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Debian reference guide (23 Feb 2010)

1. g MODE GNUCP cp GNU c MODE CPIOP cpio p C MODE CPIOI cpio 1 s MODE CPIOSSH cpio ssh S MODE AFIOSSH afio ssh t MODE TARSSH tar ssh r MODE RSYNCSSH rsync ssh 1 OPT alv hardlink GNU cp L OPT av copy GNU cp ay INNIS WirelalW ee AC Al AENOR man CWS RIR x set x trace e EXTP S OPTARG hostname f h HOST S OPTARG user remotehost example com T ODE TEST test find mode echo use x for trace esac done SES CA SOLID il te Sep sete 0 17 laca for x in S do cp SOPT Sx xa TEMI done elif SMODE GNUCP then mschis jo Yo SU ano TOD Y SO arer SORT a Us SOY elif SMODE CPIOP then EC A SE chamo FOO ASE UN SFIND cpio aqui TL spars PART SBU elif SMODE CPIOI then SHIEND colo Ow md se E UN is plo FI elif SMODER aC POS SH REREN SHEND Coon Ove mul sche SEOST LTTE ANEP E UNES po sien it elif SMODE AFIOSSH then SFIND afio ov 0 ssh C HOST mkdircd SEXTP SBU amp amp afio i elif SMODE TARSSH then tar cvf Plss C SEOST tE ANS EPS BUIN eae va Y elif SMODE RSYNCSSH then rsync rlpt S HOST S EXTP BKUP TIME else echo Any other idea to backup SFIND xargs 0 n 1 echo ial This is meant to be command examples Please read script and edit it by yourself before using it Debian Reference 199 265
2. runlevel directory description of runlevel usage N none system bootup NONE level no etc rcN d directory 0 etc rc0 d halt the system S etc rcs d single user mode on boot alias s 1 etc rcl d single user mode switched from multi user mode 2 etc rc2 d multi user mode 3 etc rc3 d da 4 etc rc4 d R 5 etc rc5 d da 6 etc rc6 d reboot the system 7 etc rc7 d valid multi user mode but not normally used 8 etc rc8 d 3 9 etc rco d s Table 3 3 List of runlevels and description of their usage Caution The Debian system does not pre assign any special meaning differences among the runlevels between 2 and 5 The system administrator on the Debian system may change this l e Debian is not Red Hat Linux nor Solaris by Sun Microsystems nor HP UX by Hewlett Packard nor AIX by IBM nor Caution I The Debian system does not populate directories for the runlevels between 7 and 9 when the package is installed Traditional Unix variants don t use these runlevels 3 5 2 The configuration of the runlevel The name of the symlink in each runlevel directory has the form S lt 2 digit number gt lt original name gt or K lt 2 d igit number gt lt original name gt The 2 digit number is used to determine the order in which to run the scripts S is for Start and K is for Kill When init 8 or telinit 8 commands goes i
3. Debian Reference 143 265 7 6 Fonts in the X Window The font configuration on Debian system can be summarized with historical perspective as follows e Each application used to require specific manual operation to configure installed fonts before woody e Debian Font Manager defoma was created to automate this font configuration by providing a Debian specific glue layer in 2000 Each font package publishes application independent font data to defoma Each application package uses these data to configure each installed font via its package script For X server the actual program to configure TrueType fonts and CID fonts as well as CMaps was packaged as x ttcidfont conf e Fontconfig 2 0 was created to provide a distribution independent library for configuring and customizing font access in 2002 As of lenny release almost all programs which access font data seem to use this system After squeeze Debian solely uses Fontconfig 2 0 and drops Debian Font Manager defoma Font supports on X Window System can be summarized as follows Legacy X server side font support system The original core X11 font system provides backward compatibility for older version of X client applications The original core X11 fonts are installed on the X server Modern X client side font support system Modern X system supports all fonts listed below Section 7 6 1 Section 7 6 2 and Section 7 6 3 with adva
4. Note The gzipped t ar 1 archive uses the file extension tgz or tar gz Note The xz compressed t ar 1 archive uses the file extension txz or tar xz Note Popular compression method in FOSS tools such as tar 1 has been moving as follows gzip bzip2 gt xz Debian Reference 192 265 Note cp 1 scp 1 and tar 1 may have some limitation for special files cpio 1 and afio 1 are most versatile Note cpio 1 and afio 1 are designed to be used with find 1 and other commands and suitable for creating backup scripts since the file selection part of the script can be tested independently Note afio 1 compresses each file in the archive This makes afio to be much safer for the file corruption than the globally compressed tar or cpio archives and to be the best archive engine for the backup script Note Internal structure of OpenOffice data files are jar file 10 1 2 Copy and synchronization tools Here is a summary of simple copy and backup tools available on the Debian system package popcon size tool function coreutils i Gpopoont psize1 GNU cp locally copy files and directories a for recursive openssh client ERa G psizel1 scp remotely copy files and directories client x for openssh server Eiai S psize1 sshd remotely copy files and directories remote server rsync a eon psizel1 1 way rem
5. Debian Reference 12 265 group description for accessible files and devices dialout full and direct access to serial ports dev ttyS 0 3 dip limited access to serial ports for Dialup IP connection to trusted peers cdrom CD ROM DVD RW drives audio audio device video video device scanner scanner s adm system monitoring logs staff some directories for junior administrative work usr local home Table 1 7 List of notable system provided groups for file access group accessible commands sudo execute sudo without their password lpadmin execute commands to add modify and remove printers from printer databases plugdev execute pmount 1 for removable devices such as USB memories Table 1 8 List of notable system provided groups for particular command executions Some notable system provided groups allow their members to execute particular commands without root privilege For the full listing of the system provided users and groups see the recent version of the Users and Groups document in usr share doc base passwd users and groups html provided by the base passwd package See passwd 5 group 5 shadow 5 newgrp 1 vipw 8 vigr 8 and pam_group 8 for management commands of the user and group system 1 2 6 Timestamps There are three types of timestamps for a GNU Linux file type meaning mtime the file modification time ls 1 c
6. psizel QEMU full system emulation binaries qemu user popcon1 psizel QEMU user mode emulation binaries qemu utils popcon1 psizel QEMU utilities qemu kvm popcon1 psizel KVM full virtualization on x86 hardware with the hardware as virtualbox ose popcon1 psizel VirtualBox x86 virtualization solution on 1386 and amd64 popcon1 wine psizel Wine Windows API Implementation standard suite dosbox ei C psizel DOSBox x86 emulator with Tandy Herc CGA EGA VGA SV dosemu a psizel DOSEMU The Linux DOS Emulator vzctl E gain psizel OpenVZ server virtualization solution control tools vzquota ida oponie psizel OpenVZ server virtualization solution quota tools Ixe Co popgoni S psizel Linux containers user space tools Table 9 23 List of virtualization tools Debian Reference 187 265 The file tree can be created by mkdir p path to chroot The raw disk image file can be created with dd 1 see Section 10 2 1 and Section 10 2 5 qemu img 1 can be used to create and convert disk image files supported by QEMU The raw and VMDK file format can be used as common format among virtualization tools e Mount the disk image with mount 8 to the filesystem optional For the raw disk imag
7. 6 2 2 The mail configuration strategy for workstation The most simple mail configuration is that the mail is sent to the ISP s smarthost and received from ISP s POP3 server by the MUA see Section 6 4 itself This type of configuration is popular with full featured GUI based MUA such as icedove 1 evolution 1 etc If you need to filter mail by their types you use MUASs filtering function For this case the local MTA see Section 6 3 need to do local delivery only The alternative mail configuration is that the mail is sent via local MTA to the ISP s smarthost and received from ISP s POP3 by the mail retriever see Section 6 5 to the local mailbox If you need to filter mail by their types you use MDA with filter see Section 6 6 to filter mail into separate mailboxes This type of configuration is popular with simple console based MUA such as mutt 1 gnus 1 etc although this is possible with any MUAs see Section 6 4 For this case the local MTA see Section 6 3 need to do both smarthost delivery and local delivery Debian Reference 120 265 6 3 Mail transport agent MTA For normal workstation the popular choice for Mail transport agent MTA is either exim4 x x or post fix packages It is really up to you package popcon size description xim4 daemon 1light ooo S psize1 Exim4 mail transport agent MTA Debian default exim4 base gt ESO psizel Exim4 documen
8. Caution You should basically list only one of stable testing or unstable suites in the deb line If you list any combination of stable testing and unstable suites in the deb line APT programs slow down while only the latest archive is effective Multiple listing makes sense for these when the etc apt preferences file is used with clear objectives see Section 2 7 3 Note For the Debian system with the stable and testing suites it is a good idea to include lines with http security debian org inthe etc apt sources list to enable security updates as in the example above Each Debian archive consists of 3 components Components are alternatively called categories in Debian Policy or areas in Debian Social Contract The component is grouped by the compliance to The Debian Free Software Guidelines DFSG component number of packages criteria of package main main packages DSFG compliant and no dependency to non free contrib contrib packages DSFG compliant but having dependency to non free non free non free packages not DSFG compliant Table 2 3 List of Debian archive components Here the number of packages in the above is for the arch architecture Strictly speaking only the main component archive shall be considered as the Debian system The Debian archive organization can be studied best by pointing your browser to the each archive URL appended with
9. Debian Reference 107 265 e Upon finding the Ethernet cable the interface is brought up e Upon some time after unplugging the Ethernet cable the interface is brought down automatically e Upon plugging in another Ethernet cable the interface is brought up under the new network environment Tip The arguments for the i fp1ugd 8 command can set its behaviors such as the delay for reconfiguring interfaces 5 4 2 The ifmetric package The ifmeric package enables us to manipulate metrics of routes a posteriori even for DHCP The following sets the et hO interface to be preferred over the wlan0 interface 1 Install the ifmet ric package 2 Add an option line with met ric 0 just below the iface eth0 inet dhcp line 3 Add an option line with metric 1 just below the iface wlan0 inet dhcp line The metric 0 means the highest priority route and is the default one The larger metric value means lower priority routes The IP address of the active interface with the lowest metric value becomes the originating one See ifmet ric 8 5 4 3 The virtual interface A single physical Ethernet interface can be configured as multiple virtual interfaces with different IP addresses Usually the purpose is to connect an interface to several IP subnetworks For example IP address based virtual web hosting by a single network interface is one such application For example let s suppose the following e A single Ethernet interface
