrueType fonts covering the UCS char acter set ttf thryomanes A TrueType Unicode font covering Latin Greek Cyrillic and IPA e Asian fonts tfm arphic bsmi001p Chinese Arphic AR PL Mingti2L Big5 TrueType font TeX font metric data t m arphic bkai00mp Chinese A
27. WEB MRE pa ya ii gae Bo OAS Se BEER ee i 36 ce 2 ona hed i ein de kw ee OE See Ee eee ed ee eRe AS 37 o ors ee cae aE e e SS a aa E a a 38 Mo SAMBA CONAEUEAMON y bai e a EERE o E e A 38 SG PrntereoniguraloN o ees asiad uee e AA OR EEE ES 39 A gt E IA 39 362 CUESTA RE AE A A e Oe 39 3 7 Other host installation hints 2 hike Sb de ee EERE neredu BS 40 CONTENTS iv 3 7 1 Install a few more packages after initial install 40 Dee MORAS gt esy sn ee as areas ada a 41 37o CD RW PASES ir AER a A HE RE a 41 3 74 Large memory and auto power off lt oo a 41 3 7 5 Strange access problems with some websites 42 a2 Dialup PPP configuration cs cara a saaran 43 3 7 7 Other configuration files to tweak in etc 2 6644s oocinds 43 4 Debian tutorials 45 Bl CEE started so ss sacr A A RRA eee RA Ee 45 4 1 1 Login to a shell prompt as root cpo corredor OEE EO 45 41 2 Setup minimal newbie environment 2 2225 26 va sed erens 46 AS ee Seer ae ok ea kk Ke EA a OS 47 4 1 4 Switch between virtual console oo o 47 ALSO How toshutdown 1 0 arre E e RR eS 47 Al Play Mess ar A AAA AA E AAA e eS 48 42 NU Commander YO es A A A A AE ee 48 421 nance A III GEES tet HSS amp S 49 doo SUMO nk eee Oe eee oe ake ee oe od ee ae oe ees 49 429 Filemanagerin MG cda RRA A a AS 49 424 Command line trieksin MC 2 aa eara rra eras aa 49 12S AMONIO score A 50 426 Vi
28. clear sign message dash escaped patchfile verify clear signed file clear sign patchfile detach sig file creat verify file with file sig r name detached signature encrypt e file public key encryption intended for name gpg gpg o file decrypt crypt_file Managing GnuPG Key management o crypt_file symmetric c file symmetric encryption decryption gpg dit key user_ID help for help interactive gpg o file exports export all keys to file gpg imports file import all keys from file gpg send keys user_ID send key of user_ID to keyserver gpg recv keys user_ID recv key of user_ID from keyserver gpg list keys user_ID list keys of user _ ID gpg list sigs user_ID list sig of user_ID gpg check sigs user_ID check sig of user_ID gpg fingerprint user_ID check fingerprint of user_ID gpg list sigs grep sig grep User id not found A awk print 2 sort u xargs gpg recv keys get unknown keys update keys for all unknown sigs S gpg refresh keys update local keyring Trust code No ownertrust assigned not yet calculated e Trust calculation has failed a Not enough information for calculation n Never trust this key m Marginally trusted f Fully trusted u Ultimately trusted The following will upload my key A8061F32 to the popular keyserver hkp subke
29. is a symbolic link to etch This means that Sarge is the current stable distribution and Etch is the current testing distribution unstable is a permanent symbolic link to sid as Sid is always the unstable distribution 2 1 8 Codenames used in the past Codenames that have already been used are Buzz for release 1 1 Rex for release 1 2 Bo for releases 1 3 x Hamm for release 2 0 Slink for release 2 1 Potato for release 2 2 Woody for release 3 0 and Sarge for release 3 1 2 1 9 The source for codenames So far they have been characters taken from the movie Toy Story by Pixar e Buzz Buzz Lightyear was the spaceman e Rex was the tyrannosaurus e Bo Bo Peep was the girl who took care of the sheep e Hamm was the piggy bank e Slink Slinky Dog was the toy dog e Potato was of course Mr Potato Head e Woody was the cowboy e Sarge was a leader of the Green Plastic Army Men e Etch Etch a Sketch was the blackboard e Sid was a boy next door who destroyed toys Chapter 2 Debian fundamentals 9 2 1 10 The pool directory Historically packages were kept in the subdirectory of dists corresponding to the distribu tion that contained them This turned out to cause various problems such as large bandwidth consumption on mirrors when major changes were made Packages are now kept in a large pool structured according to the name of the source package To make this m
30. isa pnp Chapter 7 The Linux kernel under Debian 100 New Low level PCMCIA driver yenta_socket does not seem to be needed in my case The rest is taken care of by PCMCIA scripts from the pcmcia cs package depmod and kmod I think I needed isa pnp because my laptop is an old ISA PCMCIA Recent laptops with CardBus PCMCIA may not require this Voice of the genius Miquel van Smoorenburg lt miquels cistron nl gt I simply removed the entire pcmcia stuff from the laptop here at work including the cardmgr etc and just installed a 2 4 kernel with cardbus support and the new hotplug package from woody As long as you only have 32 bit cards you don t need the pcmcia package 2 4 has card services built in And the standard tulip driver should work fine with your dlink card Mike See Linux PCMCIA HOWTO http www tldp org HOWTO PCMCIA HOWTO html and Network configuration and PCMCIA on page 198 7 2 2 SCSI NOT TESTED etc modules needs to contain the following for SCSI to function SCSI core scsi_mod SCSI generic driver sg SCSI disk sd_mod All other needed HW modules depmod may take care of some of the above modules 7 2 3 Network function etc modules needs to contain the following for extra network function net ipv 4 ip_gre ipip net ipv 4 netfilter Chapter 7 The Linux kernel under Debian 101 iptable in order ip_tables ip_conntrack ip_conntrack_
31. modules to it as described in The Linux kernel under Debian on page 97 Configuration of network devices is explained below The information in this chapter has been updated for Sarge Much of it does not apply to earlier releases 10 1 Basics of IP networking A Debian host may have several interfaces each with a different Internet Protocol IP address Interfaces may be of several different types including e Loopback lo e Ethernet eth0 ethi e Wi Fi wlan0 wlan1 e Token Ring tr0 tr1 e PPP ppp0 pppl There is a wide range of other network devices available including SLIP PLIP serial and parallel line IP shaper devices for controlling the traffic on certain interfaces frame relay AX 25 X 25 ARCnet and LocalTalk Every network interface connected directly to the Internet or to any IP based network is iden tified by a unique 32 bit IP address The IP address can be divided into the part that addresses INote that a Wi Fi interface is really an alias for an Ethernet interface that gives access to the configuration parameters peculiar to Wi Fi These parameters are controlled using the iwconfig program This is true if IP version 4 is being used In IPv6 addresses are 128 bits See http www ipv6 org Chapter 10 Network configuration 178 the network and the part that addresses the host If you take an IP address set to 1 the bits that are part of the network address and set t
32. system sync nodev nosuid gid 100 umask 000 users dev Edo Chapter 3 Debian System installation hints 33 e Create cdrom and floppy links in home user that point to var autofs misc cdromand var autofs misc floppy respectively e Add user to the users group NFS mount The external Linux NFS server goofy resides behind a firewall gateway I have a very re laxed security policy on my LAN since I am the only user To enable NFS access the NFS server side needs to add etc exports as follows etc exports the access control list for filesystems which may be exported to NFS clients See exports 5 rw no_root_squash This is needed to activate the NFS server in addition to installing and activating the NES server and client packages For simplicity I usually create a single partition of 2GB for an experimental or secondary lazy Linux install I optionally share swap and tmp partitions for these installs A multipartition scheme is too involved for these usages If only a simple console system is needed 500MB may be more than sufficient 3 1 12 DRAM memory guidelines Following are rough guidelines for DRAM 4MB Bare minimum for Linux kernel to function 16MB Minimum for reasonable console system 32MB Minimum for simple X system 64MB Minimum for X system with GNOME KDE 128MB Comfortable for X system with GNOME KDE 256MB or more Why not if you can afford it DRAM
33. variables are LC_CTYPE Character classification and case conversion e LC_COLLATE Collation order e LC_TIME Date and time formats e LC_NUMERIC Non monetary numeric formats e LC_MONETARY Monetary formats e LC_MESSAGES Formats of informative and diagnostic messages and interactive responses e LC_PAPER Paper size e LC_NAME Name formats e LC_ADDRESS Address formats and location information e LC_TELEPHONE Telephone number formats e LC_MEASUREMENT Measurement units Metric or Other e LC_IDENTIFICATION Metadata about the locale information 16 LANG If this is non null and LC_ALL is undefined the value is used for all LC_ locale categories with undefined values POSIX 1 Usually C Note that some applications e g Netscape 4 ignore LC_ settings Chapter 9 Tuning a Debian system 170 The locale program can display active locale settings and available locales see locale 1 NOTE locale a lists all the locales that your system knows about this does not mean that all of them are compiled See Activating locale support on the preceding page 9 7 6 ISO 8601 date format locale The locale support for the international date standard of yyyy mm dd ISO 8601 date format is provided by the locale called en_DK English in Denmark which is a bit of joke This seems to work only in a console screen for 1s 9 7 7 Example for the US ISO 8859 1 Add the following lines to bash_p
34. 1 Mask 255 0 0 0 route Kernel IP routing table Chapter 10 Network configuration 181 Destination Gateway Genmask Flags Metric Ref Use Iface 192 168 0 0 LID LID LO U 0 0 0 etho 10 0 0 0 192 168 0 1 255 0 0 0 UG 0 0 O etho For more information see ifconfig 8 and route 8 10 2 2 Low level network configuration ip The ip equivalents of the preceding ifconfig and route commands are e ip link show e ip route list e ip link set eth0 down e ip addr del dev eth0 local 192 168 0 3 e ip addr add dev eth0 local 192 168 0 111 24 broadcast 192 168 0 255 e ip link set eth0 up e ip route add dev eth0 to 10 0 0 0 8 src 192 168 0 111 via 192 168 0 1 The ip program prints its command syntax when run with the argument help For example ip link help prints Usage ip link set DEVICE up down arp on off dynamic on off multicast on off txqueuelen PACKETS name NEWNAME address LLADDR broadcast LLADDR mtu MTU ip link show DEVICE See also ip 8 10 2 3 Configuring a Wi Fi interface For Wi Fi interfaces the iwconfig program which comes in the wireless tools package is used in addition to either ifconfig or ip See iwconfig 8 10 2 4 Configuring a PPP interface If you access the Internet through a modem connected to a dial up telephone line then the connection is negotiated using the Point to Point Protocol PPP Such connections are accessed as ne
35. 118 Script snippets for piping commands on page 120 and Perl short script madness on page 122 for some script examples 4 4 1 Regular expressions Regular expressions are used in many text processing tools They are analogous to the shell wildcards see Shell wildcards on page 57 but they are both more complicated and more powerful The regular expression describes the matching pattern and is made up of text characters and metacharacters The metacharacter is just a character with a special meaning There are 2 major styles BRE and ERE depending on the text tools as described in Unix like text processing on the facing page For the EREs the metacharacters include Y The reg ular expression means ec This matches the non metacharacter c e c This matches the literal character c This matches any character including newline This matches the beginning of a string es This matches the end of a string e lt This matches the beginning of a word e gt This matches the end of a word Chapter 4 Debian tutorials 62 aba d This character list matches any of the characters abc e fabs a This negated character list matches any of the characters except abc o rx This matches zero or more regular expressions identified by r e r This matches one or more regular expressions identif
36. 127 SiO CRESOE sois sr a a A ee See a 127 8 636 How to Check hard links occur a a a Oo 129 8 6 37 mount hard disk image lle 66k cee tea eae ee ee ds eee 129 20 30 DIMAS ls a AR a aa e Sad 130 8 6 39 Utilities lor foreign filesystems o cscs AA A 130 8 7 Typical mistakes to BEBO os ecs eee oe ASE a Se eS 130 GLL om E g ea pE ya e E E a ee ew ore E 130 S22 Pie FELO PassWd oca haa aad RA a ae a A Pe Ke 131 CONTENTS A 9 Tuning a Debian system 133 91 se o AA II 133 911 Customizing IMtSCripis ae cios oa E AA 133 9 1 2 Customizing system logging aaa 134 SS Optimizmg hardware c core soi eee AAA 134 Oa ESIICUO ACCESE 2 it aa AAA A bi i 135 9g21 Restrict ng logins with PAM atra A 135 9 2 2 Why GNU su does not support the wheel group 136 9 2 3 Purposes of standard groups 264 o oo A 136 924 Working moresafely sudo o sasira sori hat eee ede a 137 View Resmicune o o ea maoe roa d geaen Bowes a i ei 137 92 6 Centralizing authentication LDAP o s sa coo 9 02 oa aoa moe a E 138 Oy CREWE G eee ee SB es eee ea s Soh Ss ee Ce A E Ea oe 138 Oia OO AA 139 932 Approach I modules lil ss siso raas i sda AA EO 139 9339 Approach 2 recompile the kernel cc coea arcana ea a e a 139 934 Postconfipuration Steps 05 ecc ea bo Re ee eRe we OR Rara 140 930 CD amage eee e anes Ob Bee Oe reed a EES 140 930 Write tothe CD writer R RW ce ce recre eG OS re Dobai eae oes 141 93 7 Makean image tile Gla osc ca c
37. 211 run GDB M x gdb describe GDB mode C h m step one line M s next line M n step one instruction stepi M i finish current stack frame C C continue M c up arg frames M u down arg frames M d copy number from point insert at the end C x amp set break point C x SPC 11 3 5 Vim configuration In order to use all Vim features and syntax highlighting include the following lines in vimrc or etc vimrc set nocompatible set nopaste set pastetoggle lt f11 gt syn on Paste mode enables one to avoid autoindent interfering with cut and paste operations on a console terminal It does more than just a simple set noai See Using GnuPG with Vim on page 243 for GnuPG integration 11 3 6 Ctags apt get install exuberant ctags and run ctags on the source files Type tag function_name in Vim to jump to the line where function_name starts The tags work for C C Java Python and many other languages Emacs has the same ctags capabilities 11 3 7 Convert a syntax highlighted screen to HTML source so SVIMRUNTIME syntax 2html vim from Vim command mode will convert high lighted text to HTML text Save with w file html and q Useful for C code etc Chapter 11 Editors 212 11 3 8 Split screen with vim vim can edit multiple files in a multi split screen environment Type help usr_08 txt for details To split the screen display between different files type at the vi command
38. 4 2 4 Command line tricks in MC e Any cd command will change the directory shown on the selected screen e Ctrl Enter or Alt Enter will copy a filename to the command line Use this with the cp or mv command together with command line editing e Alt Tab will show shell filename expansion choices lyf you do not understand what exactly I am talking here you can do this later 12Tf one is in a terminal such as kon and kterm for Japanese that has issues with certain graphics characters adding a to MC s command line may help prevent problems Chapter 4 Debian tutorials 50 e One can specify the starting directory for both windows as arguments to MC for exam ple mc etc root e Esc numberkey En i e Esc 1 Fl etc Esc 0 F10 e Esc key Alt key Meta M i e type Esc c for Alt C 4 2 5 Editor in MC The internal editor has an interesting cut and paste scheme Pressing F3 marks the start of a selection a second F3 marks the end of selection and highlights the selection Then you can move your cursor If you press F6 the selected area will be moved to the cursor location If you press F5 the selected area will be copied and inserted at the cursor location F2 will save the file F10 will get you out Most cursor keys work intuitively This editor can be directly started on a file S mc e filename_to_edit S mcedit filename_to_edit This is not a multi window editor but one ca
39. 4 Differential backup and data synchronization Differential backup and data synchronization can be implemented with several methods e xcs backup and history text only e rdiff backup backup and history symlink OK e pdumpfs backup and history within a filesystem symlink OK e rsync 1 way synchronization e unison 2 way synchronization e cvs multi way synchronization with server backup and history text only mature See Concurrent Versions System CVS on page 213 e arch multi way synchronization with server backup and history no such thing as a working directory e subversion multi way synchronization with server backup and history Apache Combination of one of these with the archiving method described in Copy and archive a whole subdirectory on page 109 and the automated regular job described in Schedule activity cron at on page 124 will make a nice backup system I will explain three easy to use utilities Chapter 8 Debian tips 112 8 4 1 Differential backup with rdiff rdiff backup offers nice and simple backup with differential history for any types of files including symlinks To back up most of to mnt backup rdiff backup include tmp keep exclude tmp mnt backup To restore three day old data from this archive to o1ld rdiff backup r 3D mnt backup old See rdiff backup 1 8 4 2 Daily backup with pdumpfs pdumpfs is a simple daily backup
40. 9 Tuning a Debian system 162 9 6 1 Mail transport agents MTAs For a full featured MTA use exim in Woody and use exim4 in Sarge References e exim doc and exim doc html packages for exim e exim4 doc info and exim4 doc html packages for exim4 e http www exim org The only reasonable alternative MTA is post fix if you care about security sendmail and qmail are available as Debian packages but are not recommended If you do not need the relay capability of an MTA as in the case of a satellite system such as a laptop PC you may consider using one of these lightweight packages e ssmtp needs an SMTP connection and is alias capable or e nullmailer can spool but is not alias capable At this moment I find exim to be more suitable even for my personal workstation machine which is a laptop PC You may need to remove exim for the installation of these conflicting packages dpkg P force depends exim apt get install nullmailer or ssmtp Smarthost If you are running exim4 or exim on a host which is connected through the consumer grade services please make sure to send outgoing mail through a smarthost offered by your ISP or some others There are few good reasons e to ensure SMTP retries since your ISPs smarthost usually have more reliably connection e to avoid sending mail directly from a dynamic IP address which will likely be blocked by dial up spam lists e to save your local bandwidth to send mails w
41. A procedure like the following will help you recover from this situation In the first line you can replace links with your favorite browser command links http http us debian org debian pool main d dpkg download the good dpkg_version_arch deb su password x x x ar x dpkg_version_arch deb mv data tar gz data tar gz cd tar xzfv data tar gz Se e 38 For 1386 http packages debian org dpkg may also be used as the URL 6 4 Debian nirvana commands Enlightenment with these commands will save a person from the eternal karmic struggle of upgrade hell and let him reach Debian nirvana 6 4 1 Information on a file To find the package to which a particular file belongs dpkg S search pattern search for pattern in installed packages zgrep e pattern local copy of debian woody Contents 1386 gz find filename pattern of files in the debian archive Chapter 6 Debian package management 87 Or use specialized package commands aptitude install dlocate conflicts with slocate secure version of locate dlocate filename fast al lternative to dpkg L and dpkg S aptitude install auto apt on demand package installation tool auto apt update S auto apt search pattern search for pattern in al 6 4 2 Information on a package create db fi Search and display information from package archives Make sure proper archive s by editing
42. AA 164 96 3 Processing Mall Procmail lt sses sacs s Be Sas ere ee 165 364 Pr c ssing spam with crmlld sso ve sa eh ES sa tdas s wasise 165 965 Reading mal Muti 2 ia eai e ke ee de ae tele eed a a e ee 165 97 Localza on esc si i siose a AA Aa ds 165 AL Basies LICONSA AAA REEDS ERS 166 A es carp s poaa ie ES le OS SOE OP EE a E Me 167 9 7 3 Introduchon t locales sas i eee ee Ea ee e RRA A 167 97A Activating locale support ee se s sarea es para A 169 975 Activating a particular locale o o sog ea A A e a 169 9 7 6 ISO 8601 date format locale cud od boo eo risas a 170 977 Exampletor the US ISO occ e s stro sag bare a wa a RS 170 9 7 8 Example for France with Euro sign ISO 8859 15 170 9 7 9 Example for a multilingual X window system 0 170 9 7 10 Alternative X input methods 2 2646 4h bees REBAR hie Eo 173 CONTENTS xii 97 11 X terminal emulators lt oa so cs escarto caton e e 174 9 7 12 UTF 8 support for the X terminal emulator 2 4 40 eee dees 174 9 7 13 Example for UTF 8 in a framebuffer console 4 4 a a anaana anaana 175 97 14 Beyond locales o scrices rara AA AR a e OH 175 10 Network configuration 177 10 1 esis OF IP HEIWOIRING o o e AR IA A RE GTa 177 10 2 Low level network configuration oaoa Riedie OUR es a 179 10 2 1 Low level network configuration ifconfig and route 179 10 2 2 Low level network configuration ip 2 64 462 o a 181 10 2 3 C
43. All of these XF3 servers depend on xserver common v3 For most cases x window system is the package to install If you want console login be sure to disable xdm as described in Let me disable X on boot on page 107 9 4 2 Hardware detection for X To enable hardware detection during the X configuration stage install the following packages prior to installing the X system Chapter 9 Tuning a Debian system 145 e discover hardware identification system e mdetect mouse device autodetection tool e read edid hardware information gathering tool for VESA PnP monitors 9 4 3 The X server See XFree86 1x for X server information Invoke X server from a local console startx lt display gt vtXX e g startx 1 vt8 bpp 16 start on vt8 connected to localhost 1 with 16 bpp mode Arguments given after are for the X server Note when using a xserverrc script to customize the X server startup process be sure to exec the real X server Failing to do this can make the X server slow to start and exit For example bin sh exec usr bin X11 X dpi 100 nolisten tcp Configuring the X server version 4 To re configure an XF4 server dpkg reconfigure priority low xserver common dpkg reconfigure priority low xserver xfree86 will generate etc X11 XF86Config 4 file and configure X using the script dexconf Configuring the X server version 3 To re configure a
44. Append SRCS wildcard c OBJS f00 c 0 OBJS f00 c 0 OBJS patsubst c 0 foo DIRS dir directory filename ext Extracts directory notdir NAMES basename NAMES suffix NAMES Run make p f dev null to see automatic internal rules 13 7 C Preparation apt get install glibc doc manpages dev libc6 dev gcc References for C Chapter 13 Programming 231 e info libc C library function reference e gcc 1 e each_C_library_function_name 3 e Kernighan amp Ritchie The C Programming Language 2nd edition Prentice Hall 13 7 1 Simple C program gcc A simple example to compile example c with a library libm into an executable run_example cat gt example c lt lt EOF include lt stdio h gt include lt math h gt include lt string h gt int main int argc char argv char envp double x char y 11 x sqrt argct7 5 strncpy y argv 0 10 prevent buffer overflow y 10 0 fill to make sure string ends with 0 printf S 5i 5 3f 10s 10s n argc xX y return 0 EOF gcc Wall g o run_example example c lm run_example 1 2 915 run_exam null run_example 1234567890qwerty 2 3 082 run_exam 1234567890qwerty argv 1 Here 1m is needed to link library libm for sqrt The actual library is in 1ib with filename 1ibm so 6 which is a symlink to 1ibm 2 1 3
45. Bcast 192 168 255 255 Mask 255 255 0 0 UP BROADCAST RUNNING MULTICAST MTU 1500 Metric 1 RX packets 23363 errors 0 dropped 0 overruns 0 frame 0 TX packets 21798 errors 0 dropped 0 overruns 0 carrier 0 collisions 0 txqueuelen 100 Chapter 10 Network configuration 180 RX bytes 13479541 12 8 MiB TX bytes 20262643 19 3 MiB Interrupt 9 lo Link encap Local Loopback inet addr 127 0 0 1 Mask 255 0 0 0 UP LOOPBACK RUNNING MTU 16436 Metric 1 RX packets 230172 errors 0 dropped 0 overruns 0 frame 0 TX packets 230172 errors 0 dropped 0 overruns 0 carrier 0 collisions 0 txqueuelen 0 RX bytes 22685256 21 6 MiB TX bytes 22685256 21 6 MiB route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192 168 0 0 239 203 010 U 0 0 O eth0 default 192 168 0 1 255 255 255 255 UG 0 0 O eth0 First we bring down the interface ifconfig eth0 inet down ifconfig lo Link encap Local Loopback no more ethO entry route no more routing table entries Then we bring it up with the new IP address and new routing ifconfig eth0 inet up 192 168 0 111 netmask 255 255 255 0 broadcast 192 168 0 255 route add net 10 0 0 0 netmask 255 0 0 0 gw 192 168 0 1 dev eth0 The result ifconfig eth0 Link encap Ethernet HWaddr 08 00 46 7A 02 B0 inet addr 192 168 0 111 Bcast 192 168 0 255 Mask 255 255 255 0 UP BROADCAST RUNNING MULTICAST MTU 1500 Metric 1 lo Link encap Local Loopback inet addr 127 0 0
46. INPUT is open For a more thorough redirect rule set consider installing the ipmasq package and adding M30redirect def http www debian org doc manuals debian reference examples to the etc ipmasq rules directory Chapter 10 Network configuration 205 10 14 2 Manage multiple net connections FIXME Policy routing by Phil Brutsche lt pbrutsch tux creighton edu gt See the iproute manual http lartc org for details Traffic control tc may also be interest ing Environment eth0 192 168 1 2 24 gateway 192 168 1 1 eth1 10 0 0 2 24 gateway 10 0 0 1 No masquerading on this machine Special magic 1 ip rule add from 192 168 1 2 lookup 1 ip rule add from 10 0 0 2 lookup 2 ip route add to default via 10 0 0 1 metric 0 ip route add to default via 192 168 1 1 metric 1 ip route add table 1 to 192 168 1 0 24 via ethO ip route add table 1 to 10 0 0 2 24 via eth1 ip route add table 1 to default via 192 168 1 1 ip route add table 2 to 192 168 1 0 24 via ethO 9 ip route add table 2 to 10 0 0 2 24 via eth1 10 ip route add table 2 to default via 10 0 0 2 CONA TF WN FIXME I ve never done this How to set up dialup as backup to a fast connection with auto dial features Please send me a patch here Chapter 10 Network configuration 206 207 Chapter 11 Editors 11 1 Popular editors Linux offers many alternatives for console text editors Among them vim Powerful and light BSD herita
47. Midnight Commander MC on the current page and later with the proper way Unix like work environment on page 51 4 2 Midnight Commander MC Midnight Commander MC is a GNU Swiss army knife for the Linux console and other terminal environments This gives newbie a menu driven console experience which is much easier to learn than standard Unix commands Use this command to explore the Debian system This is the best way to learn Please explore few key locations just using the cursor keys and Enter key e etc and its subdirectories The left Ctrl key the left Alt Key and the Delete are pressed together from the console In the default system this will cause system reboot You need to modify etc inittab to have shutdown command with h option as described in Install a few more packages after initial install on page 40 This is because the Debian system is even just after the default installation configured with the proper file permissions which prevent non privileged user to damage the system Of course there may still exist some holes which can be exploited but those who worry about this issue should not be reading this section but should be reading Securing Debian Manual http www debian org doc manuals securing debian howto The left Ctrl key and the d key are pressed together No need to press the Shift key even though these control characters are referred as control D with the upper case 101f you
48. PATH environment variable The value of the PATH environment variable is also called the shell s search path In the default Debian installation the PATH environment variable of user accounts may not include sbin So if you want to run any commands such as ifconfig from sbin you must change the PATH environment variable to include it The PATH environment variable is usually set by the initialization file bash_profile see Bash configuration on page 34 4 3 7 Command line options Some commands take arguments The arguments starting with or are called options and control the behavior of the command S date Mon Oct 27 23 02 09 CET 2003 date R Mon 27 Oct 2003 23 02 40 0100 Here the command line argument R changes the date command behavior to output RFC 2822 compliant date string 4 3 8 Shell wildcards Often you want a command to work with a group of files without typing all of them The filename expansion pattern using the shell wildcards facilitate this needs This matches any group of 0 or more characters This does not match a filename started with This matches exactly one character This matches exactly one character with any character enclosed in brackets e a z This matches exactly one character with any character between a and z e sia This matches exactly one character other than any character enclosed in brackets excluding For example try the followin
49. Robinson The X server on page 145 a program on a local host that displays an X window and or desk top on a user s monitor CRT LCD and accepts keyboard and mouse input X clients on page 147 a program on a local or remote host that runs X compatible applica tion software This reverses the ordinary use of server and client in other contexts There are several ways of getting the X server display side to accept remote connections from an X client application side e xhost method the host list mechanism very insecure non encrypted protocol prone to eavesdropping attack Do not use this if possible See Connecting to a remote X server xhost on page 151 and xhost 1x e xauth method the MIT magic cookie mechanism insecure but better than xhost non encrypted protocol prone to eavesdropping attack use this only for local connection since it is less CPU intensive than ssh X See Getting root in X on page 153 and xauth 1x Chapter 9 Tuning a Debian system 144 e xdm wdm gdm kdm methods the MIT magic cookie mechanism insecure as xauth See xdm 1x and Xsecurity 7 for the basics of X display access control See wdm 1x gdm 8 and kdm options 5 for more information if these are installed See Customizing runlevels on page 21 for how to disable xdm to gain a Linux con sole upon boot without purging the xdm
50. TERM normal kill 9 KILL kill hard 8 5 2 Alt SysRq Insurance against system malfunction is provided by the kernel compile option Magic SysRq key Pressing Alt SysRq on an i386 followed by one of the keys r 0 k e i s u b does the magic Un r aw restores the keyboard after things like X crashes Changing the console loglevel to 0 reduces error messages sa k system attention key kills all processes on the current vir tual console t e rminate kills all processes on the current terminal except init kill kills all processes except init S ync u mount and re b oot are for getting out of really bad situations Debian default installation kernels are not compiled with this option at the time this doc ument is written Recompile the kernel to activate this function Detailed information is in usr share doc kernel doc version Documentation sysrq txt gz or usr src kernel version Documentation sysrq txt gz 8 6 Nifty little commands to remember 8 6 1 Pager less is the default pager file content browser Hit h for help It can do much more than more less can be supercharged by executing eval lesspipe oreval lessfile in the shell startup script See more in usr share doc lessf LESSOPEN The R option allows raw character output and enables ANSI color escape sequences See less 1 w3m may be a useful alternative pager for some code systems EUC 8 6 2 Free memory free and top g
51. add testing sources to this new list If you want to upgrade to unstable then also add unstable sources cd etc apt grep e deb sources list gt srcs gt sources list cp f srcs sources list sed e s stable testing srcs gt gt sources list sed e s stable unstable srcs gt gt sources list apt get update apt get install apt apt utils SF ode de de Se de e 3 See Beginning Debian package management on page 78 for the art of tuning etc apt sources list and etc apt preferences 5 3 Upgrading After properly setting up etc apt sources list and etc apt preferences as de scribed above you can begin the upgrade Note that tracking the testing distribution of Debian can have the side effect of delaying the installation of packages containing security fixes since such packages are uploaded to unstable and only later migrate to testing See Debian package management on page 77 for the basics and see APT upgrade trou bleshooting on page 84 if you encounter problems Chapter 5 Upgrading a distribution to stable testing or unstable 75 5 3 1 Using dselect If a system has many packages which include dev packages etc the following method using dselect is recommended for fine grained package control dselect update always do this before upgrade dselect select select additional packages All your current packages will be selected when dselect starts dselect may prompt you
52. an entity wins For example lt entity gref INCLUDE gt lt Sqref lt entity param Data 1 gt gt lt entity param Data 2 gt amp param This ends up as Data 1 If the first line has IGNORE instead of INCLUDE this ends up as Data 2 the second line is a conditional statement Also repeating phrases can be defined in advance separately from the context lt entity whoisthis my gt Hello amp whoisthis friend This is amp whoisthis book This results in the following Hello my friend This is my book See the short SGML example sample sgm1 in the examples http www debian org doc manuals debian reference examples When SGML documents become bigger sometimes TeX which is used as the backend text processor may cause errors See TeX LaTeX on the current page 13 9 3 TeX LaTeX Preparation tasksel select Miscellaneous gt TeX LaTeX environment References for LaTeX e The teTeX HOWTO The Linux teTeX Local Guide http www tldp org HOWTO TeTeX HOWTO html e tex 1 Chapter 13 Programming 238 e latex 1 e The TeXbook by Donald E Knuth Addison Wesley de e LaTeX A Document Preparation System by Leslie Lamport Addison Wesley e The LaTeX Companion by Goossens Mittelbach Samarin Addison Wesley This is the most powerful typesetting environment Many SGML processors use this as their back end text processor Lyx provid
53. and to control login via a GUI screen etc X11 Xsession is directly executed The console can be made available as in Let me disable X on boot on page 107 Custom X sessions The default startup script etc X11 Xsession is effectively a combination of etc X11 Xsession d 50xfree86 common_determine startup and etc X11 Xsession d 99xfree86 common_start Execution of etc X11 Xsession is somewhat affected by etc X11 Xsession options and is essentially an execution of a program which was first found in the following order with the exec command 1 xsession or Xsession if it is defined 2 usr bin x session manager if it is defined 3 usr bin x window manager if it is defined 4 usr bin x terminal emulator if it is defined The exact meaning of these commands is determined by the Debian alternative system de scribed in Alternative commands on page 94 For example update alternatives config x session manager res OLR update alternatives config x window manager Chapter 9 Tuning a Debian system 149 In order to make any X window manager a default while keeping GNOME and KDE session managers installed replace etc X11 Xsession d 50xfree86 common_determine startup with the one attached in the second bug report at http bugs debian org 168347 I hope this will be included soon and edit etc X11 Xsession options as follows to disallow the X session manager etc X11 Xsession options
54. and command line front end for APT synaptic Gtk GUI front end for APT dselect Menu driven package manager tasksel Task installer These tools aren t all alternatives to one another For example dselect uses both APT and dpkg APT uses var lib apt lists for tracking available packages while dpkg uses var lib dpkg available If you have installed packages using aptitude or other APT front ends and you want to use dselect to install packages then the first thing you should do is update var lib dpkg available by selecting U pdate from dselect s menu or by running dselect update apt get automatically installs all packages upon which a requested package Depends It does not install the packages that a requested package merely Recommends or Suggests aptitude in contrast can be configured to install packages that a requested package Recom mends or Suggests dselect presents the user with a list of packages that a selected package Recommends or Sug gests and allows these to be selected or deselected individually See Package dependencies on page 15 6 1 2 Convenience tools dpkg reconfigure reconfigure an already installed package if it uses debconf dpkg source manage source package file dpkg buildpackage automate the building of a package file apt cache check package archive in local cache 6 2 Beginning Debian package management 6 2 1 Setup APT Set up sources list as describe
55. another Linux distribution than the one you have installed on your system you can use alien to convert it to your preferred package format and install it alien also supports LSB packages 6 4 13 Automatically install command auto apt is an on demand package installation tool sudo auto apt update update database auto apt x y run Entering auto apt mode bin bash Exit the command to leave auto apt mode less usr share doc med bio copyright access non existing file Install the package which provide this file Also install dependencies Chapter 6 Debian package management 93 6 4 14 Verify installed package files debsums enables verification of installed package files against MD5 checksums Some pack ages do not have available MD5 checksums A possible temporary fix for sysadmins cat gt gt etc apt apt conf d 90debsums DPkg Post Install Pkgs xargs usr bin debsums sg D per Joerg Wendland lt joergland debian org gt untested 6 4 15 Optimized sources list In short fancy efforts to create an optimized sources list did not produce a signifi cant improvement for me from a location in the USA I manually chose a nearby site using apt setup apt spy creates sources list automatically based on latency and bandwidth netselect apt creates a more complete sources list but uses an inferior method of choosing the best mirror ping time comparison aptitude install apt spy cd etc apt m
56. cat ssh id_dsa pub ssh userl remote A cat gt gt ssh authorized_keys One can change the passphrase later with ssh keygen p Make sure to verify settings by testing the connection In case of any problem use ssh v You can add options to the entries in authorized_keys to limit hosts and to run specific commands See sshd 8 for details Note that SSH2 has HostbasedAuthentication For this to work you must adjust the settings of HostbasedAuthentication to yes in both etc ssh sshd_config on the server machine and etc ssh ssh_config or HOME ssh config on the client machine 9 5 4 Dealing with alien SSH clients There are a few free SSH clients available for non Unix like platforms Windows puTTY http www chiark greenend org uk sgtatham putty GPL Windows cygwin SSH in cygwin http www cygwin com GPL Macintosh Classic macSSH http www macssh com GPL Note that Mac OS X in cludes OpenSSH use ssh in the Terminal application See also SourceForge net site documentation http www sourceforge net docman group_id 1 6 CVS Instructions Chapter 9 Tuning a Debian system 161 9 5 5 Setting up ssh agent It is safer to protect your SSH authentication key with a passphrase If it was not set use ssh keygen p to set it Place your public key e g ssh id_rsa pub into ssh authorized_keys on a remote host using a password based connection to the remote host as d
57. command changed its option for bz2 files between Potato and Woody so use bzip2 in scripts instead of its short form I Potato or j Woody 8 3 4 pax The new POSIX IEEE Std 1003 2 1992 pages 380 388 section 4 48 and pages 936 940 section E 4 48 all singing all dancing Portable Archive Interchange utility pax will read write and list the members of an archive file and will copy directory hierarchies pax operation is independent of the specific archive format and supports a wide variety of different archive formats pax implementations are still new and wet behind the ears apt get install pax pax rw p e newdir or find depth pax rw p newdir Chapter 8 Debian tips 111 8 3 5 cpio cpio copies files into or out of a cpio or tar archive The archive can be another file on the disk a magnetic tape or a pipe find depth printO cpio null sparse pvd new dir 8 3 6 afio afio is a better way of dealing with cpio format archives It is generally faster than cpio provides more diverse magnetic tape options and deals somewhat gracefully with input data corruption It supports multivolume archives during interactive operation afio can make compressed archives that are much safer than compressed tar or cpio archives afio is best used as an archive engine in a backup script find depth printO afio px 0a new dir All my backups onto tape use afio 8
58. commands The following scripts will do nice things as a part of a pipe find usr egrep v usr var usr tmp usr local find all files in usr excluding some files run command for all items from stdin split white space separated items into lines merge all lines into a line extract lines containing pattern xargs n 1 command xargs n 1 echo xargs echo grep e pattern cut O f 3S extract third field separated by passwd file etc awk print 3 extract third field separated by whitespaces awk F t print 3 extract third field separated by tab Chapter 8 Debian tips 121 col bx expand sort ul Er A LEEN pe e tr TAFA Taz sed s sed s ext g sed n e 2p head n 2 tail n 2 remove backspace and expand tabs to spaces expand tabs sort and remove duplicates concatenate lines into one line remove CR convert uppercase to lowercase make each line a comment remove ext print the second line print the first 2 lines print the last 2 lines Ss de e e e e 8 6 19 Script snippets for looping over each file The following ways of looping over each file matching ext ensures proper handling of funny file names such as ones with spaces and performs equivalent process e Shell loop This is multi line input with PS2 gt for x in ext do if te
59. configuration Typical network service configuration on the desktop or home server environment involves The Internet super server and TCP IP daemon wrapper see Restricting access to services on page 137 etc inetd conf e ssh OpenSSH secure shell see SSH on page 158 etc ssh ssh_config etc ssh sshd_config e exim mail transport agent see Mailname on page 185 and Mail transport agents MTAs on page 162 etc exim exim conf etc mailname etc aliases Chapter 10 Network configuration 201 etc email addresses e fetchmail daemon to fetch mail from a POP3 account see Fetching mail Fetchmail on page 164 etc fetchmailrc e procmail local mail delivery and filter program see Processing mail Procmail on page 165 procmailre e Hostname and DNS proxy cache see Hostname on page 185 and Domain Name Service DNS on page 186 etc host conf etc hostname etc hosts etc hosts allow etc hosts deny etc resolv conf etc bind named conf edit etc bind db lan add for LAN hosts etc bind db 192 168 0 add for LAN reverse e DHCP see Configuring network interfaces using DHCP on page 188 etc dhcp3 dhclient conf DHCP client side etc default dhcp3 server DHCP server side etc dhcp3 dhcpd conf DHCP server side e cvs concurrent versions system see Concurrent Versions System CVS
60. directories and peek into the system using above commands as a training If you have questions on any of the console commands please make sure to read the manual page For example these commands are the good start S man man man bash S man ls Also this is a good timing to start vim and press F1 key You should at least read the first 35 lines Then do the online training course by moving cursor to tutor and pressing Ctrl See Editors on page 207 to learn more about editors Please note that many Unix like commands including ones from GNU and BSD will display brief help information if you invoke them in one of the following ways or without any argu ments in some cases commandname help commandname h Try also examples in Debian tips on page 105 as your self training 2_ zip2 is used here instead of new short option j to ensure this to work with old version of tar in Potato 2__bzip2 is used here again to ensure compatibility Chapter 4 Debian tutorials 56 4 3 3 The command execution Now you have some feel on how to use the Debian system Let s look deep into the mechanism of the command execution in the Debian system 4 3 4 Simple command A simple command is a sequence of 1 variable assignments optional 2 command name 3 arguments optional 4 redirections optional gt gt gt lt lt lt etc 5 control operator optional 8 lt newline gt 8 For more comp
61. e Export DEB_BUILD_OPTIONS nostrip noopt for building the Debian package See Policy 10 1 http www debian org doc debian policy ch files html s10 1 for more info Check dependency on libraries Use ldd to find out a program s dependency on libraries ldd bin ls librt so 1 gt lib librt so 1 0x4001e000 libc so 6 gt lib libc so 6 0x40030000 libpthread so 0 gt lib libpthread so 0 0x40153000 1ib 1d linux so 2 gt lib ld linux so 2 0x40000000 Chapter 13 Programming 233 For 1s to work in a chrooted environment the above libraries must be available in your chrooted environment The following commands will also be useful e strace trace system calls and signals e ltrace trace library calls Debugging with memory leak detection tools There are several memory leak detection tools available in Debian e njamd e valgrind e dmalloc e electric fence e memprof e memwatch not packaged get this from GNU memwatch http www gnu org directory devel debug memwatch htm1 e mpatrol e leaktracer e libgc 6 e Insure from Parasoft http www parasoft com non free commercial for fee Also check out Debugging Tools for Dynamic Storage Allocation and Memory Management http ww cs colorado edu homes zorn public_html MallocDebug html 13 7 3 Flex a better Lex flex is a fast lexical analyzer generator References for flex e info flex tutorial e flex 1
62. e start a Japanese compatible application such as Vim 6 x emacs21 mc 4 5 mutt 1 4 in kterm for Japanese Emacs seems to be the most popular platform though I do not use it e press Shift Space to toggle Japanese character input mode on and off for Japanese e read the localized manual page by starting command in localized console for all For other CJK language supports see the following sections and SuSE pages for CJK http www suse de mfabian suse cjk suse cjk html 9 7 10 Alternative X input methods There are many alternative X input methods support packages available The slash in sect ion enables entry to the initial menu and the leading space in title Mozilla Navigator enables entry to the top of the list Chapter 9 Tuning a Debian system 174 Language LC_CTYPE XIM server XMODIFIERS Start key Japanese ja_JP kinput2 im kinput2 shift Space Korean ko_KR ami im Ami shift Space Chinese T zh_TW Big5 xcin im xcin zh_TW big5 Ctrl Space Chinese S zh_CN GB2312 xcin im xcin zh_CN GB2312 Ctrl Space Japanese input method kinput2 is offered by the packages such as kinput2 canna wnn kinput2 canna and kinput2 wnn Japanese needs dictionary server such as canna and freewnn jserver to be practical 9 7 11 X terminal emulators There are many X consoles which support simple 8 bit encodings when pertinent font packages are installed e xterm The X terminal emulator e
63. enter root instead of penguin here and the corresponding password you will gain the access to the root account This procedure will be needed to regain the access to the root account Chapter 4 Debian tutorials 49 e var log and its subdirectories e usr share doc and its subdirectories e sbinand bin 4 2 1 Enhance MC In order to make MC to change working directory upon exit you need to modify bashrc or etc bash bashrc called from bashrc as detailed in its manual page mc 1 under the P option 4 2 2 Start MC mc MC takes care of all file operations through its menu requiring minimal user effort Just press F1 to get the help screen You can play with MC just by pressing cursor keys and function keys 12 4 2 3 File manager in MC The default is two directory panels containing file lists Another useful mode is to set the right window to information to see file access privilege information etc Following are some essential keystrokes With the gpm daemon running one can use a mouse too Make sure to press the shift key to obtain the normal behavior of cut and paste in MC e Fl Help menu e F3 Internal file viewer e F4 Internal editor e F9 Activate pulldown menu e F10 Exit Midnight Commander e Tab Move between two windows e Insert Mark file for a multiple file operation such as copy e Del Delete file be careful set MC to safe delete mode e Cursor keys Self explanatory