10. Tip keep this bkup in my usr local bin directory issue this bkup command without any option in the working directory whenever need a temporary snapshot backup Tip For making snapshot history of a source file tree or a configuration file tree it is easier and space efficient to use git 7 see Section 10 9 4 10 1 10 Removable storage device Removable storage devices may be any one of the following e Hard disk e Any format of flash memory devices e Digital camera which are connected via USB IEEE 1394 Firewire PC Card etc These removable storage devices can be automatically mounted as a user under modern desktop environment such as GNOME using gnome mount 1 Mount point under GNOME is chosen as media lt disk_label gt which can be customized by the following mlabel 1 for FAT filesystem genisoimage 1 with V option for ISO9660 filesystem tune2fs 1 with L option for ext2 ext3 filesystem The choice of encoding may need to be provided as mount option see Section 8 3 6 The ownership of the mounted filesystem may need to be adjusted for use by the normal user Note Automounting under modern desktop environment happens only when those removable media devices are not listed in et c fstab Tip When providing wrong mount option causes problem erase its corresponding setting under system storage via gc onf editor 1 When sharing data with other sys
11. platform EOL code control decimal hexadecimal Debian unix LF J 10 UA MSDOS and Windows CR LF M J 13 10 OD 0A Apple s Macintosh CR M 13 UD Table 11 3 List of EOL styles for different platforms The EOL format conversion programs fromdos 1 todos 1 frommac 1 and tomac 1 are quite handy recode 1 is also useful Note Some data on the Debian system such as the wiki page data for the python moinmoin package use MSDOS style CR LF as the EOL code So the above rule is just a general rule Note Most editors eg vim emacs gedit can handle files in MSDOS style EOL transparently Tip The use of sed e Xr s Xr instead of todos 1 is better when you want to unify the EOL style to the MSDOS style from the mixed MSDOS and Unix style e g after merging 2 MSDOS style files with dif 3 1 This is because todos adds CR to all lines Debian Reference 233 265 11 1 5 TAB conversion There are few popular specialized programs to convert the tab codes function bsdmainutils coreutils expand tab to spaces col x expand unexpand tab from spaces col p unexpand Table 11 4 List of TAB conversion commands from bsdmainutils and coreutils packages indent 1 from the indent package completely reformats whitespaces in the C program Editor programs such as vim and emacs can be used for TAB conversion too For example with vim you can expand T
12. popcon1 psize1 debug memory allocation library mpatrolc2 popcon1 psize1 library for debugging memory allocations Table 12 13 List of memory leak detection tools 12 4 7 Memory leak detection tools There are several memory leak detection tools available in Debian 12 4 8 Static code analysis tools There are lint like tools for static code analysis package popcon size description splint a Gpopconne psize1 tool for statically checking C programs for bugs rats a Gpogeani s psize1 rough Auditing Tool for Security C C PHP Perl and Python c popcon1 p y flawfinder psizel1 tool to examine C C source code and looks for security weakne perl Pii apent psize1 interpreter with internal static code checker B Lint 3perl pylint ER S psize1 Python code static checker jlint E psize1 Java program checker weblint perl E EEN qe psize1 syntax and minimal style checker for HTML linklint apean psize1 fast link checker and web site maintenance tool libxml2 utils A psize1 utilities with xm11int 1 to validate XML files Table 12 14 List of tools for static code analysis 12 4 9 Disassemble binary You can disassemble binary code with ob jdump 1 by the following Debian Reference 260 265 S objdump m i386 b binary D usr lib grub
13. rx rx match zero or more regular expressions identified by r r r match one or more regular expressions identified by r r r match zero or one regular expressions identified by r 5 r1 r2 match one of the regular expressions identified by r1 or r2 Ni r2 11 12 match one of the regular expressions identified by r1 or r2 a Table 1 24 Metacharacters for BRE and ERE The regular expression of emacs is basically BRE but has been extended to treat and as the metacharacters as in ERE Thus there are no needs to escape them with in the regular expression of emacs grep 1 can be used to perform the text search using the regular expression For example try the following Debian Reference 32 265 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 Tip See Section 9 2 7 1 6 3 Replacement expressions For the replacement expression some characters have special meanings replacement expression description of the text to replace the replacement expression amp what the regular expression matched use amp in emacs n what the n th bracketed regular expression matched n being number Table 1 25 The replacement expression For Perl replacement string n is used instead of An a
14. basic utilities from 4 4BSD Lite moreutils ae S psizel additional Unix utilities Table 12 8 List of packages containing small utility programs for shell scripts Tip Although moreutils may not exist ouside of Debian it offers interesting small programs Most notable one is sponge 8 See Section 1 6 4 12 1 7 Shell script dialog The user interface of a simple shell program can be improved from dull interaction by echo and read commands to more interactive one by using one of the so called dialog program etc Debian Refere nce 254 265 package popcon size description x11 utils Ai psizel xmessage 1 display a message or query in a window X whiptail a G psizel displays user friendly dialog boxes from shell scripts newt dialog o SO psizel displays user friendly dialog boxes from shell scripts ncurses zenity G SEO psizel display graphical dialog boxes from shell scripts gtk2 0 popcon d S ssft psizel Shell Scripts Frontend Tool wrapper for zenity kdialog and dialog wit gettext ONE psizel usr bin gettext sh translate message Table 12 9 List of user interface programs 12 1 8 Shell script example with zenity Here is a simple script which creates ISO image with RSO2 data supplemented by dvdisaster 1 bin sh e gmkrs02 set x error_exit sel USA exit 1 Initialize Copyri
15. caching proxy server for Debian archive files compiled OCaml pr popcon1 S S lt apt proxy psize1 Debian archive proxy and partial mirror builder Python program apt cacher Sian E psize1 Caching proxy for Debian package and source files Perl program apt cacher ng Opopconl1 psize1 Caching proxy for distribution of software packages compiled C debtorrent popcon psize1 Bittorrent proxy for downloading Debian packages Python progre Table 2 19 List of the proxy tools specially for Debian archive Debian Reference 72 265 Caution When Debian reorganizes its archive structure these specialized proxy tools tend to require code rewrites by the package maintainer and may not be functional for a while On the other hand generic web http proxy servers are more robust and easier to cope with such changes 2 7 12 Small public package archive Here is an example for creating a small public package archive compatible with the modern secure APT system see Sec tion 2 5 2 Let s assume few things e Account name foo e Host name www example com e Required packages apt utils gnupg and other packages e URL http www example com foo home foo public_html index html e Architecture of packages amd64 Create an APT archive key of Foo on your server system as the following ssh foo www e
16. modprobe nbd max_part 16 qemu nbd v c dev nbd0 disk img mkdir mnt partl mount dev nbd0p1 mnt partl Tip You may export only the first partition of disk img using P 1 option to qemu nbd 8 9 8 4 Chroot system chroot 8 offers most basic way to run different instances of the GNU Linux environment on a single system simultaneously without rebooting e Caution Examples below assumes both parent system and chroot system share the same CPU architecture Debian Reference 188 265 You can learn how to setup and use chroot 8 by running pbuilder 8 program under script 1 as follows S sudo mkdir sid root sudo pbuilder creat no targz debug buildplace sid root You see how deboot st rap 8 or cdeboot st rap 1 populate system data for sid environment under sid root Tip These debootstrap 8 or cdeboot st rap 1 are used to install Debian by the Debian Installer These can also be used to install Debian to a system without using a Debian install disk but instead from another GNU Linux distribution sudo pbuilder login no targz debug buildplace sid root You see how a system shell running under sid environment is created as the following 1 Copy local configuration etc hosts etc hostname etc resolv conf 2 Mount proc filesystem a Mount dev pts filesystem 4 Create usr sbin policy rc d which always exits with 101 5
17. Debian Reference 189 265 wget http cdimage debian org debian cd 5 0 3 amd64 iso cd debian 503 amd64 netinst iso qemu img creat E qcow2 virtdisk qcow2 5G gemu haa virtdisk qcow2 carom debian 503 amd64 netinst iso boot d m 256 See more tips at Debian wiki QEMU VirtualBox comes with Qt GUI tools and quite intuitive Its GUI and command line tools are explained in VirtualBox User Manual and VirtualBox User Manual PDF Tip Running other GNU Linux distributions such as Ubuntu and Fedra under virtualization is a great way to learn configuration tips Other proprietary OSs may be run nicely under this GNU Linux virtualization too Debian Reference 190 265 Chapter 10 Data management Tools and tips for managing binary and text data on the Debian system are described Warning l The uncoordinated write access to actively accessed devices and files from multiple processes must not be done to avoid the race condition File locking mechanisms using lock 1 may be used to avoid it 10 1 Sharing copying and archiving The security of the data and its controlled sharing have several aspects The creation of data archive The remote storage access The duplication The tracking of the modification history The facilitation of data sharing The prevention of unauthorized file access The detection of unauthorized file modification These can be realized by using some combinat
18. Gsecurity log analyzer in aptitude 8 Note CRM114 provides language infrastructure to write fuzzy filters with the TRE regex library Its popular use is spam mail filter but it can be used as log analyzer Debian Reference 158 265 package popcon size description logwat ch a aae psize1 log analyzer with nice output written in Perl fail2ban or apoE psize1 ban IPs that cause multiple authentication errors analog EN es psize1 web server log analyzer awstats A conker psize1 powerful and featureful web server log analyzer sarg oF Oey psize1 squid analysis report generator pflogsumm CSE popeoni psize1 Postfix log entry summarizer syslog summary popcon1 psize1 summarize the contents of a syslog log file popcon1 lire psize1 full featured log analyzer and report generator fwlogwatch ene psize1 firewall log analyzer squidview oo GR psize1 monitor and analyze squid access log files visitors G psize1 fast web server log analyzer swatch SE G psize1 log file viewer with regexp matching highlighting and hooks Vpopconl crm114 psize1 Controllable Regex Mutilator and Spam Filter CRM114 icmpinfo a o psize1 interpret ICMP messages Table 9 3 List of system log analyzers Debian Reference 159 265