64. files and non dot directories under current direc e rm rf rm El tory e rm rf removes every dot files and dot directories under current directory removes everything under parent directory and parent directory itself FH Fh e rm ri 8 7 2 rm etc passwd Loss of some important files such as etc passwd through your stupidity is tough The Debian system makes regular backups of them in var backups When you restore these files you may manually have to set the proper permissions cp var backups passwd etc passwd chmod 644 etc passwd See also Recover package selection data on page 85 Chapter 8 Debian tips 132 133 Chapter 9 Tuning a Debian system This chapter describes only the basics of system configuration through a command line inter face Before reading this chapter you should read Debian System installation hints on page 25 If you are concerned about security then you should read the Securing Debian Manual http www debian org doc manuals securing debian howto which comes in the harden doc package 9 1 System initialization Debian uses the System V init script system See The init program on page 20 for an intro duction 9 1 1 Customizing init scripts The easiest way to control the behavior of an init script is by changing environment variable assignments in the file named like the init script in the etc default directory Fo
65. for any Windows supported printer no bidirectional communication is supported You have to select the cor responding printer configuration on the Windows machine If you do not have a PostScript printer you need to set up a filtering system using gs There are many autoconfiguration tools provided for setting up etc printcap Any of these com binations is an option e gnulpr 1pr ppd and printtool lI use this e lprand apsfilter e lprand magicfilter e lprng and lprngtool e lprng and apsfilter e lprng and magicfilter In order to run GUI configuration tools such as printtoo1 see Getting root in X on page 153 to gain root privilege Printer spools created with printtool use gs and act like PostScript printers So when accessing them use PostScript printer drivers On the Windows side Apple LaserWriter is the standard one 3 6 2 CUPS Install the Common UNIX Printing System or CUPS Chapter 3 Debian System installation hints 40 apt get install cupsys foomatic bin foomatic db apt get install cupsys bsd cupsys driver gimpprint Then configure the system using any web browser mybrowser http localhost 631 For example to add your printer on some port to the list of accessible printers e click Printers from the main page and then Add Printer e enter root for the username and its password e proceed to add the printer following the prompts e go back to th
66. for optimum compatibility Set os level according to the following system equivalences the larger the number the higher the priority as server O Samba with a loose attitude will never become a master browser 1 WfW 3 1 Win95 Win98 Win Me 16 Win NT WS 3 51 17 Win NT WS 4 0 32 Win NT SVR 3 51 333 Win NT SVR 4 0 2554 Samba with mighty power Make sure that users are members of the group owning the directory that gives shared access and that the directory path has its execution bit set to access Chapter 3 Debian System installation hints 39 3 6 Printer configuration The traditional method is lpr 1pd There is a new CUPS system Common UNIX Printing System PDQ is another approach See the Linux Printing HOWTO http www tldp org HOWTO Printing HOWTO html for more information 3 6 1 lpr lpd For the 1pr 1pd type spoolers lpr lprng and gnulpr setup etc printcap as follows if they are connected to a PostScript or text only printer the basics lp alias sd var spool lpd lp mx 0 sh lp dev 1p0 Meaning of the above lines e Head line lp name of spool alias alias e mx 0 max file size unlimited e sh suppress printing of burst page header e lp dev Ip0 local printer device or port host for remote This is a good configuration if you are connected to a PostScript printer Also when print ing from a Windows machine through Samba this is a good configuration
67. from the GNU shellutils package to set a command s nice value when starting renice bsdutils and top can renice a process A nice value of 19 represents the slowest lowest priority process negative values are not nice with 20 being a very fast high prior ity process Only the superuser can set negative nice values nice 19 top very nice nice 20 cdrecord v eject speed 2 dev 0 0 disk img very fast Sometimes an extreme nice value does more harm than good to the system Use this command carefully Chapter 8 Debian tips 124 8 6 27 Schedule activity cron at Use cron and at to schedule tasks under Linux See at 1 crontab 5 crontab 8 Run the command crontab e to create or edit a crontab file to set up regularly scheduled events Example of a crontab file use bin sh to run commands no matter what etc passwd says SHELL bin sh mail any output to paul no matter whose crontab this is MAILTO paul Min Hour DayOfMonth Month DayOfWeek command Day are OR ed run at 00 05 every day Oe MO BEY SA SHOME bin daily job gt gt SHOME tmp out 2 gt 6 amp 1 run at 14 15 on the first of every month output mailed to paul 15 14 1 SHOME bin monthly run at 22 00 on weekdays 1 5 annoy Joe for newline last for cc Q 22 1 5 mail s It s 10pm joe Joe Where are your kids 23 2 12 echo run 23 minutes after Oam 2am 4am on Feb 1 5 4
68. is chosen for a physical interface being brought up according to some property of the adapter that underlies it Suppose for example you have two different network adapters which you use with networks net1 and net2 respectively The usr share doc ifupdown examples directory con tains a mapping script that can be used to select a logical interface based on the Media Access Controller address MAC address of the adapter First install the script to an appropriate directory install m770 usr share doc ifupdown examples match mac address sh usr local sbin Then add a stanza like the following to etc network interfaces mapping eth0 script usr local sbin match mac address sh map 02 23 45 3C 45 3C netl map 00 A3 03 63 26 93 net2 Chapter 10 Network configuration 196 See Multi stage mapping on page 199 for a more complex example In applying either method the property that is most commonly used to identify the adapter is the MAC address 10 10 Triggering network configuration We have seen how interfaces can be configured or reconfigured This needs to be done at appropriate times Traditionally the network was configured during the boot sequence via the etc rcS d S40networking initscript and was rarely reconfigured Services that depended on network ing were started later in the boot sequence On shutdown or reboot the initscripts were run in the opposite order Currently however there is a trend in
69. kind of file S while read first last month year do echo month done lt DPL same output as the first Awk example Here read built in command uses the characters in IFS internal field separators to split lines into words MD If you change IFS to you can parse etc passwd with shell nicely Chapter 8 Debian tips 120 S oldIFS SIFS save old value IFS while read user password uid gid rest_of_line do if user osamu then echo Suser s ID is uid Er done lt etc passwd osamu s ID is 1001 IFS SoldIFS restore old value If Awk is used to do the equivalent use FS to set the field separator IFS is also used by the shell to split results of parameter expansion command substitution and arithmetic expansion These do not occur within double or single quoted words The default value of IFS is lt space gt lt tab gt and lt newline gt combined Be careful about using this shell IFS tricks Strange things may happen when shell interprets some parts of the script as its input S IFS ise st and Tyr as TES S echo IFS SIFS IFS SIFS echo is a Bash built in IFS IFS date R just a command output Sat 23 Aug 2003 08 30 15 0200 echo date R sub shell gt input to main shell Sat 23 Aug 2003 08 30 36 0200 unset IFS reset IFS to the default echo date R Sat 23 Aug 2003 08 30 50 0200 8 6 18 Script snippets for piping
70. last 2 passwd 3 user substr tolower first 1 1 tolower last Chapter 13 Programming 227 uid startuid record 1 gid uid printf Ss s d d s s home s bin bash n user passwd uid gid first last user Two packages provide POSIX awk in Debian e mawk Priority required Installed Size 228 Smaller and much faster good for default install Compile time limits exist NF 32767 x sprintf buffer 1020 e gawk Priority optional Installed Size 1708 Larger and featureful many extensions implemented x System V Release 4 version of UNIX Bell Labs awk GNU specific 13 4 Perl This is the interpreter on a Unix like system References for Perl e perl 1 e Programming Perl 3rd edition O Reilly The Perl Directory http www perl org Short program example creates newusers command entry usr bin perl C Osamu Aoki Sun Aug 26 16 53 55 UTC 2001 Public Domain Spid 1000 while lt STDIN gt if next chop Spid Snl n2 n3 split print Sni _ n2 2 sn3 Mit Spid a Jar Spid wa r home n1 L n2 ws bin bash n Chapter 13 Programming 228 Install Perl module module_name perl MCPAN e install module_name 13 5 Python It s a nice object oriented interpreter References for Python e python 1 e Learning Python O Reilly e Python Programming
71. mail Mutt Use mutt as the mail user agent MUA in combination with vim Customize with mutt rc for example use visual mode and gq to reformat quotes set editor vim c set tw 72 et ft mail header weeding taken from the manual Sven s Draconian header weeding ignore unignore from date subject to cc unignore user agent x mailer hdr_order from subject to cc date user agent x mailer auto_view application msword Add the following to etc mailcap or HOME mailcap to display HTML mail and MS Word attachments inline text html lynx force_html s needsterminal application msword usr bin antiword s copiousoutput description Microsoft Word Text nametemplate s doc 9 7 Localization Debian is internationalized offering support for a growing number of languages and local us age conventions The next subsection lists some of the forms of diversity that Debian currently Chapter 9 Tuning a Debian system 166 supports and the following subsections discuss localization the process of customizing your working environment to allow current input and output of your chosen language s and con ventions for dates numeric and monetary formats and other aspects of a system that differ according to your region 9 7 1 Basics of localization There are several aspects to customizing for localization and national language support Localizing the keyboard Debian is distri
72. more safely sudo My usage of sudo is mostly a protection from my own stupidity Personally I consider using sudo a better alternative to always using the system as root Install sudo and activate it by setting options in etc sudoers http www debian org doc manuals debian reference examples Also check out the sudo group feature in usr share doc sudo OPTIONS The sample configuration provides staff group members access to any commands run as root under sudo and also gives src members access to selected commands run as root under sudo The advantage of sudo is that it only requires an ordinary user s password to log in and activity is monitored This is a nice way to give some authority to a junior administrator For example sudo chown R myself mygrp Of course if you know the root password as most home users do any command can be run under root from a user account S su c shutdown h now Password I know I should tighten the admin account s sudo privileges But since this is my home server I have not bothered yet For a different program that allows ordinary users to run commands with root privileges see the super package 9 2 5 Restricting access to services The Internet super server inetd is started at boot time by etc rc2 d S20inetd for RUN LEVEL 2 which is a symlink to etc init d inetd Essentially inetd allows one run ning daemon to invoke several others reducing load o
73. new user account Suppose you wish this new username to be penguin type root foo root adduser penguin answer all the questions will create it Before going further let s learn few things first 4 1 4 Switch between virtual console In the default Debian system there are six independent pseudo terminals available i e you can use the PC s VGA character console screen as 6 switchable VT 100 terminals Switch from one to another by pressing the Left Alt key and one of the F1 F6 keys simultaneously Each pseudo terminal allows independent login to accounts The multiuser environment is a great Unix feature and very addictive If you accidentally typed Alt F7 on a system running the X Window System and the console screen displays graphic screen regain the access to the character console by pressing Ctrl Alt F1 Just try to move to different console and come back to the original one to get used to this 4 1 5 How to shut down Just like any other modern OSs where the file operation involves caching data in the memory the Debian system needs the proper shutdown procedure before power can safely be turned off to maintain the integrity of files Use the following command from the root command prompt to shutdown the system shutdown h now This is for the normal multiuser mode If you are in the single user mode use following from the root command prompt poweroff i f 5I tend to name this account created duri
74. newl gt file patchoO diff u old file newl file gt file patchl The diff file alternatively called patch file is used to send a program update The receiving party will apply this update to another file by patch p0 file lt file patchO patch p1 file lt file patchl If you have three versions of source code you can merge them more effectively using diff3 S diff3 m file mine file old file yours gt file Chapter 8 Debian tips 119 8 6 16 Convert a large file into small files split b 650m file split file into 650MB chunks cat x gt largefile merge files into 1 large file 8 6 17 Extract data from text file table Let s consider a text file called DPL in which all previous Debian project leader s names and their initiation days are listed in a space separated format Tan Murdock August 1993 Bruce Perens April 1996 Tan Jackson January 1998 Wichert Akkerman January 1999 Ben Collins April 2001 Bdale Garbee April 2002 Martin Michlmayr March 2003 Awk is frequently used to extract data from these types of files awk print 3 lt DPL month started August April January January April April March awk 1 Tan print lt DPL DPL called Ian Tan Murdock August 1993 Tan Jackson January 1998 awk 2 Perens print 3 4 lt DPL When Perens started April 1996 Shells such as Bash can be also used to parse this
75. of the following examples at the 1i1o boot prompt will work Chapter 8 Debian tips 108 boot Linux S boot Linux 1 boot Linux s If you want to boot the system with less memory than system actually has say 48MB for a system with 64MB use this input at the 1i 10 boot prompt boot Linux mem 48M Make sure not to specify more than the actual memory size here otherwise the kernel will crash If one has more than 64MB of memory e g 128MB unless one executes mem 128M at the boot prompt or includes a similar append line in etc lilo conf old kernels and or a motherboard with an old BIOS will not use memory beyond 64MB 8 1 6 Setting GRUB boot parameters GRUB is a new boot manager from the GNU Hurd project and is much more flexible than Lilo but has slightly different handling of boot parameters grub gt find vmlinuz grub gt root hd0 0 grub gt kernel vmlinuz root dev hdal grub gt initrd initrd grub gt boot Here you must be aware of the Hurd device names the Hurd GRUB Linux MSDOS Windows d0 dev d0 A hd0 0 dev hdal C usually hd0 3 dev hda4 F usually hdl 3 dev hdb4 See usr share doc grub README Debian and usr share doc grub doc html for details 8 2 Recording activities 8 2 1 Recording shell activities System administration involves much more elaborate tasks in a Unix environment than in an ordinary personal computer environment Make sure to kno
76. on page 213 etc cvs cron conf etc cvs pserver conf e nfs kernel server network file system see NFS configuration on page 38 for unix like systems etc exports e samba network file and printer share for Windows see Samba configuration on page 38 and Samba on page 130 etc samba smb conf e Printer daemon system see Printer configuration on page 39 etc printcap for lpr e apache and apache2 web server etc apache etc apache2 e squid web proxy cache server etc squid 10 13 Network troubleshooting If you encounter problems then check the output of the following as the first reality check ifconfig Chapter 10 Network configuration 202 cat proc pci cat proc interrupts dmesg more Also see the sections following Network testing basics on page 126 If you have problems with certain websites see Strange access problems with some websites on page 42 10 14 Building a gateway router A Debian host can be an all purpose gateway machine that does Network Address Translation NAT also known as masquerading mail transfer DHCP DNS caching HTTP proxy caching CVS service NFS serving and Samba serving See Hosts and IP to use for LAN on page 29 for the example of such set up 10 14 1 Netfilter configuration The netfilter iptables project is a firewalling subsystem for Linux 2 4 and after See Netfilt
77. opposite way in X window plus refers to the keys on the numeric keypad e Ctrl Alt Backspace Terminate the X Server program e Alt X Alt C Alt V Usual Windows Mac Cut Copy Paste keys combinations with Ctrl keys are replaced by these Alt keys in some programs such as Netscape Composer 4 7 Further study At this moment I recommend you to read the key guide books from The Linux Documentation Project Guides http www tldp org guides html e The Linux System Administrators Guide This covers all of the aspects of keeping the system running handling user accounts backups configuration of the system Chapter 4 Debian tutorials 72 package sysadmin guide file usr share doc sysadmin guide sag html index html web http www tldp org LDP sag index html e The Linux Network Administrator s Guide Second Edition This is a single reference for network administration in a Linux environment package not available file notapplicable web http www tldp org LDP nag2 index html e The Linux Cookbook This provides over 1 500 time saving recipes and hints for busy modern computer users package linuxcookbook file usr share doc linuxcookbook cookbook_toc html web http www tldp org LDP linuxcookbook html index html See Support for Debian on page 245 for more learning resources 73 Chapter 5 Upgrading a distribution to stable testing or unstable
78. origin CP1251 Bulgarian Byelorussian MS Windows origin eucJP Unix style Japanese ujis eucKR Unix style Korean GB2312 Unix style Simplified Chinese GB eucCN for zh_CN Big5 Traditional Chinese for zh_TW sjis Microsoft style Japanese Shift JIS As for the meaning of basic encoding system jargons ASCII 7 bits 0 0x7f ISO 8859 8 bits 0 Oxff ISO 10646 1 Universal Character Set UCS 31 bits 0 0x7fffffff UCS 2 First 16 bit of UCS as straight 2 Octets Unicode 0 Oxffff UCS 4 UCS as straight 4 Octets UCS 0 0x7fffffff UTF 8 UCS encoded in 1 6 Octets mostly in 3 Octets ISO 2022 7 bits 0 Oxff with the escape sequence ISO 2022 JP is the most popular en coding for the Japanese e mail EUC 8 bits 16 bits combination 0 Oxff Unix style Shift JIS 8 bits 16 bits combination 0 0xff Microsoft style ISO 8859 EUC ISO 10646 1 UCS 2 UCS 4 and UTF 8 share the same code with ASCII for the 7 bit characters EUC or Shift JIS uses high bit characters 0x80 0xff to indicate that part of encoding is 16 bit UTF 8 also uses high bit characters 0x80 Oxff to indicate non 7 bit character sequence bytes and this is the most sane encoding system to handle non ASCII characters Please note the byte order difference of Unicode implementation Standard UCS 2 UCS 4 big endian Microsoft UCS 2 UCS 4 little endian for ix86 machine dependent See Convert a text file with recode on page 117 for
79. package e ssh X method port forwarding mechanism through secure shell secure encrypted protocol a waste of resources if used locally use this for remote connections See Connecting to a remote X server ssh on page 152 All remote connection methods except ssh require TCP IP connection enabled on the X server See Using X over TCP IP on page 151 9 4 1 X packages There are a few meta packages provided to ease installation of the X system in Woody x window system core This metapackage provides the essential components for a stand alone workstation running the X Window System It provides the X libraries an X server xserver xfree86 a set of fonts and a group of basic X clients and utilities x window system This metapackage provides substantially all the components of the X Window System as developed by the XFree86 Project as well as a set of historically pop ular accessory programs Notably it depends on x window system core twm and xdm i e no need to install x window system core if you install this xserver common v3 Files and utilities common to XFree86 3 x X servers XF3 xserver Supplemental XF3 server packages to support hardware not supported by the new XF4 server xserver xfree86 for whatever reason Some old ATI mach64 cards are not supported in XF4 other cards hang badly in the Woody version of XF4 etc For available packages use apt cache search xserver less
80. package upgrades If a default version of a locally configurable file is shipped in the package itself then the file is listed as a conffile The package management system does not upgrade conffiles that have been changed by the administrator since the package was last installed without getting the administrator s permission On the other hand if the conffile has not been changed by the administrator then the conffile will be upgraded along with the rest of the package This is almost always desirable and so it is advantageous to minimize changes to conffiles To list the conffiles belonging to a package run the following command dpkg status package The list follows the Conffiles line For more information about conffiles you can read the section of the Debian Policy Manual entitled Configuration files See References on page 245 2 2 5 Debian maintenance scripts Debian maintenance scripts are executable scripts which are automatically run before or after a package is installed Along with a file named control all of these files are part of the control section of a Debian archive file The individual files are preinst This script executes before its package is unpacked from its Debian archive deb file Many preinst scripts stop services for packages which are being upgraded until their installation or upgrade is completed following the successful execution of the postinst script
81. page 2 1 6 The frozen distribution When the testing distribution is mature enough it becomes frozen meaning no new code is accepted anymore just bugfixes if necessary Also a new testing tree is created in the dists directory assigned a new codename The frozen distribution passes through a few months of testing with intermittent updates and deep freezes called test cycles The recent Woody Chapter 2 Debian fundamentals 8 release process did not create a symbolic link frozen so frozen was not a distribution but just a development stage of the testing distribution We keep a record of bugs in the frozen distribution that can delay a package from being re leased or bugs that can hold back the whole release Once that bug count lowers to maximum acceptable values the frozen distribution becomes stable it is released and the previous stable distribution becomes obsolete and moves to the archive 2 1 7 Debian distribution codenames Physical directory names in the dists directory such as sarge and etch are just code names When a Debian distribution is in the development stage it has no version number but a codename instead The purpose of these codenames is to make the mirroring of the Debian distributions easier if a real directory like unstable suddenly changed its name to stable a lot of stuff would have to be needlessly downloaded again Currently stable is a symbolic link to sarge and testing
82. quickly as mutt was the inspiration for the expression syntax See SEARCHING LIMITING AND EXPRES SIONS in usr share doc aptitude README e aptitude in full screen mode has su functionality embeded and can be run from normal user until you really need administrative privileges 6 2 4 dselect In stable releases up to and including Potato dselect was the principal package maintenance tool For Sarge you should consider using apt itude instead When started dselect automatically selects all Required Important and Standard packages dselect has a somewhat strange user interface Most people get used to it however It has four commands Capital means CAPITAL Key stroke Action Q Quit Confirm current selection and quit anyway override dependencies R Revert I did not mean it D Damn it I do not care what dselect thinks Just Do it U Set all to sUggested state With D and you can select conflicting selections at your own risk Handle these commands with care Add a line containing the option expert in etc dpkg dselect cfg to reduce noise If your machine runs dselect slowly then you might consider running dselect on another faster machine in order to determine the packages you want to install then use apt get install on the slow machine to install them 6 2 5 Tracking a distribution using APT To track the testing distribution as it changes make your etc apt preferences fi
83. shell allows you to open files using the exec built in with an arbitrary file descriptor echo Hello gt foo S exec 3 lt foo 4 gt bar open files S cat lt amp 3 gt amp 4 redirect stdin to 3 stdout to 4 exec 3 lt amp 4 gt amp Close files cat bar Hello Here n lt amp and n gt amp mean to close the file descriptor n 13 2 5 Shell conditionals Each command returns an exit status which can be used for conditional expressions Success O True e Error 1 255 False Note that the use here of a 0 value to mean true differs from the usual convention in some other areas of computing Also is the equivalent of the test command which evaluates its arguments up to as a conditional expression Basic conditional idioms to remember are command amp amp if _success_run_this_command_too true command if_not_success_run_this_command_instead if conditional_expression then if _success_run _this_ command else if_not_success_run _this_command fi Here true was needed to ensure this shell script will not exit at this line accidentally when shell is invoked with e flag File comparison operators in the conditional expression are Chapter 13 Programming 225 e file True if file exists d file True if file exists and is a directory f file True if file exists and is a regular file w file True if file exists and is writable x file True if file exist
84. so Look at the last parameter in the output text There are more than 10 characters even though 10s is specified The use of pointer memory operation functions without boundary checks such as sprintf and strcpy is deprecated to prevent buffer overflow exploits that leverage the above overrun effects Instead use snprintf and strncpy 13 7 2 Debugging Debugging with gdb Preparation Chapter 13 Programming 232 apt get install gdb References for gdb e info gdb tutorial e gdb 1 e http www unknownroad com rtfm gdbtut gdbtoc html Use gdb to debug a program compiled with the g option Many commands can be abbrevi ated Tab expansion works as in the shell gdb program gdb b 1 set breakpoint at line 1 gdb run argl arg2 arg3 run program gdb next next line gdb step step forward gdb p parm print parm gdb p parm 12 set value to 12 For debugging from within Emacs refer to Editor command summary Emacs Vim on page 209 Since all installed binaries should be stripped on the Debian system by default most debug ging symbols are removed In order to make gdb useful for debugging Debian packages pertinent packages need to be rebuild with following care e Edit debian control to bump the package version http www debian org doc debian policy ch controlfields html s f Version e Check build scripts and ensure to use CFLAGS g Wall for compiling binaries
85. the previ ous calling chain e extended targets LOG turns on kernel logging REJECT sends back an error packet and drops the packet SNAT alters the source address of the packet and is used only in the POSTROUTING Chain nat table only to source ipaddr ipaddr port port MASQUERADE is the same as SNAT but for dynamically assigned IP dialup con nections nat table only to ports port port DNAT alters the destination address of the packet and is used in the PREROUT ING and OUTPUT chains and user defined chains which are only called from those chains nat table only to destination ipaddr ipaddr port port REDIRECT alters the destination IP address to send the packet to the machine itself to ports port port Netfilter commands The basic commands of iptables are iptables N chain create a chain iptables A chain add rule to chain t table use table filter nat mangle p protocol tcp udp icmp or all Chapter 10 Network configuration 204 s source address mask sport port port source port if p is tcp or udp d destination address mask dport port port dest port if p is tcp or udp j target what to do if match i in interface name for INPUT FORWARD PREROUTING 0o out interface name for FORWARD OUTPUT POSTROUTING Network Address Translation Machines on a LAN can access Internet resources throug
86. to the service when the package was installed The disable the service rename the symbolic link so that its name begins with a K instead of with an S and its sequence number is 100 minus xy It is convenient to use a runlevel editor such as sysv rc conf or ksysv for these purposes It is possible to delete the S symlink for a service in a particular runlevel directory instead of renaming it This does not disable the service but leaves it in a floating state as far as the sysv rc init system is concerned on runlevel changes the service will be neither started nor stopped but will be left as it was whether running or not running Note however that a service left in such a floating state will be started if its package is upgraded whether or not it was running before the upgrade This is a known shortcoming of the current Debian system Note also that you should retain a service s K symlinks in runlevels 0 and 6 If you delete all the symlinks for a service then on upgrade the service s package will restore the symlinks to their factory default state It is not advisable to make any changes to symlinks in etc rcS d 2 5 Supporting diversity Debian offers several avenues to accommodate any wishes of the system administrator without breaking the system Chapter 2 Debian fundamentals 22 e dpkg divert see The dpkg divert command on page 93 e equivs see The equivs package on page 94 e update alternative see
87. to write this document To the extent Osamu Aoki considered within the fair quotation stature many parts of them especially command definitions were used as phrase pieces after careful editorial efforts to fit them into the style and the objective of this document Most of the contents of Debian fundamentals on page 5 originally came from The Debian FAQ March 2002 e 5 The Debian FTP archives ftparchives sgml entire chapter e 6 Basics of the Debian Package Management System pkg_basics sgml entire chap ter e 7 The Debian Package Management Tools pkgtools sgml entire chapter e 8 Keeping Your Debian System Up To Date uptodate sgml entire chapter e 9 Debian and the kernel kernel sgm1 entire chapter e 10 Customizing your installation of Debian GNU Linux customizing sgml part of chapter These sections of The Debian FAQ were included in this document after major reorganiza tion to reflect changes in the Debian system Both documents are updated concurrently now The original Debian FAQ was made and maintained by J H M Dassen Ray and Chuck Stickelman Authors of the rewritten Debian FAQ are Susan G Kleinmann and Sven Rudolph After them The Debian FAQ was maintained by Santiago Vila The current main tainer is Josip Rodin Parts of the information for The Debian FAQ came from e The Debian 1 1 release announcement by Bruce Perens http www perens com e The Lin
88. tricks with the boot prompt on page 107 If APM is compiled as a module as in Debian default 2 4 kernels run insmod apm power_off 1 after boot or set etc modules by echo apm power_off 1 gt gt etc modules Alternatively compiling ACPI support achieves the same goal with newer kernels and seems to be more SMP friendly this requires a newer motherboard The 2 4 kernel on newer moth erboards should detect large memory correctly CONFIG_PM y CONFIG_ACPI y CONF IG_ACPI_BUSMGR m CONF IG_ACPI_SYS m and add the following lines in etc modules in this order ospm_busmgr ospm_system ai Or recompile the kernel with all of the kernel options above set to y In any case none of the boot prompt parameters are needed with ACPI 3 7 5 Strange access problems with some websites Recent Linux kernels enable ECN by default which may cause access problems with some websites on bad routers To check ECN status cat proc sys net ipv4 tcp_ecn vas OF sysctl net ipv4 tcp_ecn To turn it off use echo 0 gt proc sys net ipv4 tcp_ecn ian OF sysctl w net ipv4 tcp_ecn 0 To disable TCP ECN on every boot edit etc sysct1 conf and add net ipv4 tcp_ecn 0 Chapter 3 Debian System installation hints 43 3 7 6 Dialup PPP configuration Install the pppconfig package to set up dialup PPP access apt get install pppconfig pppconfig follow the directions to configure dialu
89. your system has a permanent Internet connec tion Set time with sporadic Internet connection Use the chrony package Chapter 8 Debian tips 115 8 6 5 How to control console features such as the screensaver For disabling the screensaver use following commands In the Linux console setterm powersave off Start the kon2 kanji console with kon SaveTime 0 While running X xset s off or xset dpms or xscreensaver command prefs Read the corresponding manpages for controlling other console features See also stty 1 for changing and printing terminal line settings 8 6 6 Search administrative database Glibc offers getent 1 for searching entries from administrative databases i e passwd group hosts services protocols or networks getent database key 8 6 7 Disable sound beep One can always unplug the PC speaker For the Bash shell echo set bell style none gt gt inputre 8 6 8 Error messages on the console screen In order to quiet on screen error messages the first place to check is etc init d klogd Set KLOGD c 3 in this script and run etc init d klogd restart An alternative method is to run dmesg n3 Here error levels mean Chapter 8 Debian tips 116 KERN_EMERG system is unusable KERN_ALERT action must be taken immediately KERN_CRIT critical conditions KERN_ERR error conditions KERN_WARNING warning conditions KERN_
90. 1 a h now 3 7 2 Modules Modules for the device drivers are configured during the initial installation modconf pro vides menu driven module configuration afterward This program is quite useful when some modules were left out during the initial installation or a new kernel was installed after the initial installation All preloading module names need to be listed in etc modules I also use 1smod and depmod to control them manually Also make sure to add a few lines in etc modules to handle IP masquerading FTP etc for 2 4 kernels See The modularized 2 4 kernel on page 99 specifically Network function on page 100 3 7 3 CD RW basic setup Edit the following files etc lilo conf add append hdc ide scsi ignore hdc run lilo to activate dev cdrom symlink cd dev ln sf scd0 cdrom etc modules add ide scsi and sg If needed sr after this See CD writers on page 138 for details 3 7 4 Large memory and auto power off Edit etc lilo conf as follows to set boot prompt parameters for large memory for 2 2 kernels and auto power off for APM append mem 128M apm on apm power off noapic Chapter 3 Debian System installation hints 42 Run lilo to install these settings apm power off is needed for a SMP kernel and noapic is needed to avoid problems for my buggy SMP hardware The same can be done directly by entering options at the boot prompt See Other boot
91. 3hij4 s d ess Leal PLONE TADA oay Chapter 4 Debian tutorials 63 zzz labc2efg3hi34 echo zzzlabc2efg3hij4 s d e s 1fla z1 0 9 2 s 1 zzzefg3hi34 1labc echo zzzlabc2efg3hij4 perl pe s 1 a z 0 9 2 1 zzzefg3hi34 1labc echo zzzlabc2efg3hij4 perl pe s 1 a z 0 9 amp ZZZ amp Here please pay extra attention to the style of the bracketed regular expression and how the matched strings are used in the text replacement process on different tools These regular expressions can be used for the cursor movements and the text replacement actions in the editors too Please read all the related manual pages to learn these commands 4 5 Unix like filesystem In the GNU Linux and other Unix like OS systems the files are organized into directories 28 All files and directories are arranged in one big tree the file hierarchy rooted at These files and directories can be spread out over several devices The mount 8 command serves to attach the file system found on some device to the big file tree Conversely the umount 8 command will detach it again 4 5 1 Unix file basics Here are the basics e Filenames are case sensitive That is MYFILE and MyFile are different files e The root directory is referred to as simply Don t confuse this root with the root user See Login to a shell promp
92. 4 8 6 33 Clear file contents In order to clear the contents of a file such as a logfile do not use rm to delete the file and then create a new empty file because the file may still be accessed in the interval between commands The following is the safe way to clear the contents of the file gt file to be cleared 8 6 34 Dummy files The following commands will create dummy or empty files S dd if dev zero of filename bs 1k count 5 5KB of zero content dd if dev urandom of filename bs 1m count 7 7MB of random content touch filename create OB file if file exists updates mtime For example the following commands executed from the shell of the Debian boot floppy will erase all the content of the hard disk dev hda completely for most practical uses dd if dev urandom of dev hda dd if dev zero of dev hda 8 6 35 chroot The chroot program chroot 8 enables us to run different instances of the GNU Linux environment on a single system simultaneously without rebooting One may also run a resource hungry program such as apt get or dselect under the chroot of a fast host machine while NFS mounting a slow satellite machine to the host as r w and the chroot point being the mount point of the satellite machine Run a different Debian distribution with chroot A chroot Debian environment can easily be created by the deboot st rap command in Woody For example to create a Sid chroot on sid root while having fast In
93. 6 1 Startthe X Window System 4 ee so sos asma o e ee 71 46 2 Menu in the X Window System e esos hee ee ee we a E eA 71 4 6 3 Keyboard sequence for the X Window System o o o o o 71 By TOC se oea ea eee i eR ESRD EMS SOR Eee he a 71 5 Upgrading a distribution to stable testing or unstable 73 5 1 Upgrading from Potato to Woody naoa aaa e e DS 73 Bie Prcpanne for PERES ccs cosci ee ew Ea bh popan A Rd 74 Oe UPE DE a LEE AA AS EA AA BREED A ey 74 Al USE ASCO e A RANA AA A A oe od 75 A MS a BS eed A See ERS 75 CONTENTS vi 6 Debian package management 77 GL TOGO e soss al AAA A BEER EES 77 611 Mainpackage management tools o osos s cae cesa soa sa sipa th 78 6 1 2 CONVENIENCE tools 2c 2s ece REIR Eek eo ale BBs 78 6 2 Beginning Debian package management 6444 60s be eed eee ee es 78 Gl SELMPAL L o iia eee SSS ESS A 455 es 78 6242 MSANE II 79 Oe ape o e tar a OES AS nt a eed 79 624 GS6lSCE ck comi ae a a A Ee ae eS 80 625 Tracking a distribution using APT is ice ee peewee eee ede eas 80 6 2 6 aptitude apt get and apt cache commands 81 6 3 Debian survival commands edicion 83 65 1 Check buest Debian and seek help cs s coore doka ede ee eee e 83 622 APT upgrade troubl shooting lt lt 60s misessa d eae bees 84 Gor Rescue Using APRI es d sodo ou rhe warok AAA 84 6 3 4 Recover package selection data ooo a 85 639 Rescuesystem after crashing Val 64 c s roe ea a a A 85
94. 8 10 6 1 Configuring an interface with a static IP address Suppose you want to configure an Ethernet interface such that it has a fixed IP address of 192 168 0 123 This address begins with 192 168 0 so it must be on a LAN Suppose further that 192 168 0 1 is the address of the LAN s gateway to the Internet Edit etc network interfaces so that it includes a stanza like this face eth0 inet static address 192 168 0 111 netmask 255 255 255 0 gateway 192 168 0 1 H You can configure other aspects of the interface or perform other actions after the interface is brought up or before it is brought down by specifying appropriate commands on up and down lines iface eth0 inet static address 192 168 0 111 netmask 255 255 255 0 gateway 192 168 0 1 up route add net 10 0 0 0 netmask 255 0 0 0 gw 192 168 0 2 dev SIFAC down route del net 10 0 0 0 netmask 255 0 0 0 gw 192 168 0 2 dev IF up echo Interface IFACE going up usr bin logger t ifup down echo Interface IFACE Going down usr bin logger t ii Alternatively commands can be inserted into scripts in the etc network if up d and etc network if down d directories Such scripts can also implement extended options See interfaces 5 for details For example the resolvconf package includes scripts that allow you to add options specifying DNS information to be included in etc resolv conf while the interface is up
95. AP HOWTO index html e LDP LDAP Implementation HOWTO http www tldp org HOWTO LDAP Implement at ion HOWTO index html e OpenLDAP extensive use reports http portal aphroland org aphro ldap docs ldap htm1 e Open LDAP with Courier IMAP and Postfix http annapolislinux org docs plc postfix courier howto txt 9 3 CD writers CD writers with ATAPI IDE interfaces have recently become a very popular option Itis a nice medium for system backup and archiving for the home user needing lt 640MB capacity For the most authoritative information see the LDP CD Writing HOWTO http www tldp org HOWTO CD Writing HOWTO html Chapter 9 Tuning a Debian system 139 9 3 1 Introduction First any disruption of data sent to the CD writer will cause irrecoverable damage to the CD Get a CD writer with as large a buffer as possible If money is no object do not bother with ATAPI IDE just get a SCSI version If you have a choice of IDE interface to be connected use the one on the PCI bus i e on the motherboard rather than one on the ISA bus an SB16 card etc When a CD writer is connected to IDE it has to be driven by the IDE SCSI driver instead of an ordinary IDE CD driver for Linux 2 2 and 2 4 kernels Also the SCSI generic driver needs to be activated There are two possible approaches to doing this assuming a kernel distributed with modern distributions as of March 2001 9 3 2 Approach 1 modules lilo Add t
96. DP http debian linux org pl Marcin Andruszkiewicz Mariusz Centka lt mariusz centka debian linux org pl gt Bartosz Fe ski lt feniofdebian linux org pl gt leader pl Rados aw Grzanka lt radekgldebian linux org pl gt Bartosz Xebord Janowski Jacek Lachowicz Rafa Michaluk Leonard Milcin Jr Tomasz Z Napiera a lt zenftdebian linux org pl gt Oskar Ostafin lt cx debian linux org pl gt Tomasz Pi ko Jacek Politowski Mateusz Prichacz lt mateuszfdebian linux org pl gt Marcin Rogowski Pawe R a ski Mariusz Strzelecki Krzysztof cierski Przemys aw Adam Smiejek lt tristan debian linux org pl gt Mateusz Tryka lt uszekfdebian linux org pl gt Cezary Uchto Krzysztof Witkowski lt t jup debian linux org pl gt Bartosz Zapatowski lt zapal debian linux org pl gt e Chinese simplified translation Hao Lyoo LIU lt iamlyoo 163 net gt leader zh cn Ming Hua lt minghua rice edu gt e Chinese traditional translation Tang Wei Ching lt wctang csie nctu edu tw gt leader zh tw e Japanese translation Shinichi Tsunoda lt tsuno ngy 1st ne jp gt leader ja Chapter A Appendix 255 QREF was short for the original document title Quick Reference name at qref sourceforge net and also is the project Many manual pages and info pages on the Debian system were used as the primary references
97. Debian Reference Osamu Aoki lt osamu debian org gt Editor David Sewell lt dsewell virginia edu gt Authors on page 253 CVS Fri Aug 13 02 13 33 UTC 2004 Abstract This Debian Reference http qref sourceforge net is intended to provide a broad overview of the Debian system as a post installation user s guide It covers many aspects of system administration through shell command examples Basic tutorials tips and other information are provided for topics including fundamental concepts of the Debian system system installation hints Debian package management the Linux kernel under Debian system tuning building a gateway text editors CVS programming and GnuPG for non developers Copyright Notice Copyright O 2001 2004 by Osamu Aoki lt osamu debian org gt Copyright Chapter 2 1996 2001 by Software in the Public Interest This document may be used under the terms of the GNU General Public License version 2 or higher http www gnu org copyleft gpl html Permission is granted to make and distribute verbatim copies of this document provided the copyright notice and this permission notice are preserved on all copies Permission is granted to copy and distribute modified versions of this document under the conditions for verbatim copying provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one Permission is granted to copy and distri
98. Debian standard method Classic method Kernel headers Fook MOMIAS e a a ds A A a ts ta SSR oe SCSI ores RSS KERR Bee e Se CERES EP ERRS ES EAS SEES e EE 7 29 Network functi e e 644 Bh A KSA RAMEE ES EE aea SERS ES Vom EXIS Slesystem LA es ade BS ORNS BPRS Mk ee we ES foe Realtek RTL 8139 supportin 24 gt spo ra seose Opoa One eS ral Paralel POR SUDOR BER Ee EE RS 7 3 Tuning the kernel through the proc filesystem o o o o o fon TOO DION Open Ges cos di A A RA AAA A fom Disk fish interyals a our 7 3 3 Sluggish old low memory machines cios eones ben es 8 Debian tips 8 1 Booting the system 8 1 1 812 I forgot the root password 1 I forgot the root password 2 92 92 93 93 93 93 94 94 94 95 97 97 97 98 99 99 99 100 100 101 103 103 103 103 104 104 CONTENTS viii 8 2 8 3 8 4 8 5 8 6 Slo Cannorpoorihe sytem lt lt 4 chee ChE ee LEGS EEE Stee eS 106 8 14 Letme disable LON GOO cria BSE BEERS a ERS 107 8 1 5 Other boot tricks withthe boot prompt 2 2 4 eee ecew ee eva 107 8 16 Setting GRUB boot parameters lt lt cs cd vei ede as eae Eee 108 a o e s cce aoe e PE RS EEE OER OE SOE 108 8 2 1 Recording shell activities 2 6664 SES EERE A RS KRERERS 108 8 2 2 Recording ASEOS cc end EA AT AN 109 Copy and archives wholesubdirectory o c sa coe na rl a ee RS 109 8 3 1 Basic commands for copying a whole subdirectory
99. EM VALUE MEANING source tree project x All source codes Project name project x Name for this project Vendor Tag Main branch Tag for the entire branch Release Tag Release initial Tag for a specific release Then cd project x dive into source directory create a source tree cvs import m Start project x project x Main branch Release initial 5 cd rm R project x Work with CVS To work with project x using the local CVS repository WY Ur unrnnnnnnnn UY NN UN Ur nn cd cvs cd cvs cvs cvs vi cvs cvs cvs CVS cvs cvs cvs cd cvs move to the work area co project x get sources from CVS to local project x make changes to the content diff u similar to diff u repository local up C modified_file undo changes to a file ci m Describe change save local sources to CVS newfile_added add newfile_added ci m Added newfile_added up merge latest version from CVS to create all newly created subdirectories from CVS use cvs up d P instead watch out for lines starting with C filename unmodified code is moved to tfilename version search for lt lt lt lt lt lt lt and gt gt gt gt gt gt gt in filename tag Release 1 add release tag edit further tag d Release 1 remove release tag ci m more comments tag Release 1 re add release tag move back to the work area co r Release initial d old project x Chapter 12 Ver
100. ER In this example 2 bug work arounds are deployed for the version of blackbox in 2003 I use sh c in command Also menu entry is not used but root requiring etc menu was used instead Chapter 9 Tuning a Debian system 172 Hitt activate input method for Japanese with kinput2 kinput2 amp XMODIFIERS im kinput2 export XMODIFIERS How about blackbox window manager lightweight exec blackbox texec xfwm texec wmaker e set locale in bash_profile for Linux consoles for all e remove locale settings from bashrc if existed for all e create few files in etc menu for all etc menu xterm local add new entries to menu package xterm needs x11 section XShells longtitle XTerm terminal emulator en_US ISO 8859 1 title XTerm en_US ISO 8859 1 command sh c LC_ALL en_US ISO 8859 1 xterm package xterm needs x11 section XShells longtitle XTerm terminal emulator de_DE ISO 8859 1 title XTerm de_DE ISO 8859 1 command sh c LC_ALL de_DE ISO 8859 1 xterm T xterm de package xterm needs x11 section XShells longtitle XTerm terminal emulator for X with Unicode support title UXTerm ja_JP UTF 8 command sh c LC_ALL ja_JP UTF 8 uxterm etc menu kterm override the system default package kterm needs x11 section XShells command sh c LC_ALL ja_JP eucJP PAGER w3m usr X11R6 bin kter t
101. GNU and Linux toward supporting hardware and cir cumstances that change dynamically First support was added for hot swappable PCMCIA cards more recently the hotplug mechanism has been added so that many more peripherals can be swapped in and out while the computer is running This includes networking hard ware Note that services that depend on hardware that is hot swapped must only be started after the hardware is inserted and must be stopped when the hardware is removed This means that such services must be removed from the control of the System V init system and put under the control of i fupdown instead For example suppose service foo controlled by initscript etc init d foo depends on dynamically reconfigured network interface et h0 e First remove foo from the control of the init system If you are using the sysv rc init system then do the following rm etc rc 2345 d S foo e Then put foo under the control of ifupdown by adding up and down options to the eth0 stanza in etc network interfaces which contain calls to the foo initscript iface ethO inet dhcp up etc init d foo start down etc init d foo stop 10 10 1 Triggering network configuration at boot time On boot the etc rcS d S40networking init script runs the command ifup a This brings up all physical interfaces listed in auto stanzas in etc network interfaces These days it is often better to handle network configuration using dynamic methods Once
102. LAN Gateway machine external port eth0 IP given by ISP s DHCP old notebook PC IBM Thinkpad 486 DX2 50MHz 20MB RAM Linux 2 4 kernel with ext3 filesystem ipmasq package with stronger patch NAT and firewall dhcp client package configured for ethO override DNS setting dhcp package configured for ethl exim as the smarthost mode 2 Chapter 3 Debian System installation hints 30 K un fetchmail with a long interval fallback run bind as the cache nameserver for Internet from LAN as authoritative nameserver for LAN domain from LAN run ssh on port 22 and 8080 connect from anywhere run squid as the cache server for the Debian archive for APT LAN Gateway machine internal port ethl IP 192 168 1 1 fixed LAN Switch 100base T Some fixed IP clients on LAN Some DHCP clients on LAN IP 192 168 1 2 127 fixed IP 192 168 1 128 200 dynamic See Network configuration on page 177 for the details of configuring the network See Build ing a gateway router on page 202 for the details of configuring the LAN gateway server 3 1 10 User accounts In order to have a consistent feel across machines the first few accounts are always the same in my system I always create a first user account with a name like admin uid 1000 I forward all root email there This account is given membership in the adm group see Why GNU su doe
103. Language http www python org Short program example creates newusers command entry usr bin env python import sys string C Osamu Aoki Sun Aug 26 16 53 55 UTC 2001 Public Domain Ported from awk script by KMSelf Sat Aug 25 20 47 38 PDT 2001 This program is distributed WITHOUT ANY WARRANTY def usages print A Usage sys argv 0 start_UID filename n tstartUID is the starting userid to add n tfilename is input filename If not specified standard input n n Input file format n tfirst_name last_name password n return 1 def parsefile startuid main filtering uid startuid while 1 line infile readline if not line break if line 0 F continue first last passwd string split string lower line above crashes with wrong of parameters user first 0 last Chapter 13 Programming 229 gid uid lineout s s d d s s home s bin bash n user passwd uid gid first last user sys stdout write lineout uid if _name_ __main__ if len sys argv 1 usages else uid int sys argv 1 print UID start from din uid if len sys argv gt 1 infilename string join sys argv 2 infile open infilename r print Read file from Ssinin infilename else infile sys stdin parsefile uid 13 6 Make Reference
104. NIX domain socket tmp X11 unix XD so it s only reachable from host D S is equivalent to host unix D S where host is the local hostname The default displayname for the X client program application side can be set by the DIS PLAY environment variable For example prior to running an X client program executing one of the following commands achieves this export DISPLAY 0 The default local machine using the first X screen export DISPLAY hostname fulldomain name 0 2 S export DISPLAY localhost 0 Its startup can be customized by xinitrc For example Chapter 9 Tuning a Debian system 148 xrdb load HOME Xresources xsetroot solid gray xclock g 50x50 0 0 bw 0 xload g 50x50 50 0 bw 0 xterm g 80x24 0 0 xterm g 80x24 0 0 twm As described in Custom X sessions on the current page this overrides everything normal execution of Xsession does when started from startx Use xsession instead and use this approach only as the last resort See xsetroot 1x xset 1x and X resources on page 152 9 4 5 X sessions An X session X server X client can be started by e startx wrapper script command for xinit to start an X server and client from a Linux character console If xinitrc does not exist etc X11 Xsession is executed through etc X11 xinit xinitre e xdm gdm kdm or wdm X display manager daemons to start the X server and client
105. NOTICE normal but significant condition KERN_INFO informational e 7 KERN_DEBUG debug level messages e DOF WNF If one particular useless error message bothers you a lot consider making a trivial kernel patch like shutup abit bp6 available in the examples subdirectory http www debian org doc manuals debian reference examples Another place to look may be etc syslog conf check to see whether any messages are logged to a console device 8 6 9 Set console to the correct type Console screens in Unix like systems are usually accessed using n curses library routines These give the user a terminal independent method of updating character screens with rea sonable optimization See ncurses 3X and terminfo 5 On a Debian system there are quite a lot of predefined entries S toe less all entries S toe etc terminfo less user reconfigurable entries Export your selection as environment variable TERM If the terminfo entry for xterm doesn t work with a non Debian xterm change your terminal type from xterm to one of the feature limited versions such as xterm r6 when you log in to a Debian system remotely See usr share doc libncurses5 FAO for more dumb is the lowest common denominator for terminfo 8 6 10 Get the console back to a sane state When the screen goes berserk after cat some binary file you may not be able to see the command echoed as you type S reset 8 6 11 Co
106. P o dr AAA AAA A E AAA 212 12 Version Control Systems 213 12 1 Concurrent Versions System CVS se s ie s aa ARA HS 213 121 1 Installing 4CVS Server o ro a e a RAM SEERA ES 213 CONTENTS xiv 121 2 O O Sessa mplES ejes a A e KS 213 12 1 3 Troubleshooting CVS edad ea da ic e He 217 A As o AI 217 e A OMe Ow Ee Se eee Re ee ORS Boe ES 218 1221 Installing a Subversion Server sss 20 so ee ME Re wae Ree eas 218 12 2 2 Moving a CVS repository to Subversion lt lt en eae eae s 219 122 3 Sabyersion usage examples oios Goo A AA 219 13 Programming 221 131 Where fastari 6c Gee ak ee a hea eee eh eae Ee ee Cele a 221 EL Seo Oa Ow eee RA Ee Be oe oe ee ee a aa 221 13 2 1 Bash GNU standard interactive shell 221 1922 POSIX Spele e ta o EE EA A a ee 222 13 29 Shell parametefs o oora a AA e a BR 223 13 24 Shell redirection ek o E paka pane d RR RO 223 13 25 Shell conditionals 22 oee ee SRS SEES RA E a a A ERS 224 13 26 Command line processing lt a oes e ane Sed Be eA ee a 225 A A IE 226 Noe A eee be ed eRe ee Eee FOSS oe ES 227 LIO a be ee AA ICE Ree eee ee 228 USO MARE ce he shee a BR Ge AAA eee OS Se ee Ss 229 WR te a oe ee a eB ee A ee ee ee ee 230 14 21 Simple C programi GGG as ee SH Pe Sat oes EES 231 1372 Od eid AREA BE DAO AE eRe 231 1937 Flex a etter LES oc a ERR ES REO EERE a RRA RS 233 13 74 Bison ab etter Yace se ek AAA SE a RE eS 234 13 75 BONGCONE 2 wos B44 ERE EEE EES ERAS EMELEREEEEE
107. PCMCIA There are several possible approaches to configuring PCMCIA network interfaces for 2 4 and 2 6 kernels e For 32 bit PCI CardBus PCMCIA network cards ifupdown controlled by hotplug e For 16 bit ISA PCMCIA network cards ifupdown controlled by hotplug with pcmcia cs recommended Chapter 10 Network configuration 199 x For Woody and Sarge pcmcia cs You must locally disable it by adding the line exit 0 to the beginning of the start method in etc pemcia network ifupdown controlled by pemcia cs with the Debian default etc pcmcia network default for Woody and Sarge deprecated low level tools controlled by pcmcia cs customized by enabling features of etc pemcia network by editing etc pcemcia network opts deprecated The recommended approach for 16 bit cards takes advantage of the fact that the Linux 2 4 hot plug subsystem now supports PCMCIA Simply follow the directions in Triggering network configuration hotplug on page 197 18 In order to ensure PCMCIA network cards to be fully configured before starting network ser vices at etc rc d S20 following actions are needed for 16 bit PCMCIA cards 19 e Set CARDMGR_OPTS f in etc default pcmcia to force cardmgr to run in the foreground e Move default symlink from etc rc d S20pcemcia to something like etc rc d S12pemcia Note that pemcia cs is still needed if you use 16 bit PCMCIA cards The cardmgr daemon that it contai
108. RK RE Oe Eww ESSER EDS 257 CONTENTS xvi Chapter 1 Preface This Debian Reference http qref sourceforge net is intended to provide a broad overview of the Debian system as a post installation user s guide Its target reader is someone who is willing to read shell scripts I expect the reader to have gained basic skills in Unix like systems prior to reading this document I made a conscious decision not to explain everything in detail if it can be found on a manual page an info page or in a HOWTO document Instead of full explanations I have tried to give more directly practical information by providing exact command sequences in the main text or example scripts under http www debian org doc manuals debian reference examples You must understand the content of examples before issuing commands Your system may require slightly different command sequences Much of the information included consists of reminders or pointers to the authoritative refer ences listed in References on page 245 This document originated as a quick reference but it grew Nevertheless Keep It Short and Simple KISS is my guiding principle For help with emergency system maintenance proceed to Debian survival commands on page 83 immediately 1 1 Official document The latest official document is in the Debian archives with the package name debian referenc n and is also available from http www debian org doc manuals deb
109. SS ES 234 18 WED ETT 235 13 9 Document preparan spa A E A E 235 Moe DOLE OSG O a ee ee Bl ee ee 235 1392 SGMI ia dad a oa BS ee ee ERE o Ke 236 CONTENTS XV 15593 TeX LaTek sind ara he ee HE e SS de dh ee as le 237 13 94 Literate Programining o cor a RRA a aS 238 ia AN 239 1310 1 Packaging a single Dinary espresso da ee eS 240 13 107 Packaging with t ols 2 666 ea sa eee RE Rao Owe ee ie So 240 14 GnuPG 241 141 a a cee a sor ai aoea Sop OS oa ORAS EK EES OS 241 142 USE GUIAS 4 tadi paa AAA A e eee E 241 14 3 MADAME GnuPG e ee e onde E EA Re er Ee ONG Ew de Es 242 144 Using GnuPG with applications 25 8 cb bk eee ee ee eee ees 243 1441 Using CGPC WH M t e a cot ea a ae ee RES 243 144 2 Using GnuPG WHR VIDE scoio ANA AA AER 243 15 Support for Debian 245 15 1 Refer nc s lt co csoc netet II 245 15 2 Finding the meaning ofa WOW oeoa uoi sa asies o OS Se eR RR RR EES 249 15 3 Finding the popularity of a Debian package nonono 250 15 4 The Debian bug tracking syste cc o a ca ee wa bare a ee turan 250 15 9 Mailing ook g nese memen IAEA AAA AA A 250 156 Internet Relay Chat URC isis ea e EER ES 250 Ta Geane A II 251 15 9 WEDOS cr ke a ee an A Sas E A 252 A Appendix 253 A A 253 AZ Wattanties 25 24 05 6 4200 a 29 03 A a eS 256 Aa Feedback or oO a eee ee A ee Oe 2S 256 AA Document format ea we RS we RE BE ee RA A OR OH 256 AD Tie Vea ae essa A OH EK ered el 256 A6 The Debian GUuGIes 2 9 tianara
110. Xresources after installing all the pertinent fonts set large font UXTerm font misc fixed medium r normal 18 120 100 100 c 90 isol10646 1 Use XIM for Japanese inputMethod kinput2 Then run xrdb merge Xresources to update X resources as described in X resources on page 152 Although most of the popular console program packages such as vim mutt and emacs have been made compatible with UTF 8 recently Woody Sarge Program such as mc still is not UTF 8 compatible but simply 8 bit clean If you are editing 7 bit ASCII part of unknown or mixed encoding file it is safer to use the locale unaware 8 bit clean editor See The Unicode HOWTO http ww tldp org HOWTO Unicode HOWTO htm1l 9 7 13 Example for UTF 8 in a framebuffer console UTF 8 support on a FB console is provided by bterm used in the debian installer 9 7 14 Beyond locales When you are first setting the system up for a national language environment please con sider using tasksel or aptitude to find out what packages are selected by choosing the corresponding language environment task The package choice made is useful even for a mul tilingual setup If you encounter any package dependency conflicts during the install to your carefully configured system avoid installing any software that conflicts with the existing sys tem You may have to use update alternat ive to regain the original state for some com mands since a newly installed one m
111. ackage can t be upgraded easily then you may want to backport it as described in Port a package to the stable system on page 90 Chapter 1 Preface 4 Tracking the testing distribution can have the side effect of delaying the installation of packages containing security fixes Such packages are uploaded to unstable and migrate to testing only after a delay If you mix distributions e g testing with stable or unstable with stable you will eventually pull in core packages such as 1ibc6 from testing or unstable and there is no guarantee that these will not contain bugs You have been warned Running the testing or unstable distribution increases your risk of hitting serious bugs This risk can be managed by deploying a multibooting scheme with a more stable Debian dis tribution or by deploying the nice trick of using chroot as described in chroot on page 127 The latter will enable running different Debian distributions simultaneously on different con soles After an explanation of the fundamentals of the Debian distribution in Debian fundamentals on the next page you will be given some basic information to help you live happily with the latest software taking advantage of the testing and unstable distributions of Debian The impatient should proceed immediately to Debian survival commands on page 83 Happy upgrading Chapter 2 Debian fundamentals This chapter provides fundamental information on the Debi
112. additional contribution David Sewell lt dsewell virginia edu gt leader en style Thomas Hood lt jdthood yahoo co uk gt network related Brian Nelson lt nelson bignachos com gt especially X related Jan Michael C Alonzo lt jmalonzo spaceants net gt Daniel Webb lt webb robust colorado edu gt Feedback from all translators e French translation Guillaume Erbs lt gerbs free fr gt leader fr R nald Casagraude lt rcasagraude interfaces fr gt Jean Pierre Delange lt delange imaginet fr gt Daniel Desages lt daniel desages com gt e Italian translation Davide Di Lazzaro lt mc0315 mclink it gt leader it e Portuguese Brazil translation Chapter A Appendix 254 Paulo Rog rio Ormenese lt pormenese uol com br gt leader pt br Andre Luis Lopes lt andrelop ig com br gt Marcio Roberto Teixeira lt marciotex pop com br gt Rildo Taveira de Oliveira lt to_rei yahoo com gt Raphael Bittencourt Simoes Costa lt raphael bsctbol com br gt Gustavo Noronha Silva lt kov debian org gt coordinator e Spanish translation Walter Echarri lt wecharri infovia com ar gt leader es Jos Carreiro lt f x urbanet ch gt e German translation Jens Seidel lt tux masterfweb de gt leader de Willi Dyck lt wdyck gmx net gt Stefan Schr der lt stefan fkp uni hannover de gt Agon S Buchholz lt asb kefk net gt e Polish translation the following members of PD
113. age Not available in install doc Bug 155374 File DebianCDunder doc e Release Notes primary A must read before installation and upgrade even if you are experienced Web http www debian org releases stable releasenotes Web http www debian org releases testing releasenotes work in progress sometimes this may not exist Package Not available in install doc Bug 155374 File DebianCDunder doc e FAQ secondary Frequently asked questions Chapter 15 Support for Debian 246 Web http www debian org doc manuals debian faq Package doc debian File usr share doc debian FAQ index html e Debian Reference secondary Most comprehensive post install user manual Web http www debian org doc manuals debian reference Package debian reference en File usr share doc Debian reference e APT HOWTO secondary Detailed user guide for Debian package management Woody Web http www debian org doc manuals apt howto Package apt howto File usr share doc Debian apt howto e Securing Debian Manual secondary Detailed user guide for securing and hardening of the default Debian installation Woody Web http www debian org doc manuals securing debian howto Package harden doc File usr share doc harden doc html securing debian howto e dselect Documentation for Beginners secondary Tutorial for dselect Web http www
114. ail transport agent If either one is installed then any program that Depends on the installation of a mail transport agent will be satisfied by the existence of this virtual package Debian has a mechanism such that if more than one package which Provides the same virtual package is installed on a system the system administrator can set one as the preferred package The relevant command is update alternatives and is described further in Alternative commands on page 94 2 2 8 Package dependencies The Debian packaging system handles dependency declarations which are used to express the fact that one package requires another package to be installed in order to work or in order to work better e Package A Depends on Package B if B absolutely must be installed in order to use A In some cases A Depends not only on B but on a specific version of B In this case the version dependency is usually a lower limit in the sense that A Depends on any version of B more recent than some specified version e Package A Recommends Package B if the package maintainer judges that most users would not want A without also having the functionality provided by B e Package A Suggests Package B if B contains files that are related to and enhance the func tionality of A The same relationship is expressed by declaring that Package B Enhances Package A e Package A Conflicts with Package B when A will not operate properly if B is installed on the system
115. ails in my example scripts http www debian org doc manuals debian reference examples I like a transparent system so I set umask to 002 or 022 PATH is set by the following configuration files in this order etc login defs before the shell sets PATH etc profile may call etc bash bashrc bash_profile may call bashrc 3 3 Mouse configuration 3 3 1 PS 2 mice In the case of a PS 2 connector mouse on an ATX motherboard the signal flow should be mouse gt dev psaux gt gpm gt dev gpmdata dev mouse gt X Here a symlink dev mouse is created and is pointing to dev gpmdata to make some configuration utilities happy and to make reconfiguration easy E g if you decide not to use the gpm daemon after all just point the symlink dev mouse to dev psaux after getting rid of the gpm daemon Chapter 3 Debian System installation hints 85 This signal flow allows the keyboard and mouse to be unplugged and reinitialized by restart ing gpm upon reconnect X will stay alive The protocol of the signal flow between gpm output and X input can be implemented in either of two ways as ms3 use the Microsoft 3 button serial mouse protocol or raw use the same protocol as the mouse that is connected and this choice dictates the choice of protocol used in X configuration I will demonstrate the configuration examples using a Logitech 3 button traditional Unix style mouse PS 2 mo
116. an developers take system security seriously Many daemon services are installed with the fewest services and features enabled Run ps aux or check the contents of etc init d and etc inetd conf if you have any doubts about Exim DHCP Also check etc hosts deny as in Restricting logins with PAM on page 135 The pidof command is also useful see pidof 8 X11 doesn t allow TCP IP remote connections by default in recent versions of Debian See Using X over TCP IP on page 151 X forwarding in SSH is also disabled See Connecting to a remote X server ssh on page 152 Chapter 6 Debian package management 96 97 Chapter 7 The Linux kernel under Debian Debian has its own method of recompiling the kernel and related modules See also Debian and the kernel on page 22 7 1 Kernel recompile The use of gcc binutils and modutils from Debian unstable may help when compiling the latest Linux kernel See usr share doc kernel package README gz especially the bottom of this for the official information Since it is a moving target kernel compilation is a difficult subject that may confuse even the most admired developer Manoj Srivastava wrote initrd requires a Debian only cramfs patch Herbert Xu wrote No it does not all you have to do to use a filesystem other than CRAMFS is to set MKIMAGE in etc mkinitrd mkinitrd conf Be careful and always rely on the usr share doc kerne
117. an find out what package is really contained in any given file of name filename by running the following command dpkg info filename The Debian revision number is specified by the Debian developer or by whoever built the package A change in revision number usually indicates that some aspect of the packaging has changed The debian installer project introduced package filenames that ends in udeb In short it is a micro deb format which doesn t need to follow Debian policy exactly lacks contents such as documentation and is meant to be used only by the debian installer the new Debian installer being developed for the Sarge release The file format of deb and udeb are identical The udpkg program used to handle udeb packages has limited capability than standard dpkg and supports fewer package relationships The difference in name is because the Debian archive maintainers weren t happy with debs in the archive that didn t follow policy so a different name was chosen to accentuate this and to make it less likely that people would unwittingly install them on real systems udebs are used in an initial ramdisk during the base install only to create a very restricted Debian system Chapter 2 Debian fundamentals 13 2 2 4 Preservation of local configuration Files that are intended to be changeable by the local administrator are kept in etc De bian policy dictates that all changes to locally configurable files be preserved across
118. an system for non developers For authoritative information see e Debian Policy Manual e Debian Packaging Manual Potato e Debian Developer s Reference e Debian New Maintainers Guide listed under References on page 245 If you are looking for less detailed how to explanations jump directly to Debian package management on page 77 or other relevant chapters This chapter is based on documents taken from the Debian FAQ greatly reorganized to allow the ordinary Debian system administrator to get started 2 1 The Debian archives 2 1 1 Directory structures The software that has been packaged for Debian is available in one of several directory trees on each Debian mirror site http www debian org misc README mirrors through FTP or HTTP The following directories can be found on each Debian mirror site under the debian directory dists This directory contains the distributions and this used to be the canonical way to access the currently available packages in Debian releases and pre releases Some old packages and Packages gz files are still in here pool The new physical location for all packages of Debian releases and pre releases tools DOS utilities for creating boot disks partitioning your disk drive compress ing decompressing files and booting Linux Chapter 2 Debian fundamentals 6 doc The basic Debian documentation such as the FAQ the bug reporting system instruc
119. anageable the pool is subdivided by section main contrib and non free and by the first letter of the source package name These directories contain sev eral files the binary packages for each architecture and the source packages from which the binary packages were generated You can find out where each package is placed by executing a command like apt cache showsrc mypackagename and looking at the Directory line For example the apache packages are stored in pool main a apache Since there are so many 1ib packages these are treated specially for instance 1ibpaper packages are stored in poo1 main libp libpaper The dists directories are still used for the index files used by programs like apt Also at the time of writing older distributions have not been converted to use pools so you ll see paths containing distribution names such as pot ato or woody in the Directory header field Normally you won t have to worry about any of this as new apt and probably older dpkg ftp will handle it seamlessly If you want more information see the RFC implemen tation of package pools http lists debian org debian devel announce 2000 debian devel announce 200010 msg00007 html 2 1 11 Historical notes about Sid When the present day Sid did not exist the Debian archive site organization had one major flaw there was an assumption that when an architecture was created in the current unstable it would be released
120. ant to avoid corresponding command line options e Start the X server on the local host e Open an xterm in the local host e Run ssh to establish a connection with the remote site localname localhost ssh q X 1 loginname remotehost domain Password e Run X application commands on the remote site loginname remotehost gimp This method allows the display of the remote X client output as if it were locally connected through a local UNIX domain socket 9 4 9 The X terminal emulator xterm Learn everything about xterm at http dickey his com xterm xterm faq html 9 4 10 X resources Many older X programs such as xterm use the X resource database to configure their ap pearance The file Xresources is used to store user resource specifications This file is automatically merged into the default X resources upon login The system wide defaults of X resources are stored in etc X11 Xresources and application defaults of them are stored in etc X11 app defaults Use these settings as the starting points Here are some helpful settings to add to your Xresources file Chapter 9 Tuning a Debian system 153 Set the font to a more readable 9x15 XTerm font 9x15 Display a scrollbar XTerm scrollBar true Set the size of the buffer to 1000 lines XTerm saveLines 1000 Large kterm screen KTerm VT100 fontList fixed medium r normal 24 gothic medium r normal 24 A min
121. apter 12 Version Control Systems 219 Configuring Apache2 To allow access to the repository via user authentication add or uncomment the following in etc apache2 mods available dav_svn conf lt Location repos gt DAV svn SVNPath var local repos AuthType Basic AuthName Subversion repository AuthUserFile etc subversion passwd lt LimitExcept GET PROPFIND OPTIONS REPORT gt Require valid user lt LimitExcept gt lt Location gt Then create a user authentication file with the command htpasswd2 c etc subversion passwd some username Restart Apache2 and your new Subversion repository will be accessible with the URL http hostname repos 12 2 2 Moving a CVS repository to Subversion 12 2 3 Subversion usage examples The following sections teach you how to use different commands in Subversion Create a new Subversion archive To create a new Subversion archive type the following cd your project go to your source directory svn import http localhost repos your project project name m initial project import This creates a directory named project name in your Subversion repository which contains your project files Look at http localhost repos to see if it s there Chapter 12 Version Control Systems 220 Working with Subversion Working with project y using Subversion cd move to the work area svn co http localhost repos project y Check out sources Ur cd proje
122. archive can be made in this way de e de e e aptitude install dpkg dev cd usr local install d pool physical packages are located here install d dists unstable main binary 1386 ls 1 pool sed s _ priority section uniq gt override editor override adjust priority and section dpkg scanpackages pool override usr local gt dists unstable main binary 1386 Packages cat gt dists unstable main Release lt lt EOF Archive unstable Version 3 0 Component main Chapter 6 Debian package management 92 Origin Local Label Local Architecture 1386 EOF echo deb file usr local unstable main gt gt etc apt sources list Alternatively a quick and dirty local deb repository can be made aptitude install dpkg dev mkdir usr local debian mv some where package deb usr local debian dpkg scanpackages usr local debian dev null gzip gt usr local debian Packages gz echo deb file usr local debian gt gt etc apt sources list Se de e OSE These archives can be remotely accessed by providing access to these directories through either HTTP or FTP methods and changing entries in etc apt sources list accordingly 6 4 12 Convert or install an alien binary package alien enables the conversion of binary packages provided in Red Hat rpm Stampede slp Slackware tgz and Solaris pkg file formats into a Debian deb package If you want to use a package from
123. at traffic destined for the Internet at large will be routed toward gateway 192 168 50 254 also through etho0 IP addresses in the table may also appear as names that are obtained by looking up addresses in etc networks or by using the C Library resolver In addition to routing the kernel can perform network address translation traffic shaping and filtering See the Net HOWTO http www tldp org HOWTO Net HOWTO index html and other networking HOWTOs http www tldp org HOWTO Networking Overview HOWTO html for more background information 10 2 Low level network configuration The traditional low level network configuration tools on GNU Linux systems are the ifconfig and route programs which come in the net tools package These tools have officially been superseded by ip which comes in the iproute package The ip program works with Linux 2 2 and higher and is more capable than the old tools However the old tools still work and are more familiar to many users 10 2 1 Low level network configuration ifconfig and route Here is an illustration of how to change the IP address of interface eth0 from 192 168 0 3 to 192 168 0 111 and to make eth0 the route to network 10 0 0 0 via 192 168 0 1 We begin by running ifconfig and route without interface arguments in order to display the current status of all network interfaces and routing ifconfig eth0 Link encap Ethernet HWaddr 08 00 46 7A 02 B0 inet addr 192 168 0 3
124. ate NAT on this host as described in Building a gateway router on page 202 then you can share the Internet connection with all the hosts on the LAN 10 6 7 Configuring virtual interfaces Using virtual interfaces you can configure a single Ethernet card to be an interface to several IP subnetworks For example suppose your host is on LAN network 192 168 0 x 24 You want to connect the host to the Internet using a public IP address provided via DHCP using your existing Ethernet card Edit etc network interfaces so that it includes stanzas like these iface ethO inet static address 192 168 0 1 netmask 255 255 255 0 network 192 168 0 0 broadcast 192 168 0 255 iface eth0 0 inet dhcp The interface et h0 0 is a virtual interface When it is brought up so will its parent eth0 10 7 Network configuration using logical interface definitions In the following it will be important for the reader to understand the difference between a physical interface and a logical interface A physical interface is what we have been calling the interface the thing that the kernel names et h0 eth1 ppp0 or what have you A logical interface is a set of values that can be assigned to the variable parameters of a physical interface If you find that confusing replace the expression configured as logical interface X with the expression configured with interface profile X as you read The iface definitions in etc network
125. ay have higher priority than existing ones Newer major programs are using glibc 2 2 and are mostly internationalized So a specially localized version such as jvim for Vim may not be needed as its functionality is offered by vim version 6 0 in X In reality it is still somewhat rough edged Since jvim has a version compiled with direct Japanese input method canna support even in the console and addresses many other Japanese specific issues maturely you may still want it Programs may need to be configured beyond locale configuration to enable a comfortable working environment The language env package and its command set language env greatly eases this process Also see the internationalization document Introduction to il8n http www debian org doc manuals intro i18n It is aimed at developers but is also useful for system administrators Chapter 9 Tuning a Debian system 176 177 Chapter 10 Network configuration This chapter focuses on network administration in Debian For a general introduc tion to GNU Linux networking read the Net HOWTO http www tldp org HOWTO Net HOWTO index html In order for a Debian host to be able to access the Internet its network interfaces need to be supported by the kernel and properly configured The first requirement is kernel support for network interface devices such as Ethernet cards Wi Fi cards and modems To obtain this support you may need to recompile the kernel or add
126. ay negatively impact file I O performance a little bit But this secures file contents except for the last one second which is shorter than the default five seconds This is true even for journaling filesystems 7 3 3 Sluggish old low memory machines For some old low memory systems it may still be useful to enable over commit of memory through the proc filesystem echo 1 gt proc sys vm overcommit_memory 105 Chapter 8 Debian tips 8 1 Booting the system See the LDP BootPrompt HOWTO http www tldp org HOWTO BootP rompt HOWTO html for detailed information on the boot prompt 8 1 1 I forgot the root password 1 It is possible to boot a system and log on to the root account without knowing the root pass word as long as one has access to the console keyboard This assumes there are no password requests from the BIOS or from a boot loader such as 1i1o that would prevent one from boot ing the system This is a procedure which requires no external boot disks and no change in BIOS boot settings Here Linux is the label for booting the Linux kernel in the default Debian install At the lilo boot screen as soon as boot appears you must press a shift key at this point on some systems to prevent automatic booting and when 1ilo uses the framebuffer you have to press TAB to see the options you type enter boot Linux init bin sh This causes the system to boot the kernel and run bin sh instead of
127. books Many long info documents can be obtained as paperbacks from GNU http www gnu org The next four sections contain sample scripts in different languages for creating a text file of ac count information to be added to etc passwd using a batch processor such as the newusers program Each script requires as input a file with lines of the form first_name last_name password Actual user home directories will not be created via these scripts 13 2 Shell Reading shell scripts is the best way to understand how a Unix like system works Here I give some pointers and reminders for shell programming See Shell Mistakes http www greenend org uk rjk 2001 04 shell htm1 to learn from mistakes 13 2 1 Bash GNU standard interactive shell References for Bash e bash 1 Chapter 13 Programming 222 e info bash e the LDP BASH Programming Introduction HOWTO http www tldp org HOWTO Bash Prog Intro HOWTO html as starter information e mc usr share doc bash examples usr share doc bash Install the bash doc package to see the example files e Learning the bash Shell 2nd edition O Reilly Short program example creates account entries for newusers from standard input bin bash C Osamu Aoki Sun Aug 26 16 53 55 UTC 2001 Public Domain pid 1000 while read nl n2 n3 do if nl 0 1 then let pid pid 1 echo n1 _ n2 password pid pid home n1 _ n2 bin bash f
128. boot parameters during the boot process since it is slightly different from lilo configuration 3 1 7 Choice of boot floppies For Potato I liked the IDEPCI disk set for normal install to a desktop For Woody I like the bf2 4 boot disk set They both use a version of boot floppies to create boot floppies If you have a PCMCIA network card you need to use the standard boot disk set largest num ber of floppies but all driver modules available and configure the NIC in the PCMCIA setup do not try to set up an NIC card in the standard network setup dialogue For special systems you may need to create a custom rescue disk This can be done by re placing the kernel image named linux on the Debian rescue disk by overwriting it with another compressed kernel image compiled off site for the machine Details are documented in readme txt on the rescue disk The rescue floppy uses the MS DOS filesystem so you can use any system to read and edit it This should make life easier for people with a special network card etc For Sarge debian installer and or pgi is expected to be used for creating boot floppies Chapter 3 Debian System installation hints 29 3 1 8 Installation Follow the official instructions found in http www debian org releases stable installmanual or http www debian org releases testing installmanual work in progress sometimes this may not exist If you are installing a system using boot floppies in the test
129. break if you use them directly instead they should be compiled against the headers with which glibc was built which are the versions in usr include linux and usr include asm of the Debian system So do not put symlinks to the directories in usr src linux from usr include linux and usr include asm as suggested by some outdated documents If you need particular kernel headers for some kernel specific application programs alter the makefile s so that their include path points to dir of particular kernel headers include linux and dir of particular kernel headers include asm 7 2 The modularized 2 4 kernel The new Debian 2 4 kernels provided by kernel image 2 4 NN are very modularized You have to make sure those modules are activated to make the kernel function as you intend Although I have many examples for etc modules in the following section as a quick fix I hear that the correct way to fix these module related issues is to provide an alias for the device in a file in etc modutils since there are enough aliases available with current kernels Some modules may be auto activated by hardware detection programs such as discover See also Hardware detection for X on page 144 See Special provisions for dealing with modules on page 24 and Documentation txt in the Linux source for the precise information 7 2 1 PCMCIA etc modules may need to contain the following for some old PCMCIA to function ISA PnP driver
130. bute translations of this document into another lan guage under the above conditions for modified versions except that this permission notice may be included in translations approved by the Free Software Foundation instead of in the original English Contents 1 Preface 1 LI Omal document s e sie a Bay ee ee a ORE td EO 1 1 2 Document conventions se o e045 e i aw Dee bee a poe 2 LS eT ise e Ae ek AA Ook OER ORS REE Ae ed OH 2 E AI 2 1 5 Basics of the Debian distributions gt see c cer rar A BW RS 3 2 Debian fundamentals 5 21 The Debiamarchiyes 0 6 4 40244 2 44 26058 2 Ph e ERE a a 5 A a oso sag hs EPMA Oe EES BEE OG OES 5 212 Webiardistributons scsi ew RA e AR a a ae Ho 6 213 The Stable distribution ica a Pare eae oY nk eal a oad 6 214 Theses cing distribution eree a se panad ateu ara a B54 7 215 Thetnstabledistibull n 00 ecne eccer Ook a a ek 7 216 Thefrozen disttibuhon src s 04 4 4 oe ba ea ah ean Rae ES 7 217 Debian disttibution codengmes 6 6 04 stete 484 5444044 os a 8 LLS Codenames used MS PAE ode eee ae kh BEDS ER RS EES CdS 8 2 1 9 The source forcodenames 00 00 eee ee ee ee eee 8 2 L10 Te WG A 9 2 1 11 Historical notes about Sid omic a ew ee ee ee we 9 21 12 Uploaded packages in incomi g ro aos Pe wes 10 2 1 13 Retrieving at older package o o 25 28 Rb by oo A o aa 10 2 1 14 Architecture sections ee 10 2 1 15 The sourcecode cios Baa ee RSA aa a a ea 10 CONTENTS ii
131. buted with keymaps for nearly two dozen keyboards In Woody reconfigure the keyboard by e dpkg reconfigure priority low console data console e dpkg reconfigure priority low xserver xfree86 XF4 e dpkg reconfigure priority low xserver common v3 XF3 Localizing data files The vast majority of Debian software packages support data handling of non US ASCII char acters through the LC_CTYPE environment variable offered by the locale technology in glibc e 8 bit clean practically all programs e other Latin character sets e g ISO 8859 1 or ISO 8859 2 the majority of programs e multibyte languages such as Chinese Japanese or Korean many new applications Localizing the display X can display any coding including UTF 8 and supports all fonts The list includes not only all the 8 bit fonts but also 16 bit fonts such as Chinese Japanese or Korean Multibyte character input method is supported by the Alternative X input methods on page 173 mechanism See Example for a multilingual X window system on page 170 and UTF 8 support for the X terminal emulator on page 174 Japanese EUC code display is also available in a S VGA graphics console through the kon2 package There is an alternative new Japanese display jfbterm which uses a frame buffer console too In these console environments the Japanese input method must be supplied by the application Use egg package for Emacs and use japanized jvim package for a V
132. c is now the preferred Gtk GUI front end for APT Its package filtering capability is easier to use than aptitude s It also has experimental support for Debian Package Tags http deb usability alioth debian org debtags To reduce the network load on the Debian repositories and to speed up your downloads you should get packages from Debian mirror sites If you need to install the same package on several machines on your local network then you can set up a local HTTP proxy using squid for packages downloaded through APT If necessary set the ht tp_proxy environment variable or set the http value in etc apt apt conf Although APT s pinning feature described in apt_preferences 5 is powerful its effects can be difficult to understand and manage You should consider it an Advanced Feature The use of the method described in chroot on page 127 is desirable for simultaneously se curing both system stability and access to the latest versions of software This chapter is based on a post Woody system Some features may require a Sarge system or later 6 1 Introduction If reading all the developer documentation is too much for you read this chapter first and start enjoying the full power of Debian with test ing unstable Chapter 6 Debian package management 78 6 1 1 Main package management tools dpkg Debian package file installer apt get Command line front end for APT aptitude Advanced text
133. cally in var cache apt archives or remotely at http snapshot debian net See also Rescue using dpkg on page 84 Downgrading from a later release of a distribution to an earlier one is not officially supported either and is very likely to cause problems However this may be worth trying as a last resort if you are desperate 6 2 6 aptitude apt get and apt cache commands While tracking testing as described in the above example you can manage the system by using the following commands e aptitude upgrade or apt get upgrade or aptitude dist upgrade or apt get dist upgrade These track the test ing distribution they upgrade each package on the system after installing versions of packages upon which it Depends from the testing distribution 2 The difference between upgrade and dist upgrade only appears when new versions of packages stand in Chapter 6 Debian package management 82 e apt get dselect upgrade This tracks the testing distribution it upgrades each package on the system accord ing to the selections of dselect e aptitude R G install package or apt get install package This installs package and packages upon which it Depends from the testing distribu tion e aptitude r G install package This installs package and packages upon which it Depends and packages that it Recom mends from the testing distribution e aptitude r g install package This installs package and packages upon which i
134. cho medium r normal 24 To make these settings take effect immediately merge them into the database using the com mand xrdb merge Xresources See xrdb 1x 9 4 11 Keymaps and pointer button mappings in X The xmodmap program is used to edit and display the keyboard modifier map and keymap table that are used by client applications to convert event keycodes into keysyms in X xmodmap pm display the current modifier map xmodmap pk pager display the current keymap table xmodmap e pointer 3 2 1 set mouse for the left hand xmodmap xmodmaprc set keyboad as in xmodmaprc It is usually run from the user s session startup script xsession To get the keycode run xev in X and press keys To get the meaning of keysym look into the MACRO definition in usr include X11 keysymdef h file All the define statements in this file are named as XK_ prepended to the keysym names See xmodmap 1x 9 4 12 Getting root in X If a GUI program needs to be run with root privilege use the following procedures to display program output on a user s X server Never attempt to start an X server directly from the root account in order to avoid possible security risks Chapter 9 Tuning a Debian system 154 Start the X server as a normal user and open an xterm console Then XAUTHORITY HOME Xauthority export XAUTHORITY S su root Password printtool amp
135. cies on page 15 below Debian s packaging tools can be used to e manipulate and manage packages or parts of packages Chapter 2 Debian fundamentals 12 e aid the user in the splitting of packages that must be transmitted through a limited size medium such as floppy disks e aid developers in the construction of package archives and e aid users in the installation of packages which reside on a remote Debian archive site 2 2 2 Debian package format A Debian package or a Debian archive file contains the executable files libraries and doc umentation associated with a particular program suite or set of related programs Normally a Debian archive file has a filename that ends in deb The internals of this Debian binary package format are described in the deb 5 manual page Because this internal format is subject to change between major releases of Debian always use dpkg deb 8 for manipulating deb files Through at least the Sarge distribution all Debian archive files have been manipulable by the standard Unix commands ar and tar even when dpkg commands are not available 2 2 3 Naming conventions for Debian package filenames The Debian package filenames conform to the following convention foo_ver rev_arch deb where usually foo is the package name ver is the upstream version number rev is the Debian revision number and arch is the target architecture Files are easily renamed of course You c
136. conversion between various charac ter sets For more see Introduction to il8n http www debian org doc manuals intro i18n Chapter 9 Tuning a Debian system 169 9 7 4 Activating locale support Debian does not come with all available locales pre compiled Check usr lib locale to see which locales besides the default C are compiled for your system If the one you need is not present you have two options e Edit etc locale gen to add the desired locale then run 10cale gen as root to com pile it See locale gen 8 and the manpages listed in its SEE ALSO section e Run dpkg reconfigure locales to reconfigure the locales package Or if it is not already installed installing locales will invoke the debconf interface to let you choose needed locales and compile the database 9 7 5 Activating a particular locale The following environment variables are evaluated in this order to provide particular locale values to programs 1 LANGUAGE This environment variable consists of a colon separated list of locale names in order of priority Used only if the POSIX locale is set to a value other than C in Woody the Potato version always has priority over the POSIX locale GNU extension 2 LC_ALL If this is non null the value is used for all locale categories POSIX 1 Usually null 15 LC_ If this is non null the value is used for the corresponding category POSIX 1 Usually C LC_
137. cord ing to the DFSG For example some packages have licenses that prohibit commercial distribution Others can be redistributed but are shareware e stable contrib Each package in this directory is itself DFSG free but somehow Depends on a package that is not DFSG free Now in addition to the above locations new physical packages are located under the pool directory The pool directory on page 9 The current status of stable distribution bugs is reported on the Stable Problems http ftp master debian org testing stable_probs html web page Chapter 2 Debian fundamentals 7 2 1 4 The testing distribution Package entries for the testing distribution Debian Etch are recorded into the testing symlink to etch directory after they have undergone some degree of testing in unstable Now in addition to the above locations new physical packages are located under the pool directory The pool directory on page 9 There are also main contrib and non free subdirectories in test ing which serve the same functions as in stable These packages must be in sync on all architectures where they have been built and must be installable they must also have fewer release critical bugs than the versions currently in unstable This way we hope that test ing is always close to being a release candidate More details of the testing mechanism are at http ftp master debian org testing The latest status of the testing dis