19. Special file that points to another file by name ln s foo bar See the following example for changes in link counts and the subtle differences in the result of the rm command S eche Original Content foo Ile li OO ZIV 1015 ie 1 penguin penguin 17 Sa o0 Deuz hard link ln s foo baz symlink Is i ioe bar eiz 20 9802 iy ie 1E 2 penguin penguin 17 2398538 lrwxrwxrwx 1 penguin penguin 3 DINSA IEEE 1E 2 penguin penguin 17 rm foo echo New Content gt foo S de 11 wee loe Dez S 129 212 UL penguim pencu Ly 2398538 lrwxrwxrwx 1 penguin penguin 3 DAS eye 12 1 penguin penguin 12 cat bar Original Content cat baz New Content 2007 04 29 200704 29 2007 04 29 2007 04 29 2007 04 29 Z0 07 04 29 2007 04 29 08 08 08 08 08 08 DIS 15 US 16 15 15 16 17 foo bar baz foo bar baz foo gt FOO gt COO The hardlink can be made within the same filesystem and shares the same inode number which the i option with 1s 1 reveals The symlink always has nominal file access permissions of rwxrwxrwx as shown in the above example with the effective access permissions dictated by permissions of the file that it points to Debian Reference 14 265 Caution It is generally good idea not to create complicated symbolic links or hardlinks at all unless you have a very good reason It may cause nightmares where the logica
20. You may be able to use following special URL strings for some browsers to confirm their settings e about e about config Debian Reference 118 265 e about plugins Debian offers many free browser plugin packages in the main component which can handle not only Java software platform and Flash but also MPEG MPEG2 MPEG4 DivX Windows Media Video wmv QuickTime mov MP3 mp3 Ogg Vorbis files DVDs VCDs etc Debian also offers helper programs to install non free browser plugin packages as contrib or non free components package popcon size component description icedtea gcjwebplugin a psizel main Java plugin using Hotspot JIT sun Java6 plugin ice S psizel non free Java plugin for Sun s Java SE 6 1386 swfdec mozilla in es psizel main Flash plugin based on libswfdec mozilla plugin gnash o e psizel main Flash plugin based on Gnash flashplugin nonfree in S psizel contrib Flash plugin helper to install Adobe F mozilla plugin vlc e E psizel main Multimedia plugin based on VLC me totem mozilla oo S psizel main Multimedia plugin based on GNOME gecko mediaplayer oe qe psizel main Multimedia plugin based on GNOMI nspluginwrapper oo S psizel contrib A wrapper to run 1386 Netscape plugi Table 6 2 List of browser plugin packages Tip We Although use of above Debian packages are much easier browser plu
21. allow hotplug eth0 iface eth0 inet manual pre up sbin ifconfig eth0 up up ifup ppp0 ds1 down ifdown ppp0 dsl post down sbin ifconfig eth0 down The following is used internally only iface dsl inet ppp provider dsl provider 5 3 12 The network configuration state of ifupdown The etc network run ifstate file stores the intended network configuration states for all the currently active net work interfaces managed by the i fupdown package are listed Unfortunately even if the i fupdown system fails to bring up the interface as intended the etc network run ifstate file lists it active Unless the output of the i f config 8 command for an interface does not have a line like following example it can not be used as a part of IPV4 network imet actes Iez GSA cases loz Les til 255 Measlee255 255545540 Note For the Ethernet device connected to the PPPoE the output of the i fconfig 8 command lacks a line which looks like above example 5 3 13 The basic network reconfiguration When you try to reconfigure the interface e g lt t hO you must disable it first with the sudo ifdown eth0 command This removes the entry of et h0 from the etc network run ifstate file This may result in some error message if et ho is not active or it is configured improperly previously So far it seems to be safe to do this for the simple single user work station at any time You are now free to rewrite the etc network int
22. e VEZ XM data soe goes dl A L A A E EET e ee ade de d 11 2 1 11 2 2 11 2 3 Basic hints for XML sange RR ence ap Gad De be Ril Sieh Beech ee ee oe ge ee ee Be aha dw E 9 XML processin 1446004446544 A eb aw ee we eee de eS The XML data extraction 11 3 Printable data voice ee Be als Gee Soe ew Ee ees SRE Sew ER a le E 11 3 1 11 3 2 11 3 3 11 3 4 Ghostscript 455 i254424 e885 4G5 4p Soe Gee Ree ee eK SEE RE Ee a E a Merge tw PSor PDF files iones hehe ee PbS ERD SHEE eee SAS GS Printable data utilities cocer 45 4 fea SEX Bee ew ee eA ee ee Y Be eee 3 Printing with CUPS cupra ri a RE Re ERASE A po de A Samara eee 11 4 Typesetting a a e see AERO E ER A eee EH h 11 4 1 11 4 2 11 4 3 11 4 4 roff typesetting osos ER RR RE OS ee a ee ee a TEXTO 08 de Bate eras Se A BE a ee eee MDS Se sa A Pretty print amanual page p eers ee eR Re a eR de ee we Creating a manual page so cepo RR RRR ee 11 5 The mail data Conversion o acs ec N L a Ree R A R A R E A ee R a ar i ew A a 11 5 1 Mail data basics ee 11 0 Graphic data Le 5 22 we eee ed eee SER bee ee ew sd ea id Adan e ees 3 11 7 Miscellaneous data conversion 2 ee 12 Programming 12 1 The shell script saris 2 222424854 e EMSS PRES e e E SER eee PHS ES 12 1 1 12 1 2 12 1 3 12 1 4 12 1 5 12 1 6 12 1 7 12 1 8 POSIX shell compatibility 200 00 a Shelliparameters asia 2b ke aS ERR eee RAG BRE A Ae A eee
23. popcon psizel base package for ALSA and OSS sound systems alsa base popcon psizel ALSA driver configuration files alsa utils popcon1 psizel utilities for configuring and using ALSA oss compat popcon psizel OSS compatibility under ALSA preventing dev dsp r esound common popcon psizel Enlightened Sound Daemon ESD common Enlightenmer esound popcon psizel Enlightened Sound Daemon ESD server Enlightenment lt esound clients popcon1 psizel Enlightened Sound Daemon ESD client Enlightenment a popconl libesd0 o psizel1 Enlightened Sound Daemon ESD library Enlightenment arts eo psizel aRts server KDE libartslc2a a cane psizel aRts library KDE libartscO E psize1 aRts library KDE popcon1 A i jackd psizel JACK Audio Connection Kit JACK server low latency libjack0 ee ae psize1 JACK Audio Connection Kit JACK library low latency nas RG S psizel Network Audio System NAS server libaudio2 EA E psizel Network Audio System NAS library pulseaudio en S psizel1 PulseAudio server replacement for ESD libpulse0 open psize1 PulseAudio client library replacement for ESD libgstreamer0 10 0 pop
24. psize2 import the data out of Sul git svn 1 git svn E a psize2 provide bidirectional ope git cvsimport l git cvs a PER psize2 import the data out of CV git cvsexportcommit l git cvs a psize2 export a commit to a CV git cvsserver l git cvs core psize2 CVS server emulator for git send email 1 git email popcon2 psize2 send a collection of patch stg 1 stgit popcon2 psize2 quilt on top of git Pythot git buildpackage l git buildpackage popcon2 psize2 automate the Debian pacl guilt 7 guilt popcon2 psize2 quilt on top of git SH A Table 10 20 List of git related packages and commands Tip With git 1 you work on a local branch with many commits and use something like git rebase i master to reorga nize change history later This enables you to make clean change history See git rebase 1 and git cherry pick 1 10 9 4 Git for recording configuration history You can manually record chronological history of configuration using Git tools Here is a simple example for your practice to record etc apt contents cd etc apt sucio eje iaie sudo chmod 700 git sudo git add sudo gue Commute a OF UY UY UY UY Commit configuration with description Debian Reference 229 265 Make modification to the configuration files
25. the output of commana command the output of command Debian Reference e The shell expands pathname glob to matching file names if not within x any characters one character any one of the characters in e The shell looks up command from the following and execute it function definition builtin command executable file in SPATH 253 265 OR e e The shell goes to the next line and repeats this process again from the top of this sequence 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 1s quite handy for debugging 12 1 6 Utility programs for shell script In order to make your shell program as portable as possible across Debian system it is good idea to limit utility programs to ones provided by essential packages e aptitude search E lists essential packages e dpkg L lt package_name gt grep man man lists manpages for commands offered by lt package_nam e gt package package popcon size description popcon1 a coreutils o psizel1 GNU core utilities debianutils SR an a psize1 miscellaneous utilities specific to Debian bsdmainutils ae a psize1 collection of more utilities from FreeBSD bsdutils A psize1
26. 265 8 3 6 Filename encoding For cross platform data exchanges see Section 10 1 10 you may need to mount some filesystem with particular encodings For example mount 8 for vfat filesystem assumes CP437 if used without option You need to provide explicit mount option to use UTF 8 or CP932 for filenames Note When auto mounting a hot pluggable USB memory stick under modern desktop environment such as GNOME you may provide such mount option by right clicking the icon on the desktop click Drive tab click to expand Setting and entering utf8 to Mount options The next time this memory stick is mounted mount with UTF 8 is enabled Note If you are upgrading system or moving disk drives from older non UTF 8 system file names with non ASCII characters may be encoded in the historic and deprecated encodings such as SO 8859 1 or eucJP Please seek help of text conversion tools to convert them to UTF 8 See Section 11 1 Samba uses Unicode for newer clients Windows NT 200x XP but uses CP850 for older clients DOS and Windows 9x Me as default This default for older clients can be changed using dos charset in the etc samba smb conf file e g to CP932 for Japanese 8 3 7 Localized messages and translated documentation Translations exist for many of the text messages and documents that are displayed in the Debian system such as error messages standard program output menus and manual pages GNU gettext 1
27. Debian Reference 226 265 S svn cp file srv svn project modulel tags Release initial file srv svn project modulel branches Release initial bugfixes cd path to svn co file srv svn project modulel branches Release initial bugfixes old Sued ole Ur Tip Use modulel trunk 2005 12 20 ISO 8601 date format instead of module1 tags Release initial to specify particular date as the branch point Work on this local source tree pointing to branch Release initial bugfixes which is based on the original version Work on this branch by yourself until someone else joins to this Re lease initial bugfixes branch Sync with files modified by others on this branch by the following S svin Wa Edit files to fix conflicts as needed Check in changes to Subversion by the following S svn ci m checked into this branch Update the local tree with HEAD of trunk by the following svn switch file srv svn project modulel trunk Update the local tree content HEAD of trunk by merging from the Release initial bugfixes branch by the following svn merge file srv svn project modulel branches Release initial bugfixes Fix conflicts with editor Check in changes to Subversion by the following svn ci m merged Release initial bugfixes Make archive by the following Sed mv old old modulel bugfixes tar cvzf old modulel bugfixes tar gz old modulel bugfixes r