138. ct y z do some work svn diff similar to diff u repository local svn revert modified_file undo changes to a file svn ci m Describe changes check in your changes to the repository vi newfile added svn add newfile_added svn add new_dir recursively add all files in new_dir svn add N new_dir2 nonrecursively add the directory svn ci m Added newfile_added new_dir new_dir2 svn up merge in latest version from repository svn log shows all changes committed svn copy http localhost repos project y http localhost repos project y branch m creating my branch of project y branching project y svn copy http localhost repos project y http localhost repos proj y_releasel 0 m project y 1 0 release added release tag note that branching and tagging are the same The only difference is that branches get committed whereas tags do not make changes to branch S merge branched copy back to main copy svn merge http localhost repos project y http localhost repos project y branch svn co r 4 http localhost repos project y get revision 4 221 Chapter 13 Programming Do not use test as the name of an executable test file test is a shell built in 13 1 Where to start References e Documents and examples under usr share doc package e Unix Programming Information http arioch unomaha edu jclark info e Linux Programming Bible John Goerzen IDG
139. d For example alias la ls la Now la works as a short hand for 1s la which lists all files in the long listing format You can identity exact path or identity of the command using t ype command For example S type ls ls is hashed bin 1s S type la la is aliased to 1s la type echo echo is a shell builtin type file file is usr bin file Here 1s was recently searched while file was not thus 1s is hashed i e the shell has an internal record for the quick access to the location of the 1s command 4 4 Unix like text processing There are few standard text processing tools which are used very often on the Unix like system e No regular expression is used Chapter 4 Debian tutorials 61 head outputs the first part of files tail outputs the last part of files sort sorts lines of text files unig removes duplicate lines from a sorted file tr translates or deletes characters diff compares files line by line e Basic regular expression BRE is used grep matches text with the pattern ed is a primitive line editor sedis a stream editor vi isa screen editor emacs is a screen editor e Extended regular expression ERE is used egrep matches text with pattern awk does simple text processing See Awk on page 226 perl does every conceivable text processing See Perl on page 227 See Regular expression substitution on page
140. d see http bugs debian org 149236 Detailed instructions for using the kernel package package are given in the file usr share doc kernel package README gz 2 7 3 Alternative boot loaders To employ alternative boot loaders such as grub or loadlin copy the compiled Linux kernel bzimage to other locations e g to boot grub or to an MS DOS partition 2 7 4 Custom boot floppies The task of making a custom boot floppy was greatly aided by the Debian package boot floppies used to be found in the admin section of the Debian FTP archive for Potato and older Shell scripts in this package produce boot floppies in syslinux format These are MS DOS formatted floppies whose master boot records have been altered so that they di rectly boot Linux or whatever other operating system has been defined in the syslinux cfg file on the floppy Other scripts in this package produce emergency root disks and can even reproduce the base disks You will find more information about this in the usr doc boot floppies README file after installing the boot floppies package Chapter 2 Debian fundamentals 24 2 7 5 Special provisions for dealing with modules Debian s modconf package provides a shell script usr sbin modconf which can be used to customize the configuration of modules This script presents a menu based interface prompting the user for particulars on the loadable device drivers in his system The responses are used to cu
141. d command substitution command if not within split into words with IFS if not within expand in pathname if not within 1 Or look up command function built in file in PATH loop Single quotes within double quotes have no effect Executing set x in the shell or invoking the shell with x option make the shell to print all of commands executed This is quite handy for debugging Chapter 13 Programming 226 13 3 Awk References for Awk e Effective awk Programming 3rd edition O Reilly e Sed s awk 2nd edition O Reilly e mawk 1 and gawk 1 e info gawk Short program example creates newusers command entry usr bin awk f Script to create a file suitable for use in the newusers command from a file consisting of user IDs and passwords in the form first_name last_name password Copyright c KMSelf Sat Aug 25 20 47 38 PDT 2001 Distributed under GNU GPL v 2 or at your option any later version This program is distributed WITHOUT ANY WARRANTY Se de de de e BEGIN Assign starting UID GID if ARGC gt 2 startuid ARGV 1 delete ARGV 1 else printf Usage newusers startUID file n A where n A startUID is the starting userid to add and n file is an input file in form n u first_name last_name password n infile ARGV 1 printf Starting UID s n n startuid next record first 1
142. d in Preparing for upgrade on page 74 Also refer to Debian System installation hints on page 25 Upgrading a distribution to stable testing or unstable on page 73 and Rescue editors on page 207 If you track test ing or unstable you can remove references to stable from etc apt sources list and etc apt preferences because testing starts as a copy of stable Chapter 6 Debian package management 79 6 2 2 Installing tasks You can install sets of packages typically required in order to put a Debian system to a certain use These sets of packages are called tasks The simplest way to install tasks at the time of initial installation is to use tasksel Note that you must run dselect update before using it aptitude can also install tasks and is the tool recommended for this purpose It enables you to deselect individual packages within tasks before proceeding to the installation step 6 2 3 aptitude aptitude is anew menu driven package installer similar to dselect but built from scratch on top of APT It can be used as an alternative to apt get for most commands See aptitude 1 and usr share doc aptitude README Once you start using aptitude it is best to continue using it rather than alternative methods of installing packages otherwise you lose the advantage of apt itude keeping track of which packages you have deliberately installed aptitude in full screen mode accepts single key comman
143. dd the following line in etc apt apt conf Dpkg Options force confold This equivalent to running aptitude y install packagename or apt get q y install packagename Because this automatically answers yes to all prompts it may cause problems so use this trick with care See apt conf 5 and dpkg 1 You can configure any particular packages later by following Reconfigure installed packages on the current page 6 4 4 Reconfigure installed packages Use the following to reconfigure any already installed package dpkg reconfigure priority medium package dpkg reconfigure all reconfigure all packages dpkg reconfigure locales generate any extra locales dpkg reconfigure p low xserver xfree86 reconfigure X server Do this for debconf if you need to change the debconf dialog mode permanently Some programs come with special configuration scripts apt setup create etc apt sources list install mbr install a Master Boot Record manager tzconfig set the local time zone gpmconfig set gpm mouse daemon sambaconfig configure Samba in Potato Woody uses debconf eximconfig configure Exim MTA texconfig configure teTeX apacheconfig configure Apache httpd cvsconfig configure CVS sndconfig configure sound system update alternatives set default command e g vim as vi update rc d System V init script management update men
144. debian org releases woody i386 dselect beginner Package Not available in install doc Bug 155374 File DebianCDunder doc e Debian Policy Manual primary Technical backbone of Debian Web http www debian org doc debian policy Package debian policy File usr share doc debian policy e Debian Developer s Reference primary Basic knowledge for developers The rest of us should also browse this once Web http www debian org doc manuals developers reference Package developers reference File usr share doc developers reference e Debian New Maintainers Guide primary Practical guide for developers Packaging tutorials for the rest of us Web http www debian org doc manuals maint guide Chapter 15 Support for Debian 247 Package maint guide File usr share doc maint guide e Packaging Manual Potato packaging manual package in Potato Moved into appendix of Developer s Ref erence e Unix style manual pages primary dlocate man package name list available man section command name e GNU style info pages primary info access top level info command name e Package specific documents primary Find them under usr share doc package name e LDP Linux Documentation Project secondary General Linux HOWTOs and mini HOWTOs Web http www tldp org Package doc linux text and doc linux html File
145. der Debian version for example var tar gz http people debian org osamu pub and place it in the root directory of the broken system Then ca mv var var old if any useful contents are left tar xvzf var tar gz use Woody skeleton file aptitude or dselect This should provide a working system You can expedite the recovery of package selections by using the technique described in Recover package selection data on the current page FIXME This procedure needs more experiments to verify 6 3 6 Install a package into an unbootable system Boot into Linux using a Debian rescue floppy CD or an alternative partition in a multiboot Linux system See Booting the system on page 105 Mount the unbootable system on target and use the chroot install mode of dpkg Chapter 6 Debian package management 86 dpkg root target i packagefile deb Then configure and fix problems By the way if a broken 1110 is all that prevents booting you can boot using a standard Debian rescue disk At boot prompt assuming the root partition of your Linux installation is in dev hda12 and you want runlevel 3 enter boot rescue root dev hdal2 3 Then you are booted into an almost fully functional system with the kernel on floppy disk There may be minor glitches due to lack of kernel features or modules 6 3 7 What to do if the dpkg command is broken A broken dpkg may make it impossible to install any deb files
146. dict put a weird word here Chapter 15 Support for Debian 250 15 3 Finding the popularity of a Debian package Many packages exist in Debian and it is sometimes difficult to know which one to try first See Debian Popularity Contest Results http www debian org apenwarr popcon to get insight into what others are using Also install the popularity contest package to contribute 15 4 The Debian bug tracking system The Debian distribution has a bug tracking system BTS http bugs debian org which files details of bugs reported by users and developers Each bug is given a number and is kept on file until it is marked as having been dealt with You should check to see whether your bug report has already been filed by someone else before submitting it Lists of currently outstanding bugs are available on the World Wide Web http lbugs debian org and elsewhere http www debian org Bugs Access See also Check bugs in Debian and seek help on page 893 There may be many release critical bug reports marked with FTBFS This means Fails To Build From Source Instructions for reporting a bug are given at http www debian org Bugs Reporting 15 5 Mailing lists Read at least debian devel announce English read only and low traffic to stay current with Debian The mailing lists of most interest to Debian users are debian user English open and high traffic and other debian user language l
147. down when the interface is removed As noted above it is now recommended to use hotplug to do this Others still use the special system of calling low level network configuration commands that gets activated when certain variables in etc pemcia network opts are set to y This system has several problems It is afflicted by race conditions it only works for 16 bit PCMCIA cards it does what is better left to i fupdown to do Consequently it is deprecated This is not needed for 32 bit PCMCIA cards Chapter 10 Network configuration 200 The first mapping stage takes the hotplug group name and outputs the kernel assigned in terface name if the interface is to be hot plugged The second mapping stage takes a kernel assigned interface name and outputs an adapter name The third mapping stage maps adapter names to logical interface names based on the network environment Allow hotp mapping hotplug script echo Determin whether interface is lug to bring up interfaces wired or Wi Fi mapping eth script map 02 map 00 A3 03 63 26 93 wii Detect which mapping wired script guessnet ifupdown map work wired map home usr local sbin match mac address sh 23 45 3C 45 3C wired Ei wired network is available Detect which Wi Fi network is available mapping wii Ei script ifscout map starbucks map work wireless iface work wired inet static 10 12 Network service
148. ds which are usually lowercase Notable key strokes are Keystroke Action F10 Menu 2 Help for keystroke complete listing u Update package archive information Mark the package to be upgraded or newly installed Mark the package to be removed keep config Mark the package to be purged remove config Place the package on hold Mark all upgradable packages to be upgraded Download and install selected packages Quit current screen and save changes Quit current screen and discard changes Enter View information about a package C View a package s changelog Change the limit for the displayed packages Search for the first match Repeat the last search xXx OO G a NH Chapter 6 Debian package management 80 Like apt get aptitude installs packages upon which a selected package Depends aptitude also offers the option to pull in packages that a to be installed package Recom mends or Suggests You can change the default behavior by choosing F10 gt Options gt Dependency handling in its menu Other advantages of aptitude are e aptitude offers access to all versions of a package e aptitude logs its actions in var log aptitude aptitude makes it easy to keep track of obsolete software by listing under Obsolete and Locally Created Packages e aptitude includes a fairly powerful system for searching particular packages and lim iting the package display Users familiar with mutt will pick up
149. e See Tuning the kernel through the proc filesystem on page 103 and proc 5 4 6 X Window System See X on page 143 Chapter 4 Debian tutorials 71 4 6 1 Start the X Window System The X Window System can be started automatically with xdm like graphical login daemon or type following from the console exec startx 4 6 2 Menu in the X Window System Since X environment can accommodate many window managers their user interfaces vary quite a bit Please remember that right clicking the root window will bring up menu selections This is always available e To gain the shell command prompt start Xterm from menu XShells gt XTerm e For graphical browsing of the web pages start Mozilla from menu Apps gt Net gt Mozilla Navigator For graphical browsing of the PDF files start Xpdf from menu Apps gt Viewers gt Xpdf If you do not find menu entry install the pertinent packages See Beginning Debian package management on page 78 4 6 3 Keyboard sequence for the X Window System Followings are the important keystrokes to remember when running the X Window System e Ctrl Alt F1 through F6 Switch to other pseudo terminals from an X window DOSEMU etc e Alt F7 Switch back to X window e Ctrl Alt minus Change screen resolution in X window minus refers to the keys on the numeric keypad e Ctrl Alt plus Change screen resolution
150. e Printers page and click Configure Printer and e proceed to configure the paper size resolution and other parameters See more information at http localhost 631 documentation html and http www cups org cups help html For a 2 4 kernel see also Parallel port support on page 103 3 7 Other host installation hints 3 7 1 Install a few more packages after initial install Once you have made it this far you have a small but functioning Debian system It is a good time to install bigger packages e Runtasksel See Installing tasks on page 79 You may choose these if you need them End user X Window System Development C and C Development Python Development Tcl Tk Miscellaneous TeX LaTeX environment For others I prefer to use tasksel as a guide by looking into their components listed under lt Task Info gt and installing them selectively through dselect e Rundselect Here the first thing you may want to do is select your favorite editor and any programs you need You can install many Emacs variants at the same time See dselect on page 80 and Popular editors on page 207 Also you may replace some of the default packages with full featured ones Chapter 3 Debian System installation hints 41 lynx ssh instead of lynx I usually edit etc inittab for easy shutdown What to do when CTRL ALT DEL is pressed ca 12345 ctrlaltdel sbin shutdown t
151. e 10 character not the same as the number zero ASCII See Dummy files on page 127 Device node number The device node number are displayed by executing 1s as ls l dev hda dev ttyS0 dev zero bIw rw 1 root disk 3 O Mar 14 2002 dev hda crw rw 1 root dialout 4 64 Nov 15 09 51 dev ttyS0 crw rw rw 1 root root Ly 5 Aug 31 03 03 dev zero Here e dev hda has the major device number 3 and the minor device number 0 This is read write accessible by the user who belongs to disk group e dev ttyS0 has the major device number 4 and the minor device number 64 This is read write accessible by the user who belongs to dialout group and e dev zero has the major device number 1 and the minor device number 5 This is read write accessible by anyone In the older system the installation process creates the device nodes using sbin MAKEDEV command See MAKEDEV 8 In the newer system the filesystem under in the dev is automatically populated by the device filesystem similar to the proc filesystem 4 5 9 proc filesystem The proc filesystem is a pseudo filesystem and contains information about the system and running processes People frequently panic when they notice one file in particular proc kcore which is generally huge This is more or less a copy of the contents of your computer s memory It s used to debug the kernel It doesn t actually exist anywhere so don t worry about its siz
152. e belongs to g and e all other users o For a file each corresponding permission allows e read r to examine contents of the file e write w to modify the file and e execute x to run the file as a command For a directory each corresponding permission allows e read r to list contents of the directory e write w to add or remove files in the directory and e execute x to access files in the directory Here execute permission on the directory means not only to allow reading of files in its direc tory but also to allow viewing their attributes such as the size and the modification time To display permission information and more for files and directories 1s is used See 1s 1 When 1s invoked with the 1 option it displays the following information in the order given e the type of file first character normal file d directory symlink character device node block device node named pipe s socket e the file s access permissions the next nine characters consisting of three characters each for user group and other in this order e the number of hard links to the file e the name of the user who owns the file e the name of the group which the file belongs to e the size of the file in characters bytes e the date and time of the file mtime e the name of the file l Or O OE To change the owner of the file chown is used from the root account To change the group of the f
153. e configuration file for init which is etc inittab specifies that the first script to be executed should be etc init d rcs What happens next depends on whether the sysv rc package or the file rc package is installed The following assumes that the sysv rc package is installed file rc contains its own etc init d rcs script and uses a file instead of symlinks in rc directories to control which services are started in which runlevels The etc init d rcsS file from the sysv rc package runs all of the scripts in etc rcS d in order to perform initialization such as checking and mounting file systems loading mod ules starting the network services setting the clock and so on Then for compatibility it also runs all the files except those with a in the filename in etc rc boot The latter directory is reserved for system administrator use and using it is deprecated See System ini tialization on page 133 and System run levels and init d scripts http www debian org doc debian policy ch opersys html s sysvinit in the Debian Policy Manual for more info Debian does not use a BSD style rc local directory 2 4 2 Runlevels After completing the boot process init starts all services that are configured to run in the default runlevel The default runlevel is given by the entry for id in etc inittab Debian ships with id 2 Debian uses the following runlevels e 1 single user mode e 2 through 5 multiu
154. e dees ao a ee OE e 141 938 Deban CD Mages sore pd A dd ct KS 142 939 Backup thesystemi to CDR ccris he ESS ESSER aa a 142 93 10 Copy amuse CD to CUR es eis eea coea ERA 142 DA Koe AAA e o ees Be ee A 143 94I APORTES o ar A EE AAA AAA EA 144 94 2 Hardware detectionforX o o e 144 JAS The AI 145 DAA ACeS oep aa ra EA a ee U 147 OAS GN SESSIONS e a rada a ew piak See e a eek 148 946 Usen over TCP IP orar AA AR A A 151 947 Connechng toa remote Xsetver xhost cra 24542458544 es 151 CONTENTS xi 946 Connecting toa remote XSetyer esh sucios es 152 949 The X terminal emulator xterM o o e 152 SAO ATESOUECES coral as UR SOAS A a A ee 152 9 4 11 Keymaps and pointer button mappingsinX o ooo 153 Til Getting TODA ece AAA AA AAA A 153 9413 Iruelype TONI TILA o es o AE A AA A AA 155 9 4 14 Web rowsersin X acia A A AR 187 UN DU ene rad Peek Ae NE AA a oe ee 158 A o AI ee RE ee ES HS OSE R GE Re 158 9 5 2 Port forwarding for SMTP POP3 tunneling 159 955 Connecting with fewer passwords RSA 24 4 2ee Bane ceed es 160 O54 Deding with alen SSH chents lt lt GRR BOERS Be Le E 160 400 Sone tp ESE bee es 64 da CA we eo eee 161 95 6 Troubleshooting SSH 04445424 ba Chee eae Cae EME RR 161 0 Mallo eae oe a Oe ee SRE Oe OE ee ee is Ee ee ES 161 96 1 Mail transportagents M AS sierras a EHS 162 952 Fetd ng mal Fetchimall occiso recrea
155. e dw ea e e sd 22 2 7 1 Compiling a kernel from non Debian source o o o ooo ooo 22 2 7 2 Tools to build custom kernels 23 CONTENTS iii 2 7 3 Alternative boot loaders 2 anaa aaa 44 E44 444 23 274 Custom boot floppies esco se spata ea aeiaai mai eee dd 23 2 7 5 Special provisions for dealing with modules 24 2 7 6 De installing an old kernel package noonoo aaa 24 3 Debian System installation hints 25 3 1 General Linux system installation hints oaao a 25 3 1 1 Hardware compatibility basics ooo a 25 3 1 2 Determining a PC s hardware and chipset lt soia aaite moema amp 26 3 1 3 Determining a PC s hardware via Debian 26 3 14 Determining a PC s hardware via other OSs 2 2 6 lt lt lt lt 27 So ALO a AAA RD A a HS 27 SO GRUB a eee KR OE eRe OE A A 28 Oda Choiceofbootfloppies lt RMSE SERA a OS 28 Siler isthe o 2 ued eee ee Ree ee Ee ee oe A ER OE ee e 29 319 Hostsand IPtousefor LAN ocio eii da vee neka resi 29 Salad User accounts lt sa ea Ab wok ass Shee Bo ee OE ee a 30 541 peat eSVSICING ore BG eS ER ELE ERG ERS Ee de 30 3 1 12 DRAM memory guidelines lt lt i eo cheese dew bowed thaneds 33 RE e e p ea SE PA kw E B E a R RE R E ER A 33 de Bashconfig rafion e recse Saee RARA A RA AA Es 34 A e s o a be a a a ee Oe ee a a a G ee i 34 Sol PM a amp dee aoe a a Se ts de atthe aa a Be 34 Sone
156. e taking action The following makes apt get always do this cat gt gt etc apt apt conf lt lt Always show packages to be upgraded u APT Get Show Upgraded true Use the no act option to simulate actions without actually installing removing etc any packages 6 3 Debian survival commands With this knowledge you can live the life of eternal upgrade 6 3 1 Check bugs in Debian and seek help If you are experiencing problems with a specific package make sure to check out these sites first before you seek help or file a bug report lynx links and w3m work equally well lynx http bugs debian org lynx http bugs debian org package name if you know package name S lynx http bugs debian org bugnumber if you know bug number Search Google www google com with search words including site debian org When in doubt read the fine manual Set CDPATH as follows export CDPATH usr local usr share doc and type cd packagename S pager README Debian if this exists mc More support resources are listed at Support for Debian on page 245 Chapter 6 Debian package management 84 6 3 2 APT upgrade troubleshooting Package dependency problems may occur when upgrading in unstable or testing as de scribed in Upgrading on page 74 Most of the time this is because a package that will be upgraded Depends on a package that is not yet available These problems are fixed by
157. e tpconfig A program to configure touchpad devices e apmd Utilities for Advanced Power Management APM e acpi displays information on ACPI devices e acpid Utilities for using ACPI e lphdisk prepares hibernation partition for Phoenix NoteBIOS e sleepd puts a laptop to sleep during inactivity e noflushd allow idle hard disks to spin down e big cursor larger mouse cursors for X e acme Enables the multimedia buttons found on laptops e tpct1 IBM ThinkPad hardware configuration tools e mwavem Mwave ACP modem support e toshset Access much of the Toshiba laptop hardware interface e toshutils Toshiba laptop utilities e sjog A program to use the Jog Dial on Sony Vaio Laptops e spicctrl Sony Vaio controller program to set LCD backlight brightness Here ACPI is a newer framework for the power management system than APM Some of these packages require special kernel modules They are already included in the latest kernel source in many cases In case of trouble you may need to apply the latest patch to the kernel yourself 9 2 Restricting access 9 2 1 Restricting logins with PAM PAM Pluggable Authentication Modules allow you to control how users log in etc pam d etc pam d login etc security etc securetty etc login defs PAM control files PAM control file for login PAM module parameters this controls root login by console login this controls login behaviors login e e H
158. ed boot CD project http www 1nx bbc org e Linux info by Karsten Self partitioning backup browsers http kmself home netcom com Linux index html e Backup info HOWTO by Alvin Oga http www Linux Backup net e Security info HOWTO by Alvin Oga http www Linux Sec net e Various UNOFFICIAL sources for APT http www apt get org e Laptop Ethernet Configuration http www orthogony com g3w lap lap ether intro html 253 Appendix A Appendix A 1 Authors Debian Reference was initiated by Osamu Aoki lt osamu debian org gt as a personal instal lation memo that was eventually called Quick Reference Many contents came from the archives of the debian user mailing list Also Debian Installation Manual and Debian Release Notes were referenced Following a suggestion from Josip Rodin who is very active with the Debian Documentation Project http www debian org doc ddp DDP and is the current maintainer of The Debian FAQ this document was renamed as Debian Reference and was merged with sev eral chapters from the The Debian FAQ with reference like contents Then Debian Quick Reference was formed as an excerpt This document has been edited translated and expanded by the following OREF team mem bers e English originals for original Quick Reference Osamu Aoki lt osamu debian org gt leader all contents e English proofreading and
159. ed by lyx 1yx xforms or 1yx qt and GNU TeXmacs provided by texmacs package offers nice WYSIWYG editing environment for LaTeX while many use Emacs and Vim as the choice for the source editor There are many online resources available e teTeX A Documentation Guide usr share doc texmf newhelpindex html tetex doc package e A Quick Introduction to LaTeX http www msu edu user pfaffben writings e A Simple Guide to Latex Lyx http www stat rice edu helpdesk howto lyxguide html e Word Processing Using LaTeX http www h eng cam ac uk help tpl textprocessing latex_basic latex_basic html e Local User Guide to teleX LaTeX http supportweb cs bham ac uk documentation LaTeX lguide local guide local guide html When documents become bigger sometimes TeX may cause errors You must increase pool size in etc texmf texmf cnf or more appropriately edit etc texmf texmf d 95NonPath and run update texmf to fix this 13 9 4 Literate Programming Instead of writing code containing documentation the literate programmer writes documen tation containing code This approach ensures a good documentation for a program For more on literate programming see Literate Programming http www literateprogramming com Noweb Preparation apt get install nowebm References for Noweb 2The TeX source of this book is available at ftp ftp dante de pub tex systems knuth tex texbook tex ftp ftp dante de pub tex syst
160. ed up using the 1ibc6 resolver If you want to cache results for other hosts on your local network then you may want to run a caching forwarding nameserver such as dnsmasq or pdnsd If you wish you can also use bind9 s named as a caching forwarding nameserver It is a heavy program though so unless you need its advanced features you are better off with one of the packages mentioned earlier All of these packages work well with resolvconf 10 4 4 Providing Domain Name Service bind If you need to provide authoritative name service for a domain then you need a fully fledged nameserver such as named which comes in the bind9 package If you install bind9 you should also install dnsutils You may also want to install these utility packages bind9 host dns browse dnscvsutil nslint You may also want to install this documentation package bind9 doc You may also want to install these develop ment packages 1ibbind dev libnet dns perl If you configure interfaces using DHCP then you may find this package useful dhcp dns Install bind9 or dpkg reconfigure it to do the basic set up Configuration consists of edit ing named conf In Debian this file is found in etc bind and is used mainly to define Chapter 10 Network configuration 188 the basic DNS zones it includes two other files named conf local used for defining local zones and named conf options used for setting options The latter is processed by resolvconf to pr
161. ee ee ee es 194 10 8 2 Automatic network configuration using laptop net 195 10 9 Dealing with inconsistent naming of interfaces by the kernel 195 10 10Triggering network configuration ze css else ere EER EY 196 10 10 1 Triggering network configuration at boot time 196 10 10 2 Triggering network configuration hotplug 197 10 10 3 Triggering network configuration ifplugd oooo oo 198 10 10 4 Triggering network configuration waproamd o ooo ooo 198 10 105 Network configuration and PCMCIA case 0 2 198 OATES mapping yx ada o A A a AAA ia 199 10 12Network Servico configuration 644d dee ee is ee ead AR 200 10 18 Network troubl sh oting s so eo coria a A OO 201 10 14Bu ilding a gateway router 6 oh Poa es A AAA A 202 10 14 1 Netfilter c nfig ration o se cas ecr iga AAA 202 10 14 2 Manage multiple net connections sooo cede 205 11 Editors 207 111 Populareditors so se da s Sak Pee a e he ia RA AA 207 11 2 Rescue editors e E ete EA A a E 207 11 3 Emacsand ViM s ee cadea eama ki a g aa a KS 208 MEA AAA II 208 IL Emacs MMS a os AN a CES ee oe 208 TILA Srne CONO ca ceas oe AAA a A ES 208 11 3 4 Editor command summary Emacs Vim o o ooo ooo 209 11 3 5 Vimconfigufation ds ARA A e eH ESS 211 JAN IAE es begs Cee ee Ce BES Ae ee A 211 11 3 7 Convert a syntax highlighted screen to HTML source 211 LIS DPI IN
162. een superseded by the introduction of the APT sys tem Chapter 2 Debian fundamentals 19 2 3 2 APT APT the Advanced Packaging Tool is an advanced interface to the Debian packaging sys tem consisting of several programs whose names typically begin with apt apt get apt cache and apt cdrom are the command line tools for handling packages These also function as the user s back end programs to other tools such as dselect and aptitude For more information install the apt package and read apt get 8 apt cache 8 apt cdrom 8 apt conf 5 sources list 5 apt_preferences 5 Woody and usr share doc apt guide html index html An alternative source of information is the APT HOWTO http www debian org doc manuals apt howto This can be installed by apt howto at usr share doc Debian apt howto apt get upgrade and apt get dist upgrade pull only the packages listed under De pends and overlook all the packages listed under Recommends and Suggests To avoid this use dselect 2 3 3 dselect This program is a menu driven user interface to the Debian package management system It is particularly useful for first time installations and large scale upgrades See dselect on page 80 For more information install the install doc package and read usr share doc install doc dselect beginner en html or dselect Documentation for Beginners http www debian org releases woody i386 dse
163. efaults 0 2 dev hda8 var ext2 defaults o 2 dev hda6 var lib cvs ext2 defaults 0 2 noatime will speed up file access for read access dev hda9 usr ext2 defaults noatime 0 2 dev hda1l0 var cache apt archives ext2 defaults 0 2 very big partition for proxy cache dev hda11 var spool squid ext2 rw 0 2 backup bootable DOS dev hdal mnt dos vfat rw noauto 0 0 backup bootable Linux system not done dev hda2 mnt linux ext2 rw noauto 0 0 nfs mounts mickey mnt mickey nfs ro noauto intr 0 0 goofy mnt goofy nfs ro noauto intr 0 0 minnie mnt minnie smb fs ro soft intr credentials filename 0 2 For NFS I use noauto intr combined with the default hard option This way it is possible to recover from a hung process due to a dead connection using Ctrl C For a Windows machine connected with Samba smbfs rw auto so idea See Samba configuration on page 38 ft intr may be good For a floppy drive using noauto rw sync user exec instead prevents file corruption af ter accidental disk eject before unmount but this slows the write process Autofs mount Key points to auto mount e Load the vfat module to allow etc auto misc to contain fstype auto modprobe vfat prior to the floppy access attempt or to automate this setting echo vfat and reboot the e Set etc auto misc as follows floppy fstype auto where gid 100 is gt gt etc modules
164. eight GNOME alternative Install package icewm exec usr bin X11 icewm e FVWM2 virtual window manager lightweight Win95 like Install package fvwm exec usr bin fvwm2 e Windowmaker window manager somewhat NexT like Install package wmaker exec usr bin wmaker e Enlightenment window manager loaded Install package enlightenment exec usr bin enlightenment See Window Managers for X http www xwinman org fluxbox for its Chapter 9 Tuning a Debian system 151 Setting up KDE and GNOME In order to setup full KDE or GNOME environment the following metapackages are useful e KDE install the kde package e GNOME install the gnome package Installing these packages with tools which handle Recommends such as dselect and aptitude provides you with richer choices of software than just installing these with apt get If you want console login be sure to disable X display managers such as kdm gdm and wdm which may be pulled in by the dependencies as described in Let me disable X on boot on page 107 If you want to have GNOME as the system default over KDE make sure to configure x session manager as in Alternative commands on page 94 9 4 6 Using X over TCP IP Because a remote TCP IP socket connection without encryption is prone to an eavesdropping attack the default setting for X in recent Debian versions disables the TCP IP socket Consider using ssh for a remote X co
165. ell Xft1 is highly deprecated and is basically only used by GNOME1 4 and KDE2 2 Edit etc X11 XftConfig and add a line like dir var lib defoma x ttcidfont conf d dirs TrueType Though this is not available in Woody you can install this from Sarge 3The package in Woody does not work as of 8 2002 due to a change in Microsoft s website Use Sarge version even in Woody instead Chapter 9 Tuning a Debian system 157 before the other dir lines For GNOME2 and KDE3 post Sarge release you need to setup font config which Xft2 uses to find fonts You shouldn t need to install anything extra for this because every package using font config Depends on it indirectly already First look in etc fonts fonts conf There should be a line like the one below If not open up etc fonts local conf and add this lt dir gt var lib defoma x ttcidfont conf d dirs TrueType lt dir gt just after the lt fontconfig gt line Fontconf ig should pick these up immediately and fc list should list your new fonts An other neat feature of font config is that you can just drop fonts in fonts and all your fontconfigified programs will have access to them immediately If you manually install a new set of TrueType fonts while in X without using Debian package run xset fp rehash to get XFree86 to look at the contents of that directory again and to pickup new ones 9 4 14 Web browsers in X
166. em as described in Run a different Debian distribution with chroot on the preceding page type from the root shell of the main system main echo 8 23 respawn usr sbin chroot sid root sbin getty 38400 tty8 gt gt etc inittab main init q reload init Setting up X for chroot You want to run the latest X and GNOME safely in your chroot That s entirely possible The following example will make GDM run on virtual terminal vt 9 First install a chroot system using the method described in Run a different Debian distribution with chroot on the page before From the root of the main system copy key configuration files to the chroot system main cp etc X11 XF86Config 4 sid root etc Xx11 XF86Config 4 main chroot sid root or use chroot console chroot apt get install gdm gnome x window system Chapter 8 Debian tips 129 chroot vi etc gdm gdm conf do s vt7 vt9 in servers section chroot etc init d gdm start Here etc gdm gdm conf was edited to change the first virtual console from vt 7 to vt 9 Now you can easily switch back and forth between full X environments in your chroot and your main system just by switching between Linux virtual terminals e g by using Ctrl Alt F7 and Ctrl Alt F9 Have fun FIXME Add a comment and link to the init script of the chrooted gdm Run other distributions with chroot A chroot environment for another Linux distribution can easily be created You ins
167. empting to install a package this way fails due to dependency violations and you re ally need to install the package then you can override dependency checks using dpkg s ignore depends force depends and other options See dpkg 8 for details Chapter 6 Debian package management 85 6 3 4 Recover package selection data If var lib dpkg status becomes corrupt for any reason the Debian system loses package selection data and suffers severely Look for the old var lib dpkg status file at var 1ib dpkg status o1d or var backups dpkg status Keeping var backups in a separate partition may be a good idea since this directory con tains lots of important system data If no old var lib dpkg status file is available you can still recover information from directories in usr share doc ls usr share doc grep v A Z grep v texmfS grep v debian awk print 1 install A dpkg set selections dselect expert reinstall system de select as needed 6 3 5 Rescue system after crashing var Since the var directory contains regularly updated data such as mail it is more susceptible of corruption than e g usr Putting var ona separate partition reduces risks If disaster happens you may have to rebuild the var directory to rescue your Debian system Obtain the skeleton content of the var directory from a minimum working Debian system based on the same or ol
168. ems knuth lib manmac tex contains most of the required macros You can process this document with tex after commenting lines 7 to 10 and adding input manmac proofmodefalse It s strongly recommended to buy this book and all other books from Donald E Knuth instead of using the online version but the source is a great example of TeX input Chapter 13 Programming 239 e Noweb A Simple Extensible Tool for Literate Programming http www eecs harvard edu nr noweb e noweb 1 This is a WEB like literate programming tool which is simpler while providing extensibility and language independence 3 When noweb is invoked it writes the program source code to the output files mentioned in the noweb file and it writes a TeX file for typeset documentation The Debian i fupdown package is a fine example S apt get source ifupdown cd ifupdown make ifupdown pdf H fupdown ps Doxygen Preparation apt get install doxygen doxygen doc doxygen gui References for Doxygen created by doxygen e Homepage http www doxygen org e usr share doc doxygen doc html index html It can generate HTML RTF Unix manual pages PostScript and PDF using LaTeX documen tation for C C Java IDL and to some extent PHP and C programs Doxygen is compatible to JavaDoc 1 1 Qt Doc KDOC and was specifically designed to be used for projects that make use of Troll Tech s Ot http www trolltech no qt too
169. en su c dpkg i foo_version revision_arch deb to install the newly built package See Port a package to the stable system on page 90 2 2 14 Creating new Debian packages For detailed information on creating new packages read the New Maintainers Guide available in the maint guide package or at http www debian org doc manuals maint guide 2 3 Upgrading a Debian system One of Debian s goals is to provide a smooth secure and reliable upgrade process The packag ing system alerts the administrator to important changes and sometimes asks the administrator to take decisions You should also read the Release Notes it is shipped on all Debian CDs and is available on the WWW athttp www debian org releases stable releasenotes orhttp www debian org releases testing releasenotes A practical guide to upgrades is provided in Debian package management on page 77 This section merely provides an outline beginning with the packaging tools 2 3 1 dpkg This is the main program for manipulating package files read dpkg 8 for a full description dpkg comes with several primitive supplemental programs e dpkg deb Manipulate deb files dpkg deb 1 e dpkg ftp An older package file retrieval command dpkg ftp 1 e dpkg mountable An older package file retrieval command dpkg mountable 1 e dpkg split Splits a large package into smaller files Apkg split 1 dpkg ftp and dpkg mountable have b
170. er http www netfilter org where many network configuration issues are explained Basics of netfilter Netfilter process packets use five built in chains PREROUTING INPUT FORWARD OUT PUT and POSTROUTING routing decision IN gt PRE gt gt FORWARD Si gt POST gt QUT interface ROUTING filter ROUTING interface DNAT tracking a SNAT REDIRECT MASQUERADE Vv INPUT OUTPUT filter filter DNAT Vv X gt Local Process user space programs Netfilter table Packets are processed at each built in chain using the following tables Chapter 10 Network configuration 203 e filter packet filter default INPUT for packets coming into the box itself FORWARD for packets being routed through the box OUTPUT for locally generated packets e nat network address translation PREROUTING for altering packets as soon as they come in OUTPUT for altering locally generated packets before routing POSTROUTING for altering packets as they are about to go out e mangle network address mangling good only after 2 4 18 all five built in chains Netfilter target Firewall rules have several targets e four basic targets ACCEPT means to let the packet through DROP means to drop the packet QUEUE means to pass the packet to userspace if supported by the kernel RETURN means stop traversing this chain and resume at the next rule in
171. er customizations to etc X11 XF86Config file through upgrade run the following commands as root Chapter 9 Tuning a Debian system 147 cp etc X11 XF86Config 4 etc X11 XF86Config 4 custom md5sum etc X11 XF86Config 4 gt var lib xfree86 XF86Config 4 md5sum dpkg reconfigure xserver xfree86 In order to achieve font de uglification you need to edit etc X11 XF86Config 4 as de scribed in TrueType fonts in X on page 155 Please also check the other parts of your X configuration Bad monitor settings can be even more of a headache than bad fonts so make sure your refresh rate is as high as your monitor can handle 85 Hz is great 75 Hz is OK 60 Hz is painful 9 44 X clients Most X client programs can be started with a command like this client xterm geometry 80x24 30 200 fn 6x10 display hostname 0 amp Here the optional command line arguments mean e geometry WIDTHxHEIGHT XOFF YOFF the initial size and location of the window e fn FONTNAME the font to use for displaying text FONTNAME can be al4 Normal size font a24 Large size font check available fonts with x1sfont e display displayname the name of the X server to use displayname can be hostname D S means screen S on display D of host hostname the X server for this display is listening to TCP port 6000 D host unix D S means screen S on display D of host host the X server for this display is listening to U
172. er file access for the read See mount 8 Use touch 1 command to change timestamps of existing files 31Of course this method works only for 3 digit wide numeric mode Chapter 4 Debian tutorials 68 4 5 5 Links There are two methods of associating a file foo with a different filename bar e a hard link is a duplicate name for an existing file 1n foo bar e asymbolic link or symlink is a special file that points to another file by name 1n s foo bar See the following example for the changes in link counts and the subtle differences in the result of the rm command S echo Original Content gt foo ls l foo rw r r 1 osamu osamu 4 Feb 9 22 26 foo ln foo bar hard link ln s foo baz symlink ls 1 foo bar baz rw r r 2 osamu osamu 4 Feb 9 22 26 bar lrwxrwxrwx 1 osamu osamu 3 Feb 9 22 28 baz gt foo rw r r 2 osamu osamu 4 Feb 9 22 26 foo S rm foo S echo New Content gt foo cat bar Original Content cat baz New Content The symlink always has nominal file access permissions of rwxrwxrwx as shown in the above example with the effective access permissions dictated by the permissions of the file that it points to The directory links to the directory that it appears in thus the link count of any new directory starts at 2 The directory links to the parent directory thus the link count of the directory increases with the addition of new subdirec
173. ersions u list of upgradeable packages S aptitude install apt show versions u b fgrep unstable upgrade all unstable packages to their newest versions Chapter 6 Debian package management 90 6 4 8 Prune cached package files Package installation with APT leaves cached package files in var cache apt archives and these need to be cleaned aptitude autoclean removes only useless package files aptitude clean removes all cached package files 6 4 9 Record copy system configuration To make a local copy of the package selection states dpkg get selections gt myselections or use makes myselect ions include package entries for purge too You can transfer this file to another computer and install it there with dselect update dpkg set selections lt myselections apt get u dselect upgrade or dselect install 6 4 10 Port a package to the stable system For partial upgrades of the stable system rebuilding a package within its environment using the source package is desirable This avoids massive package upgrades due to their dependen cies First add the following entries to etc apt sources list deb src http http us debian org debian testing main contrib non free deb src http non us debian org debian non US testing non US A main contrib non free deb src http http us debian org debian unstable main contrib non free deb src http non us debian or
174. escribed in Connecting with fewer passwords RSA on the preceding page ssh agent bash or run zsh tcsh pdksh program instead S ssh add ssh id_rsa Enter passphrase for home osamu ssh id_rsa Identity added home osamu ssh id_rsa home osamu ssh id_rsa scp foo user remote host foo no passphrase needed from here on D terminating ssh agent session For the X server normal Debian startup scripts execute ssh agent as parent process So you only need to execute ssh add once For more read ssh agent 1 and ssh add 1 9 5 6 Troubleshooting SSH If you have problems check the permissions of configuration files and run ssh with the v option Use the P option if you are root and have trouble with a firewall this avoids the use of server ports 1 1023 If ssh connections to a remote site suddenly stop working it may be the result of tinkering by the sysadmin most likely a change in host_key during system maintenance After making sure this is the case and nobody is trying to fake the remote host by some clever hack one can regain a connection by removing the host_key entry from S HOME ssh known_hosts on the local machine 9 6 Mail Mail configuration divides into three categories e mail transfer agent MTA exim4 exim postfix sendmail qmail ssmtp nullmailer e mail utilities procmail fetchmail mailx crm114 e mail user agent MUA mutt emacs gnus Chapter
175. etc apt sources list If you want to see how packages in testing unstable do against the currently installed one use apt cache policy quite nice apt get apt cache apt cache apt cache apt cache apt cache UY UY 141 47 147 4 0 4 e S P S Ss S heck earch olicy how a howsrc howpkg dpkg audit C dpkg s status package dpkg 1 package dpkg L package pattern package package package package s e e e e e Le for auto apt l packages installed or not to point APT to the update cache and check for broken packages search package from text description package priority dists information show description of package in all dists show description of matching source package package information for debugging search for partially installed packages description of installed package status of installed package 1 line each list filenames installed by the package apt cache showsrc is not documented as of the Woody release but works You can also find package information in I use mc to browse these var lib apt lists var lib dpkg available The comparison of the following files provides information on what exactly has happened in the last few install sessions var lib dpkg status var backups dpkg status Chapter 6 Debian package management 88 6 4 3 Unattended installation with APT For an unattended installation a
176. ewer AMO gt ccecce eetere A Aa e ado o Peale ge 50 427 Autostart features O MC cuco 0 rr DEED e a 51 128 Pl virtual filesystem 6f MC so so so scoa aaa RA 51 4 3 Unix like work environment casas serere cererea a a 51 Biel Spedal keystrokes q qi ek ai eii A a A 51 432 Basic Unix commands cscs 06 Fe arresta eee ee RR A 52 4 3 3 The command execution a oaoa a a eee es 56 aoe e A IEA 56 4 3 5 Command execution and environment variable 56 CONTENTS 7 Boe Command Searcy pathi ece BA aa eon Ere Oea a e 57 437 Command neoplan cdas pack da Ree a a 57 Oa Shel WEES cad AA A ES 57 43 9 Return value of the command aaa a 58 43 10 Typical command sequences lt lt w sOi hae car Bee eee 58 4311 Command CUBS o ea sa ee eA e i a AAA ee Ee 60 A4 Unix like text processing y ecaa AAA ARA A 60 44 1 Reg larexpressions o so socs eass asmak a ei 61 4432 Replacement expressi s o eoe socs od aen A AR 62 45 Unielk Mlesystem s occ ta a ara a en e a 63 O50 Umik tile Waste iras enaa a para pa A AA RS 63 4 5 2 The filesystem concept in Debian 2524 25 44 25 nara 64 453 Pileand directory access permissions lt s 64 8 ossos to sa siras s 65 A AI 67 ARS MS lt gt see rr da E ee see Brida eee CER eI 68 A56 Named pipes PUROS lt lt orar pane a ERY a RS 68 A AN TAR 69 458 Devic files s oco cae ceas eine A A AR OS 69 A59 o EII 70 AG XWindow Systems o suca ie gee Pe AAA AAA a da ds 70 4
177. ftp iptable_nat iptable_filter iptable_mangle ip_nat_ftp ip_queue ipt_LOG ipt_MARK ipt_MASQUERADE ipt_MIRROR ipt_REDIRECT ipt_REJECT ipt_TCPMSS ipt_TOS ipt_limit ipt_mac ipt_mark ipt_multiport ipt_owner ipt_state ipt_tcpmss ipt_tos ipt_unclean ipchains ipfwadm The preceding may not be optimized depmod may take care of some of the above modules 7 2 4 EXT3 filesystem gt 2 4 17 Enabling a journaling filesystem with the EXT3 FS involves the following steps using a Debian precompiled kernel image gt 2 4 17 package cd etc mv fstab fstab old sed s ext2 ext3 ext2 g lt fstab old gt fstab vi etc fstab k set root filesystem type to auto instead of ext3 ext2 cd etc mkinitrd Chapter 7 The Linux kernel under Debian 102 e e H SHE e echo jbd gt gt modules echo ext3 gt gt modules echo ext2 gt gt modules cd apt get update apt get install kernel image 2 4 17 686 smp install latest kernel and set up boot lilo is run here tune2fs j i 0 dev hdal tune2fs j i 0 dev hda2 For all EXT2 FS s converted to EXT3 shutdown r now Now EXT3 journaling is enabled Using ext3 ext2 as the fstab type entry ensures safe fallback to EXT2 if the kernel does not support EXT3 for non root partitions If you have previously installed a 2 4 kernel and do not wish to reinstall perform the above steps up to the apt get commands then
178. g and think yourself mkdir junk cd junk touch 1 txt 2 txt 3 c 4 h 5 txt Chapter 4 Debian tutorials 58 echo txt 1 txt 2 txt S echo 1 txt 2 txt 3 c 4 h echo hc 326 Aah S echo PMi 31 cd rm rf junk 4 3 9 Return value of the command Each command returns its exit status as the return value e return value 0 if the command executes successfully e return value non zero if the command exits with error This return value can be accessed by the shell variable immediately after the execution 1 1 echo 1 2 echo Rh Q Please note that when the return value is used in the logical context for the shell success is treated as the logical TRUE This is somewhat non intuitive since success bears value zero See Shell conditionals on page 224 4 3 10 Typical command sequences Let s try to remember following shell command idioms See Shell parameters on page 223 Shell redirection on page 223 Shell conditionals on page 224 and Command line process ing on page 225 after reading these idioms command amp The command is executed in the subshell in the background Background jobs allow users to run multiple programs in a single shell Chapter 4 Debian tutorials 59 The management of the background process involves the shell built ins jobs fg bg and ki11 Please read the sections of the bash 1 manual page under
179. g debian non US unstable non US main contrib non free Here each entry for deb src is broken into two lines because of printing constraints but the actual entry in sources list should consist of a single line Then get the source and make a local package Chapter 6 Debian package management 91 UY UY UY Ur apt get update update the source package search list apt get source package dpkg source x package dsc cd package version inspect required packages Build Depends in dsc file and install them too You need the fakeroot package also dpkg buildpackage rfakeroot or no sig dpkg buildpackage rfakeroot us uc use debsign later if needed Then to install su c dpkg i packagefile deb Usually one needs to install a few packages with the dev suffix to satisfy package depen dencies debsign is in the devscripts package auto apt may ease satisfying these de pendencies Use of fakeroot avoids unnecessary use of the root account In Woody these dependency issues can be simplified For example to compile a source only pine package apt get build dep pine apt get source b pine 6 4 11 Local package archive In order to create a local package archive which is compatible with APT and the dselect system Packages needs to be created and package files need to be populated in a particular directory tree A local deb repository similar to an official Debian
180. ge editor VI iMproved emacs Ultimate and heavy GNU heritage editor RMS Richard M Stallman original xemacs Emacs The Next Generation originally from Lucid mcedit Newbie GNU editor Identical to mc internal editor See Editor in MC on page 50 ae Default small editor Potato Avoid this nano Default small GNU editor Woody Emulates pico joe For WordStar or TurboPascal old timers jed Fast full featured menu driven editor with Emacs key bindings jove Very small editor with Emacs key bindings nvi New vi Bug for bug compatible with the original vi Use update alternatives config editor to change the default editor Also many programs use environment variables EDITOR or VISUAL to decide which editor to use See Editor in MC on page 50 Also a few X based text editors are noteworthy gvim Vim with GUI vim and vim gtk package emacs The One True Emacs auto detect X e xemacs Next generation Emacs auto detect X These xclient commands take standard options such as fn a24 which makes life easy for older folks like me See X clients on page 147 11 2 Rescue editors There are a few editors which reside in bin One of these should be installed to ease editing files when usr is not accessible Chapter 11 Editors 208 e elvis tiny Minimum vi editor vi to start e nano tiny Minimum non vi editor nano t iny to start e nano Minimum non vi editor nano to start Sa
181. general Unix guide and resources The UNIX System by The Open Group http www unix org A UNIX Introductory Course from Ohio State University http www wks acs ohio state edu unix_course unix html UNIXhelp from The University of Edinburgh http unixhelp ed ac uk Unix Programming Information http arioch unomaha edu jclark info comp unix questions FAQ http www faqs org faqs unix faq faq comp unix user friendly FAQ http www camelcity com noel usenet cuuf FAQ htm FreeBSD Documentation http www freebsd org docs html The FreeBSD Handbook http www freebsd org doc en_US 1S08859 1 books handbook index html UNIX GUIDE http ieee uow edu au documents The Unix Heritage Society http www tuhs org e Free software project home pages GNU Project http www gnu org The Linux Documentation Project http www tldp org The Linux Kernel Archives http www linux org The XFree86 Project Inc http www xfree86 org GNOME http www gnome org K Desktop Environment http www kde org GNU software at Red Hat http sources redhat com Mozilla http www mozilla org FreeBSD http www freebsd org OpenBSD http www openbsd org NetBSD http www netbsd org 15 2 Finding the meaning of a word Many words used in Debian are cryptic jargon or acronyms The following will solve most questions
182. gnome terminal xterm for Gnome e konsole xterm for KDE e rxvt VT102 terminal lighter e aterm VT102 for Afterstep WM e eterm VT102 for Enlightment WM e wterm VT102 for WindowMaker WM Multi byte encoding supports of X console are provided by xterm through UTF 8 encoding UTF 8 support for the X terminal emulator on this page Other traditional encoding sup ports are in progress as of 2003 Following packages offer traditional encoding supports e aterm ml Multi lingual e kterm Multi lingual Japanese e rxvt ml Multi lingual e wterm ml Multi lingual e cxterm big5 Chinese Trad Big5 e cxterm gb Chinese Simp GB e cxterm ks Chinese KS e cxterm jis Japanese e hanterm classic Korean Hangul e hanterm xf Korean Hangul e hztty Chinese GB Big5 zW HZ For kterm and possibly others you may want to activate XIM through menu after Ctrl middle click mouse action 9 7 12 UTF 8 support for the X terminal emulator UTF 8 support for X terminal emulator is provided by the uxterm program in the xterm package for XFree86 4 x It enables support for all languages It is a wrapper around the xterm 1 program that invokes the latter program with the UXTerm X resource class set Chapter 9 Tuning a Debian system 175 For example to enable nice large display of English Russian Japanese Chinese and Korean characters add following to your
183. ground job Basic parameter expansions to remember Form var string var string S var string S var string If var Svar string Svar Svar is set If var is not set string null string and run var string echo string and then exit Here the colon in all of these operators is actually optional e With operator test for exist and not null e Without operator test for exist only Basic parameter substitutions to remember Form S var ssuffix S vars suffix S vartprefix S var prefix Result Remove Remove Remove Remove 13 2 4 Shell redirection smallest suffix pattern largest suffix pattern smallest prefix pattern largest prefix pattern Basic redirection to remember here the n is an optional number to specify the file descriptor n gt file nl gt gt file n lt file Redirect stdout or n to file Append stdout or n to file Redirect stdin or n from file Chapter 13 Programming 224 n1 gt 8n2 Redirect stdout or ni to n2 2 gt file gt amp 2 Redirect stdout and stderr to file gt file 2 gt 6 amp 1 Redirect stdout and stderr to file command Pipe stdout to command 2 gt amp 1 command Pipe stderr and stdout to command Here e stdin standard input file descriptor 0 e stdout standard output file descriptor 1 e stderr standard error file descriptor 2 The
184. gure physical interfaces though For more information consult the well written docu mentation in laptop net doc 10 9 Dealing with inconsistent naming of interfaces by the kernel The names eth0 eth1 etc are assigned by the kernel in the order that the kernel creates the interfaces that go by those names While adapters that are detected at boot time are usually detected in the same order every time and are therefore assigned the same names every time the same is not true of adapters that are hot plugged These can be detected in any order and end up getting assigned different names by the kernel on different occasions Because of this fact on a system into which network adapters are hot plugged it won t always do to define logical interfaces in etc network interfaces with names eth0 eth1 etc and to rely on the default mapping Instead you must give distinct names to the logical in terfaces and use one of the following two methods to restrict which logical interfaces can be assigned to which adapters One method is to use either the namei f utility in the net tools package or the more flexible ifrename utility in the ifrename package to make the kernel assign names to interfaces according to properties of the underlying adapters With this naming scheme in effect the physical interface name can be used to infer which adapter underlies it Another method is to use i fup s mapping mechanism in such a way that a logical interface
185. h a gateway that translates IP address on the LAN to IP addresses usable on the Internet apt get install ipmasq Apply example rules to strengthen the ipmasq protection See usr share doc ipmasq examples stronger README For Debian kernel image 2 4 under woody make sure to load the proper modules Sarge version of ipmasq fixed this issue See Network function on page 100 for configuration instructions For Debian kernel image 2 2 edit Z92timeouts rul in etc masq rules as follows to ensure a longer connection to remote sites good for large emails etc tcp tcp fin udp 2hr 10 sec 160 sec default 1 day 10 min 10 min longer example SIPCHAINS M S 86400 600 600 Also if the network is accessed through a PCMCIA NIC ipmasq needs to be started either from etc pemcia network opts read usr share doc ipmasq ipmasq txt gz or from etc network interfaces read Network configuration and PCMCIA on page 198 and Triggering network configuration on page 196 Redirect SMTP connection 2 4 Suppose you have a notebook PC which is configured to use other LAN environments and you want to use your mail user agent on the notebook PC without reconfiguring it Adding the following rules through the iptables command to the gateway machine will redirect the SMTP connection to the gateway machine iptables t nat A PREROUTING s 192 168 1 0 24 j REDIRECT p tcp dport smtp to port 25 smtp 25
186. he following line to etc lilo conf if you are using a stock Debian kernel If multiple options are used list them separated by spaces append hdx ide scsi ignore hdx Here the location of the CD writer which is accessed through the ide scsi driver is indicated by hdx where x represents one of the following hda for a master on the first IDE port hdb for a slave on the first IDE port hdc for a master on the second IDE port hdd for a slave on the second IDE port hde hdh for a drive on an external IDE port or ATA66 100 IDE port Type the following commands as root to activate after finishing all the configuration lilo shutdown h now 9 3 3 Approach 2 recompile the kernel Debian uses make kpkg to create a kernel Use the new append_to_version with make kpkg to build multiple kernel images See The Linux kernel under Debian on page 97 Use the following setup through make menuconfig e bzImage e Exclude the IDE CD driver not a must but simpler to do this e Compile in ide scsi and sg or make them modules Chapter 9 Tuning a Debian system 140 9 3 4 Post configuration steps Kernel support for the CD writer can be activated during booting by the following echo ide scsi gt gt etc modules echo sg gt gt etc modules cd dev ln sf scd0 cdrom Manual activation can be done by modprobe ide scsi modprobe sg After reboot you can check installation by
187. header of outgoing e mail will be e From foo myhost dom if the MUA has no From header set e From bartmyhost dom ifthe MUA has From bar set Chapter 10 Network configuration 186 e From bartbogus dom if the MUA has From bar bogus dom set Even when the MUA has a From header set the MIA may add a Sender foo herman dom header to indicate its true origin Of course when any involved MTA performs address rewriting as discussed in Setting up a catchall for nonexistent email addresses under Exim on page 163 and Configuring selective address rewriting for outgoing mail under Exim on page 163 the e mail address seen by the recipient can be changed to anything 10 4 Domain Name Service DNS Hosts are referred to by domain name as well as by IP address DNS is a client server system in which name resolvers consult nameservers in order to associate domain names with IP ad dresses and other properties of hosts The GNU C Library resolver 3 can also look up IP addresses in files or consult Network Information Services NIS To see what domain name is associated with the local host use the hostname fqdn com mand This prints out the first fully qualified domain name that the resolver finds for the local hostname 10 4 1 The resolver The job of finding out what IP addresses are associated with a particular domain name is the job of a resolver The most commonly used resolve
188. her OSs Hardware information can also be obtained from other OSs Install another commercial Linux distribution Hardware detection on those tends to be bet ter than on Debian as of now This situation should even out once debian installer is introduced with Sarge Install Windows Hardware configuration can be obtained by right clicking My Computer to get to Properties Device Manager Record all resource information such as IRQ I O port address and DMA Some old ISA cards may need to be configured under DOS and used ac cordingly 3 1 5 A Lilo myth Lilo is limited to 1024 cylinders Wrong Chapter 3 Debian System installation hints 28 The newer lilo used after Debian Potato has lba32 support If the BIOS of your motherboard is recent enough to support lba32 1i1o should be able to load beyond the old 1024 cylinder limitation Just make sure to add a line reading lba32 somewhere near the beginning of your lilo conf file if you have kept an old lilo conf See usr share doc lilo Manual txt gz 3 1 6 GRUB The new boot loader grub from the GNU Hurd project can be installed on a Debian Woody system apt get update apt get install grub doc mc usr share doc grub doc html read contents apt get install grub pager usr share doc grub README Debian read it HE To edit the GRUB menu edit boot grub menu 1st See Setting GRUB boot parameters on page 108 for how to set
189. hich you selected during the install process In the Debian system following the Unix tradition the password is case sensitive Then the system starts with the greeting message and presents you with the root command prompt waiting for your input foo login root The left Ctrl key the left Alt key and the F1 key are pressed together 2Note that if you edited the greeting message in etc motd this will be different Chapter 4 Debian tutorials 46 Password Last login Sun Oct 26 19 04 09 2003 on tty3 Linux foo 2 4 22 1 686 6 Sat Oct 4 14 09 08 EST 2003 1686 GNU Linux Most of the programs included with the Debian GNU Linux system are freely redistributable the exact distribution terms for each program are described in the individual files in usr share doc copyright Debian GNU Linux comes with ABSOLUTELY NO WARRANTY to the extent permitted by applicable law root foo root You are ready to perform the system administration from this root command prompt This root account is also called superuser or privileged user From this account you can do anything e read write and remove any files on the system irrespective of their file permissions e set file ownership and permission of any files on the system e set the password of any non privileged users on the system e login to any accounts without their passwords It is extremely bad idea to share the access to the root account by sharing the passwo
190. hmail fetchmail is run in daemon local mail system Configure mode to fetch mail from a POP3 account with an ISP into the etc init d fetchmail etc rce d fetchmail run update rc d fetchmail default priority 30 configuration file chown 600 owned by fetchmail etc fetchmailre Information on how to start fetchmail as a daemon from the init d script for Potato is confusing Woody fixed this See the sample etc init d fetchmail and etc fetchmailrc files in the example scripts http www debian org doc manuals debian reference examples If your email headers are contaminated by M due to your ISP s mailer add stripcr to your options in SHOME fetchmai options fetchall no Lee keep stripcr Chapter 9 Tuning a Debian system 165 9 6 3 Processing mail Procmail procmail is a local mail delivery and filter program One needs to create SHOME procmailrc for each account that uses it Example _procmailre http www debian org doc manuals debian reference examples 9 6 4 Processing spam with crm114 crm114 package provides usr share crm114 mailfilter crm script which is written in CRM114 This script provides a very effective spam filter which can be trained by feeding the spam and the ham CRM114 is a small language designed to write filters in consider it to be a version of grep with super powers See crm 1 9 6 5 Reading
191. hmod 600 foo Make an existing file foo to be non readable and non writable by the other people non executable for all e chmod 644 foo Make an existing file foo to be readable but non writable by the other people non executable for all e chmod 755 foo Make an existing file foo to be readable but non writable by the other people exe cutable for all e top Display process information using full screen Type q to quit e ps aux pager Display information on all the running processes using BSD style output See commandl command2 on page 59 e ps ef pager Display information on all the running processes using Unix system V style output e ps aux grep e e xim4 Display all processes running exim or exim4 Learn the regular expression from grep 1 manual page by typing man grep 2 e ps axf pager Display information on all the running processes with ASCII art output e kill 1234 Killa process identified by the process ID 1234 See Kill a process on page 112 e grep e pattern html Find a pattern in all of the files ending with htm1 in current directory and display them all e gzip foo Compress foo to create foo gz using the Lempel Ziv coding LZ77 e gunzip foo gz Decompress foo gz to create foo e bzip2 foo Compress foo to create foo bz2 using the Burrows Wheeler block sorting text compression algorithm and Huffman coding Better compression than gzip e bu
192. i done 13 2 2 POSIX shells Several packages provide a POSIX shell in Debian e dash Sarge Priority optional Installed Size 176 Smallest and fastest by far best for initial boot e ash Woody Priority optional Installed Size 180 Smaller and much faster good for initial boot e bash Essential yes Priority required Installed Size 580 Larger and featureful many extensions implemented e pdksh Priority optional Installed Size 408 Complete AT amp T ksh look alike If you are writing a shell script for portability it is best to write it as a POSIX shell script Use bin sh linked to ash or dash to test its POSIX compliance Avoid writing scripts with bashisms or the zshisms For example avoid e if foo bar then e diff u file c orig e mkdir foo bar baz Chapter 13 Programming 223 The description for the shell in this document applies only for the POSIX type shells and thus does not apply for the csh type shells including tcsh 13 2 3 Shell parameters Several special parameters to remember S0 name of the shell or shell script 1 first 1 shell argument 9 ninth 9 shell argument S number of positional parameters URSE s1 2 3 4 Sn seu US woo SBN sq aan Sn exit status of the most recent command S PID of this shell script PID of most recently started back
193. ian retference The latest development version is http qref sourceforge net Debian The project is hosted athttp qref sourceforge net where this document is available for down load in plain text HTML PDF SGML and PostScript formats Chapter 1 Preface 2 1 2 Document conventions This Debian Reference provides information through short bash shell commands Here are the conventions used command in root account command in user account description of action These shell command examples use PS2 See Bash GNU standard interactive shell on page 221 for more information on bash Reference to e a UNIX style manual page is given in the form bash 1 e a GNU TEXINFO page is given in the form info libc e a book is given in the form The C Programming Language ea URL is given in the form http www debian org doc manuals debian reference e a file on the system is given in the form usr share doc Debian reference The following abbreviations are used e LDP Linux Documentation Project http www tldp org e DDP Debian Documentation Project http www debian org doc Other abbreviations are defined in the text before they are used In this document only URL references are given for LDP documents However LDP docu ments have been packaged for Debian when the packages are installed the documents are available in usr share doc HOWTO See References on page 245
194. ice Make sure you have all required kernel functions activated through kernel compile time con figuration or modules Under Input core support Input core support CONFIG_INPUT input o Mouse support CONFIG_INPUT_MOUSEDEV mousedev o e Under USB support Support for USB CONFIG_USB usbcore o Chapter 3 Debian System installation hints 37 Preliminary USB device filesystem CONFIG_USB_DEVICEFS UHCI or OHCI CONFIG_USB_UHCI CONFIG_USB_UHCI_ALT CON FIG_USB_OHCI usb uhci o ll uhci o I usb ohci o USB Human Interface Device full HID support CONFIG_USB_HID hid o and HID input layer support CONFIG_USB_HIDINPUT Here lower case names are module names If you re not using devfs create a device node dev input mice with major 13 and minor 63 as follows cd dev mkdir input mknod input mice c 13 63 For typical scroll USB mice configuration combinations should be etc gpm conf etc X11 X86Config 4 device dev input mice Section InputDevice responsiveness Identifier Generic Mouse repeat_type raw Driver mouse type autops2 Option SendCoreEvents true append Option Device dev input mice sample_rate Option Protocol IMPS 2 Option Buttons 5 Option ZAxisMapping 4 5 EndSection See the Linux USB Project http www 1linux usb org for more information 3 3 3 Touchpad Alth
195. iders ISPs use PPP to negotiate connections even though customer machines are connected to them through Ethernet and or ATM networks This is accomplished by means of PPP over Ethernet PPPoE which is a technique for the encapsulation of PPP streams inside of Ethernet frames Suppose your ISP is called myisp First configure PPP and PPPoE for peer myisp The easiest way to do this is to install the pppoeconf package and to run pppoeconf from the console Then edit etc network interfaces so that it includes a stanza like this iface ethO inet ppp provider myisp There are sometimes Maximum Transmit Unit MTU issues with PPPoE over Digital Sub scriber Line DSL See DSL HOWTO http www tldp org HOWTO DSL HOWTO for details Note that if your broadband modem contains a router then the modem router handles the PPPoE connection itself and appears on the LAN side as a simple Ethernet gateway to the Internet 10 6 6 Configuring multiple Ethernet interfaces for a gateway Suppose eth0 is connected to the Internet with a DHCP configured IP address and eth1 is connected to the LAN with static IP address 192 168 1 1 Edit etc network interfaces so that it includes stanzas like these See bug 196877 http bugs debian org 196877 See bug 127786 http bugs debian org 127786 Chapter 10 Network configuration 192 iface eth0 inet dhcp iface ethl inet static address 192 168 1 1 netmask 255 255 255 0 If you activ
196. ied by r e p sl This matches zero or one regular expressions identified by r e rijr2 This matches one of the regular expressions identified by r1 or r2 e r1 r2 This matches one of the regular expressions identified by 11 or r2 and treats it as a bracketed regular expression In BREs the metacharacters lose their special meaning instead use the backslashed versions 1 11 Thus the grouping construct 11 12 needs to be quoted as r1 r2 in BREs Since emacs although being basically BRE treats 2 as the metacharacters Thus there are no needs to quote them See Replacement ex pressions on the current page for how the grouping construct is used For example grep can be used to perform the text search using the regular expression egrep GNU LICENSE Yoyodyne usr share common licenses GPL GNU GENERAL PUBLIC LICENSE GNU GENERAL PUBLIC LICENSE Yoyodyne Inc hereby disclaims all copyright interest in the program 4 4 2 Replacement expressions For the replacement expression following characters have special meanings This represents what the regular expression matched use amp in emacs o n This represents what the n th bracketed regular expression matched For Perl replacement string n is used instead of n and amp has no special meaning For example echo zzzlabc2efg
197. ile chgrp is used from the file s owner or root account To change file and directory access permissions chmod is used from the file s owner or root account Basic syntax to manipulate Chapter 4 Debian tutorials 66 foo file is chown newowner foo chgrp newgroup foo chmod ugoa rwx foo See chown 1 chgrp 1 and chmod 1 for the detail For example in order to make a directory tree to be owned by a user foo and shared by a group bar issue the following commands from the root account cd some location chown R foo bar chmod R ug rwX o rX There are three more special permission bits e set user ID s or S instead of user s x e set group ID s or S instead of group s x and e sticky bit t or T instead of other s x Here the output of 1s 1 for these bits is capitalized if execution bits hidden by these outputs are unset Setting set user ID on an executable file allows a user to execute the executable file with the owner ID of the file for example root Similarly setting set group ID on an executable file allows a user to execute the executable file with the group ID of the file for example root Because these settings can cause security risks enabling them requires extra caution Setting set group ID on a directory enables the BSD like file creation scheme where all files created in the directory belong to the group of the directory Setting the sticky bit on a directory
198. im environment Installation of non Unicode fonts to X will help in displaying documents with any encoding in X So do not worry too much about encoding of fonts Chapter 9 Tuning a Debian system 167 Localizing messages and documentation Translations exist for many of the text messages and documents that are displayed in the De bian system such as error messages standard program output menus and manual pages Currently support for manual pages in German Spanish Finnish French Hungarian Ital ian Japanese Korean Polish Portuguese Chinese and Russian is provided through the manpages LANG packages where LANG is a comma separated list of two letter ISO coun try codes Use apt cache search manpages less to get a list of available Unix manual pages To access an NLS manual page the user must set the environment variable LC_MESSAGES to the appropriate string For example in the case of the Italian language manual pages LC_MESSAGES needs to be set to it The man program will then search for Italian manual pages under usr share man it 9 7 2 Locales Debian supports locale technology Locale is a mechanism that allows programs to provide suitable output and functionality according to local conventions such as character set format for date and time currency symbol and so on It uses environment variables to determine the appropriate behavior For example assuming you have both the American English and German locale
199. imal keystroke replace M x replace string Ss aaa bbb g replace regexp M x replace regexp Ss aaa bbb g query replace M Ss aaa bbb gc query replace M x query replace query replace regexp M x query replace regexp Open file Case GHE r file Save file C x C s Iw Save all buffers C x s wa Save as C x C w file w file Prompt for buffer C x b List buffers C x C b buffers Toggle read only C x C q set ro Prompt and kill buffer C x k Split vertical C x 2 split Split horizontal C x 3 vsplit ver 6 Move to other window C X 0 Wp Delete this window C x 0 A Delete other window s C x 1 Wo run shell in bg M x compile kill shell run in bg M x kill compilation run make make Makefile check error message C x echo errmsg run shell and record M x shell script a tmp ca Clean BS cs col b lt tmp gt record save recall shell record C x C w record r record run shell M sh sh run command M cmd lema run command and insert C u M cmd x comd run filter M file visual w file run filter and insert C u M filter visual filter show option se t option reset option to default se t option amp reset boolean option se t nofoption toggle boolean option se t inv option wrap text at column 72 se tw 72 do not wrap se tw 0 autoindent se al expand tab se et specify comment mail se comments n gt n Chapter 11 Editors
200. ing distribution you may need to open a console terminal during the install process by pressing Alt F2 and manually edit etc apt sources 1list entries changing stable to testing to adjust APT sources I tend to install 1ilo into places like dev hda3 while installing mbr into dev hda This minimizes the risk of overwriting boot information Here is what I choose during the install process e MD5 passwords yes e shadow passwords yes e Install advanced dselect and select Exclude emacs if selected nvi tex telnet talk d Include mc vim either one of nano tiny or elvis tiny See dselect on page 80 Even if you are an Emacs fan avoid it now and be content with nano during install Also avoid installing other large packages such as TeX Potato used to do this at this stage See Rescue editors on page 207 for the reason for installing nano tiny or elvis tiny here i e All configuration questions y replace current during each package install dialog e exim select 2 for machine since I send mail through my ISP s SMTP server For more information on dselect see dselect on page 80 3 1 9 Hosts and IP to use for LAN Example of LAN configuration C subnet 192 168 1 0 24 Internet KH RR HG External ISP provides POP service accessed by fetchmail Access point ISP provides DHCP service and SMTP relay service Cable modem Dialup
201. interfaces are actually definitions of logical in terfaces not of physical interfaces 14 If you never want to reconfigure your interfaces then you can ignore this fact since the physical interface foo will by default be configured as logical interface foo This terminology is used in the i fupdown documentation MN ote that the interfaces named on auto lines must be physical interfaces not logical interfaces Chapter 10 Network configuration 193 However suppose your computer is a laptop that you transport between home and work When you connect the computer to the corporate network or to your home LAN you need to configure eth0 accordingly First define two logical interfaces home and work instead of eth0 as we did earlier which describe how the interface should be configured for the home network and the work network respectively iface home inet static address 192 168 0 123 netmask 255 255 255 0 gateway 192 168 0 1 iface work inet static address 81 201 3 123 netmask 255 255 0 gateway 81 201 1 1 o Then physical interface eth0 can be brought up for the home network with the appropriate configuration by specifying it on the command line ifup ethO home To reconfigure et h0 for the work network issue the commands ifdown eth0 ifup eth0 work Note that with the interfaces file written as above it will no longer be possible to bring up eth0 by doing ifup eth0 alone The reason is
202. ion instead of xinitrc User specific additional X resources can be stored in Xresources See X resources on page 152 User customized keymaps and pointer button mappings in X can also be specified in the user s start up script See Keymaps and pointer button mappings in X on page 153 Starting an X session for a user Following the principle described at Custom X sessions on the preceding page a user specific X session window manager can be activated by installing the package indicated and setting Chapter 9 Tuning a Debian system 150 the contents at the end of xsession file as follows I like blackbox 1 simple style and fast speed e default X session manager See Alternative commands on page 94 exec usr bin x session manager e default X window manager See Alternative commands on page 94 exec usr bin x window manager e GNOME session manager loaded Install package gnome session exec usr bin gnome session e KDE session manager loaded Install package kdebase or kdebase3 for KDE3 exec usr bin kde2 Blackbox window manager lightweight slick Install package blackbox exec usr bin blackbox e Fluxbox window manager lightweight new blackbox Install package fluxbox exec usr bin fluxbox e Xfce window manager Mac OS X SUN CDE like Install package xfce exec usr bin xfwm e Ice WM window manager lightw
203. ired locales using the method described at Localization on page 165 for all e install Kana to Kanji conversion system and dictionary for Japanese canna Local server free beer license or freewnn jserver Network extensible server Public Domain e install Japanese input method system for Japanese kinput2 canna for X or kinput2 canna wnn for X and egg directly works with Emacsen even in console optional e Install compatible terminals for all xterm X for ISO 8859 1 and UTF 8 kterm X for Japanese EUC and mlterm X multilingual e add all the required font packages for all e create the xsession that sets the user specific X environment as described in Cus tom X sessions on page 148 for all bin sh This makes X work when I su to root if z SXAUTHORITY then XAUTHORITY SHOME Xauthority export XAUTHORITY Set specific environment through debian menu system Reset locale unset LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES unset LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT unset LC_IDENTIFICATION LC_ALL LANG LANGUAGE PAGER set locale default in X LANG C export locale export LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES export LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT export LC_IDENTIFICATION LC_ALL LANG LANGUAGE PAG
204. is cheap Using the boot option mem 4m or lilo append mem 4m will show how the system would perform with 4MB of memory installed A lilo boot parameter is needed for a system contain ing more than 64MB of memory with an old BIOS 3 1 13 Swap space I use the following guidelines for swap space e Each swap partition is lt 128MB if using an old 2 0 kernel lt 2GB with recent kernels e Total either 1 to 2 times installed RAM or 128MB to 2GB as a guideline Chapter 3 Debian System installation hints 34 e Spread them on different drives and mount all of them with sw pri 1 options in etc fstab This ensures that the kernel does a striping RAID of the swap partitions and offers the maximum swap performance e Use a central portion of the hard disk when possible Even if you never need it some swap space 128MB is desirable so the system will slow down before it crashes hard with a program which leaks memory 3 2 Bash configuration I modify shell startup scripts to my taste across the system etc bash bashre Replace with private one etc profile Keep distribution copy w gt W etc skel bashre Replace with private copy etc skel profile Replace with private copy etc skel bash_profile Replace with private copy bashre Replace with private copy for all accounts profile Replace with private copy for all accounts bash_profile Replace with private copy for all accounts See det
205. ists for other languages For information on these lists and details of how to subscribe see http lists debian org Please check the archives for answers to your question prior to posting and also adhere to standard list etiquette If you do not wish to get CCed for the reply to your mailing list posting use the Mail Followup To header which is a very effective measure This is the informal con vention of mailing lists as explained in http cr yp to proto replyto html 15 6 Internet Relay Chat IRC IRC Internet Relay Chat is a way to chat with people from all over the world in real time IRC channels dedicated to Debian can be found on the freenode http www freenode info IRC network To connect you need an IRC client Some of the most popular clients are Chapter 15 Support for Debian 251 XChat BitchX ircll irssi epic4 and KSirc all of which have been packaged for Debian Once you have the client installed you need to tell it to connect to the server In most clients you can do that by typing server irc debian org Once you are connected join channel debian by typing join debian To leave channel debian type part debian You can quit the irc client by typing quit To send a private message Hello Mr Foo to foo type msg foo Hello Mr Foo Note that anything you type without the preceding is sent to the channel as a message Note clients like XChat often have a different graphical use
206. ites which use even more recent versions of the headers The kernel headers distributed with the kernel source are located in usr include linux include If you need to compile a program with kernel headers that are newer than those provided by libc6 dev then you must add 1 usr src linux include to your command line when compiling This came up at one point for example with the packaging of the auto mounter daemon amd When new kernels changed some internals dealing with NFS amd needed to know about them This required the inclusion of the latest kernel headers Chapter 2 Debian fundamentals 23 2 7 2 Tools to build custom kernels Users who wish to or must build a custom kernel are encouraged to download the package kernel package This package contains the script to build the kernel package and provides the capability to create a Debian kernel image package just by running the command make kpkg kernel_image in the top level kernel source directory Help is available by executing the command make kpkg help and through the manual page make kpkg 8 and The Linux kernel under Debian on page 97 Users must separately download the source code for the most recent kernel or the kernel of their choice from their favorite Linux archive site unless a kernel source version package is available where version stands for the kernel version The Debian initrd boot script requires a special kernel patch called initr
207. ith multiple recipients The only conceivable exceptions are e the emergency cure for your ISP s SMTP service trouble e an experiment for the educational purpose e your host being a professionally hosted server Basic configuration of Exim In order to use exim4 or exim as your MTA configure the following etc exim exim conf eximconfig to create and edit exim Following sections use exim in examples For Sarge replace this with exim4 as needed You must follow this rule for any hosts on dial up DSL cable services or LAN through some broadband router Even if your home host has a fixed IP from your ISP it is still a good idea to follow this rule Most workstations and home servers fall into this category Chapter 9 Tuning a Debian system 163 etc exim4 dpkg reconfigure exim4 to create and edit exim4 etc inetd conf comment out smtp to run exim as daemon etc email addresses Add spoofed source address lists check filters using exim4 or exim with brw bf bF bV etc Setting up a catchall for nonexistent email addresses under Exim In etc exim exim conf Woody or later in the DIRECTORS part at the end after the lo caluser director add a catch all director that matches all addresses that the previous directors couldn t resolve per Miquel van Smoorenburg catchall driver smartuser new_address webmaster mydomain com If one wants to have more a detailed recipe for each virtual d
208. itle Kanji Terminal package kterm needs x11 section XShells command sh c LANG ja_JP eucJP 9 Use a file name which does not overwrap with any package names Use a file name which overwraps with the package name Chapter 9 Tuning a Debian system 173 LC_MESSAGES en_US ISO 8859 1 PAGER w3m usr X11R6 bin k title Kanji Terminal bilingal etc menu mozilla local add a new shortcut package mozilla browser needs x11 section title Mozilla Navigator command mozilla 1 5 hints W icon usr share pixmaps mozilla xpm run update menus from the root account e add the following lines to muttrc for Japanese UTF 8 support is not popular in popular Japanese EMACS environment 7 bit encoding of iso 2022 jp is easier for everyone default encoding order us ascii gt iso 8859 1 gt iso 2022 jp set send_charset us ascii iso 8859 1 iso 2022 3p set allow_8bit no e activate XIM kinput2 for X applications for Japanese add inputMethod kinput2 and KTerm VT100 OpenIm true to your X resources file Xresources it looks like Debian takes care of this automatically somehow Some applications such as m1t erm also allow you to set up inputMethod and other information dynamically at runtime press Ctrl MouseButton 3 in mlterm e start X by typing startx or from one of the display managers xdm gdm kdm wdm for all
209. itory vendortag releasetag Login logon lgn Chapter 12 Version Control Systems 218 log lo rlog 1 rlog options files rdiff patch pa flags V vn r t D d r t2 D d2 modules release re rel d directories remove rm delete HIR Ptr b sy lt rtag rt rfreeze falnR b d r tag D date A symbolic_tag modules status st stat 1R v files tag ta freeze 1R F b d r tag D date A symbolic_tag files update up upd Adf1PpR d r tag D date files 12 2 Subversion Subversion is a next generation version control system that is intended to replace CVS The developers currently consider it to be in the alpha stage but it is probably stable enough for most uses At the time of this writing Subversion is only available in Debian unstable 12 2 1 Installing a Subversion server The subversion server meta package depends on the packages needed libapache2 dav svn and subversion tools to set up a server Setting up a repository Currently the subversion package does not set up a repository so one must be set up man ually One possible location for a repository is in var local repos Create the directory mkdir p var local repos Create the repository database Svnadmin create var local repos Make the repository writable by the WWW server chown R www data www data var local repos Ch
210. its standard init Now you have gained root privileges and a root shell Since is currently mounted read only and many disk partitions have not been mounted yet you must do the following to have a reasonably functioning system init 2 03 mount n o remount rw init 2 03 mount avt nonfs noproc nosmbfs init 2 03 cd etc init 2 03 vi passwd init 2 03 vi shadow Chapter 8 Debian tips 106 If the second data field in etc passwd is x for every username your system uses shadow passwords and you must edit etc shadow To disable the root password edit the second data field in the password file so that itis empty Now the system can be rebooted and you can log on as root without a password When booting into runlevel 1 Debian at least after Potato requires a password which some older distributions did not It is a good idea to have a minimal editor in bin in case usr is not accessible see Rescue editors on page 207 Also consider installing the sash package When the system becomes unbootable execute boot Linux init bin sash sash serves as an interactive substitute for sh even when bin sh is unusable It s stati cally linked and includes many standard utilities as built ins type help at the prompt for a reference list 8 1 2 I forgot the root password 2 Boot from any emergency boot root disk set If dev hda3 is the original root partition the following will let one edi
211. ittle use to users who are unfamiliar with them or have specialized requirements that make them unsuit able for Optional Please note the differences among Priority required Section base and Essential yes in the package description Section base means that this package is installed before everything else on a new system Most of the packages in Section base have the Priority required or at least Priority important and many of them are tagged with Essential yes Essential yes means that this package requires to specify an extra force option to the package manage ment system such as dpkg when removing from the system For example 1ibc6 mawk and makedev are Priority required and Section base but are not Essential yes Chapter 2 Debian fundamentals 15 2 2 7 Virtual packages A virtual package is a generic name that applies to any one of a group of packages all of which provide similar basic functionality For example both the tin and trn programs are news readers and either one should therefore satisfy the need of a program that requires a news reader on the system in order to be useful They are therefore both said to Provide the virtual package called news reader Similarly many packages such as exim exim4 sendmail and postfix provide the func tionality of a mail transport agent They are therefore said to Provide the virtual package m
212. ive good information on memory resources Do not worry about the size of used in the Mem line but read the one under it 38792 in the example below free k for 256MB machine total used free shared buffers cached Mem 257136 230456 26680 45736 116136 75528 Chapter 8 Debian tips 114 buffers cache 38792 218344 Swap 264996 0 264996 The exact amount of physical memory can be confirmed by grep Memory var log dmesg which in this case gives Memory 256984k 262144k available 1652k kernel code 412k reserved 2944k data 152k init Total 262144k 256M 1k 1024 1M 1024k Free to dmesg 256984k Total kernel reserved data init Free to shell 257136k Total kernel reserved data About 5MB is not usable by the system because the kernel uses it 8 6 3 Set time BIOS date MMDDhhmmCCYY hwclock utc systohc hwclock show This will set system and hardware time to MM DD hh mm CCYY Times are displayed in local time but hardware time uses UTC If the hardware BIOS time is set to GMT change the setting to UTC yes in the etc default rcs 8 6 4 Set time NTP Reference Managing Accurate Date and Time HOWTO http www tldp org HOWTO TimePrecision HOWTO index html Set time with permanent Internet connection Set system clock to the correct time automatically via a remote server ntpdate server This is good to have in etc cron daily if