28. gs cjk resource popcon psizel resource files for gs cjk Ghostscript CJ K TrueType extensio cmap adobe cnsl popcon psizel CMaps for Adobe CNS1 for traditional Chinese support cmap adobe gbl popcon psizel CMaps for Adobe GB 1 for simplified Chinese support cmap adobe japanl popcon psizel CMaps for Adobe Japanl for Japanese standard support cmap adobe Japan2 popcon psizel CMaps for Adobe Japan2 for Japanese extra support cmap adobe koreal popcon psizel CMaps for Adobe Koreal for Korean support libpoppler5 popcon psizel PDF rendering library based on xpdf PDF viewer libpoppler glib4 popcon psizel PDF rendering library GLib based shared library poppler data popcon psizel CMaps for PDF rendering library for CJK support Adobe Table 11 12 List of Ghostscript PostScript interpreters Tip gs h can display the configuration of Ghostscript 11 3 2 Merge two PS or PDF files You can merge two PostScript PS or Portable Document Format PDF files using gs 1 of Ghostscript gs q dNOPAUSE gs q dNOPAUSE dBATCH sDEVICE pswrite sOutputFile bla ps f fool ps foo2 ps dBATCH sDEVICE pdfwrite sOutputFile bl
29. 9 2 3 Recording the shell activities cleanly The simple use of script 1 see Section 1 4 9 to record shell activity produces a file with control characters This can be avoided by using co1 1 as the following S Solo Script started file is typescript Do whatever and press Ctr1 D to exit script S col bx lt typescript gt cleanedfile vim cleanedfile If you don t have script for example during the boot process in the initramfs you can use following instead S sh i 2 gt amp 1 tee typescript Tip Some x terminal emulator such as gnome terminal can record You may wish to extend line buffer for scrollback Tip You may use screen 1 with A H see Section 9 1 2 to perform recording of console Tip You may use emacs 1 with M x shell M x eshell or M x term to perform recording of console You may later use C x C w to write the buffer to a file 9 2 4 Customized display of text data Although pager tools such as more 1 and less 1 see Section 1 4 5 and custom tools for highlighting and formatting see Section 11 1 8 can display text data nicely general purpose editors see Section 1 4 6 are most versatile and customizable Tip For vim 1 and its pager mode alias view 1 set hls enables highlighted search 9 2 5 Customized display of time and date The default display format of time and date by the 1s 1 command depends on the locale see Section 1 2 6 for value Th
30. 9 3 5 Optimization of filesystem by mount options 2 000000 0020 164 9 3 6 Optimization of filesystem via superblock o ee 165 9 3 7 Optimization Of hard disk 2 2 aae RRR i k E e a ee 165 9 3 8 Using SMART to predict hard disk failure ee 166 9 3 9 Expansion of usable storage space via LVM 2 2 2 ee 166 9 3 10 Expansion of usable storage space by mounting another partition 000 166 9 3 11 Expansion of usable storage space using symlink o o 0 0000000004 167 9 3 12 Expansion of usable storage space using aufs e 167 94 Data encryption tips lt s se raresa mea eee O ee ew Oe EE a 167 9 4 1 Removable disk encryption with dm crypt LUKS 2 0 000000000 168 9 4 2 Encrypted swap partition with dm crypt 2 2 2 ee ee 169 9 4 3 Automatically encrypting files witheCryptfs o o e 169 9 4 4 Automatically mounting eCryptfs 0 000 0002 0000022 ee 169 Debian Reference xiii 9 5 Monitoring controlling and starting program activities e 170 9 5 1 Timing ai process sa sir a e a A a a A e 170 9 5 2 The scheduling priority lt ee s e e e e ee 170 953 The ps command ear e E A A A eds 170 954 Thetop command 4 240464 e Get dpe oe Ged eee G Se As be 172 9 5 5 Listing files opened by a process ee 172 9 5 6 Tracing program activities ooo 172 9 5 7 Identification of
31. Additional user accounts can be created with adduser 8 by root The system starts with the greeting message stored in etc mota Message Of The Day and presents a command prompt Debian Reference 2 265 Debian GNU Linux lenny sid foo ttyl foo login penguin Password Sisa locas Sun or 22 0929834 2007 om civil Linux snoopy 2 6 20 1 amd64 1 SMP Sun Apr 15 20 25 49 UTC 2007 x86_64 The programs included with the Debian GNU Linux system are free software 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 foo Here the main part of the greeting message can be customized by editing the etc motd tail file The first line is generated from the system information using uname snrvm Now you are in the shell The shell interprets your commands 1 1 2 The shell prompt under X If you installed X Window System with a display manager such as GNOME s gdm by selecting Desktop environment task during the installation you are presented with the graphical login screen upon starting your system You type your username and your password to login to the non privileged user account Use tab to navigate between username and password or use the mouse and primary click You can gain the shell prompt under X by starting a x terminal emulator program such as gnom
32. Contents Compress gzip bzip2 BinDirectory dists unstable main binary amd64 Packages dists unstable main binary amd64 Packages Contents dists unstable Contents amd64 SrcPackages dists unstable main source Sources e Tree dists unstable Sections main Architectures amd64 source y OF You can automate repetitive updates of APT archive contents on your server system by configuring dupload 73 265 Place all package files into foo public_html debian pool main by executing dupload t foo change s_file in client while having dupload conf containing the following Scfgl too fqdn gt www example com method gt scpb incoming gt home foo public_html debian pool main The dinstall on ftp master sends emails itself dinstall_runs gt 1 L Scfg foo postupload changes n Scno sel jalo lie Tara T y apt ftparchive generat c aptftp conf aptgenerate conf apt ftparchive release c aptftp conf dists unstable gt dists unstable Release rm f dists unstable Release gpg gpg u 3A3CB5A6 bao dists unstable Release gpg dists unstable Release ssh foo www example com 2 gt dev null echo Package archive created The postupload hook script initiated by dupload 1 creates updated archive files for each upload You can add this small public archive to the apt line of your client system by the following sudo bash ech
33. IP PPPoE 1492 1500 8 2 bytes for PP Ethernet link ISP s backbone ATM IP DHCP or fixed 1462 48 31 18 8 author s spect Ethernet link ISP s backbone ATM IP PPPoE 1454 48 31 8 18 8 see Optimal Table 5 18 Basic guide lines of the optimal MTU value In addtion to these basic guide lines you should know the following e Any use of tunneling methods VPN etc may reduce optimal MTU further by their overheads e The MTU value should not exceed the experimentally determined PMTU value e The bigger MTU value is generally better when other limitations are met 5 7 2 Setting MTU Here are examples for setting the MTU value from its default 1500 to 1454 For the DHCP see Section 5 3 4 you can replace pertinent iface stanza lines in the etc network interfaces with the following iface eth0 inet dhcp hostname mymachine pre up sbin ifconfig SIFACE mtu 1454 For the static IP see Section 5 3 5 you can replace pertinent i face stanza lines in the etc network interfaces with the following iface eth0 inet static acdare ss OA Sry LL L00 metemeasis 255 255 255 0 loncoarcloeisic 192 108 11 205 gateway 192 168 11 1 mtu 1454 dns domain lan dns nameservers 192 168 11 1 Debian Reference 116 265 For the direct PPPoE see Section 5 2 5 you can replace pertinent mtu line in the etc ppp peers dsl provider with the following mtu 1454 The maximum segment size MSS is used as an
34. In the interactive full screen mode of apt it ude 8 packages in the package list are displayed as the next example idA libsmbclient AAAs Sas 25e i S340 52962 Here this line means from the left as the following Debian Reference 47 265 key key binding F10 or Ctrl t menu display help for keystroke more complete listing F10 Help User s Manual display User s Manual u update package archive information mark the package for the upgrade or the install mark the package for the remove keep configuration files mark the package for the purge remove configuration files place the package on hold mark all upgradable packages function as full upgrade start downloading and installing selected packages quit current screen and save changes quit current screen and discard changes Enter view information about a package view a package s changelog change the limit for the displayed packages search for the first match repeat the last search AxN H al mlx hala al Table 2 8 List of key bindings for aptitude s The current state flag the first letter s The planned action flag the second letter e The automatic flag the third letter s The Package name e The change in disk space usage attributed to planned action s The current version of the package e The candidate version of the package Tip The full list of flags are gi
35. ME E a a aa a a A Na Debian Reference 5 1 6 The network device support 98 265 Although most hardware devices are supported by the Debian system there are some network devices which require DSFG non free external hardware drivers to support them Please see Section 9 7 8 5 2 The network connection method Caution l The connection test method described in this section are meant for testing purposes It is not meant to be used directly for the daily network connection You are advised to use them via the i fupdown package see Section 5 3 The typical network connection method and connection path for a PC can be summarized as the following PC connection method connection path Serial port opp0 PPP lt modem POTS dial up access point ISP Ethernet port et h0 PPPoE DHCP Static lt gt BB modem lt gt BB service BB access point ISP Ethernet port et h0 DHCP Static lt gt LAN 2 BB router with network address translation NAT lt BB n Table 5 3 List of network connection methods and connection paths Here is the summary of configuration script for each connection method connection method configuration backend package s PPP pppconf ig to create deterministic chat pppconfig ppp PPP alternative wvdialconf to create heuristic chat ppp wvdial PPPoE pppoeconf to create deterministic chat pppoeconf p
36. Microsoft Windows style encoding CP1252 code page 1252 Microsoft Windows style ISO 885 KOI8 R old Russian UNIX standard for the Cyrillic alphabet ISO 2022 JP standard encoding for Japanese e mail which uses 0 eucJP old Japanese UNIX standard 8 bit code and complet Shift JIS JIS X 0208 Appendix 1 standard for Japanese see Table 11 2 List of encoding values and their usage Note Some encodings are only supported for the data conversion and are not used as locale values Section 8 3 1 For character sets which fit in single byte such as ASCII and ISO 8859 character sets the character encoding means almost the same thing as the character set For character sets with many characters such as JIS X 0213 for Japanese or Universal Character Set UCS Unicode ISO 10646 1 for practically all languages there are many encoding schemes to fit them into the sequence of the byte data s EUC and ISO IEC 2022 also known as JIS X 0202 for Japanese s UTF 8 UTF 16 UCS 2 and UTF 32 UCS 4 for Unicode For these there are clear differentiations between the character set and the character encoding The code page is used as the synonym to the character encoding tables for some vendor specific ones Note Please note most encoding systems share the same code with ASCII for the 7 bit characters But there are some exceptions If you are converting old Japanese C programs and URLs data from the casually called shift JIS encoding format to UTF 8 f
37. SMTI rfc2822 rfc822 Mail rfc2045 Multi rfc819 DNS rfc2616 HTTH rfc2396 URI d Table 6 20 List of popular RFCs Debian Reference 137 265 Chapter 7 The X Window System The X Window System on the Debian system is based on the source from X Org As of July 2009 they are X11R7 1 etch X11R7 3 lenny X11R7 3 squeeze and X11R7 4 sid 7 1 Key packages There are a few meta packages provided to ease installation For the basics of X refer to X 7 the LDP XWindow User HOWTO 7 2 Setting up desktop environment A desktop environment is usually a combination of a X window manager a file manager and a suite of compatible utility programs You can setup a full desktop environment such as GNOME KDE Xfce or LXDE from the apt itude under the task menu Tip Task menu may be out of sync with the latest package transition state under Debian unstable testing environment In such situation you need to deselect some meta packages listed under apt itude 8 task menu to avoid package conflicts When deselecting meta packages you must select certain packages providing their dependencies manually to avoid them deleted automatically You may alternatively setup a simple environment manually just with a X window manager such as Fluxbox See Window Managers for X for the guide to the X window manager and the desktop environment 7 2 1 Debian menu Debian menu system provides a general interface for both text and
38. Table 12 7 List of string comparison operators in the conditional expression e until condition do command done repeats command while condition is not true e break enables to exit from the loop e continue enables to resume the next iteration of the loop Tip The C language like numeric iteration can be realized by using seq 1 as the foo1 foo2 generator Tip See Section 9 5 9 12 1 5 The shell command line processing sequence The shell processes a script roughly as the following sequence e The shell reads a line e The shell groups a part of the line as one token if itis within or e The shell splits other part of a line into tokens by the following Whitespaces lt space gt lt tab gt lt newline gt Metacharacters lt gt amp e The shell checks the reserved word and for each token to adjust its behavior if not within ea TOET T reserved word if then elif else fi for in while unless do done case esac s The shell expands alias if not within or s The shell expands tilde if not within or won current user s home directory lt user gt lt user gt s home directory e The shell expands parameter to its value if not within parameter SPARAMETER or PARAMETER s The shell expands command substitution if not within S command
39. Tip Please use the screen 1 program to enable remote shell process to survive the interrupted connection see Section 9 1 6 9 1 Basics of SSH l Warning etc ssh sshd_not_to_be_run must not be present if one wishes to run the OpenSSH server SSH has two authentication protocols Debian Reference 131 265 SSH protocol SSH method description SSH 1 RSAAuthentication RSA identity key based user authentication ae RhostsAuthentication xchosts based host authentication insecure disabled 5 RhostsRSAAuthentication rhosts based host authentication combined with RSA h K ChallengeResponseAuthentication RSA challenge response authentication sa PasswordAuthentication password based authentication SSH 2 PubkeyAuthentication public key based user authentication 7 YR R A nee eee rhosts or etc hosts equiv based host auth authentication disabled 25 ChallengeResponseAuthentication challenge response authentication nc PasswordAuthentication password based authentication Table 6 14 List of SSH authentication protocols and methods e Caution Be careful about these differences if you are using a non Debian system See usr share doc ssh README Debian gz ssh 1 sshd 8 ssh agent 1 and ssh keygen 1 for de tails Following are the key configuration files configuration file des
40. You simply formatting it as the following ls 1 dev mapper total 0 erw rw 1 Foot root 10 bru bw l root Chek 2 547 mkfs vfat dev mapper sdx1 shred v n 1 dev sdx fdisk dev sdx h Wow ELOY ca Meta cryptsetup luksFormat dev sdx1 cryptsetup luksOpen dev sdx1 sdx1 cryptsetup luksClose sdx1 60 2008 10 04 18 44 ORZO00S 1001 RS cons aa badblocks c 10240 s w t random v dev sdx SOmteroll Then it can be mounted just like normal one on to media lt disk_label gt except for asking password see Sec tion 10 1 10 under modern desktop environment such as GNOME using gnome mount 1 The difference is that every data written to it is encrypted You may alternatively format media in different file format e g ext3 with mkfs ext3 de v sdx1 Note If you are really paranoid for the security of data you may need to overwrite multiple times in the above example This operation is very time consuming though Debian Reference 169 265 9 4 2 Encrypted swap partition with dm crypt Let s assume that your original etc fstab contains the following dev sda7 swap sw 0 0 You can enable encrypted swap partition using dm crypt by as the following aptitude install cryptsetup swapoff a echo cswap dev sda7 dev urandom swap gt gt etc crypttab perl i p e s dev sda7 dev mapper cswap etc fstab etc init d cryptdisks restart He de e Se e
41. grep status 1 and grep available 1 commands can be used to search any file which has the general format of a Debian package control file The dpkg S lt file_name_pattern gt can be used search package names which contain files with the matching name installed by dpkg But this overlooks files created by the maintainer scripts If you need to make more elaborate search on the dpkg meta data you need to run grep e regex_pattern command in the var lib dpkg info directory This makes you search words mentioned in package scripts and installation query texts If you wish to look up package dependency recursively you should use apt rdepends 8 Debian Reference 56 265 2 5 Debian package management internals Let s learn how the Debian package management system works internally This should help you to create your own solution to some package problems 2 5 1 Archive meta data Meta data files for each distribution are stored under dist lt codename gt on each Debian mirror sites e g http f tp us debian org debian Its archive structure can be browsed by the web browser There are 6 types of key meta data file location C Release top of distribution a ORERE Si Release gpg top of distribution k L Contents lt architecture gt top of distribution li eii eee al Release top of each distribution component architecture combination a Packages top of each distribution co
42. it The apt pinning is completely optional operation and its use is not something encourage you to use Caution Archive level Release files see Section 2 5 3 are used for the rule of apt_preferences 5 Thus apt pinning works only with suite name for normal Debian archives and security Debian archives This is different from Ubuntu archives For example you can do Pin release a unstable but can not do Pin release a s id inthe etc apt preferences file j Caution When you use non Debian archive as a part of apt pinning you should check what they are intended for and also check their credibility For example Ubuntu and Debian are not meant to be mixed Note Even if you do not create the etc apt preferences file you can do fairly complex system operations see Sec tion 2 6 4 and Section 2 7 2 without apt pinning Debian Reference 66 265 Here is a simplified explanation of apt pinning technique APT system choses highest Pin Priority upgrading package from available package sources defined in the etc apt sour ces list file as the candidate version package If the Pin Priority of the package is larger than 1000 this version restriction for upgrading is dropped to enable downgrading see Section 2 7 7 Pin Priority value of each package is defined by Pin Priority entries in the etc apt preferences file or uses its default value d
43. lt file gt lt file gt exists and is a regular file w lt file gt lt file gt exists and is writable x lt file gt lt file gt exists and is executable lt filel gt nt lt file2 gt lt filel gt is newer than lt file2 gt modification lt filel gt ot lt file2 gt lt filel gt is older than lt file2 gt modification lt filel gt ef lt file2 gt lt filel gt and lt file2 gt are on the same device and the same inode number Table 12 6 List of file comparison operators in the conditional expression Arithmetic integer comparison operators in the conditional expression are eq ne 1t le gt and ge 12 1 4 Shell loops There are several loop idioms to use in POSIX shell e for x in fool foo2 do command done loops by assigning items from the list fool foo2 x to variable x and executing command e while condition do command done repeats command while condition is true Debian Reference 252 265 equation condition to return logical true z lt str gt the length of lt str gt is zero n lt str gt the length of lt str gt is non zero lt strl gt lt str2 gt lt str1 gt and lt str2 gt are equal lt strl gt lt str2 gt lt str1 gt and lt str2 gt are not equal lt strl gt lt lt str2 gt lt str1 gt sorts before lt str2 gt locale dependent lt strl gt gt lt str2 gt lt str1 gt sorts after lt str2 gt locale dependent
44. lt group_name gt browse group information of lt group_name gt passwd manage password for the account passwd e set one time password for the account activation chage manage password aging information Table 4 3 List of commands to manage account information You may need to have the root privilege for some functions to work See crypt 3 for the password and data encryption Note On the system set up with PAM and NSS as the Debian alioth machine the content of local etc passwa etc group and etc shadow may not be actively used by the system Above commands are valid even under such environment 4 3 Good password When creating an account during your system installation or with the passwd 1 command you should choose a good password which consists of 6 to 8 characters including one or more characters from each of the following sets according to passwd 1 e Lower case alphabetics e Digits O through 9 e Punctuation marks l Warning Do not chose guessable words for the password 4 4 Creating encrypted password There are independent tools to generate encrypted password with salt Debian Reference 88 265 package popcon size command function whois oo ae psizel mkpasswd over featured front end to the crypt 3 library openssl S psizel openssl passwd compute password hashes OpenSSL passwd 4 5 PAM and NSS Table 4 4 L
45. usr share doc etckeeper R EADME gz Debian Reference 162 265 Essentially running sudo etckeeper init initializes the git repository for etc just like the process explained in Section 10 9 4 but with special hook scripts for more thorough setups As you change your configuration you can use git 1 normally to record them It automatically records changes nicely every time you run package management commands too Tip You can browse the change history of etc by executing sudo GIT_DIR etc git gitk with clear view for new installed packages removed packages and version changes of packages 9 3 Data storage tips Booting your system with Linux live CDs or debian installer CDs in rescue mode make it easy for you to reconfigure data storage on your boot device See also Section 10 3 9 3 1 Disk partition configuration For disk partition configuration although fdisk 8 has been considered standard parted 8 deserves some attention Disk wow non partitioning data partition table partition map and disk label are all synonyms Most PCs use the classic Master Boot Record MBR scheme to hold disk partitioning data in the first sector i e LBA sector 0 512 bytes Note Some new PCs with Extensible Firmware Interface EFI including Intel based Macs use GUID Partition Table GPT scheme to hold disk partitioning data not in the first sector Although disk 8 has bee