213. ket Unfortunately it doesn t always work and it isn t available in pre Woody versions Try using ps2 or imps2 in gpm conf instead of autops2 for such cases To find out the specific types of mouse gpm knows about type gom t help See gpm 8 If a 2 button PS 2 mouse is used set the X protocol to enable Emulate3Buttons The dif ference of protocol between the 2 button mouse and the 3 button mouse is autodetected and auto adjusted for gpm after tapping the middle button once For X protocol with The raw protocol approach on the page before or without gpm use e IntelliMouse serial port mouse gpm repeater with ms3 e PS 2 PS 2 port mouse always test this first e IMPS 2 any PS 2 port mice 2 3 or scroll mice better e MouseManP lusPS 2 Logitech PS 2 port mouse See more at Mouse Support in XFree86 http www xfree86 org current mouse html A typical Microsoft scroll mouse is reported to work best with etc gpm conf etc Xx11 X86Config 4 device dev psaux Section InputDevice responsiveness Identifier Configured Mouse repeat_type raw Driver mouse type autops2 Option CorePointer append Option Device dev mouse sample_rate Option Protocol IMPS 2 Option Buttons gt Option ZAxisMapping 4 5 EndSection For some recent thin Toshiba notebook PCs activating gpm before PCMCIA in the System V init script may help prevent system lockup Weird but true 3 3 2 USB m
214. ki http people debian org osamu at lt osamu debian org gt in English or to each translator in their respective lan guage Although I used to live in the USA Iam a non native English user Any grammatical correc tions are welcomed The best feedback is a patch against the SGML version but a patch against the text version is also welcomed See Official document on page 1 for the official document site The original SGML files used to create this document are also available in CVS at pserver anonymous cvs gref sf net cvsroot qref or http qref sourceforge net Debian gref tar gz A 4 Document format This document was written using the DebianDoc SGML DTD rewritten from LinuxDoc SGML The DebianDoc SGML system enables us to create files in a variety of formats from one source e g this document can be viewed as HTML plain text TeX DVI PostScript PDF and GNU info Conversion utilities for DebianDoc SGML are available in the Debian package debiandoc sgml A 5 The Debian maze The Linux system is a very powerful computing platform for a networked computer However learning how to use all its capabilities is not easy Setting up the printer is a good example Chapter A Appendix 257 There is a complete detailed map called the SOURCE CODE This is very accurate but very hard to understand There are also references called HOWTO and mini HOWTO They are easier to understand but tend t
215. l package README gz by Manoj and Kent Make sure to obtain the latest unstable version of the kernel package package if you are to compile the latest version of the kernel initrd is not needed for a kernel compiled only for one machine I use it since I want my kernel to be almost the same as the one provided by the kernel image packages If you use initrd make sure to read mkinitrd 8 and mkinitrd conf 5 See also http bugs debian org 149236 7 1 1 Debian standard method Watch out for bug reports on kernel package gcc binutils and modutils Use new versions of them as needed Compiling a custom kernel from source under a Debian system requires special care Use the new append_to_version with make kpkg to build multiple kernel images Chapter 7 The Linux kernel under Debian 98 apt get install debhelper modutils kernel package libncurses5 dev apt get install kernel source 2 4 18 use latest version apt get install fakeroot vi etc kernel pkg conf input my name and email cd usr sre build directory tar bzip2 xvf kernel source 2 4 18 tar bz2 cd kernel source 2 4 18 if this is your kernel source S cp boot config 2 4 18 386 config get current config as default make menuconfig customize as one wishes make kpkg clean must run per man make kpkg fakeroot make kpkg append_to_version 486 initrd revision rev 01 kernel_image A modules_image modu
216. lds packages at the install process of each package file The same effect can be obtained through dselect Simply enter the S elect screen find the package you wish to hold in its present state and press the key or H The changes will take effect immediately after you exit the S elect screen The APT system in the Woody distribution has a new alternative mechanism for hold ing packages during the archive retrieval process using Pin Priority See the man ual page apt_preferences 5 along with http www debian org doc manuals apt howto or the apt howto package 2 2 12 Source packages Source packages are distributed in a directory called source and you can either download them manually or use apt get source foo to fetch them see the apt get 8 manual page on how to set up APT for doing that 2 2 13 Building binary packages from a source package For a package foo you will need all of foo_ dsc foo_ tar gz and foo_ diff gz to compile the source note there is no diff gz for a Debian native package Once you have them if you have the dpkg dev package installed the command dpkg source x foo_version revision dsc Chapter 2 Debian fundamentals 18 will extract the package into a directory called foo version Issue the following command to build the binary package S cd foo version su c apt get update apt get install fakeroot dpkg buildpackage rfakeroot us uc Th
217. le look like this Chapter 6 Debian package management 81 Package Pin release a testing Pin Priority 800 Package Pin release a stable Pin Priority 600 Note that tracking the test ing distribution can have the side effect of delaying the installation of packages containing security fixes Such packages are uploaded to unstable and migrate to testing only after a delay See apt_preferences 5 for more complicated examples which will allow you for exam ple to track testing while installing selected packages from unstable Examples which lock particular packages at particular versions while tracking other pack ages as they are released are available in the examples subdirectory http www debian org doc manuals debian reference examples as preferences testing and preferences unstable If you mix distributions e g testing with stable or unstable with stable you will eventually pull in core packages such as 1ibc6 from testing or unstable and there is no guarantee that these will not contain bugs You have been warned Another example preferences stable forces all packages to be downgraded to stable Downgrading from a later release of a package to an earlier one is not officially supported in Debian However you may find that you have to downgrade a specific package in order to re install a version of a package that works when a new version malfunctions You may find these previous package files lo
218. le speed nice 10 cdrecord dummy speed 2 dev 0 0 disk img Then if OK write to CD R with nice 10 cdrecord v ject speed 2 dev 0 0 disk img Or write to a CD RW disk with nice 10 cdrecord v eject blank fast speed 2 dev 0 0 disk img Some CD RW drives work better with nice 10 cdrecord v blank all speed 2 dev 0 0 disk img followed by nice 10 cdrecord v ject speed 2 dev 0 0 disk img Two steps are needed to prevent SCSI timeouts during blanking from interfering with the burning step The argument value to nice may require some adjustments 9 3 7 Make an image file of a CD Some CD Rs and commercial CDs have junk sectors at the end that make copying by dd im possible the Windows 98 CD is one of them The cdrecord package comes with the readcd command Use this to copy any CD contents to an image file Ifitis a data disk mount it and run df to see its actual size Divide the number shown in blocks 1 block 1024 bytes by 2 to get the number of actual CD sectors 1 sector 2048 bytes Run readcd with options and use this disk image to burn the CD R RW readcd dev target lun scsibusno select function 11 Chapter 9 Tuning a Debian system 142 Here set all three parameters to 0 for most cases Usually the number of sectors given by readcd is excessive Use the above number from an actual mount for better results It should be noted that the use of dd has a few problems if used on CD ROM The firs
219. lect beginner 2 3 4 Upgrading a running system The kernel filesystem in Debian systems supports replacing files even while they re being used When packages are upgraded any services provided by those packages are restarted if they are configured to run in the current runlevel The Debian system does not require use of the single user mode to upgrade a running system 2 3 5 Downloaded and cached deb archive files If you have manually downloaded package files to your disk which is not absolutely neces sary see above for the description of dpkg ftp or APT then after you have installed the packages you can remove the deb files from your system If APT is used these files are cached in the var cache apt archives directory You may erase them after installation apt get clean or copy them to another machine s var cache apt archives directory to save downloading during subsequent installations Chapter 2 Debian fundamentals 20 2 3 6 Record keeping for upgrades dpkg keeps a record of the packages that have been unpacked configured removed and or purged but does not currently keep a log of terminal activity that occurred while a package was being so manipulated The simplest way to work around this is to run your dpkg dselect apt get etc sessions within the script 1 program 2 4 The Debian boot process 2 4 1 The init program Like all Unices Debian boots up by executing the program init Th
220. les_image is for pcmcia cs etc SCA lt lt dpkg i kernel image deb pcmcia cs deb install make kpkg kernel_image actually does make oldconfig and make dep Do not use initrd if initrd is not used If one wants to use modules from pcmcia cs or no pemcia one should select General setup gt to PCMCIA CardBus support gt in make menuconfig and set the configuration to lt gt PCMCIA CardBus support i e uncheck the box On an SMP machine set CONCURRENCY_LEVEL according to kernel pkg conf 5 7 1 2 Classic method Get pristine sources from e Linux http www kernel org pcmcia cs http pemecia e8 sourceforge nst or use equivalent sources in Debian and do the following cd usr sre tar xfvz linux whatever tar gz rm rf linux ln s linux whatever linux tar xfvz pemcia cs whatever tar gz ln s pemcia cs whatever pcmcia cd linux dk de de e de e 3 make menuconfig configure stuff make dep make bzImage edits for lilo grub move usr src linux arch i386 boot bzImage to boot sho Chapter 7 The Linux kernel under Debian 99 sbin lilo or whatever you do for grub make modules make modules_install cd pemcia make config make all make install add needed module names to etc modules shutdown r now boot to new kernel SF de dE dE OSH 7 1 3 Kernel headers Most normal programs don t need kernel headers and in fact may
221. lex commands with quotations and substitutions see Command line process ing on page 225 4 3 5 Command execution and environment variable Typical command execution uses a shell line sequence like the following 7 date Sun Oct 26 08 17 20 CET 2003 LC_ALL fr_FR date dim oct 26 08 17 39 CET 2003 Here the program date is executed in the foreground job The environment variable LC_ALL is e unset system default same as C for the first command e set to fr_FR French locale for the second command Most command executions usually do not have preceding environment variable definition For the above example you can alternatively execute LC_ALL fr_FR S date dim oct 26 08 17 39 CET 2003 As you can see here the output of command is affected by the environment variable to produce French output If you want the environment variable to be inherited to the subprocesses e g when calling shell script you need to export it instead by using export LC_ALL Here I have simplified reality for the newbie See bash 1 for the exact explanation 26To obtain the following output you need to install French locale see Locales on page 167 This is not essential for the tutorial This is done only to indicate its potential effects Chapter 4 Debian tutorials 57 4 3 6 Command search path When you type a command into the shell the shell searches the command in the list of directo ries contained in the
222. lkit It creates include dependency graphs collaboration diagrams and graphical class hierarchy graphs even for not documented programs The output is similar to Qt s documentation 13 10 Packaging Preparation apt get install debian policy developers reference maint guide dh make debhelper apt get install packaging manual if Potato References for packaging e The Debian package management system on page 11 basics This WEB has nothing to do with World Wide Web WEB for PASCAL and CWEB for C C are traditional literate programming tools Chapter 13 Programming 240 e Debian New Maintainers Guide tutorial e dh make 1 e Debian Developer s Reference best practice e Debian Policy Manual authoritative e Packaging Manual Potato 13 10 1 Packaging a single binary Quick and dirty method to Package a single binary per Joey Hess mkdir p mypkg usr bin mypkg DEBIAN cp binary mypkg usr bin cat gt mypkg DEBIAN control Package mypackage Version 1 Architecture i386 Maintainer Joey Hess lt joeyh debian org gt Description my little package Don t expect much D dpkg deb b mypkg 13 10 2 Packaging with tools Use dh_make from the dh make package to create a baseline package Then proceed accord ing to instructions in dh make 1 This uses debhelper in debian rules An older approach is to use deb make from the debmake package This uses no debhel
223. mechanisms for supporting dynamically changing hardware are in place it becomes simplest to treat static hardware as if it were dynamic too Booting can then be treated as just another hotplug event See Triggering network configuration hotplug on the next page Note that this leaves the stop links etc rc d K f00 behind See Runlevels on page 20 for more information Chapter 10 Network configuration 197 However in almost all cases one wants at least the loopback interface 1o to be brought up on boot Therefore make sure that etc network interfaces includes the following stanzas auto lo iface lo inet loopback You can list additional physical interface names in auto stanzas if you want them to be brought up on boot too Never list PCMCIA interfaces in auto stanzas The PCMCIA cardmgr is started later in the boot sequence than when etc rcS d S40networking runs 10 10 2 Triggering network configuration hotplug For hot plug support install the hotplug package Networking hardware can be hot plugged either at boot time or after a card e g a PCMCIA card is inserted into the machine or after a utility such as di scover runs and loads necessary driver modules When the kernel detects new hardware it initializes the driver for the hardware and then runs the hotplug program to configure it Later if the hardware is removed then the kernel runs hotplug again with different environment variable set
224. mmand 1 usr bin elvis tiny 2 usr bin vim 3 usr bin nvi Enter to keep the default or type selection number 2 Items in the Debian alternatives system are kept in etc alternatives as symlinks To set your favorite X Window environment apply update alternatives to usr bin x session manager and usr bin x window manager For details see Custom X sessions on page 148 bin sh is a direct symlink to bin bash or bin dash It s safer to use bin bash to be compatible with old Bashism contaminated scripts but better discipline to use bin dash to enforce POSIX compliance Upgrading to a 2 4 Linux kernel tends to set this to bin dash 6 5 4 Runlevel usage When installed most Debian packages configure their services to run in runlevels 2 through 5 Thus there are no differences between runlevels 2 3 4 and 5 on a Debian system that has not been customized Debian leaves it up to the local administrator to customize runlevels as described in Customizing runlevels on page 21 This differs from the way runlevels are used by some other popular GNU Linux distributions One change you may want to make is to Chapter 6 Debian package management 95 disable xdm or gdm in runlevel 2 so that the X display manager is not started at the end of the boot sequence you can then start it by switching to runlevel 3 For more information about runlevels see Runlevels on page 20 6 5 5 Disabled daemon services Debi
225. n Hall Software Series e UNIX Power Tools The book to read to learn Unix tips By Jerry Peek Tim O Reilly and Mike Loukides Published by O Reilly and Associates e Essential System Administration second edition The book to read to learn about Unix system administration for many Unix flavors By Aeleen Frisch Published by O Reilly and Associates e Linux Rute User s Tutorial and Exposition A nice online and hardcover book covering GNU Linux system administration By Paul Sheer Published by Prentice Hall Web http www icon co za psheer book index html gz Package rutebook from non free File usr share doc rutebook e Bell Labs Computing Sciences Research Rich archive of Unix history Main http cm bell labs com cm cs Selected technical reports http cm bell labs com cm cs cstr html Some papers ht e Online Linux general Debian Planet h debianHELP ht tp cm bell labs com cm cs papers html support resources ttp www debianplanet org tp www debianhelp org Chapter 15 Support for Debian 249 Linux com http linux com The Linux Home Page at Linux Online http www linux org Red Hat commercial Linux vender http www redhat com RPM Sys V init SuSE Inc commercial Linux vender http www suse de RPM Sys V init Slackware http www slackware com TGZ BSD style init e Online
226. n XF3 server for example for ATI mach64 dpkg reconfigure priority low xserver common v3 dpkg reconfigure priority low xserver mach64 will generate et c X11 XF86Config file and configure X using the script x 86config v3 Chapter 9 Tuning a Debian system 146 Configuring the X server manually For Woody to add user customizations to etc X11 XF86Config 4 file do not edit the configuration file between the text BEGIN DEBCONF SECTION snip END DEBCONF SECTION Instead add the customizations before the text For example to use a custom video device add something resembling the following text to the top of the file Section Device Identifier Custom Device Driver ati Option NoAccel EndSection Section Screen Identifier Custom Screen Device Custom Device Monitor Generic Monitor DefaultDepth 24 Subsection Display Depth 8 Modes 1280x960 1152x864 1024x768 800x600 640x480 EndSubsection Subsection Display Depth 16 Modes 1280x960 1152x864 1024x768 800x600 640x480 EndSubsection Subsection Display Depth 24 Modes 1280x960 1152x864 1024x768 800x600 640x480 EndSubsection EndSection Section ServerLayout Identifier Custom Screen Custom Screen InputDevice Generic Keyboard CoreKeyboard InputDevice Configured Mouse CorePointer EndSection For Sarge testing at the time of writing if you wish to retain us
227. n executables configuration files man info pages copy right information and other documentation These packages are distributed in a Debian specific archive format see Debian package format on the following page they are usually distinguished by having a deb file extension Binary packages can be unpacked using the Debian utility dpkg details are given in its manual page e Source packages which consist of a dsc file describing the source package including the names of the following files a orig tar gz file that contains the original unmod ified source in gzip compressed tar format and usually a diff gz file that contains the Debian specific changes to the original source The utility dpkg source packs and un packs Debian source archives details are provided in its manual page Installation of software by the package system uses dependencies which are declared by the package maintainers These dependencies are documented in the cont rol file associated with each package For example the package containing the GNU C compiler gcc Depends on the package binutils which includes the linker and assembler If a user attempts to install gcc without having first installed binutils the package management system dpkg will print an error message that it also needs binut ils and stop installing gcc However this facility can be overridden by the insistent user see dpkg 8 For additional details see Package dependen
228. n key to 123456789e prior to bringing eth0 up using DHCP edit etc network interfaces so that it includes a stanza like this iface eth0 inet dhcp wireless essid myessid wireless key 123456789e Note that you should not use this method of setting the ESSID and key if you are running waproamd for this interface By the time i fup is run waproamd has already set the ESSID and key See Triggering network configuration waproamd on page 198 10 6 4 Configuring a PPP interface The ifup and ifdown programs use pon and poff to add and remove PPP interfaces so first read Configuring a PPP interface on page 181 Suppose you have set up PPP to work with peer myisp Edit etc network interfaces so that it includes a stanza like this Chapter 10 Network configuration 191 iface ppp0 inet ppp provider myisp With this stanza in place ifup ppp0 does pon myisp Unfortunately it is currently not possible to provide additional pppd options in a ppp stanza in etc network interfaces It is currently not possible to use ifupdown to perform auxiliary configuration of PPP inter faces Because pon exits before pppd has finished making the connection i fup runs up scripts before the PPP interface is ready for use Until this bug is fixed it remains necessary to do auxiliary configuration in etc ppp ip up or etc ppp ip up d 10 6 5 Configuring a PPPoE interface Many broadband Internet Service Prov
229. n the system Chapter 9 Tuning a Debian system 138 Whenever a request for service arrives its protocol and service are identified by looking them up in the databases in etc protocols and etc services inetd then looks up a nor mal Internet service in the etc inetd conf database or a Sun RPC based service in etc rpc conf For system security make sure to disable unused services in etc inetd conf Sun RPC services need to be active for NFS and other RPC based programs Sometimes inetd does not start the intended server directly but starts the t cpa TCP IP dae mon wrapper program with the intended server name as its argument in etc inetd conf In this case tcpd runs the appropriate server program after logging the request and doing some additional checks using etc hosts deny and etc hosts allow If you have problems with remote access in a recent Debian system comment out ALL PARA NOID in etc hosts deny if it exists For details see inetd 8 inetd conf 5 protocols 5 services 5 tcpd 8 hosts_access 5 and hosts_options 5 For more information on Sun RPC see rpcinfo 8 portmap 8 and usr share doc portmap portmapper txt gz 9 2 6 Centralizing authentication LDAP Use Lightweight Directory Access Protocol LDAP References e OpenLDAP http www openldap org e OpenLDAP Admin Guide in the openldap guide package e LDP LDAP Linux HOWTO http www tldp org HOWTO LD
230. n tool consisting of the i fup and if down programs and the etc network interfaces file If you choose to use ifupdown to do your network configuration then normally you should not use low level commands too The i fupdown program was written with the intent that it alone be used to configure and deconfigure network interfaces To update interface configuration do this 5As of April 2004 there is also a dhcp client package available This contains version 2 of the ISC DHCP Client This has been superseded by version 3 which is currently packaged as dhcp3 client The maintain ers plan to rename dhcp3 client to dhcp client after the release of Sarge Make sure you do not have the experimental versions of dhcp client installed i fupdown does not work with them The etc network interfaces file format for current versions of i fupdown is slightly incompatible with the file format for earlier Potato versions of the package The ifupdown post installation script should upgrade the file automatically if necessary However it is a good idea to check over the converted file This means also that you should not use other high level configuration tools such as whereami that call low level configuration tools Chapter 10 Network configuration 189 ifdown eth0 editor etc network interfaces tweak as you wish ifup etho For more information see interfaces 5 usr share doc ifupdown examples network interfaces gz and ifup
231. n use multiple Linux consoles to achieve the same effect To copy between windows use Alt Fn keys to switch virtual consoles and use File gt Insert file or File gt Copy to file to move a portion of a file to another file This internal editor can be replaced with any external editor of choice Also many programs use environment variables EDITOR or VISUAL to decide which editor to use If you are uncomfortable with vim set these to mcedit by adding these lines to bashre export EDITOR mcedit export VISUAL mcedit I do recommend setting these to vim if possible Getting used to vim commands is the right thing to do since Vi editor is always there in the Linux Unix world 13 4 2 6 Viewer in MC Very smart viewer This is a great tool for searching words in documents I always use this for files in the usr share doc directory This is the fastest way to browse through masses of Linux information This viewer can be directly started like so mc v filename_to_view B Actually vi or nvi are the programs you find everywhere I chose vim instead for newbie since it offers you help through F1 key while it is similar enough and more powerful Chapter 4 Debian tutorials 51 4 2 7 Auto start features of MC Press Enter on a file and the appropriate program will handle the content of the file This is a very convenient MC feature executable file Execute command man html file Pipe content to viewer softwa
232. nd do the following zcat usr share doc groff meintro me gz A gro Tascii m less R The following will make a completely plain text file zcat usr share doc groff meintro me gz GROFF_NO_SGR 1 groff Tascii me col b x gt meintro txt For printing use PostScript output groff Tps meintro txt lpr groff Tps meintro txt mpage 2 lpr 13 9 2 SGML Preparation apt get install debiandoc sgml debiandoc sgml doc References for debiandoc sgml e usr share doc debiandoc sgml doc e debiandoc sgml 1 e DocBook The Definitive Guide usr share doc docbook defguide html docbook html by Walsh and Muellner O Reilly package docbook defgui de SGML enables management of multiple formats of a document One easy SGML system is Debiandoc which is used here This requires minor conversion from original text files for the following characters e lt gt amp 1t e gt gt amp gt gt nbsp nonbreakable space e 8 gt amp e gt amp percnt e gt amp copy e gt amp ndash gt amp mdash 4 To mark a section as a nonprintable comment enter Chapter 13 Programming 237 lt l State issue here gt To mark a section with a switchable comment enter lt SFIXME State issue here gt In SGML the first definition of
233. ndows you had open Typical screen commands Once you start screen all keyboard input is sent to your current window except for the command keystroke by default A All screen commands are entered by typing A plus a single key plus any parameters Useful commands A show a help screen display key bindings A c create a new window and switch to it A n go to next window A p go to previous window A 0 go to window number 0 A w show a list of windows A a send a Ctrl A to current window as keyboard input A h write a hardcopy of current window to file A H begin end logging current window to file A X lock the terminal password protected Ad detach screen session from the terminal A DD detach screen session and log out This is only a small subset of screen s commands and features If there s something you want screen to be able to do chances are it can See screen 1 for details Backspace and or Ctrl H in screen session If you find that backspace and or Ctrl H do not work properly when you are running screen edit etc screenrc find the line reading bindkey k kb stuff 177 and comment it out i e add as the first character Equivalent program to screen for X Check out xmove See xmove 1 Chapter 8 Debian tips 126 8 6 29 Network testing basics Install netkit ping traceroute dnsutils ipchains for 2 2 kernel iptables for 2 4 kernel and net tools packages and
234. ne location versus connecting in another is the chatscript that is re quired The chatscript is different because the local access telephone number is different cat gt etc ppp peers KPN Amsterdam lt lt EOF connect usr sbin chat v f etc chatscripts KPN Amsterdam file etc ppp peers KPN EOF cat gt etc ppp peers KPN DenHaag lt lt EOF connect usr sbin chat v f etc chatscripts KPN DenHaag file etc ppp peers KPN EOF cat gt etc ppp peers Planet Amsterdam lt lt EOF connect usr sbin chat v f etc chatscripts Planet Amsterdam file etc ppp peers Planet EOF This options file is included using the ca11 option Chapter 10 Network configuration 184 cat gt etc ppp peers Planet DenHaag lt lt EOF connect usr sbin chat v f etc chatscripts Planet DenHaag file etc ppp peers Planet EOF The file directives each include one of the options files shown earlier The connect directive specifies the command that pppd uses to make the connection Normally one uses the chat program for this adapting the chatscript to the ISP Here are the chatscripts for Den Haag the chatscripts for Amsterdam might be similar except for the telephone number or they might be different if the ISP offers service through another company there cat gt etc chatscripts KPN DenHaag lt lt EOF ABORT BUSY ABORT NO CARRIER ABORT VOICE ABORT NO DIALTONE ABORT NO DIAL TONE ABORT NO ANSWER
235. nfig sets up files like those above after asking the user questions through a menu interface Configuring a PPP interface using wvdial A different approach to using pppd is to run it from wvdial which comes in the wvdial pack age Instead of pppd running chat to dial in and negotiate the connection wvdial does the dialing and initial negotiating and then starts pppd to do the rest Given only phone number username and password wvdial succeeds in making the connection in most cases 10 3 Naming the computer 10 3 1 Hostname A Debian system sometimes needs to identify itself by name For this purpose a hostname is maintained by the kernel The initscript etc init d hostname sh sets the hostname at boot time using the hostname command to the name stored in etc hostname This file should contain only the hostname not a fully qualified domain name To print out the current hostname run hostname without an argument 10 3 2 Mailname The mailname of a host is the name that mail related programs use to identify the host The file etc mailname contains of this name followed by a newline The mailname is usually one of the host s fully qualified domain names See mailname 5 What the recipient of e mail sees in the From header of mail sent by your Debian host de pends on how Mail User Agents MUA and Mail Transfer Agents MTA are configured Sup pose a local user foo sends a mail from a host with mailname myhost dom The From
236. ng before they reach unstable 2 1 13 Retrieving an older package While the most recent Debian distributions are kept under the debian directory on each De bian mirror site http www debian org misc README mirrors archives for older Debian distributions such as Slink are kept on http archive debian org or under the debian archive directory on each Debian mirror site Older testing and unstable packages can be located at http snapshot debian net 2 1 14 Architecture sections Within each of the major directory trees dists stable main dists stable contrib dists stable non free dists unstable main etc the binary package entries re side in subdirectories whose names indicate the chip architecture for which they were com piled e binary al1 for packages which are architecture independent These include for ex ample Perl scripts or pure documentation e binary platform for packages which execute on a particular binary platform Please note that the actual binary packages for testing and unstable no longer reside in these directories but in the top level pool directory The index files Packages and Packages gz have been kept though for backwards compatibility For the actual binary architectures supported see the Release Notes for each distribution They can be located at the Release Notes sites for stable http www debian org releases stable releasenotes and testing http www debian org relea
237. ng installation as admin but this can be any arbitrary name You may want to add this user penguin to the adm group to enable read access to the many logfiles in var log See passwd 5 group 5 shadow 5 group 5 vipw 8 and vigr 8 For the official meanings of users and groups see a recent version of the Users and Groups usr share doc base passwd users and groups html document Chapter 4 Debian tutorials 48 Alternatively you may type Ctrl Alt Delete to shutdown 7 Wait until the system displays System halted then shut off power If the APM or ACPI function has been turned on by the BIOS and Linux properly the system will power down by itself See Large memory and auto power off on page 41 for the detail 4 1 6 Play time Now you are ready to play with the Debian system without risks as long as you use this non privileged user account penguin Let s login to the penguin If you are at root shell prompt type Ctrl D at the root command prompt to close the root shell activity and return to the login prompt Enter your newly cre ated username penguin and the corresponding password You will be presented with the following command prompt penguint foo penguin From here on the example given will use simplified command prompt for the sake of simplic ity I will use e 4 root shell prompt e non privileged user shell prompt We will start learning the Debian system first with the easy way
238. nnection see Connecting to a remote X server ssh on the following page The method described here is not encouraged unless one is in a very secure environment be hind a good firewall system with only trusted users present Use the following command to verify your current X server setting for the TCP IP socket find etc X11 type f print0 xargs 0 grep nolisten etc X11 xinit xserverrc exec usr bin X11 X dpi 100 nolisten tcp Remove nolisten to restore TCP IP listening on the X server 9 4 7 Connecting to a remote X server xhost xhost allows access based on hostnames This is very insecure The following will disable host checking and allow connections from anywhere if a TCP IP socket connection is allowed see Using X over TCP IP on the current page xhost You can re enable host checking with xhost Chapter 9 Tuning a Debian system 152 xhost does not distinguish between different users on the remote host Also hostnames ad dresses actually can be spoofed This method must be avoided even with more restrictive host criteria if you re on an untrusted network for instance with dial up PPP access to the Internet See xhost 1x 9 4 8 Connecting to a remote X server ssh The use of ssh enables a secure connection from a local X server to a remote application server e Set X11Forwarding and AllowTcpForwarding entries to yes in etc ssh sshd_config of the remote host if you w
239. ns is responsible for managing the sockets and loading driver modules We just don t want it to call network configuration programs via etc pcmcia network In order for cardmgr to work properly you may need to edit etc pemcia config opts in order to configure resources assigned to 16 bit PCMCIA cards See PCMCIA on page 99 and the Linux PCMCIA HOWTO http ww tldp org HOWTO PCMCIA HOWTO html for more information 10 11 Multi stage mapping Suppose your network adapters are hotplugged and you enable automatic configuration as described in Triggering network configuration hotplug on page 197 Suppose further that you need to map logical interfaces to physical interfaces depending both on the adapter un derlying the physical interface as described in Dealing with inconsistent naming of interfaces by the kernel on page 195 and on the network connected to the interface as described for example in Logical interface selection using guessnet on page 194 You can accomplish this with multi stage mapping Tn past releases of Debian the standard way to configure PCMCIA network cards was through the cardmgr hook scripts etc pemcia network and etc pcmcia network opts These hook scripts were developed in the era before Linux acquired a more general purpose hot plug capability Some people still use the Debian Woody scripts in their default state wherein they simply call ifup after the interface is added and i
240. ntic method is needed cd path to old directory I find f rem cd depth printO afio p xv 0a mount point of new directory ote source directory amp amp tar cf ssh user host dom cd dest directory amp amp tar xvfp Chapter 8 Debian tips 110 If there are no linked files scp pr userl hostl dom source directory user2 host2 dom dest directory Here scp lt gt rcp and ssh lt gt rsh The following comparative information on copying a whole subdirectory was presented by Mangj Srivastava lt srivasta debian org gt to debian user lists debian org 8 3 2 cp Traditionally cp was not really a candidate for this task since it did not dereference symbolic links or preserve hard links either Another thing to consider was sparse files files with holes GNU cp has overcome these limitations however on a non GNU system cp could still have problems Also you can t generate small portable archives using cp cp a newdir 8 3 3 tar Tar overcame some of the problems that cp had with symbolic links However although cpio handles special files traditional tar doesn t tar s way of handling multiple hard links to a file places only one copy of the link on the tape but the name attached to that copy is the only one you can use to retrieve the file cpio s way puts one copy for every link but you can retrieve it using any of the names The tar
241. number of branches such as etc and usr These subdi rectories in turn branch into still more subdirectories such as etc init d and usr local The whole thing together is called the directory tree You can think of an ab solute filename as a route from the base of the tree to the end of some branch a file You ll also hear people talk about the directory tree as if it were a family tree thus sub directories have parents and a path shows the complete ancestry of a file There are also relative paths that begin somewhere other than the root directory You should remember that the directory refers to the parent directory e There s no directory that corresponds to a physical device such as your hard disk This differs from CP M DOS and Windows where all paths begin with a device name such as C See The filesystem concept in Debian on this page The detailed best practices for the file hierarchy are described in the Filesystem Hierarchy Standard usr share doc debian policy fhs fhs txt gz You should remember the following facts as the starter ae A simple represents the root directory e etc This is the place for the system wide configuration files e var log This is the place for the system log files e home This is the directory which contains all the home directories for all non privileged users 4 5 2 The filesystem concept in Debian Following the Unix tradition the Debian system pr
242. nvert a text file from DOS to Unix style Convert a DOS text file end of line M J to a Unix text file end of line J apt get install sysutils dos2unix dosfile Chapter 8 Debian tips 117 8 6 12 Convert a text file with recode Following will convert text files between DOS Mac and Unix line ending styles S recode cl cr lt dos txt gt mac txt S recode cr lt mac txt gt unix txt S recode cl lt unix txt gt dos txt Free recode converts files between various character sets and surfaces with recode charsetl surfacel charset2 surface2 lt input txt gt output txt Common character sets used are see also Introduction to locales on page 167 e us ASCII 7 bits e 11 ISO Latin 1 ISO 8859 1 Western Europe 8 bits e EUCJP EUC JP for Japanese Unix e SJIS Shift JIS for Japanese Microsoft e 1502022JP Mail encoding for Japanese 7 bits e u2 UCS 2 Universal Character Set 2 bytes e u8 UTF 8 Universal Transformation Format 8 bits Common surfaces used are e cr Carriage return as end of line Mac text e cl Carriage return line feed as end of line DOS text e Line feed as end of line Unix text e d1 Human readable bytewise decimal dump e x1 Human readable bytewise hexidecimal dump e 64 Base64 encoded text e QP Quoted Printable encoded text For more see pertinent description in the info recode There are al
243. nzip2 foo bz2 Decompress foo bz2 to create foo e tar xvvf foo tar Extract files from foo tar archive e tar xvvzf foo tar gz The and in the regular expression enable grep to avoid matching itself The 4 in the regular expression means 0 or more repeats of character 4 thus enables grep to match both exim and exim4 Although is used in shell filename wild card and regular expression their meanings are different Chapter 4 Debian tutorials 55 Extract files from gzipped foo tar gz archive e tar xvvf bzip2 foo tar bz2 Extract files from foo tar bz2 archive e tar cvvf foo tar bar Archive contents of folder bar in foo tar archive e tar cvvzf foo tar gz bar Archive contents of folder bar in compressed foo tar gz archive e tar cvvf bzip2 foo tar bz2 bar Archive contents of folder bar in foo tar bz2 archive e zcat README gz pager Display contents of compressed README gz using the default pager e zcat README gz gt foo Create a file foo with the decompressed content of README gz e zcat README gz gt gt foo Append the decompressed content of README gz to the end of the file foo If it does not exist create it first 3 4 e find name pattern find matching filenames using shell pattern slower e locate d pattern find matching filenames using shell pattern quicker using regularly generated database Please traverse
244. o O the bits that are part of the host address then you get the net mask of the network Traditionally IP networks were grouped into classes whose net address parts were 8 16 or 24 bits in length IP addresses net mask length Class A 1 0 0 0 126 255 255 255 255301040 8 Class B 128 0 0 0 191 255 255 255 255 255 0 0 16 Class C 192 0 0 0 223 255 255 255 255 255 255 0 24 IP addresses not in these ranges are used for special purposes There are address ranges in each class reserved for use on local area networks LANs These addresses are guaranteed not to conflict with any addresses on the Internet proper By the same token if one of these addresses is assigned to a host then that host must not access the In ternet directly but must access it through a gateway that acts as a proxy for individual services or else does Network Address Translation These address ranges are given in the following table along with the number of ranges in each class network addresses length how many Class A 10 x x x 8 Class B 172 16 x x 172 31 x 16 16 Class C 192 168 0 x 192 168 255 x 24 256 The first address in an IP network is the address of the network itself The last address is the broadcast address for the network All other addresses may be allocated to hosts on the network Of these the first or the last address is usually allocated to the Internet gateway for the network The routing
245. o give too much detail and lose the big picture I sometimes have a problem finding the right section in a long HOWTO when I need a few commands to invoke In order to navigate through this maze of Linux system configuration I started writing down simple reminder memos in text file format as my quick reference This list of memos grew larger and I learned debiandoc in the meantime The product is this Debian Reference A 6 The Debian quotes Here are some interesting quotes from the Debian mailing list e This is Unix It gives you enough rope to hang yourself Miquel van Smoorenburg lt miquels cistron nl gt e Unix IS user friendly It s just selective about who its friends are Tollef Fog Heen lt tollef add no gt
246. o lp gt gt etc modules See Documentation parport txt in the Linux source 7 3 Tuning the kernel through the proc filesystem The behavior of the Linux kernel can be changed on the fly using the proc filesystem For basic information on changing kernel parameters through the proc filesystem read Documentation sysct1 in the Linux source See some examples of kernel parameter manipulations in etc init d networking and Strange access problems with some websites on page 42 See sysctl conf 5 for how to set up the boot time kernel configuration through proc filesystem with etc init d procps sh script usually run from etc rcS d S30procps sh 7 3 1 Too many open files The Linux kernel may complain Too many open files This is due to the small default value 8096 for file max To fix this problem run the following command as root echo 65536 gt proc sys fs file max for 2 2 and 2 4 kernel echo 131072 gt proc sys fs inode max for 2 2 kernel only or put the following into etc sysctl conf for the permanent change file max 65536 for 2 2 and 2 4 kernel inode max 131072 for 2 2 kernel only Chapter 7 The Linux kernel under Debian 104 7 3 2 Disk flush intervals You can change disk flush intervals through the proc filesystem The following will shorten its interval from the default five seconds to one second echo 40 0 0 0 100 30000 60 0 0 gt proc sys vm bdflush This m
247. oduce var run bind named options which is the same as the origi nal except that the forwarders specification is a list of the currently available non local name servers To make use of this change the include line in named conf so that it includes var run bind named options See Managing nameserver information resolvconf on the preceding page Database files named in named conf without a full pathname will be stored in var cache bind This is the right place to store files generated by named for example database files for zones for which the daemon is secondary Static database files in etc bind are and must be referred to in named conf by their full path names See usr share doc bind9 README Debian gz for details 10 5 Configuring network interfaces using DHCP Low level configuration of network interfaces can be automated by means of the Dynamic Host Configuration Protocol DHCP Your firewall or router box or your broadband ISP may furnish IP addresses and other parameters this way To make this work you must install one of the following packages e dhcp3 client version 3 Internet Software Consortium e dhcpcd Yoichi Hariguchi and Sergei Viznyuk pump Red Hat pump is simple and widely used dhcp3 client is complex but more configurable 8 10 6 High level network configuration in Debian In order to make network configuration easier Debian provides a standard high level net work configuratio
248. of SSH First install the OpenSSH server and client apt get update amp amp apt get install ssh The non US entry in the etc apt source list is required etc ssh sshd_not_to_be_run must not be present if one wishes to run the OpenSSH server SSH has two authentication protocols e SSH protocol version 1 Potato version only supports this protocol available authentication methods RSA Authentication RSA identity key based user authentication RhostsAuthentication rhosts based host authentication insecure disabled x RhostsRSAAuthentication rhosts authentication combined with RSA host key disabled ChallengeResponseAuthentication RSA challenge response authentication x PasswordAuthentication password based authentication e SSH protocol version 2 post Woody versions use this as the primary protocol available authentication methods x PubkeyAuthentication public key based user authentication HostbasedAuthentication rhosts or etc hosts equiv authentication combined with public key client host authentication disabled x ChallengeResponseAuthentication challenge response authentication x PasswordAuthentication password based authentication Be careful about these differences if you are migrating to Woody or using a non Debian system Chapter 9 Tuning a Debian system 159 See usr share doc ssh README Debian gz ssh 1 sshd 8 ssh agent 1 and ssh keygen 1 for details Following are
249. om su Chapter 12 Version Control Systems 217 cvs co d project px check out project x alias px from CVS to directory project cd project make changes to the content 12 1 3 Troubleshooting CVS File permissions in repository CVS will not overwrite the current repository file but replaces it with another one Thus write permission to the repository directory is critical For every new repository creation run the fol lowing to ensure this condition if needed cd var lib cvs chown R root src repository chmod R ug rwX repository chmod 2775 repository if needed this and subdirectory Execution bit A file s execution bit is retained when checked out Whenever you see execution permission problems in checked out files change permissions of the file in the CVS repository with the following command chmod ugo x filename 12 1 4 CVS commands Here are CVS commands with their shortcuts add ad new k kflag m message files admin adm rcs rcs options files annotate ann options files checkout co get options modules commit ci com lnR m log_message f file A r revision files diff di dif k1 rcesdiff_options r revl D datel A r rev2 D date2 files lexportlexlexp f1Nn r rev D dat d dir k kflag module history hi his report flags options args files import im imp options repos
250. omain etc add the following at the end of etc exim exim conf per me not well tested yourdomain com lookup 1 lsearch etc email addresses Svalue fail T MRI Then have an entry in etc email addresses Configuring selective address rewriting for outgoing mail under Exim Selective address rewrite for outgoing mail to produce proper From headers can be done using exim by configuring near the end of etc exim exim conf hostl something dyndns org S if eq lookup Sl lsearch etc passwd 1 O 1 0 S1 somethig dyndns org frFs This rewrites all addresses matching host1 something dyndns org 1 It searches through etc password to see if the local part 1 is a local user or not 2 If it is a local user it rewrites the address to the same thing it was in the first place 0 3 If it is not a local user it rewrites the domain part Chapter 9 Tuning a Debian system 164 Configuring SMTP authentication under Exim Some SMTP services such a exim conf as follows remote_smtp driver smtp authenticate_hosts s yahoo com require SMTP auth Configure etc exim smtp mail yahoo com smarthost driver domainlist transport remote_smtp route_list smtp mail yahoo com bydns_a plain driver plaintext public_name PLAI N client_send cmatheson3 this_is_my_password Do not forget double quotes in the last line 9 6 2 Fetching mail Fetc