46. 111 Translation table from obsolete net tools commands to new iproute2 commands 113 List of low level network commands 2 ee 114 List of network optimization tools ee 114 Basic guide lines of the optimal MTU value 2 0 00 0 0 0000000000222 115 Listof firewall tolse coc A EE a e ha RE Be ea Re eae bea eo 116 List of Web browsers coeg be ES A A a ae 117 List of browser plugin packages ee 118 List of basic mail transport agent related packages for workstation o oo e 120 List of choices for mail transport agent MTA packages in Debian archive oo 121 List of important postfix manual pages 122 List of mail address related configuration files o o 0000000000000 2 123 List of basic MTA operation oaoa ee 124 List of mail useragent MUA 2 ee 125 List of remote mail retrieval and forward utilities 2 2 2 0 0 2 0 00 0 00 0000 0000 125 Listof MDA with filter c e R ee 127 List of POPS IMAP4 Servers ecos os HR ee ee RS OR RA pee Boe YER ees e 129 List of print servers and utilities e e a R R R RR R R E 0 000 000 0000000000000 020000 130 List of remote access server and utilities ee 130 List of SSH authentication protocols and methods e 131 List of SSH configuration files ee ee 131 List of SSH client startup examples 2 2 ee 132 List of free SSH clients for other platfor
47. 6 system the filesystem under dev is automatically populated by the udev 7 mechanism 1 2 11 Special device files There are some special device files These are frequently used in conjunction with the shell redirection see Section 1 5 8 Debian Reference 16 265 device file action description of response dev null read return end of file EOF character dev nul write return nothing a bottomless data dump pit dev zero read return the 10 NUL character not the same as the number zero ASCII dev random read return random characters from a true random number generator delivering real entropy slow dev urandom read return random characters from a cryptographically secure pseudorandom number generator dev full write return the disk full ENOSPC error Table 1 10 List of special device files 1 2 12 procfs and sysfs The procfs and sysfs mounted on proc and sys are the pseudo filesystem and expose internal data structures of the kernel to the userspace In other word these entries are virtual meaning that they act as a convenient window into the operation of the operating system The directory proc contains among other things one subdirectory for each process running on the system which is named after the process ID PID System utilities that access process information such as ps 1 get their information from this directory structure The directories under
48. 7 e See Section 12 11 for general packaging Tip The source package format described here as a set of source packages x tar gz and x diff gz is format 1 0 which is still popular See more on dpkg source 1 for other newer formats 2 4 2 Verification of installed package files The installation of debsums enables verification of installed package files against MD53sum values in the var 1lib dpk g info md5sums file with debsums 1 See Section 10 4 5 for how MD5sum works Note Because MD5sum database may be tampered by the intruder debsums 1 is of limited use as a security tool It is only good for checking local modifications by the administrator or damage due to media errors 2 4 3 Safeguarding for package problems Many users prefer to follow the unstable release of the Debian system for its new features and packages This makes the system more prone to be hit by the critical package bugs The installation of the apt 1istbugs package safeguards your system against critical bugs by checking Debian BTS auto matically for critical bugs when upgrading with APT system The installation of the apt listchanges package provides important news in NEWS Debian when upgrading with APT system 2 4 4 Searching on the package meta data Although visiting Debian site http packages debian org facilitates easy ways to search on the package meta data these days let s look into more traditional ways The grep dctr1 1
49. E aq tsuper r ALL deferred postqueue flush all mails exim4 qff postsuper r ALL postqueue f flush even frozen mails xim4 Mg queue_id postsuper h queue_id freeze one message by its queue ID exim4 Mrm queue_id postsuper d queue_id remove one message by its queue ID N A postsuper d ALL remove all messages Table 6 7 List of basic MTA operation Tip It may be a good idea to flush all mails by a script in etc ppp ip up d x 6 4 Mail user agent MUA If you subscribe to Debian related mailing list it may be a good idea to use such MUA as mutt and gnus which are the de facto standard for the participant and known to behave as expected 6 4 1 Basic MUA Mutt Customize muttrc as the following to use mutt as the mail user agent MUA in combination with vim S T T T use visual mode and gq to reformat quotes t editor vim c set tw 72 header weeding taken from the manual HT T IL Sven s Draconian header weeding Debian Reference 125 265 package popcon size type iceweasel a ES psizel X GUI program unbranded Mozilla Firefox evolution A a psizel X GUI program part of a groupware suite icedove A Kanai psizel X GUI program unbranded Mozilla Thunderbird mutt a opeonl psizel character terminal program probably used with vim gnus A S psizel character terminal program under x emacs Table 6 8 List of
50. Experienced Linux users tend to avoid spaces in filenames Note The word root can mean either root user or root directory The context of their usage should make it clear Note The word path is used not only for fully qualified filename as above but also for the command search path The intended meaning is usually clear from the context The detailed best practices for the file hierarchy are described in the Filesystem Hierarchy Standard usr share doc d ebian policy fhs fhs 2 3 txt gz and hier 7 You should remember the following facts as the starter directory usage of the directory the root directory etc system wide configuration files var log system log files home all the home directories for all non privileged users Table 1 3 List of usage of key directories 1 2 2 Filesystem internals Following the Unix tradition the Debian GNU Linux system provides the filesystem under which physical data on hard disks and other storage devices reside and the interaction with the hardware devices such as console screens and remote serial consoles are represented in an unified manner under dev Each file directory named pipe a way two programs can share data or physical device on a Debian GNU Linux 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
51. Here are a few basic methods to gain the root shell prompt by using the root password e Type root at the character based login prompt Click Applications Accessories Root Terminal under the GNOME Desktop environment e Type su 1 from any user shell prompt This does not preserve the environment of the current user e Type su from any user shell prompt This preserves some of the environment of the current user 1 1 5 GUI system administration tools When your desktop menu does not start GUI system administration tools automatically with the appropriate privilege you can start them from the root shell prompt of the X terminal emulator such as gnome terminal 1 rxvt 1 or xterm 1 See Section 1 1 4 and Section 7 8 4 Warning I Never start the X display session manager under the root account by typing in root to the prompt of the display manager such as gdm 1 Warning x Never run untrusted remote GUI program under X Window when critical information is displayed since it may eavesdrop your X screen 1 1 6 Virtual consoles In the default Debian system there are six switchable VT100 like character consoles available to start the command shell directly on the Linux host Unless you are in a GUI environment you can switch between the virtual consoles by pressing the Left Alt key and one of the F1 F6 keys simultaneously Each character console allows independen
52. ID and encryption key data to be provided when they are initialized Their high level network tools are exactly the same as that of Ethernet interfaces except interface names are a bit different like eth1 wlan0 ath0 wif10 depending on the kernel drivers used Tip The wmaster0 device is the master device which is an internal device used only by SoftMAC with new mac80211 API of Linux Here are some keywords to remember for the WLAN acronym full word NWID Network ID E SSID Extended Service Set Identifier WEP WEP2 Wired Equivalent Privacy WPA Wi Fi Protected Access WPA2 Wi Fi Protected Access 2 Table 5 11 List of acronyms for WLAN The actual choice of protocol is usually limited by the wireless router you deploy 5 3 7 The wireless LAN interface with WPA WPA2 You need to install the woasupplicant package to support the WLAN with the new WPA WPA2 In case of the DHCP served IP on WLAN connection the etc network interfaces file entry should be as the fol lowing Debian Reference 104 265 allow hotplug ath0 iface ath0 inet dhcp wpa ssid homezone hexadecimal psk is encoded from a plaintext passphrase wpa psk 000102030405060708090a0b0c0d0e0f101112131415161718191lalbicldlelf See usr share doc wpasupplicant README modes gz 5 3 8 The wireless LAN interface with WEP You need to install the wireless tools package to support the WLAN with the old WEP Your
53. New Maintainers Guide debian history popcon1 psizel History of the Debian Project debian fag popcon1 psizel Debian FAQ doc linux text popcon1 psizel Linux HOWTOs and FAQ text doc linux html popcon1 psizel Linux HOWTOs and FAQ html sysadmin guide popcon1 psizel The Linux System Administrators Guide rutebook popcon1 psizel Linux Rute User s Tutorial and Exposition non free Table 1 2 List of informative documentation packages Debian Reference 6 265 1 1 11 An extra user account If you do not want to use your main user account for the following training activities you can create a training user account e g fish by the following adduser fish Answer all questions This creates a new account named as fish After your practice you can remove this user account and its home directory by the following deluser remove home fish 1 1 12 sudo configuration For the typical single user workstation such as the desktop Debian system on the laptop PC it is common to deploy simple configuration of sudo 8 as follows to let the non privileged user e g penguin to gain administrative privilege just with his user password but without the root password echo penguin ALL ALL ALL gt gt etc sudoers This trick should only be used for the
54. PDF document conversion tools pd gnuhtml2latex dd Sd de psize1 html latex converter from html to latex latex2rtf Gade psize1 latex rtf convert documents from LaTeX to R ps2eps a a psize1 ps eps converter from PostScript to EPS E e2ps Gani psizel1 text ps Text to PostScript converter with Jag impose ae psize1 ps ps PostScript utilities pia DTE S popcon psize1 text ps da many source codes C C pdf2svg oo eS psizel1 ps svg converter from PDF to Scalable vect pdftoipe R aia psize1 ps ipe converter from PDF to IPE s XML f Table 11 13 List of printable data utilities Debian Reference 241 265 11 3 4 Printing with CUPS Both 1p 1 and 1pr 1 commands offered by Common Unix Printing System CUPS provides options for customized printing the printable data You can print 3 copies of a file collated using one of the following commands S lp n 3 o Collate True filename lpr 3 o Collate True filename You can further customize printer operation by using printer option such as o number up 2 o page set ev n o page set odd o scaling 200 o natural scaling 200 etc documented at Command Line Printing and Options 11 4 Type setting The Unix troff program originally developed by AT amp T can be used for simple typesetting It is usually used to create manpages TeX created by Donald Knuth i