251. onfiguring a Wi Fi interface c o sc sorabo saii toeau ee s 181 10 24 Configuring aP PPP mteriacE gt ok eae Qe AA AA Ea 181 10 3 Naming the compulit lt coras AAA AA E HOH 185 T031 HOSIDAMO 4 25 2 2 24 4024 a a a Rhea aa eS 185 1032 NS sc eea po E pika pane d ee h 185 10 4 Domain Name Service DNS 2 226 ee ee ee ee ee ee eee eee be wes 186 1041 ThEresglyer seo RR ek AE Ee Ss E GOE E 186 10 4 2 Managing nameserver information resolvconf 187 10 4 3 Caching looked up names nscd dnsmasq pdnsd bind9 187 10 44 Providing Domain Name Service bind 0 ce 187 10 5 Configuring network interfaces using DHCP 1 26 6 060 e ese ee ewe s 188 10 6 High level network configuration in Debian lt a censos 188 10 6 1 Configuring an interface with a static Paddress 189 10 6 2 Configuring an interface using DHCP o so oe estaa 190 10 6 0 Configuring a Wi Fi interface we ee he ee neis 190 10 64 Conteuring a PPP imterface ss e ma 1420 be eae Ree ER a 190 10 6 5 Configuring a PPPOE mitetiace lt cs ci csoro a ha p DES ERS 191 10 6 6 Configuring multiple Ethernet interfaces for a gateway 191 10 6 7 Configuring virtual interfaces 25 Shes RSG EE e a ERS 192 10 7 Network configuration using logical interface definitions 192 10 8 Magic network configuration icono a EERE ES 193 CONTENTS xiii 10 8 1 Logical interface selection using guessnet 2 6 4 2 k
252. ough the touchpad on a laptop computer emulates a 2 button PS 2 mouse as the de fault behavior the tpconfig package enables full control of the device For example setting OPTIONS tapmode 0 in etc default tpconfig will disable pesky click by tap behavior Set etc gpm conf as follows to use both touchpad and USB external mouse on the console device dev psaux responsiveness repeat_type ms3 type autops2 append M m dev input mice t autops2 sample_rate Chapter 3 Debian System installation hints 38 3 4 NES configuration Set up NFS by setting etc exports apt get install nfs kernel server echo domainname for lan hosts rw no_root_squash nohide A gt gt etc exports See my example scripts for details http www debian org doc manuals debian reference examples 3 5 Samba configuration References e http www samba org e samba doc package Setting up Samba with share mode is much easier since this creates WfW type share drives But it is preferable to set it up with user mode Samba can be configured through debconf or vi dpkg reconfigure priority low samba in Woody vi etc samba smb conf See my example scripts for details http www debian org doc manuals debian reference examples Adding a new user to the smbpasswd file can be done via smbpasswd su c smbpasswd a username Make sure to use encrypted passwords
253. ovides the filesystem under which physical data on harddisks and other storage devices and the interaction with the hardware devices such as console screens and remote serial consoles are represented in an unified manner Each file directory named pipe or physical device on a Debian system has a data structure called an inode which describes its associated attributes such as the user who owns it owner the group that it belongs to the time last accessed etc See usr include linux fs h for the exact definition of struct inode in the Debian GNU Linux system This unified representation of physical entities is very powerful since this allows us to use the same command for the same kind of operation on many totally different devices There is also another use for the word path See Command search path on page 57 The intended meaning is usually clear from the context Chapter 4 Debian tutorials 65 All your files could be on one disk or you could have 20 disks some of them connected to a different computer elsewhere on the network You can t tell just by looking at the directory tree and nearly all commands work just the same way no matter what physical device s your files are really on 4 5 3 File and directory access permissions File and directory access permissions are defined separately for the following three categories of affected users e the user who owns the file u e other users in the group which the fil
254. p PPP adduser user_name dip allow user_name to access dialup PPP Dialup PPP access can be initiated by the user user_name pon ISP_name start PPP access to your ISP enjoy the Internet S poff ISP_name stop PPP access ISP_name optional See Configuring a PPP interface on page 181 for more details 3 7 7 Other configuration files to tweak in etc You may want to add an etc cron deny file missing from the standard Debian install you can copy etc at deny Chapter 3 Debian System installation hints 44 45 Chapter 4 Debian tutorials This section provides a basic orientation to the Debian world for the real newbie If you have been using any Unix like system for a while you probably know everything I explained here Please use this as a reality check 4 1 Getting started After the installation of the Debian system on your PC you need to learn few things to make it useful Let us give you an express training 4 1 1 Login to a shell prompt as root Upon rebooting the system you will be presented either the graphical login screen or the char acter based login screen depending on your initial selection of packages For the sake of sim plicity if you are presented with the graphical login screen press Ctrl Alt F1 to gain the character based login screen Suppose your hostname is foo the login prompt looks like foo login Type root press the Enter key and type the password w
255. per scripts and depends only on the shell For examples of multiple source packages see mc dpkg source x mc_4 5 54 dsc which uses sys build mk by Adam Heath lt doogie debian org gt and glibc dpkg source x glibc_2 2 4 1 dsc which uses another system by the late Joel Klecker lt espy debian org gt 241 Chapter 14 GnuPG References e gpg 1 e usr share doc gnupg README gz e GNU privacy handbook in usr share doc gnupg doc GNU_Privacy_Handbook install ynupg doc package 14 1 Installing GnuPG gpg gen key generate a new key gpg gen revoke my_user_ID generate revoke key for my_user_ID host 1 pgp net grep www less figure out pgp keyservers A good default keyserver set up in SHOME gnupg gpg conf or old location HOME gnupg options contains keyserver hkp subkeys pgp net Here one must be careful not to create more than 2 sub keys If you do keyservers on pgp net will corrupt your key Use the newer gnupg gt 1 2 1 2 to handle these corrupted subkeys See http fortytwo ch gpg subkeys 14 2 Using GnuPG File handling gpg options command args gpg armor a sign s file sign file into a text file asc Chapter 14 GnuPG 242 nrnnnnnn Ur Ur 14 3 gpg clearsign file gpg clearsign not gpg verify file gpg o file sig b gpg verify file sig file gpg o crypt_file recipient
256. prevents a file in the directory from being removed by a user who is not the owner of the file In order to secure the contents of a file in world writable directories such as tmp or in group writable directories one must not only set write permission off for the file but also set the sticky bit on the directory Otherwise the file can be removed and a new file can be created with the same name by any user who has write access to the directory Here are a few interesting examples of the file permissions ls l etc passwd etc shadow dev ppp usr sbin pppd crw rw 1 root dip 108 O Jan 18 13 32 dev ppp rw r r 1 root root 1051 Jan 26 08 29 etc passwd rw r 1 root shadow 746 Jan 26 08 29 etc shadow rwsr xr 1 root dip 234504 Nov 24 03 58 usr sbin pppd ls ld tmp var tmp usr local var mail usr src drwxrwxrwt 4 root root 4096 Feb 9 16 35 tmp drwxrwsr x 10 root staff 4096 Jan 18 13 31 usr local Chapter 4 Debian tutorials 67 drwxrwsr x 3 root src 4096 Jan 19 08 36 usr src drwxrwsr x 2 root mail 4096 Feb 2 22 19 var mail drwxrwxrwt 3 root root 4096 Jan 25 02 48 var tmp There is an alternative numeric mode to describe file permissions in chmod 1 commands This numeric mode uses 3 to 4 digit wide octal radix 8 numbers Each digit corresponds to e 1st optional digit sum of set user ID 4 set group ID 2 and sticky bit 1 e 2nd digit sum of read 4 write 2 and e
257. prompt split another file vsplit another file Or at a shell prompt S Vio o tilde Lett filed txt Horizontal split S vi O filel txt file2 txt Vertical split will provide multiwindow vi S vimdiff file txt file txt check recent changes of file txt vimdiff file en sgml file fr sgml check changes of translation gvimdiff file txt file txt in X will provide a nice view of differences between an original and a backup file In SGML it matches tags so comparing translations in this mode works very well Special cursor movements with Ctrl W commands Ctrl W increase the size of a window Ctrl W decrease the size of a window Ctrl W h move to the window left Ctrl W 3 move to the window below Ctrl W k move to the window above Ctrl W 1 move to the window right Use the following to control screen scrolling set scrollbind set noscrollbind 213 Chapter 12 Version Control Systems 12 1 Concurrent Versions System CVS Check usr share doc cvs html cvsclient usr share doc cvs html info usr share doc cvsbook with lynx or run info cvs and man cvs for detailed infor mation 12 1 1 Installing a CVS server The following setup will allow commits to the CVS repository only by a member of the src group and administration of CVS only by a member of the staff group thus reducing the chance of shooting oneself cd var lib umask 002 mkdir cv
258. r by making choices in the Select section of dselect or by directly invoking dpkg Their meanings are e unknown the user has never indicated whether he wants the package e install the user wants the package installed or upgraded e remove the user wants the package removed but does not want to remove any existing configuration files e purge the user wants the package to be removed completely including its configuration files e hold the user wants this package not to be processed i e he wants to keep the current version with the current status whatever that is 2 2 11 Holding back packages from an upgrade There are two mechanisms for holding back packages from an upgrade through dpkg or beginning with Woody through APT With dpkg first export the list of package selections dpkg get selections gt selections txt Then edit the resulting file selections txt changing the line containing the package you wish to hold e g 1ibc6 from this 2This mechanism was provided in order to support safe upgrading of systems from a out format to ELF format where the order in which packages were unpacked was critical Chapter 2 Debian fundamentals 17 libc install to this libc6 hold Save the file and reload it into dpkg database with dpkg set selections lt selections txt Or if you know the package name to hold simply run echo libc hold dpkg set selections This procedure ho
259. r exam ple etc default hotplug can be used to control how etc init d hotplug works The etc default rcs file can be used to customize boot time defaults for motd sulogin etc If you cannot get the behavior you want by changing such variables then you can modify the init scripts themselves they are all configuration files Files in etc default contain environment variable assignments only Each file is sourced by the init script to which it corresponds in such a way that these assignments override any default variable settings in the init script itself The choice of directory name is peculiar http lists debian org debian devel 2003 debian devel 200308 msg02114 htm1l to Debian It is roughly the equivalent of the etc sysconfig directory found in Red Hat and other distributions Chapter 9 Tuning a Debian system 134 9 1 2 Customizing system logging System log mode can be configured using etc syslog conf Check the colorize pack age for a program to colorize system logfiles See also syslogd 8 and syslog conf 5 9 1 3 Optimizing hardware There are a few hardware optimization configurations that Debian leaves to the sysadmin to take care of e hdparm Hard disk access optimization Very effective Dangerous You must read hdparm 8 first hdparm tT dev hda to test disk access speed hdparm q c3 d1 ul m16 dev hda to speed up a modern IDE system It may be dangerous e setcd
260. r interface for joining servers channels 15 7 Search engines There are many search engines that serve documentation related to Debian e Debian WWW search site http search debian org e Google http www google com include site debian org as a search term e Google Groups http groups google com a search engine for newsgroups In clude group linux debian as a search term e AltaVista http www altavista com For example searching on the string cgi perl gives a more detailed explanation of this pack age than the brief description field in its control file See Check bugs in Debian and seek help on page 83 for related advice Chapter 15 Support for Debian 252 15 8 Websites The following are a few random URLs I collected for specific issues e IBM developerWorks Linux http www ibm com developerworks linux e Adrian Bunk s latest packages back port to stable http www fs tum de bunk e Linux on Laptops http www linux laptop net e Xterm FAQ http dickey his com xterm xterm faq html e EXT3 File System mini HOWTO http www zip com au akpm linux ext3 ext 3 usage html e Large File Support in Linux http www suse de aj linux_lfs html e Window Managers for X http www xwinman org e Linux USB Project http www linux usb org e SuSE pages for CJK http www suse de mfabian suse cjk suse cjk html e LNX BBC Business card siz
261. r is the set of functions that go by that name resolver 3 in the GNU C Library Another is the FireDNS resolver which comes in the libfiredns package How the LIBC resolver resolves names is governed by the hosts line in the etc nsswitch conf configuration file This line lists the services that should be used to resolve a name e g dns files nis nisplus 7 See nsswitch conf 5 Insofar as the files service is used the behavior of the resolver is also governed by the etc hosts configuration file See hosts 5 All of the above files are static and can be edited with your favorite editor Insofar as the dns service is used the behavior of the resolver is also governed by the etc resolv conf configuration file See resolv conf 5 One of the important functions of resolv conf is to list the IP addresses of nameservers that will be contacted to resolve the name This list often has to depend upon the network environment and the network envi ronment may change from time to time while your computer is running Programs such as Technically it is the FODN returned by gethostbyname 2 for the hostname returned by gethostname 2 7How the resolver resolves names is also alleged to be governed by the etc host conf configuration file The order line in this file lists the methods that should be used to resolve a name e g bind hosts nis See host conf 5 I believe that this line has been superseded by the ho
262. r spool squid The large area reserved for var spool squid is for a proxy cache for package download ing Following is fdisk 1 output to provide an idea of partition structure fdisk 1 dev hda comment dev h dev h dev h dev h dev h dev h dev h dev h dev h dev h dev h dal da2 da3 da4 da5 da6 da7 das 1 42 85 127 127 144 158 172 254 336 418 41 309928 84 325080 126 317520 629 3802680 143 128488 157 105808 171 105808 253 619888 335 619888 417 619888 629 1602688 6 83 83 5 82 83 83 83 83 83 83 Lin Lin Lin Lin Lin Lin Lin Lin Lin FAT16 DOS ux not used ux Main Extended UX Swap A few unused partitions exist These are for installing a second Linux distribution or as expan sion space for growing directory trees Mount filesystems Mounting the above filesystems properly is accomplished with the following etc fstab etc fs filesyst dev hda3 dev hda5 none tem mount point tab static filesystem information type opti ext2 swap SW ons dump pass defaults errors remount ro 0 1 0 0 Chapter 3 Debian System installation hints 32 proc proc proc defaults 0 0 dev fd0 floppy auto defaults user noauto 0 0 dev cdrom cdrom iso9660 defaults ro user noauto 0 0 keep partitions separate dev hda7 home ext2 d
263. rd Use of program such as sudo 8 is the good way to share the administrative privileges Please note that it is considered a good Unix habit to login to the non privileged user account first even when you plan to perform administrative activities Use commands sudo super or su c to gain the limited root privileged when needed See Working more safely sudo on page 137 4 1 2 Set up minimal newbie environment I think learning a computer system is like learning a new foreign language Although tutorial books are helpful you have to practice it with helper tools In this context I think it is a good idea to install few additional packages such as mc vim lynx doc linux text and debian policy gt apt get update apt get install mc vim lynx doc linux text debian policy If you already had these packages installed nothing will be installed 3I have to admit I used to use the superuser account more often than needed just because it was easy and I was sloppy Tt may also be a good idea to install gpm emacs21 and doc linux html See Mouse configuration on page 34 and Editors on page 207 Chapter 4 Debian tutorials 47 4 1 3 Add a user account During the installation you usually created a non privileged user account who receives e mails sent to the root account Since you do not want to use this special user account for the following training activities either you should create another
264. rd l username foo host force password on SSH2 For the user ssh functions as a smarter and more secure telnet will not bomb with J 9 5 2 Port forwarding for SMTP POP3 tunneling To establish a pipe to connect to port 25 of remote server from port 4025 of localhost and to port 110 of remote server from port 4110 of localhost through ssh execute on the local machine ssh q L 4025 remote server 25 4110 remote server 110 username remote server This is a secure way to make connections to SMTP POP3 servers over the Internet Set the AllowTcpForwarding entry to yes in etc ssh sshd_config of the remote host Chapter 9 Tuning a Debian system 160 9 5 3 Connecting with fewer passwords RSA One can avoid having to remember a password for each remote system by using RSAAuthen tication SSH1 protocol or Pubkey Authentication SSH2 protocol On the remote system set the respective entries RSA Authentication yes or PubkeyAuthen tication yes in etc ssh sshd_config Then generate authentication keys locally and install the public key on the remote system S ssh keygen RSAAuthentication RSAl key for SSH1 cat ssh identity pub ssh userl remote cat gt gt ssh authorized_keys ssh keygen t rsa PubkeyAuthentication RSA key for SSH2 cat ssh id_rsa pub ssh userl remote A cat gt gt ssh authorized_keys S ssh keygen t dsa PubkeyAuthentication DSA key for SSH2
265. re lilo runs in normal VGA screen and s or S is the parameter passed to init to invoke single user mode Enter the root password at the prompt There are few ways to disable all the X starting daemons e runupdate rc d dm stop 99 12 3 45 6 e insert exit 0 at the start of all etc init d dm files e rename all etc rc2 d S99 dm files to etc rce2 d K99 dm e remove all etc rc2 d S99 dm files e run gt etc Xx11 default display manager Here number in rc 2 d must correspond to the runlevel specified in the etc inittab Also dm means that you need to run the command multiple times by substituting it with all of the xdm gdm kdm and wdm Only the first one in the listis the one true way in Debian The last one is easy but only works on Debian and requires you to set the display manager again later using dpkg reconfigure Others are generic methods to disable daemons You can still start X with the startx command from any console shell 8 1 5 Other boot tricks with the boot prompt The system can be booted into a particular runlevel and configuration using the 1ilo boot prompt Details are given in the BootPrompt HOWTO http www tldp org HOWTO BootPrompt HOWTO html LDP If you want to boot the system into runlevel 4 use the following input at the 1110 boot prompt boot Linux 4 If you want to boot the system into normally functioning single user mode and you know the root password one
266. re tar gz deb file Browse its contents as if subdirectory In order to allow these viewer and virtual file features to function viewable files should not be set as executable Change their status using the chmod command or via the MC file menu 4 2 8 FTP virtual filesystem of MC MC can be used to access files over the Internet using FTP Go to the menu by press ing F9 then type p to activate the FTP virtual filesystem Enter a URL in the form username passwd hostname domainname which will retrieve a remote directory that ap pears like a local one Try http us debian org debian as URL and browse Debian file archive See The Debian archives on page 5 for how these are organized 4 3 Unix like work environment Although MC enables you to do almost everything it is very important for you to learn how to use the command line tools invoked from the shell prompt and become familiar with the Unix like work environment 4 3 1 Special key strokes In the Unix like environment there are few key strokes which have special meanings 1 e Ctrl U Erase line before cursor e Ctrl H Erase a character before cursor e Ctrl D Terminate input exit shell if you are using shell e Ctrl C Terminate a running program e Ctrl Z Temporarily stop program put it to the background job see command amp on page 58 e Ctrl S Halt output to screen e Ctrl Q Reactivate output to screen 16 Tn this tutorial chapter
267. re crazy Perl scripts http perlgolf sourceforge net may be interesting 8 6 21 Get text or a mailing list archive from a web page The following will read a web page into a text file Very useful when copying configurations off the Web lynx dump http www remote site com help info html gt textfile links and w3m can be used here too with slight differences in rendering If this is a mailing list archive use munpack to obtain mime contents from text 8 6 22 Pretty print a web page The following will print a web page into a PostScript file printer S apt get install html2ps html2ps URL lpr See lpr 1pd on page 39 Also check a2ps and mpage packages for creating PostScript files Chapter 8 Debian tips 123 8 6 23 Pretty print a manual page The following will print a manual page into a PostScript file printer man Tps some manpage lpr man Tps some manpage mpage 2 lpr 8 6 24 Merge two PostScript or PDF files You can merge two PostScript or PDF files gs q dNOPAUSE dBATCH sDEVICE pswrite sOutputFile bla ps f fool ps foo2 ps gs q dNOPAUSE dBATCH sDEVICE pdfwrite sOutputFile bla pdf f fool pdf foo2 pdf 8 6 25 Time acommand Display time used by a process time some command gt dev null real Om0 035s time on wall clock elapsed real time user 0m0 000s time in user mode sys 0m0 020s time in kernel mode 8 6 26 nice command Use nice
268. rectory e rmdir foo Remove a directory foo in the current directory e cd foo Change directory to the directory foo in the current directory or in the directory listed in the variable CDPATH See cd command in builtins 7 ecd Change directory to the root directory gad Change directory to the current user s home directory e cd foo Change directory to the absolute path directory foo erod a Change directory to the parent directory e cd foo Change directory to the home directory of the user foo gaq Change directory to the previous directory e lt etc motd pager Display contents of etc motd using the default pager See command lt foo on page 60 7 e touch junkfile Create a empty file junkfile e cp foo bar Copy a existing file foo to a new file bar e rm junkfile Remove a file junkfile 22Unix has a tradition to hide filenames which start with They are traditionally files that contain configu ration information and user preferences Default pager of the bare bone Debian system is more which can not scroll back By installing 1ess package using command line apt get install less less becomes default pager and you can scroll back with cursor keys Chapter 4 Debian tutorials 54 e mv foo bar Rename an existing file foo to a new name bar e mv foo bar baz Move an existing file foo to a new location with a new name bar baz The direc tory bar must exist e c
269. rfere with Debian cd sre configure prefix usr local S make make install this puts the files in the system Uninstall program If you still have the source and if it uses autoconf automake and if you can remember how you configured it configure all of the options you gave 1t make uninstall Chapter 13 Programming 235 Alternatively if you are absolutely sure that the install process puts files only under usr local and there is nothing important there you can erase all its contents by find usr local type f printO xargs 0 rm f If you are not sure where files are installed you should consider using checkinstall which provides a clean path for the uninstall 13 8 Web Basic interactive dynamic web pages can be made as follows e Queries are presented to the browser user using HTML form e Filling and clicking on the form entries will send an URL with encoded parameters from the browser to the web server For example http www foo dom cgi bin program pl VAR1 VAL18VAR2 VAL26VAR3 VAL3 http www foo dom cgi bin program py VAR1 VAL18VAR2 VAL28VAR3 VAL3 http www foo dom program php VAR1 VAL1 amp VAR2 VAL2 amp VAR3 VAL3 e CGI program any one of program on the web server will receive decoded param eters VARI VAL1 VAR2 VAL2 VAR3 VAL3 as the contents of environment variable QUERY_STRING and executes itself e stdout of CGI program will be sent to
270. rge e ed Minimum editor always there but tough to use 11 3 Emacs and Vim 11 3 1 Vim hints Read the VIM main help file document by pressing lt F1 gt while running the program lt F1 gt Help lt esc gt Back to normal mode V Visual mode i Insert mode Command line commands set tw 72 Set text width to 72 lt F11 gt Insert paste mode r date R Insert RFC 822 date qa Record keystrokes into register a q Stop keystroke recording Ra Execute keystrokes from register a edit foo txt Edit another file by loading foo txt wnext Write current file and edit next file q and can be used for simple macro recording and playback a macro that inserts HTML italics tags around the word at the add the tags lt i gt and lt i gt See also Using GnuPG with Vim on page 243 11 3 2 Emacs hints lt F1 gt Help lt F10 gt Menu C u M dat R Insert RFC 822 date 11 3 3 Starting the editor start editor emacs filename start in vi compatible start in vi non compatible start with compile default emacs q For instance to create cursor you could enter gii lt i gt ea lt i gt q where is the ESC key Then typing i at the start of a word would vim vim vim vim filename C N N u NONE Chapter 11 Editors 209 11 3 4 Editor command summary Emacs Vim exit C CE qa wq xa
271. rofile LC_CTYPE en_US ISO 8859 1 export LC_CTYPE 9 7 8 Example for France with Euro sign ISO 8859 15 Add the following lines to bash_profile LANG fr_FR euro export LANG LC_CTYPE fr_FR euro export LC_CTYPE Configure the keyboard for French AZERTY as described in Localizing the keyboard on page 166 add French manual pages by installing manpages fr The Right Alt key in the US is called Alt Gr in Europe Pressing this together with other keys creates numerous accented and special characters For example Alt Gr E creates a Euro sign Most western European languages can be configured similarly See Debian Euro HOWTO http www debian org doc manuals debian euro support for adding support for the new Euro currency and Utiliser et configurer Debian pour le francais http www debian org doc manuals fr debian fr howto for more details in French 9 7 9 Example for a multilingual X window system Let us set up a multilingual X window system which simultaneously supports Japanese En glish German and French with EUC UTF 8 and ISO 8859 1 encodings in different consoles Chapter 9 Tuning a Debian system 171 I will show you a customization using the Debian menu system See the details of Debian menu system in usr share doc menu html index html I also create a shortcut to the mozilla web browser in this example e add locale support for the Japanese ja_JP eucJP locale and other requ
272. rphic AR PL KaitiM Big5 TrueType font TeX ont metric data fm arphic gbsn001p Chinese Arphic AR PL SungtiL GB TrueType font TeX ont metric data t m arphic gkai00mp Chinese Arphic AR PL KaitiM GB TrueType font TeX font metric data ttf baekmuk Korean Baekmuk series TrueType fonts hbf jfs56 Chinese Jianti Fangsong 56x56 bitmap font GB2312 for CJK hbf cns40 b5 Chinese Fanti Song 40x40 bitmap font Big5 for CJK hbf kanji48 Japanese Kanji 48x48 bitmap font JIS X 0208 for CJK l m oct ob Since Free fonts are sometimes limited installing or sharing some commercial TrueType fonts is an option for a Debian users In order to make this process easy for the user some convenience packages have been created e ttf commercial e msttcorefonts gt 1 1 0 3 You ll have a really good selection of TrueType fonts at the expense of contaminating your Free system with non Free fonts All these font packages in Debian should work without any efforts and appear available to all X programs that use the regular core font system This includes things like Xterm Emacs and most other non KDE and non GNOME applications Now run xfontsel and select any TrueType fonts in the fndry menu you should be able to see many ungrayed out entries in the fmly menu For KDE2 2 and GNOME1 4 with libgdkxft0 which is a hack to get GTK 1 2 to do anti aliased font rendering you need to setup Xft1 as w
273. ry for the proper functioning of the system This includes all tools that are necessary to repair system defects You must not remove these packages or your system may become totally broken and you may not even be able to use dpkg to restore things Systems with only the Required packages are prob ably inadequate for most purposes but they do have enough functionality to allow the sysadmin to boot and install more software e Important packages should be found on any Unix like system Other packages without which the system will not run well or be usable will carry this priority This does not include Emacs or X11 or TeX or any other large applications These packages only constitute the bare infrastructure e Standard packages are standard on any Linux system including a reasonably small but not too limited character mode system This is what will install by default if users do not select anything else Standard does not include many large applications but it does include Emacs this is more a piece of infrastructure than an application and a reasonable subset of TeX and LaTeX if this turns out to be possible without X e Optional packages include all those that you might reasonably want to install even if you are unfamiliar with them and if you don t have specialized requirements This includes X11 a full TeX distribution and lots of applications e Extra packages either conflict with others with higher priorities have l
274. s Woody FSH apt get install cvs cvs doc cvsbook export CVSROOT var lib cvs cd SCVSROOT chown root src staff to restrict more for starting project chmod 3775 If above uses staff use 2775 cvs d var lib cvs init safer to specify d here explicitly cd CVSROOT chown R root staff chmod 2775 touch val tags chmod 664 history val tags chown root src history val tags 12 1 2 CVS session examples The following will set up shell environments for CVS repository access Chapter 12 Version Control Systems 214 Anonymous CVS download only Read only remote access export CVSROOT pserver anonymoustcvs qref sf net cvsroot qref cvs login cvs z3 co qref Use local CVS server Local access from a shell on the same machine export CVSROOT var lib cvs Use remote CVS pserver Remote access without SSH use RSH protocol capability in cvs S export CVSROOT pserver account cvs foobar com var lib cvs cvs login This is prone to eavesdropping attack Use remote CVS through ssh Remote access with SSH export CVSROOT ext account cvs foobar com var lib cvs or for SourceForge export CVSROOT ext account cvs qgref sf net cvsroot qref You can also use RSA authentication Connecting with fewer passwords RSA on page 160 which eliminates the password prompt Chapter 12 Version Control Systems 215 Create a new CVS archive For IT
275. s First etc chatscripts setup LT modem ABORT ERROR 1 ATZ OK ATW2X2 S7 70 S11 55 OK AT Second etc chatscripts setup ttyS0 ABORT ERROR 1 ATZ OK ATL1M1Q00V1W2X46C18D2 S6 4 S7 70 S11 55 S95 63 S109 1 FCLASS 0 OK AT The contents of these files must depend on your hardware of course Options can also be given to pppd as arguments Chapter 10 Network configuration 183 In Debian pppd is usually started using the pon command When pon is used its first argument names an options file in et c ppp peers which is also read by pppd This is where you set up options that are specific to a particular peer for example a particular Internet Service Provider ISP Suppose for example you commute between Amsterdam and Den Haag In each city you have access to two ISP services Planet and KPN First create a basic options file for each ISP cat gt etc ppp peers KPN lt lt EOF remotename KPN noauth user kpn noipdefault ipparam KPN EOF cat gt etc ppp peers Planet lt lt EOF remotename Planet auth user user3579 planet nl noipdefault mru 1000 mtu 1000 ipparam Planet EOF These files set options that differ between the two ISPs Options common to both ISPs can be placed in etc ppp options or in one of the interface specific options files as appropriate Now create options files for each ISP in each city In our example the only difference between connecting to an ISP in o
276. s and is executable filel nt file2 True if filel is newer than file2 modification filel ot file2 True if filel is older than file2 modification filel ef file2 True if they are the same device and inode numbers String comparison operators in the conditional expression are Z S n s stri s stri s SER SCFI l s SEPI lt 5 strl gt s q tr Er tr2 tr2 should tr2 tr2 tr2 q H E H H H BRR OR HK HK q e ue if t Lit md E T E TE E used he he he he in e e e e he e if strl1 sor e if stri sor strings are equal strings are equal place of strings are not equal ts before str2 ts after str2 length of str is zero length of str is non zero for strict POSIX compliance locale dependent locale dependent Arithmetic integer comparison operators in the conditional expression are eq ne 1t 1le gt and ge 13 2 6 Command line processing The shell processes a script as follows A loop loop A y or y y or J or split into tokens by the metacharacters SPACE TAB NEWLINE lt gt amp check keyword if not within expand alias if not within expand brace a 1 2 gt al a if not within expand tilde user gt user s home directory if not within expand parameter PARAMETER if not within expan
277. s for Make e info make e make 1 e Managing Projects with make 2nd edition O Reilly Simple automatic variables Rule syntax target prerequisites TAB commandi TAB command2 ignore errors TAB command3 suppress echoing Here TAB isa TAB code Each line is interpreted by the shell after make variable substitution Use at the end of a line to continue the script Use to enter for environment values for a shell script Implicit rules for the target and prerequisites can be written for example as c header h or Chapter 13 Programming 230 0 c header h Here the target contains the character exactly one of them The can match any nonempty substring in the actual target filenames The prerequisites likewise use to show how their names relate to the actual target name Suffix rules are the obsolete way of defining implicit rules for make They are still supported in GNU make for compatibility but use equivalent pattern rules whenever possible old suffix rule gt new pattern rule es gt Bue LEO O E Automatic variables for the rule foo o newl c new2 c oldl c new3 c SQ f00 0 target lt newl c first one newl c new2 c new3 c newer ones newl c new2 c oldl c new3 c all matched stem in the target pattern Variable references fool bar One time expansion foo2 bar Recursive expansion foo3 bar
278. s installed on your system the error messages of many programs can be multi lingual S LANG en_US cat foo cat foo No such file or directory S LANG de_DE cat foo cat foo Datei oder Verzeichnis nicht gefunden Glibc offers support for this functionality to programs as a library See locale 7 9 7 3 Introduction to locales Full locale description consists of 3 parts xx_YY ZZZZ e xx ISO 639 language codes lower case e YY ISO 3166 country codes upper case e ZZZZ codeset i e character set or encoding identifier For language codes and country codes see pertinent description in the info gettext Please note this codeset part may be normalized internally to achieve cross platform compat ibility by removing all and by converting all characters into lower case Typical codesets are e UTF 8 Unicode for all regions mostly in 1 3 Octets new de facto standard e ISO 8859 1 western Europe de facto old standard Chapter 9 Tuning a Debian system 168 ISO 8859 2 eastern Europe Bosnian Croatian Czech Hungarian Polish Romanian Serbian Slovak Slovenian ISO 8859 3 Maltese ISO 8859 5 Macedonian Serbian ISO 8859 6 Arabic ISO 8859 7 Greek ISO 8859 8 Hebrew ISO 8859 9 Turkish ISO 8859 11 Thai TIS 620 ISO 8859 13 Latvian Lithuanian Maori ISO 8859 14 Welsh ISO 8859 15 western Europe with euro KOIS R Russian KOI8 U Ukrainian CP1250 Czech Hungarian Polish MS Windows
279. s not support the wheel group on page 136 which can be given a good amount of root privilege through su using PAM or the sudo command See Add a user account on page 47 for details 3 1 11 Creating filesystems Hard disk partition I prefer to use different partitions for different directory trees to limit damage upon system crash E g boot bin sbin 50MB tmp 100MB var 100MB home 100MB usr 700MB with X usr local 100MB The size of the usr directory is very dependent on X Window applications and documenta tion usr can be 300MB if one runs a console terminal only whereas 2GB 3GB is not an unusual size if one has installed many Gnome applications When usr grows too big mov ing out usr share to a different partition is the most effective cure With the new large prepackaged Linux 2 4 kernels may need more than 200MB Chapter 3 Debian System installation hints 31 For example the current status of my Internet gateway machine is as follows output of the df h command Filesystem dev h dev h dev h dev h dev h dev h dev h da3 da7 da8 da6 Size 300M 100M 596M 100M 596M 596M 1 5G Used Avail Use 106M 12M 53M 834k 222M 130M 204M 179M 38 82M 13 513M 10 94M 1 343M 40 436M 23 1 2G 14 Mounted on home var var lib cvs usr var cache apt archives va
280. self provided to it on its standard input The script prints the result of the mapping on its standard output before exiting For example the following mapping stanza will cause ifup to bring up interface et h0 as the home logical interface mapping eth0 script usr local sbin echo home where usr local sbin echo home is bin sh echo home Because mapping is done with a script it is possible to select the logical interface automatically based on some sort of test See Logical interface selection using guessnet on this page for an example of this 10 8 1 Logical interface selection using guessnet Install guessnet and then add a stanza like the following to etc network interfaces mapping eth0o script guessnet ifupdown map home map work Now when you ifup eth0 guessnet will check whether eth0 can be brought up as home or work To do this it uses information stored in the logical interface definitions guessnet uses ARP requests to detect either the gateway or a host identified on a test peer line gues snet is still under development Chapter 10 Network configuration 195 10 8 2 Automatic network configuration using laptop net The laptop net package takes a different approach to automagic network reconfiguration Laptop net does not make use of i fupdown s logical interfaces but instead has its own system of configuration schemes and system profiles Laptop net still uses ifup and ifdown to confi
281. ser modes and e 0 halt the system e 6 reboot the system Runlevels 7 8 and 9 can also be used but their rc directories are not populated when packages are installed Chapter 2 Debian fundamentals 21 Switch runlevels using the telinit command When entering a runlevel all scripts in etc rcrunlevel d are executed The first letter in the name of the script determines the way in which the script is run scripts whose names begin with K are run with the argument stop Scripts beginning with S are run with the argument start The scripts are run in the alphabetical order of their names thus stop scripts are run before start scripts and the two digit numbers following the K or S determine the order in which the scripts are run The scripts in etc rcrunlevel d are in fact just symbolic links back to scripts in etc init d These scripts also accept restart and force reload as argument the latter meth ods can be used after a system has been booted in order to restart services or force them to reload their configuration files For example etc init d sendmail force reload 2 4 3 Customizing runlevels Customizing runlevels is an advanced system administration task The following advice holds for most services To enable service service in runlevel R create the symbolic link etc rcR d Sxyservice with target init d service The sequence number xy should be the sequence number that was assigned
282. ses testing releasenotes 2 1 15 The source code Source code is included for everything in the Debian system Moreover the license terms of most programs in the system require that source code be distributed along with the programs or that an offer to provide the source code accompany the programs Chapter 2 Debian fundamentals 11 Normally the source code is distributed in the source directories which are parallel to all the architecture specific binary directories or more recently in the pool directory see The pool directory on page 9 To retrieve the source code without having to be familiar with the structure of the Debian archive try a command like apt get source mypackagename Some packages notably pine are only available in a source package due to their licensing limitations Recently the pine tracker package has been provided to facilitate Pine instal lation The procedures described in Port a package to the stable system on page 90 and Packaging on page 239 provide ways to build a package manually Source code may or may not be available for packages in the contrib and non free direc tories which are not formally part of the Debian system 2 2 The Debian package management system 2 2 1 Overview of Debian packages Packages generally contain all of the files necessary to implement a set of related commands or features There are two types of Debian packages e Binary packages which contai
283. shrc should contain if SUDO_USER then sudo H u SUDO_USER xauth extract SDISPLAY xauth merge This works fine even with the home directory of the user on an NFS mount because root does not read the Xauthority file There are also several specialized packages for this purpose kdesu gksu gksudo gnome sudo and xsu Some other methods can be used to achieve similar results creat ing a symlink from root Xauthority to the user s corresponding one use of the script sux http fgouget free fr sux sux readme shtml or putting xauth merge USER_RUNNING_X Xauthority in the root initialization script See more on the debian devel mailing list http lists debian org debian devel 2002 debian devel 200207 msg00259 html 9 4 13 TrueType fonts in X The standard xfs in XFree86 4 works fine with TrueType fonts You have to install a third party font server such as xfs xtt if you are using XFree86 3 You just need to make sure that whatever applications you want to use the TrueType fonts are linked against libXft or libfreetype you probably don t even have to worry about this if you re using pre compiled debs First set up font support infrastructure e Install x ttcidfont conf and defoma packages This automates generation of the fonts scale and fonts dir files apt get install x ttcidfont conf e Edit etc X11 XF86Config 4 in the Section Files as Section Files
284. shw pager Ur Typical uses of interrupts Chapter 3 Debian System installation hints 27 IRQO timer output 8254 e IRQ1 keyboard controller e IRQ2 cascade to IRQ8 IRQ15 on PC AT e IRQ3 secondary serial port io port 0x2F8 dev ttyS1 e IRQ4 primary serial port io port 0x3F8 dev ttyS0 e IRQ5 free sound card SB16 io port 0x220 DMA low 1 DMA high 5 e IRQ6 floppy disk controller io port 0x3F0 dev d0 dev d1 e IRQ7 parport io port 0x378 dev 1p0 e IRQ8 rtc e IRQ9 software interrupt int Ox0A redirect to IRQ2 e IRQ10 free network interface card NE2000 io port 0x300 e IRQ11 free SB16 SCSI io port 0x340 SB16 IDE io port 0x1E8 0x3EE e IRQ12 PS 2 Mouse e IRQ13 free was 80287 math coprocessor e IRQ14 primary IDE controller dev hda dev hdb e IRQ15 secondary IDE controller dev hdc dev hdd For old non PnP ISA cards you may want to set IRQ5 IRQ10 and IRQ11 as non PnP from the BIOS For USB devices device classes are listed in proc bus usb devices as Cls nn e Cls 00 e Cls 01 e Cls 02 e Cls 03 e Cls 07 e Cls 08 e Cls 09 Unused Audio speaker etc Communication MODEM NIC HID Human Interface Device KB mouse joystick Printer Mass storage FDD CD DVD drive HDD Flash Hub USB hub e Cls 255 Vendor specific If the device class of a device is not 255 Linux supports the device 3 1 4 Determining a PC s hardware via ot
285. sion Control Systems 216 Ur UY UY Ur get original version to old directory cd old cvs tag b Release initial bugfixes create branch b tag now you can work on the old version Tag sticky cvs update d P don t create empty directories source tree now has sticky tag Release initial bugfixes work on this branch cvs up d P sync with files modified by others on this branch cvs ci m check into this branch cvs update kk A d P remove sticky tag and forget contents update from main trunk without keyword expansion cvs update kk d P j Release initial bugfixes Merge from Release initial bugfixes branch into the main trunk without keyword expansion Fix conflicts with editor cvs ci m merge Release initial bugfixes cd tar cvzf old project x tar gz old make archive j for bz2 cvs release d old remove local source optional Nice options to remember use as first argument s to cvs n dry run no effect Se display messages showing steps of cvs activity Export files from CVS To get the latest version from CVS use tomorrow cvs ex D tomorrow module_name Administer CVS Add alias to a project local server NY NN UU NN NY NN NN Ur su admin a member of staff export CVSROOT var lib cvs cvs co CVSROOT modules cd CVSROOT echo px a project x gt gt modules cvs ci m Now px is an alias for project x cvs release d exit or Ctrl D to get back fr
286. so more specialized conversion tools e character set conversion iconv locale encoding conversions konwert fancy encoding conversions e binary file conversion uuencode and uudecode for Unix mimencode for the mail lrecode allows more convenient aliases than iconv End of lines e Carriage return means ASCII 13 ASCII 0xD M or Mr e Line feed means ASCII 10 ASCII OxA J or n Chapter 8 Debian tips 118 8 6 13 Regular expression substitution Replace all instances of FROM_REGEX with TO_TEXT in all of the files FILES perl i p s FROM_REGEX TO_TEXT g FILES 4 i is for in place editing p is for implicit loop over FILES If the substitution is complex you can make recovery from errors easier by using the parameter i bak instead of i this will keep each original file adding bak as a file extension 8 6 14 Edita file in place using a script The following script will remove lines 5 10 and lines 16 20 in place bin bash ed 1 lt lt EOF 16 20d 5 10d wW q EOF Here ed commands are the same as vi command mode commands Editing from the back of file makes it easy for scripting 8 6 15 Extract differences and merge updates for source files Following one of these procedures will extract differences between two source files and create unified diff files file patch0 or file patch1 depending on the file location diff u file old file
287. soin etc pam d su The following will set the adm group in a Debian system as an equivalent of the BSD wheel group and allow su without a password for its members anti RMS configuration in etc pam d su auth required pam_wheel so group adm Wheel members to be able to su without a password auth sufficient pam_wheel so trust group adm 9 2 3 Purposes of standard groups A few interesting groups e root group is the default wheel group for su if pam_wheel so is used without the group argument e adm group can read logfiles e cdrom group can be used locally to give a set of users access to a CD ROM drive e floppy group can be used locally to give a set of users access to a floppy drive e audio group can be used locally to give a set of users access to an audio device e src group owns source code including files in usr src It can be used locally to give a user the ability to manage system source code Chapter 9 Tuning a Debian system 137 e staff membership is useful for helpdesk types or junior sysadmins giving them the ability to do things in usr local and to create directories in home For a complete list see the FAQ section in the Securing Debian Manual http www debian org doc manuals securing debian howto which can also be found as the harden doc package in Woody Also the new base passwd gt 3 4 6 contains an authorita tive list usr share doc base passwd users and groups html 9 2 4 Working