55. POP3 mail server courier imap a Opcon l psizel IMAP Courier mail server IMAP server maildir format on uw imapd m a psizel IMAP The University of Washington IMAP server cyrus imapd 2 2 POPEO psizel IMAP Cyrus mail system IMAP support 6 8 The print server and utility Table 6 11 List of POP3 IMAP4 servers In the old Unix like system the BSD Line printer daemon was the standard Since the standard print out format of the free software is PostScript on the Unix like system some filter system was used along with Ghostscript to enable printing to the non PostScript printer Recently Common UNIX Printing System CUPS is the new de facto standard The CUPS uses Internet Printing Protocol IPP The IPP is now supported by other OSs such as Windows XP and Mac OS X and has became new cross platform de facto standard for remote printing with bi directional communication capability The standard printable data format for the application on the Debian system is the PostScript PS which is a page description language The data in PS format is fed into the Ghostscript PostScript interpreter to produce the printable data specific to the printer See Section 11 3 1 Thanks to the file format dependent auto conversion feature of the CUPS system simply feeding any data to the 1pr command should generate the expected print output In CUPS lpr can be enabled by installing the cups bsd package Th
56. Please note the etc x11 default display manager file is checked when starting the display manager daemons xdm gdm kdm and wdm Note You can still start X from any console shell with the start x 1 command 3 5 4 The default parameter for each init script The default parameter for each init script in etc init d is given by the corresponding file in etc default which contains environment variable assignments only This choice of directory name is specific to the Debian system It is roughly the equivalent of the etc sysconfig directory found in Red Hat Linux and other distributions For example etc default cron can be used to control how etc init d cron works The etc default rcsS file can be used to customize boot time defaults for mot d 5 sulogin 8 etc If you cannot get the behavior you want by changing such variables then you may modify the init scripts themselves These are configuration files editable by system administrators 3 5 5 The hostname The kernel maintains the system hostname The init script in runlevel S which is symlinked to etc init d hostname sh sets the system hostname at boot time using the host name command to the name stored in etc hostname This file should contain only the system hostname not a fully qualified domain name To print out the current hostname run hostname 1 without an argument 3 5 6 The filesystem Although the root filesystem is mounted by the
57. QUERY_STRING VAR1 VAL1 VAR2 VAL2 VAR3 VAL3 CGI program any one of program on the web server executes itself with the environment variable SQUERY_STRI NG stdout of CGI program is sent to the web browser and is presented as an interactive dynamic web page For security reasons it is better not to hand craft new hacks for parsing CGI parameters There are established modules for them in Perl and Python PHP comes with these functionalities When client data storage is needed HTTP cookies are used When client side data processing is needed Javascript is frequently used For more see the Common Gateway Interface The Apache Software Foundation and JavaScript 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 Google server 12 10 The source code translation There are programs to convert source codes package popcon size keyword description perl pie as psizel1 AWK PERL convert source codes from AWK to PERL a2p 1 f2c as psizel1 FORTRAN C convert source codes from FORTRAN 77 to C C protoize Ce aia psizel ANSI C create remove ANSI prototypes from C code intel2gas aaa psizel intel gas converter from NASM Intel format to the GNU Ass Table 12 16 List of source code translati
58. Run chroot sid root bin bash c exec a bash bin bash Note Some programs under chroot may require access to more files from the parent system to function than pbuilder provides For example sys etc passwa etc group var run utmp var log wtmp etc may need to be bind mounted or copied Note The usr sbin policy rc d file prevents daemon programs to be started automatically on Debian system See usr share doc sysv rc README policy rc d gz Tip The original purpose of the specialized chroot package pbuilder is to construct 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 do not exist in the resulting package Tip Similar schroot package may give you an idea to run i386 chroot system under amd 64 parent system 9 8 5 Multiple desktop systems I recommend you to use QEMU or VirtualBox on a Debian stable system to run multiple desktop systems safely using virtualization These enable you to run desktop applications of Debian unstable and test ing without usual risks associated with them Since pure QEMU is very slow it is recommended to accelerate it with KVM when the host system support it The virtual disk image virtdisk qcow2 containing Debian system for QEMU can be created using debian installer Small CDs as follows
59. These may look funny to some people but are my intentional choices of style to keep this documentation as simple as possible These Noun phrases do not capitalize their starting nor end with periods following these short description convention Note Proper nouns including command names keeps their case irrespective of their location A command snippet quoted in a text paragraph is referred by the typewriter font between double quotation marks such as aptitude safe upgrade A text data from a configuration file quoted in a text paragraph is referred by the typewriter font between double quotation marks such as deb src A command is referred by its name in the typewriter font optionally followed by its manpage section number in parenthesis such as bash 1 You are encouraged to obtain information by typing the following man 1 bash A manpage is referred by its name in the typewriter font followed by its manpage section number in parenthesis such as sou rces list 5 You are encouraged to obtain information by typing the following Sanos o UE CSS IHSE An info page is referred by its command snippet in the typewriter font between double quotation marks such as info make You are encouraged to obtain information by typing the following info make A filename is referred by the typewriter font between double quotation marks such as etc passwd For configuration files you are encouraged to obtain information by typing
60. accesses backup files BUDIR var backups XDIRO Mail Desktop XDIERW St EAU Nasa A EC ches No riEs or seesi one XDIR2 CVS git svn Downloads Archive Checkout tmp SS O Aa a oa A A A O A E AS ore SIZE 99M DATE date utc SY m d SHSM d SBUDIR mkdir p BUDIR umask 077 dpkg get selections gt var lib dpkg dpkg selections list debconf get selections gt var cache debconf debconf selections find etc usr local opt var lib dpkg dpkg selections list var cache debconf debconf selections xdev printO find home SUSER root xdev regextype posix extended N type d regex SXDIRO XDIR1 prun o type f regex SXSFX prune o AS E alza VESA orvuna O 9510 find home SUSER Mail Inbox home SUSER Mail Outbox print0 find home SUSER Desktop xdev regextype posix extended type d regex SXDIR2 prun o type f regex XSFX prune o type E size SSIZE prune O print0 Pol Gite cx auL1L O E UDR BUS DAMENE chown BUUID BUDIR BU DATE cpio touch BUDIR backup stamp This is meant to be a script example executed from root T expect you to change and execute this as follows e Edit this script to cover all your important data see Section 10 1 5 and Section 10 1 6 e Replace find print0 with find newer S BUDIR backup stamp print0 to make a incre mental backup e Transfer backup files t
61. accordingly These auto installed packages are removed automatically if they are no longer needed under aptitude Note Before the Lenny release apt get and other standard APT tools did not offer the autoremove functionality 2 2 8 Package activity logs You can check package activity history in the log files file content var log dpkg log Log of dpkg level activity for all package activities var log apt term log Log of generic APT activity var log aptitude Log of aptitude command activity Table 2 12 The log files for package activities In reality it is not so easy to get meaningful understanding quickly out from these logs See Section 9 2 10 for easier way 2 2 9 Aptitude advantages Aptitude has advantages over other APT based packaging systems apt get apt cache synaptic e aptitude removes unused auto installed packages automatically using its own extra layer of package state file var 1i b aptitude pkgstates For new lenny other APT does the same aptitude makes it easy to resolve package conflicts and to add recommended packages Debian Reference 51 265 e aptitude makes it easy to keep track of obsolete software by listing under Obsolete and Locally Created Packages e aptitude gives a log of its history in var log aptitude e aptitude offers access to all versions of the package if available e aptitude includes a fairly powerful regex based system for searching part
62. and the file name in the Vim command line e g w en c utf8 new txt Please refer to the mbyte txt multi byte text support in vim on line help and Table 11 2 for locale values used with enc The emacs family of programs can perform the equivalent functions 11 1 7 Plain text extraction The following reads a web page into a text file This is very useful when copying configurations off the Web or applying basic Unix text tools such as grep 1 on the web page S w3m dump http www remote site com help info html gt textfile Similarly you can extract plain text data from other formats using the following Debian Reference 234 265 package popcon size keyword function w3m a SES psizel html text HTML to text converter with the w3m dur popcon1 S html2text o psizel html text advanced HTML to text converter ISO 8859 lynx an g psizel html text HTML to text converter with the lynx di elinks i alae S psizel html text HTML to text converter with the elinks links a epconti s psizel html text HTML to text converter with the links c links2 es a a psizel html text HTML to text converter with the links2 antiword FAEDO ON psizel MSWord text ps convert MSWord files to plain text or ps catdoc ana d psizel MSWord text TeX convert MS Word files to plain text or TeX pstotext a opponi p
63. area of an hard disk o e 210 10 3 10 Undeleting deleted but still open files o ooo e 210 10 3 11 Searching all hardlinks e e e R R R pg ER a A ee 211 10 3 12 Invisible disk space consumption 1 2 2 a 211 10 4 Data security infrastructure 2 211 10 4 1 Key management for GnuPG 2 2 00000 e 211 10 4 2 Using GnuPG on files dek E e ee E E e E e e a a 213 Debian Reference 10 5 10 6 10 7 10 8 10 9 XV 10 4 3 Using GnuPG with Mutt N RE R RRR RL RRR RRR R R RRR R e 213 10 44 Using GnuPG With Vim s sose e R eR RG RRR Re eee 213 10 43 The MIDS Sum tao da e e A AA E A 214 Source code merge tools sa sone woe E E a R eRe eee R 214 10 5 1 Extracting differences for source files o 214 10 5 2 Merging updates for source files e 214 10 5 3 Updating via 3 way merge 2 ee 214 Version control systems sc a ee ek R RS REG a AA Re AG eee eo 214 10 6 1 Comparison of VCS commands aoaaa ee 216 CVS a Se Ae a ae we a Re Al lai eal ee ee A eae ea E E 217 10 7 1 Configuration of CVS repository 218 10 72 Local access to CVS dpi de a a A ds a bh 218 10 7 3 Remote access to CVS With pserver ee 218 10 7 4 Remote access to CVS With ssh ee 218 10 7 5 Importing a new source to CVS 2 0 0 0 00 2 ee 219 10 7 6 File permissions in CVS repository o o a 219 10 7 7 Work flow Of CVS esp cane pe ee ee a A