288. st Sx then command x fi done e findand xargs combination xargs 0 find type f maxdepth 1 name ext printO A n 1 command e find with exec option with a command find type f maxdepth 1 name ext exec command e find with exec option with a short shell script exec sh find type maxdepth 1 name ext c command amp amp echo successful Y mo SIf you type this in one line you need to add few semicolons to mark the end of shell commands Chapter 8 Debian tips 122 8 6 20 Perl short script madness Although any Awk scripts can be automatically rewritten in Perl using a2p 1 one liner Awk scripts are best converted to one liner perl scripts manually For example awk 2 1957 print 3 is equivalent to any one of the following lines perl ne Gf split if 1 eq 1957 print S 2 n perl ne if f split 1 eq 1957 print Sf 2 n perl ne f split print Sf 2 if 1 1957 perl lane print F 2 if SF 1 eq 1957 Since all the whitespace in the arguments to per1 in the line above can be removed and taking advantage of the automatic conversions between numbers and strings in Perl perl lane print F 2 if F 1 eq 1957 See perlrun 1 for the command line options For mo
289. stomize the file etc modules conf which lists aliases and other arguments that must be used in conjunction with various modules through files in etc modutils and etc modules which lists the modules that must be loaded at boot time Like the new Configure help files that are now available to support the construction of custom kernels the modconf package comes with a series of help files in usr share modconf which provide detailed information on appropriate arguments for each of the modules See The modularized 2 4 kernel on page 99 for examples 2 7 6 De installing an old kernel package The kernel image NNN prerm script checks to see whether the kernel you are currently running is the same as the kernel you are trying to de install Therefore you can safely remove unwanted kernel image packages using this command dpkg purg force remov ssential kernel image NNN Replace NNN with your kernel version and revision number of course 25 Chapter 3 Debian System installation hints Official documentation for installing Debian is located at http www debian org releases stable and http www debian org releases stable installmanual The development versions are located at http www debian org releases testing and http www debian org releases testing installmanual work in progress sometimes this may not exist Although this chapter was initially written during the days of the Po
290. stribution on page 6 e testing The preferred distribution for a workstation since it contains recent releases of desktop software which have received a bit of testing See The testing distribution on page 7 e unstable Cutting edge The choice of Debian developers See The unstable dis tribution on page 7 When packages in unstable have no release critical RC bugs filed against them after the first week or so they are automatically promoted to testing Debian distributions also have code names as described in Debian distribution codenames on page 8 Before Woody was released in August 2002 the three distributions were respectively Potato Woody and Sid After Woody was released the three distributions were respectively Woody Sarge and Sid When Sarge is released the stable and unstable distributions will be Sarge and Sid a new testing distribution will then be created initially as a copy of stable and given a new code name Subscribe to the low volume mailing list debian devel announce lists debian org for important announcements about Debian See The Debian archives on page 5 If you want to use versions of packages that are more current than the versions that were released with the distribution you are using then you can either upgrade to a later distribution as described in Upgrading a distribution to stable testing or unstable on page 73 or you can upgrade only selected packages If the p
291. sts line in nsswitch conf but I am not sure Chapter 10 Network configuration 187 pppd and dhclient are able to manipulate resolv conf to add and remove lines but these features do not always work properly and they conflict with one another The resolvconf package solves the problem better by providing a standard framework for updating this file See Managing nameserver information resolvconf on the current page 10 4 2 Managing nameserver information resolvconf The resolvconf package provides a framework for dynamic management of information about available nameservers It solves the long standing problem of how to maintain dynamic lists of nameservers for the resolver and DNS caches to use Resolvconf sets itself up as the intermediary between programs that control network interfaces and supply nameserver infor mation and applications that need nameserver information resolvconf is designed to work without any manual configuration needing to be done However the package is quite new and may require some manual intervention to get it to work properly This is certainly true if you have ever customized packages so that they update etc resolv conf you will need to disable your customizations See usr share doc resolvconf README gz for details 10 4 3 Caching looked up names nscd dnsmasq pdnsd bind9 If your nameserver is slow to respond then you may want to use nscd to cache the results of things that are look
292. system similar to Plan9 s dumpfs which preserves every daily snapshot You can access the past snapshots at any time for retrieving a certain day s file Let s backup your home directory with pdumpfs and cron pdumpfs constructs the snapshot YYYY MM DD in the destination directory All source files are copied to the snapshot directory when pdump fs is run for the first time On and after the second time pdumpfs copies only updated or newly created files and stores unchanged files as hard links to the files of the previous day s snapshot in order to save disk space pdumpfs src dir dest dir dest basename See pdumpfs 8 8 4 3 Regular differential backup with RCS Changetrack will record changes to the text based configuration files in RCS archives regu larly See changetrack 1 apt get install changetrack vi changetrack conf 8 5 System freeze recovery 8 5 1 Kill a process Run top to see what process is acting funny Press P to sort by CPU usage M to sort by memory and k to kill a process Alternatively BSD style ps aux less or System V style ps efH less may be used The System V style syntax displays parent process IDs PP ID which can be used for killing zombie defunct children Chapter 8 Debian tips 113 Use kill to kill or send a signal to a process by process ID killa11 to do the same by process command name Frequently used signals 1 HUP restart daemon 15
293. system to CD R To copy key configuration files and data files to CD R use the example backup script backup http www debian org doc manuals debian reference examples Also see Copy and archive a whole subdirectory on page 109 and Differential backup and data syn chronization on page 111 9 3 10 Copy a music CD to CD R Not tested by me apt get install cdrecord cdparanoia cdparanoia s B cdrecord dev 0 0 0 speed 2 v dao ject defpregap 1 audio wav Chapter 9 Tuning a Debian system 143 or apt get install cdrdao disk at once cdrdao read cd device dev cdrom paranoia mode 3 my_cd read cd cdrdao write device dev cdrom speed 8 my_cd write a new CD cdrdao does a real copy no gaps etc 94 X The X Window System is provided by XFree86 http www xfree86 org There are two major versions of X server available on the Debian system XFree86 Version 3 3 XF3 and XFree86 Version 4 x series XF4 both based on X11R6 specifications by X Org http www x org For the basics of X refer to X 7 the LDP XWindow User HOWTO http www tldp org HOWTO XWindow User HOWTO html and the Remote X Apps mini HOWTO http www tldp org HOWTO mini Remote X Apps html1 For a Debian specific user guide read usr share doc xfree86 common FAQO gz provided in the xfree86 common package This contains an interesting and authoritative review of the key binding issues by Branden
294. t Depends and packages that it Recom mends or Suggests from the testing distribution e aptitude install package unstable This installs package from the unstable distribution while installing its dependencies from the testing distribution e aptitude install t unstable package This installs package from the unstable distribution while installing its dependencies also from the unst able distribution by setting the Pin Priority of unst able to 990 e apt cache policy foo bar This checks the status of packages foo bar e aptitude show foo bar less orapt cache show foo bar less This checks the information for packages foo bar e aptitude install foo 2 2 4 1 This installs the particular version 2 2 4 1 of the foo package e aptitude install foo bar This installs the foo package and removes the bar package e aptitude remove bar This removes the bar package but not its configuration files e aptitude purge bar This removes the bar package together with all its configuration files different dependency relationships from old versions of those packages See apt get 8 for details aptitude upgrade and aptitude dist upgrade start aptitude in the commandline mode You can switch these to full screen mode by pressing e key Chapter 6 Debian package management 83 In the above examples giving apt get the u option causes it to print a list of all packages that are to be upgraded and to prompt the user befor
295. t as root on page 45 e Every directory has a name which can contain any letters or symbols except 7 The root directory is an exception its name is pronounced slash or the root directory and it cannot be renamed e Each file or directory is designated by a fully qualified filename absolute filename or path giving the sequence of directories which must be passed through to reach it The three terms are synonymous All absolute filenames begin with the directory and Directories are called folders on some other systems 2 While you can use almost any letters or symbols in a file name in practice it s a bad idea It is better to avoid any characters that often have special meanings on the command line including spaces tabs newlines and other special characters 7 gt lt 7 467 If you want to separate words in a name good choices are the period hyphen and underscore You could also capitalize each word LikeThis Chapter 4 Debian tutorials 64 there s a between each directory or file in the filename The first is the name of a directory but the others are simply separators to distinguish the parts of the filename The words used here can be confusing Take the following example usr share keytables us map gz This is a fully qualified filename some people call it a path However people will also refer to us map gz alone as a filename e The root directory has a
296. t run of the dd command may cause an error message and may yield a shorter disk image with a lost tail end The second run of dd command may yield a larger disk image with garbage data attached at the end on some systems if the data size is not specified Only the second run of the dd command with the correct data size specified and without ejecting the CD after an error message seems to avoid these problems If for example the image size displayed by df is 46301184 blocks use the following command twice to get the right image this is my empirical information dd if dev cdrom of cd img bs 2048 count 46301184 2 9 3 8 Debian CD images To obtain the latest information on Debian CDs visit the Debian CD site http www debian org CD If you have a fast Internet connection think about installing over the network using e a few floppy images http www debian org distrib floppyinst e a minimal bootable CD image http www debian org CD netinst If you do not have a fast Internet connection think about purchasing CDs from a CD vendor http www debian org CD vendors Please do not waste bandwidth by downloading standard CD images unless you are a CD image tester even with the new jigdo method One noteworthy CD image is KNOPPIX Live Linux Filesystem On CD http www knopper net knoppix index en html This CD will boot a functioning Debian system without installing itself to the hard disk 9 3 9 Back up the
297. t the password file just as easily as the above mkdir fixit mount dev hda3 fixit cd fixit etc vi shadow de e e H vi passwd The advantage of this approach over the previous method is one does not need to know the lilo password if any But to use it one must be able to access the BIOS setup to allow the system to boot from floppy disk or CD if that is not already set 8 1 3 Cannot boot the system No problem even if you didn t bother to make a boot disk during install If 1ilo is broken grab the boot disk from the Debian installation set and boot your system from it At the boot prompt assuming the root partition of your Linux installation is on dev hda12 and you want runlevel 3 enter boot rescue root dev hdal2 3 Then you are booted into an almost fully functional system using the kernel on the floppy There may be minor glitches due to lack of kernel features or modules See also Install a package into an unbootable system on page 85 if you have a broken system If you need a custom boot floppy follow readme t xt on the rescue disk Chapter 8 Debian tips 107 8 1 4 Let me disable X on boot Chasing unstable sid is fun but buggy xdm gdm kdm and wdm started during the boot process can bite you bad First get the root shell by entering the following at the boot prompt boot Linux vga normal s Here Linux is the label for the kernel image you are booting vga normal will make su
298. table contains the kernel s information on how to send IP packets to their des tinations Here is a sample routing table printout for a Debian host on a local area network LAN with IP address 192 168 50 x 24 Host 192 168 50 1 also on the LAN is a router for the corporate network 172 20 x x 16 and host 192 168 50 254 also on the LAN is a router for the Internet at large route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 1270 040 255 0 D 0 U 0 0 2 lo 3This system was inflexible and wasted many IP addresses so today IPv4 networks are allocated with network address parts of varying length The address of the network can be obtained by bitwise ANDing an address on the network with the net mask The broadcast address can be obtained by bitwise ORing the network address with the 1 s complement of the net mask Chapter 10 Network configuration 179 1922168500 255 255 255 0 U 0 0 137 tbo 172 20 0 0 192 168 50 1 2D 00 00 UG 1 0 7 etho default 192 168 50 254 0 0 0 0 UG 1 0 36 etho0 e The first line after the heading says that traffic destined for network 127 x x x will be routed through 1o the loopback interface e The second line says that traffic destined for hosts on the LAN will be routed through etho e The third line says that traffic destined for the corporate network will be routed toward gateway 192 168 50 1 also through etho0 e The fourth line says th
299. tall a system into separate partitions using the installer of the other distribution If its root partition is in dev hda9 main cd mkdir other dist main mount t ext3 dev hda9 other dist main chroot other dist bin bash Then proceed as in Run a different Debian distribution with chroot on page 127 Setting up login for chroot on the preceding page and Setting up X for chroot on the facing page Build a package with chroot There is a more specialized chroot package pbuilder which constructs a chroot system and builds a package inside the chroot It is an ideal system to use to check that a package s build dependencies are correct and to be sure that unnecessary and wrong build dependencies will not exist in the resulting package 8 6 36 How to check hard links You can check whether two files are the same file with two hard links by ls li filel file2 8 6 37 mount hard disk image file If file img contains an image of hard disk contents and the original hard disk had a disk configuration which gives xxxx bytes sector sectors cylinder then the following will mount it to mnt Chapter 8 Debian tips 130 mount o loop offset xxxx file img mnt Note that most hard disks have 512 bytes sector 8 6 38 Samba Basics of getting files from Windows mount t smbfs o username myname uid my_uid gid my_gid server share mnt smb mount Windows files to Linux
300. tato installer most of the contents have been updated to the Woody installer and they are very similar installers Since Sarge will use a totally new installer please use this as a reference point for the Sarge installer Also some key packages have changed names and priorities For example default MTA of Sarge is exim4 instead of exim and coreutils has been introduced to replace several pack ages You may need to adjust actions 3 1 General Linux system installation hints Do not forget to check http www debian org CD netinst if you are looking for a compact CD image of the Debian installer Running the testing or unstable distribution increases the risk of hitting serious bugs This risk can be managed by deploying a multibooting scheme with a more stable Debian distribu tion or by using the nice trick provided by chroot as described in chroot on page 127 The latter will enable running different Debian distributions simultaneously on different consoles 3 1 1 Hardware compatibility basics Linux is compatible with most PC hardware and can be installed to almost any system For me it was as easy as installing Windows 95 98 Me The hardware compatibility list just seems to keep growing Chapter 3 Debian System installation hints 26 If you have a laptop PC check Linux on Laptops http www linux laptop net for installation pointers by brand and model My recommendation for desktop PC hardware is Just be conservati
301. ternet access Chapter 8 Debian tips 128 main cd mkdir sid root main debootstrap sid sid root http ftp debian org debian watch it download the whole system nain echo proc sid sid root proc proc none 0 0 gt gt etc fstab ain mount proc sid sid root proc t proc ain cp etc hosts sid root etc hosts nain chroot sid root bin bash chroot apt setup set up etc apt sources list chroot vi etc apt sources list point the source to unstable chroot dselect you may use aptitude install mc and vim Lm Lami A 3 3 At this point you should have a fully working Debian system where you can play around without fear of affecting your main Debian installation This deboot st rap trick can also be used to install Debian to a system without using a Debian install disk but instead one for another GNU Linux distribution See http www debian org releases stable i386 ch preparingtfs linux upgrade Setting up login for chroot Typing chroot sid root bin bash is easy but it retains all sorts of environment vari ables that you may not want and has other issues A much better approach is to run another login process on a separate virtual terminal where you can log in to the chroot directly Since on default Debian systems tt y1 to tty6 run Linux consoles and tt y7 runs the X Win dow System let s set up tty8 for a chrooted console as an example After creating a chroot syst
302. that i fup uses the physical interface name as the default logical interface name and now in our example no et h0 logical interface is defined 10 8 Magic network configuration Interface names can be mapped to other names when i fup runs How names are mapped can be made to depend on circumstances Thus i fup can be so configured that it brings up a given physical interface as the appropriate logical interface among a set of predefined alterna tives Logical interface name mapping occurs as follows e Ifno logical interface name is given on the i fup command line then the physical interface name is used as the initial logical interface name Chapter 10 Network configuration 194 e If the logical interface name matches the glob pattern of a mapping stanza then that map ping is applied to generate a new logical interface name This is done for each mapping stanza in turn e If the final logical interface name is the label of a logical interface definition in etc network interfaces then the physical interface is brought up as that logical inter face Otherwise i fup prints a message that it is Ignoring unknown interface and exits The syntax of a mapping stanza is mapping glob pattern script script name map script input The script named in the mapping stanza is always run with the physical interface name as its argument and with the contents of all following map lines in the stanza without the word map it
303. the command shown above so that it is equivalent to the following ifup eth0 eth0 Do not include a mapping stanza like this if you are using ifplugd or waproamd instances started by hotplug to control the interface If you want only eth0 and no other interfaces to be brought up on hot plug then use grep instead of echo as follows mapping hotplug script grep map eth0 See Magic network configuration on page 193 and usr share doc hotplug README Debian for more tips 10 10 3 Triggering network configuration ifplugd The ifplugd daemon brings an interface up or down according to whether or not its under lying hardware is plugged in to a network The program can detect a live cable connected to an Ethernet interface or an access point associated to a Wi Fi interface although waproamd is probably what you want to use in the latter case When i fp1ugd sees that the state of the link has changed it runs a proxy script which by default calls i fup or ifdown 10 10 4 Triggering network configuration waproamd The waproamd daemon is just like ifplugd except that it is designed to be used with Wi Fi cards It actively scans for access points to which the Wi Fi hardware is able to associate When association is achieved waproamd runs i fup If you are using waproamd then in general you configure the Wi Fi card via waproamd and not via wireless options in etc network interfaces 10 10 5 Network configuration and
304. the key configuration files e etc ssh ssh_config SSH client defaults See ssh 1 Notable entries are Host Restricts the following declarations up to the next Host keyword to be only for those hosts that match one of the patterns given after the keyword Protocol Specifies the SSH protocol versions The default is 2 1 PreferredAuthentications Specifies the SSH2 client authentication method The default is hostbased publickey keyboard interactive password PasswordAuthentication If you want to log in with a password you have to make sure this is not set no ForwardX11 The default is disabled This can be overridden by the command line option X e etc ssh sshd_config SSH server defaults See sshd 8 Notable entries are ListenAddress Specifies the local addresses sshd should listen on Multiple options are permitted AllowTcpForwarding The default is disabled X11Forwarding The default is disabled e SHOME ssh authorized_keys the lists of the default public keys that clients use to connect to this account on this host See ssh keygen 1 e SHOME ssh identity See ssh add 1 and ssh agent 1 The following will start an ssh connection from a client ssh username hostname domain ext ssh 1 username hostname domain ext Force SSH version 1 ssh 1 o RSAAuthentication no 1 username foo host force password on SSH1 ssh o PreferredAuthentications passwo
305. the shell means bash For more insight into the different shells see Shell on page 221 15On a normal Linux character console only the left hand Ctrl and Alt keys work as expected 16You can disable this terminal feature using stty 1 Chapter 4 Debian tutorials 52 The default shell bash has history editing and tab completion capabilities to aide the inter active use up arrow Start command history search Ctrl R Start incremental command history search TAB Complete input of the filename to the command line Ctrl V TAB Input TAB without expansion to the command line Other important keystrokes to remember Ctrl Alt Del Reboot halt the system see Install a few more packages after initial install on page 40 Left click and drag mouse Select and copy to the clipboard Click middle mouse button Paste clipboard at the cursor Meta key Emacs terminology is assigned traditionally to Left Alt key Some system may be configured to use Windows key for Meta key Here in order to use a mouse in the Linux character console you need to have gpm running as daemon See Mouse configuration on page 34 4 3 2 Basic Unix commands Let s learn the basic Unix commands 8 Try all the following commands from the non privileged user account penguin pwd Display name of current working directory whoami Display current user name file foo Display a type of file for the file foo type p commandname
306. the web browser and is presented as an interactive dynamic web page For security it is recommended not to use random handcrafted hack for parsing CGI parame ters There are established modules for them in Perl see Perl on page 227 and Python see Python on page 228 PHP http www php net comes with these functionarity When client data storage is needed cookies are used When client side data processing is needed javascript is frequently used For more see The Common Gateway Interface http hoohoo ncsa uiuc edu cgi The Apache Software Foundation http www apache org and JavaScript http www mozilla org js Searching CGI tutorial on Google by typing encoded URL http www google com search hl en amp ie UTF 8 amp q CGI tutorial directly to the browser address is a good way to see the CGI script in action on the server 13 9 Document preparation 13 9 1 roff typesetting Traditionally rof f is the main Unix text processing system Here nn is used to the encoded character of hexadecimal nn Chapter 13 Programming 236 See roff 7 groff 7 groff 1 grotty 1 troff 1 groff_mdoc 7 groff_man 7 groff_ms 7 groff_me 7 groff_mm 7 and info gro A good tutorial on me macros exists If you have groff 1 18 or newer find usr share doc groff meintro me gz a
307. tings In Debian when hotplug is called it runs scripts in etc hotplug and etc hotplug d See hotplug 8 for de tails Newly inserted network hardware is configured by the script etc hotplug net agent 16 Suppose your PCMCIA network card has been inserted resulting in interface et h0 becoming available for use etc hotplug net agent does the following ifup ethO0 hotplug Unless you have added a logical interface definition or mapping named hotplug to etc network interfaces this command will do nothing To make it so that the command will configure et h0 add the following stanza to etc network interfaces mapping hotplug script echo 16Tt may also be configured by any hook scripts that have been installed in etc hotplug d net The ifplugd and waproamd packages install hook scripts there for example 1 As of version 0 0 20040329 4 or so hotplug can optionally be put into modes wherein it behaves differently from how it is described here as behaving One such mode is so called all mode wherein hotplug brings up all hot plugged interfaces The other such mode is so called auto mode wherein hotplug brings up interfaces only if they are listed on auto lines in etc network interfaces In these alternative modes i fup is invoked without the hotplug suffix Chapter 10 Network configuration 198 As explained in Network configuration using logical interface definitions on page 192 this will map
308. tion The exchange of information may occur over the network between different hosts 4 5 8 Device files Device files refer to physical or virtual devices on your system such as your hard disk video card screen or keyboard An example of a virtual device is the console represented by dev console There are two types of devices e character device This can be accessed one character at a time that is the smallest unit of data which can be written to or read from the device is a character byte e block device This must be accessed in larger units called blocks which contain a number of char acters Your hard disk is a block device You can read and write device files though the file may well contain binary data which may be an incomprehensible to humans gibberish Writing data directly to these files is sometimes useful for the troubleshooting of hardware connections For example you can dump a text file to the printer device dev 1p0 or send modem commands to the appropriate serial port dev ttyS0 But unless this is done carefully it may cause a major disaster So be cautious dev null etc dev null is a special device file that discards anything you write to it If you don t want something throw itin dev nul1 It s essentially a bottomless pit If you read dev null you ll get an end of file EOF character immediately Chapter 4 Debian tutorials 70 dev zero is similar only if you read from it you get th
309. tions etc indices The Maintainers file and the override files project mostly developer only materials such as project experimental This directory contains packages and tools which are still being developed and are still in the alpha testing stage Users shouldn t be using packages from here because they can be dangerous and harmful even for the most experienced project orphaned Packages that have been orphaned by their old maintainers and withdrawn from the distribution 2 1 2 Debian distributions Normally there are three Debian distributions in the dists directory They are named the stable distribution the testing distribution and the unstable distribution Sometimes there is also a frozen distribution Each distribution is defined as a symlink to the actual directory with a codename in the dists directory 2 1 3 The stable distribution Package entries for the stable distribution Debian Sarge 3 110 are recorded into the stable symlink to sarge directory e stable main This directory contains the package versions belonging to the most re cent official release of the Debian system These packages are all free that is they all comply with the Debian Free Software Guidelines http www debian org social_contract guidelines DFSG also available as usr share doc debian social contract txt installed by debian doc e stable non free This directory contains packages that fail to qualify as free ac
310. tories 4 5 6 Named pipes FIFOs A named pipe is a file that acts like a pipe You put something into the file and it comes out the other end Thus it s called a FIFO or First In First Out the first thing you put in the pipe is the first thing to come out the other end If you write to a named pipe the process which is writing to the pipe doesn t terminate until the information being written is read from the pipe If you read from a named pipe the reading process waits until there s something to read before terminating The size of the pipe is always zero it doesn t store data it just links two processes like the shell However since this pipe has a name the two processes don t have to be on the same command line or even be run by the same user You can try it by doing the following Chapter 4 Debian tutorials 69 cd mkfifo mypipe echo hello gt mypipe amp put into background 1 5952 ls l mypipe prw r r 1 penguin penguin 0 2003 11 06 23 18 mypipe cat mypipe hello 1 Done echo hello gt mypipe ls mypipe prw r r 1 penguin penguin 0 2003 11 06 23 20 mypipe rm mypipe 4 5 7 Sockets The socket is similar to the named pipe FIFO and allows processes to exchange information For the socket those processes do not need to be running at the same time nor need to be the children of the same ancestor process This is the endpoint for the inter process communica
311. tribution is reported at these sites e update excuses http ftp master debian org testing update_excuses html testing problems http ftp master debian org testing testing_probs html release critical bugs http bugs debian org release critical base system bugs http bugs ga debian org cgi bin base cgi e bugs in standard and task packages http bugs qa debian org cgi bin standard cgi other bugs and bug squashing party notes http bugs qa debian org 2 1 5 The unstable distribution Package entries for the unstable distribution always codenamed Sid are recorded into the unstable symlink to sid directory after they are uploaded to the Debian archive and stay here until they are moved to test ing New physical packages are located under the pool directory The pool directory on page 9 There are also main contrib and non free subdirectories in unstable which serve the same functions as in stable The unstable distribution contains a snapshot of the most current development system Users are welcome to use and test these packages but are warned about their state of readiness The advantage of using the unstable distribution is that you are always up to date with the latest in the Debian software project but if it breaks you get to keep both parts The current status of unstable distribution bugs is reported on the Unstable Problems http ftp master debian org testing unstable_probs html web
312. twork interface ppp0 ppp1 and so on Chapter 10 Network configuration 182 A PPP interface is managed by the PPP daemon pppd which comes in the ppp package Thus for the user configuring a PPP interface means configuring pppd Configuring pppd manually For a network link to be established a communication port usually a serial port needs to be opened commands have to be sent to a communication device usually a modem a telephone number may have to be dialed identity has to be authenticated to a foreign PPP daemon a PPP interface has to be created and then routing tables have to be modified so that traffic can be sent over the link pppd can do all of this and consequently has a very long list of operating options These options are described in pppa 8 On a Debian system global options are set up in etc ppp options User specific options are set up in ppprc Options that must depend on the communication port used are stored in etc ppp options portname For example suppose you have two modems a built in Lucent LT modem accessed through dev LI modem and an external modem accessed through dev ttyS0 Create the following two options files cat gt etc ppp options LT modem lt lt EOF 115200 init usr sbin chat f etc chatscripts setup LT modem EOF cat gt etc ppp options ttyS0 lt lt EOF 115200 init usr sbin chat f etc chatscripts setup ttyso EOF These refer to the following chat script
313. us Debian menu system 3Some config scripts are disappearing in the newer Sarge releases and the package configuration function ality are moved to the debconf system Chapter 6 Debian package management 89 6 4 5 Remove and purge packages Remove a package while maintaining its configuration aptitude remove package dpkg remove package Remove a package and all configuration aptitude purge package dpkg purge package 6 4 6 Holding older packages For example holding of libc6 and libc dev for dselect and aptitude install package can be done as follows echo e libc 6 hold nlibc6 dev hold dpkg set selections aptitude install package will not be hindered by this hold To hold a package through forcing automatic downgrade for aptitude upgrade package or aptitude dist upgrade add the following to etc apt preferences Package libc6 Pin release a stable Pin Priority 2000 7 Here the Package entry cannot use entries such as libc6 If you need to keep all binary packages related to the glibc source package in a synchronized version you need to list them explicitly The following will list packages on hold dpkg get selections grep e holds 6 4 7 Mixed stable testing unstable system apt show versions can list available package versions by distribution S apt show versions fgrep testing we how many packages you have from testing apt show v
314. use as an example in the following If you are one of the unfortunate whose graphics card is not supported by the new X4 and need to use the old X3 some ATI 64 bit cards configure etc X11 X86Config instead of etc X11 X86Config 4 in the following examples while installing X3 packages The ms3 protocol approach etc gpm conf etc X11 X86Config 4 device dev psaux Section InputDevice responsiveness Identifier Configured Mouse repeat_type ms3 Driver mouse type autops2 Option CorePointer append Option Device dev mouse sample_rate Option Protocol IntelliMouse EndSection If this approach is used the mouse type adjustment is done only by editing gpm conf and X configuration stays constant See my example scripts http www debian org doc manuals debian reference examples The raw protocol approach etc gpm conf etc Xx11 X86Config 4 device dev psaux Section InputDevice responsiveness Identifier Configured Mouse repeat_type raw Driver mouse type autops2 Option CorePointer append Option Device dev mouse sample_rate Option Protocol MouseManPlusPS 2 EndSection If this approach is used the mouse type adjustment is done by editing gpm conf as well as adjusting X configuration Chapter 3 Debian System installation hints 36 How to adjust to different mice The gpm device type autops2 is supposed to autodetect most of the PS 2 mice in the mar
315. using aptitude dist upgrade If this does not work then repeat one of the following until the problem resolves itself aptitude f upgrade continue upgrade even after error sa E aptitude f dist upgrade continue dist upgrade even after error Some really broken upgrade scripts may cause persistent trouble It is usu ally better to resolve this type of situation by inspecting the var lib dpkg info packagename post pre inst rm scripts of the offending package and then running dpkg configure a configures all partially installed packages If a script complains about a missing configuration file look in etc for the corresponding configuration file If one exists with an extension of dpkg new or something similar mv it to remove the suffix Package dependency problems may occur when installing in unstable or testing There are ways to circumvent dependencies aptitude f install package override broken dependencies An alternative method to fix these situations is to use the equivs package See usr share doc equivs README Debian and The equivs package on page 94 6 3 3 Rescue using dpkg If you reach a dead end using APT you can download package files from Debian mirrors and install them using dpkg If you do have not access to the network you can look for cached copies of package files in var cache apt archives dpkg i fetchmail_6 2 5 4_i386 deb If att
316. usr share doc HOWTO e Linux Gazette secondary new issues monthly The Linux Gazette Web http www linuxgazette com Package 1g all or 1g latest two File usr share doc lg e DDP Debian Documentation Project secondary Debian specific manuals Web http www debian org doc e Debian Developers Corner secondary Key information for Debian developers Insightful for end users Web http www debian org devel e Source code absolutely primary No one can argue with this Download source code following The source code on page 10 e Internet Assigned Numbers Authority primary Web http www iana org Package doc lgna File usr share doc doc iana Chapter 15 Support for Debian 248 e Internet requests for c omments IETF standards primary Web http www ietf org rfc html Package doc r Ec File usr share doc RFC The following references are available for Unix in general Please note that there are some minor differences between different Unix systems Device names and init methods need extra attention The UNIX Programming Environment The book to read to learn about how UNIX works By B W Kernighan and R Pike Published by Princeton Hall Software Series e The C Programming Language second edition The book to read to learn about ANSI C By B W Kernighan and D M Ritchie Published by Princeto
317. ux FAQ by lan Jackson http www chiark greenend org uk ijackson e Debian Mailing List Archives http lists debian org e the dpkg programmers manual and the Debian Policy manual see References on page 245 e many developers volunteers and beta testers and e the flaky memories of its authors Some parts of Tutorial section were derived from e Debian Tutorial by Havoc Pennington Oliver Elphick Ole Tetlie James Treacy Craig Sawyer and Ivan E Moore II This document was derived from Linux User s Guide by Larry Greenfield e Debian GNU Linux Guide to Installation and Usage by John Goerzen and Ossama Othman The authors would like to thank all those who helped make this document possible Chapter A Appendix 256 A 2 Warranties Since I am not an expert I do not pretend to be fully knowledgeable about Debian or Linux in general Security considerations I use may only be applicable for home use This document does not replace any authoritative guides All warranties are disclaimed All trademarks are property of their respective trademark own ers A 3 Feedback Comments and additions to this document are always welcome Please send email to the De bian BTS system http bugs debian org under the debian reference package or under the respective translation packages Use of reportbug makes it easy to file a thor ough bug report You may still send email to Osamu Ao
318. v sources list sources list org apt spy d testing l1 sources apt 6 5 Other Debian peculiarities 6 5 1 The dpkg divert command File diversions are a way of forcing dpkg not to install a file into its default location but to a diverted location Diversions can be used through the Debian package scripts to move a file away when it causes a conflict System administrators can also use a diversion to override a package s configuration file or whenever some files which aren t marked as conffiles need to be preserved by dpkg when installing a newer version of a package which contains those files see Preservation of local configuration on page 13 dpkg divert add filename add diversion dpkg divert remove filename remove diversion It s usually a good idea not to use dpkg divert unless it is absolutely necessary Chapter 6 Debian package management 94 6 5 2 The equivs package If you compile a program from source it is best to make it into a real local debianized package deb Use equivs as a last resort Package equivs Priority extra Section admin Description Circumventing Debian package dependencies This is a dummy package which can be used to create Debian packages which only contain dependency information 6 5 3 Alternative commands To make the command vi run vim use update alternatives update alternatives display vi update alternatives config vi Selection Co
319. ve e SCSI rather than IDE for work IDE ATAPI HD for private use e IDE ATAPI CD ROM or CD RW e PCI rather than ISA especially for the network card NIC e Use a cheap NIC Tulip for PCI NE2000 for ISA are good e Avoid PCMCIA notebook as your first Linux install e No USB keyboard mouse unless you want a challenge If you have a slow machine yanking out the hard drive and plugging it into another faster machine for installation is a good idea 3 1 2 Determining a PC s hardware and chip set During installation one will be asked to identify the hardware or chip set of the PC Sometimes that information may not seem easy to find Here is one method 1 Open your PC s case and look inside 2 Record the product ID codes on the large chips on the graphics card network card chip near serial ports chip near IDE ports 3 Record card names printed on the back of the PCI and ISA cards 3 1 3 Determining a PC s hardware via Debian The following commands on a Linux system should give some idea of actual hardware and configuration pager proc pci pager proc interrupts S pager proc ioports pager proc bus usb devices These commands can be run during the install process from the console screen by pressing Alt F2 After the initial installation with the installation of optional packages such as pciutils usbutils and 1shw you can obtain more extensive system information lspci v pager lsusb v pager l
320. w the most basic means of Chapter 8 Debian tips 109 configuration in case you need to recover from system trouble X11 based GUI configuration tools look nice and convenient but are often unsuitable in these emergency situations In this context recording shell activities is a good practice especially as root Emacs Use M x she1 1 to start recording into a buffer and use C x C w to write the buffer to a file Shell Use the screen command with A H as described in Console switching with screen on page 124 or use the script command script Script started file is typescript 5 d Ctrl col o whatever D bx lt typescript gt savefile S vi savefile The following can be used instead of script bash i 2 gt amp 1 tee typescript 8 2 2 Recording X activities If you need to record the graphic image of an X application including an xterm display use gimp GUI It can capture each window or the whole screen Alternatives are xwd xbase clients import imagemagick and scrot scrot 8 3 Copy and archive a whole subdirectory 8 3 1 Basic commands for copying a whole subdirectory If you need to rearrange file structure move content including file links by Standard method cp a source directory dest directory requires GNU cp cd source directory amp amp tar cf cd dest directory amp amp tar xvfp If a hard link is involved a peda
321. when that distribution became the new stable For many architectures that wasn t the case with the result that those directories had to be moved at release time This was impractical because the move would chew up lots of bandwidth The archive administrators worked around this problem for several years by placing binaries for unreleased architectures in a special directory called sid For those architectures not yet released the first time they were released there was a link from the current stable to sid and from then on they were created inside the unstable tree as usual This layout was somewhat confusing to users With the advent of package pools see The pool directory on this page during the Woody distribution development binary packages began to be stored in a canonical location in the pool regardless of the distribution so releasing a distribution no longer causes large band width consumption on the mirrors there is however a lot of gradual bandwidth consumption throughout the development process Chapter 2 Debian fundamentals 10 2 1 12 Uploaded packages in incoming Uploaded packages are first located at http incoming debian org after being checked to insure that they really come from a Debian developer and are put in the DELAYED subdirectory in the case of a Non Maintainer Upload NMU Once a day they are moved out of incoming to unstable In an emergency you may want to install packages from incomi
322. with additional packages based on Depends Suggests and Recommends If you do not want to add any packages just type O to exit dselect again dselect install You will have to answer some package configuration questions during this part of the process so have your notes ready and allow some time for this part See dselect on page 80 Use dselect It always works 5 3 2 Using apt get apt get update apt get t stable upgrade apt get t stable dist upgrade apt get t testing upgrade apt get t testing dist upgrade apt get t unstable upgrade apt get t unstable dist upgrade e e e e Once your system has reached Sarge it is advisable to use aptitude instead of apt get aptitude accepts many of the options that apt get accepts including those above To upgrade and stay with current dselect settings apt get dselect upgrade See Package dependencies on page 15 Chapter 5 Upgrading a distribution to stable testing or unstable 76 77 Chapter 6 Debian package management aptitude is now the preferred text front end for APT the Advanced Package Tool It remem bers which packages you deliberately installed and which packages were pulled in through dependencies the latter packages are automatically de installed by aptitude when they are no longer needed by any deliberately installed packages It has advanced package filtering features but these can be difficult to configure synapti
323. xecute 1 permissions for user e 3rd digit ditto for group e 4th digit ditto for other This sounds complicated but it is actually quite simple If you look at the first few 2 10 columns from 1s 1 command output and read it as a binary radix 2 representation of file permissions being 0 and rwx being 1 this numeric mode value should make sense as an octal radix 8 representation of file permissions to you For example try Ur touch foo bar chmod u rw go r foo Ur chmod 644 bar ls 1 foo bar rw r r 1 penguin penguin 0 Nov 3 23 30 foo rw r r 1 penguin penguin 0 Nov 3 23 30 bar The default file permission mask can be set by using the umask shell built in command See builtins 7 4 5 4 Timestamps There are three types of timestamps for a GNU Linux file e mtime the modification time 1s 1 e ctime the status change time 1s 1c and e atime the last access time 1s 1u Note that ctime is not file creation time e Overwriting a file will change all of mtime ctime and atime of the file e Changing permission or owner of a file will change ctime and atime of the file e Reading a file will change atime of the file Note that even simply reading a file on the Debian system will normally cause a file write operation to update atime information in the inode Mounting a filesystem with the noat ime option will let the system skip this operation and will result in fast
324. ys pgp net gpg keyserver hkp subkeys pgp net send keys A8061F32 Chapter 14 GnuPG 243 14 4 Using GnuPG with applications 14 4 1 Using GnuPG with Mutt Add the following to muttrc to keep a slow GnuPG from automatically starting while allowing it to be used by typing S at the index menu macro index S toggle pgp_verify_sig n set pgp_verify_sig no 14 4 2 Using GnuPG with Vim Add the contents of _vimrc obtained from the examples subdirectory http www debian org doc manuals debian reference examples into vimre to run GnuPG transparently Chapter 14 GnuPG 244 245 Chapter 15 Support for Debian The following resources provide help advice and support for Debian Try your best to use self help resources before crying out loud in the mailing lists Note that you can access a lot of documentation on your system by using a WWW browser via the dwww or dhelp commands found in their respective packages 15 1 References The following references are available for Debian and Linux in general If their contents conflict with each other always rely more on primary information sources than on secondary ones such as this document e Installation Manual primary Read before installation and upgrade Web http www debian org releases stable installmanual Web http www debian org releases testing installmanual work in progress sometimes this may not exist Pack

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