64. be limited to basic configurations such as static IP or DHCP They actually overwrite contents of etc network interfaces file behind you Please check how they change etc network interfaces file by yourself Caution l They may not understand complicated advanced configuration done manually in etc network interfaces file Debian Reference 112 265 5 5 2 Automatic network configuration There are independent automatic network configuration tools such as NetworkManager NM network manager and as sociated packages and Wicd wicd package which manage network connection via daemon independent of the i fupdown package They allow easy management of wireless connections These come with its own nice GUI user interfaces Warning I Do not use these automatic network configuration tools for servers These are aimed primarily for mobile desktop users on laptops Warning These automatic network configuration tools are moving targets and documentation here is likely to be incorrect for squeeze So be warned Caution l These automatic network configuration tools may not be compatible with esoteric configurations of i fupdown in tc network interfaces such as ones in Section 5 3 and Section 5 4 Having even hostname stanza for DHCP controlled interface as described in Section 5 3 4 caused NM to ignore such interface in Lenny Check BTS of network manage
65. boot time it is even easier with following steps 1 Boot system with the kernel parameter changed to something like root dev hda6 rw init bin sh 2 Edit etc passwd and make the second entry for the root account empty 3 Reboot system The root shell of the system is now accessible without password Note Once one has root shell access he can access everything on the system and reset any passwords on the system Further more he may compromise password for all user accounts using brute force password cracking tools such as john and crack packages see Section 9 6 11 This cracked password may lead to compromise other systems The only reasonable software solution to avoid all these concerns is to use software encrypted root partition or et c partition using dm crypt and initramfs see Section 9 4 You always need password to boot the system though Debian Reference 94 265 Chapter 5 Network setup Tip For general guide to the GNU Linux networking read the Linux Network Administrators Guide The traditional TCP IP network setup on Debian system uses i fupdown package as a high level tool There are 2 typical cases e For dynamic IP system such as mobile PCs you should setup TCP IP network with the resolvconf package and enable you to switch your network configuration easily see Section 5 3 4 e For static IP system such as servers you should setup TCP IP network without the resolvconf package a
66. consumer grade router may still be using this insecure infrastructure but this is better than nothing e Caution Please note that your network traffic on WLAN with WEP may be sniffed by others In case of the DHCP served IP on WLAN connection the etc network interfaces file entry should be as the fol lowing allow hotplug eth0 iface eth0 inet dhcp wireless essid Home wireless keyl 0123 4567 89ab cdef wireless key2 12345678 wireless key3 s password wireless defaultkey 2 wireless keymode open See usr share doc wireless tools README Debian 5 3 9 The PPP connection You need to configure the PPP connection first as described before see Section 5 2 3 Then add the etc network int erfaces file entry for the primary PPP device pppo as the following iface ppp0 inet ppp provider lt isp_name gt 5 3 10 The alternative PPP connection You need to configure the alternative PPP connection with wvdial first as described before see Section 5 2 4 Then add the etc network interfaces file entry for the primary PPP device pppo as the following iface ppp0 inet wvdial 5 3 11 The PPPoE connection For PC connected directly to the WAN served by the PPPoE you need to configure system with the PPPoE connection as described before see Section 5 2 5 Then add the etc network interfaces file entry for the primary PPPoE device etho0 as the following Debian Reference 105 265
67. described in Section 5 3 with the advanced knowledge The functionalities described here are completely optional I being lazy and minimalist rarely bother to use these Caution I If you could not set up network connection by information in Section 5 3 you make situation worse by using information below 5 4 1 The ifplugd package The ifplugd package is older automatic network configuration tool which can manage only Ethernet connections This solves unplugged replugged Ethernet cable issues for mobile PC etc If you have NetworkManager or Wicd see Section 5 5 2 installed you do not need this package This package runs daemon and replaces auto or allow hotplug functionalities see Table 5 10 and starts interfaces upon their connection to the network Here is how to use the i fplugd package for the internal Ethernet port e g et h0 1 Remove stanza in etc network interfaces auto eth0 or allow hotplug eth0 2 Keep stanza in etc network interfaces iface eth0 inet and mapping 3 Install the i fplugd package 4 Run sudo dpkg reconfigure ifpluga 5 Put et hO as the static interfaces to be watched by ifplugd Now the network reconfiguration works as you desire e Upon power on or upon hardware discovery the interface is not brought up by itself Quick boot process without the long DHCP timeout No funny activated interface without proper IPv4 address see Section 5 3 12
68. desktop environment can easily achieved by using specialized package such as 1dm Your local machine becomes a secure thin client to the remote application server connected via SSH If you want to add similar feature to your normal display manager gdm create executable shell script at usr local bin ssh session as the following bin sh e Based on gdm ssh session in gdm source GPL ZENITY type p zenity ARGETHOST ZENITY width 600 eitle Milos co connect Eo emueiy N text Enter the name of the host you want to log in to as user host dom ARGETSESSION S SZENITY width 600 height 400 title Remote session name list radiolist text Select one ola Y a colu Shona COLuUMMmUdes RE omer 9er 2 Ny E etc X11 Xsession Debian Sm Atos clicar MR arcas SE gnome session GNOME session FALSE xterm Safe choice Ss S AS RE ote y FALSE gnome terminal Safe choice echo Connecting to STARGETHOST with STARGETSESSION usr bin ssh A X T n STARGETHOST STARGETSESSION SSH_ASKPASS usr bin ssh askpass usr bin ssh A X T n STARGETHOST STARGETSESSION Add followings to etc dm Sessions ssh desktop Desktop Entry Encoding UTF 8 ame SSH Comment This session logs you into a remote host using ssh Exec usr local bin ssh session Type Application
69. eh be SPS oo heea Ss en bhe SPs Ado WS SEES SS 182 9 7 4 Compiling the kernel and related modules 2 2 2 0 0000000000000 0004 183 9 7 5 Compiling the kernel source Debian standard method o o 183 9 7 6 Compiling the module source Debian standard method o oo 184 9 7 7 Compiling the kernel source classic method o oo 184 9 7 8 Non free hardware drivers R c ea ee 185 9 8 Virtualizedsystem e RR R 0 R ARR R tpe RRR RR RR RRR RRR 185 9 8 1 Virtualization tools RRR RRR RRR RR RRR RRR RRR RE 185 9 8 2 Virtualization work flow oe cok e ste ee a e ar R R TR ee 185 9 8 3 Mounting the virtual disk image file o e e 187 9 8 4 Chroot system s s sa meiak k e Seg Me a A e E eA oe a 187 9 8 5 Multiple desktop systems ooa ee 188 Debian Reference xiv 10 Data management 190 10 1 Sharing copying and archiving 2 2 0 000000 022 2 190 10 1 1 Archive and compression tools ee 191 10 1 2 Copy and synchronization tools 2 2 ee 192 10 1 3 Idioms forthe archive a ss e scce eeose ea ee 193 10 1 4 Idioms for the copy ecce gerua a E A a 193 10 1 5 Idioms for the selection of files o 194 10 1 6 Backup and recovery s compos ca Se R RR SR SG a ee RAG BO i N 195 10 1 7 Backup utility suites esst enet t teap Ern RRR RRR RR 196 10 1 8 An example script for the system backup onoo ee 197 10 1 9 A copy script for the
70. enabled by the system administrator This may creates interference with popular generic helper programs for the system configuration Debian Reference 37 265 package popcon size description aptitude a SHOES psize1 terminal based package manager current standard front ast popcon1 psize1 Advanced Packaging Tool APT front end for dpkg pro apt get apt cache commands included tasksel EPODO psize1 tool for selecting tasks for installation on Debian system unattended upgrades popcon psize1 enhancement package for APT to enable automatic install popcon dselect psize1 terminal based package manager previous standard front dpkg oe as psizel1 package management system for Debian synaptic z G psize1 graphical package manager GNOME front end for APT kpackage ae aprons psize1 graphical package manager KDE front end for APT apt utils EPOPEE psize1 APT utility programs apt extracttemplates l a apt listchanges popcon psize1 package change history notification tool apt listbugs popcon psize1 lists critical bugs before each APT installation apt file popcon psize1 APT package searching utility command line interface apt rdepends popcon psize1 recursively l
71. execution of a first program which is found in the following order with the exec builtin command 1 The script specified as the argument of etc X11 Xsession by the X display manager if it is defined The xsession or Xsession script if it is defined 2 3 The usr bin x session manager command if it is defined 4 The usr bin x window manager command if it is defined 5 The usr bin x terminal emulator command if it is defined This process is affected by the content of etc X11 Xsession options The exact programs to which these usr bin x x commands point are determined by the Debian alternative system and changed by update alternatives config x session manager etc 7 5 1 Starting X session with gdm gdm 1 lets you select the session type or desktop environment Section 7 2 and language or locale Section 8 3 of the X session from its menu It keeps the selected default value in dmrc as the following Desktop Session default Language ja_JP UTF 8 7 5 2 Customizing the X session classic method On a system where etc X11 Xsession options contains a line al low user xsession without preceding characters any user who defines xsession or Xsession is able to customize the action of etc X11 Xse ssion by completely overriding the system code The last command in the xsession file should use form of exec some window session manager to start your favo
72. exim4 conf Chose mail sent by smarthost received via SMTP or fetchmail Set IP address or host name of the outgoing smarthost to smtp hostname dom 587 Reply to Keep number of DNS queries minimal Dial on Demand as one of the following e No if the system is connected to the Internet while booting e Yes if the system is not connected to the Internet while booting Create password entries for the smarthost by editing etc exim4 passwd client S sudo vim etc exim4 passwd client S cat etc exim4 passwd client smtp hostname dom username hostname dom password Debian Reference 121 265 package popcon size capability and focus xim4 daemon 1ight popcon psizel full pos tfix popcon psizel full security xim4 daemon heavy popcon psizel full flexible sendmail bin popcon psizel full only if you are already familiar nul lmailer popcon psizel strip down no local mail ssmtp popcon psizel strip down no local mail courier mta popcon psizel very full web interface etc popcon xmail psize1 light masqmail aoe psize1 light esmtp ie aaa psize1 light esmtp run ae es psizel1 light sendmail compatibility extension t
73. following S sudo aptitude install mc Use the mc 1 command to explore the Debian system This is the best way to learn Please explore few interesting locations just using the cursor keys and Enter key e etc and its subdirectories e var log and its subdirectories e usr share doc and its subdirectories e sbin and bin Debian Reference 17 265 1 3 1 Customization of MC In order to make MC to change working directory upon exit and cd to the directory I suggest to modify bashrc to include a script provided by the mc package usr share mc bin mc sh See mc 1 under the P option for the reason If you do not understand what exactly I am talking here you can do this later 1 3 2 Starting MC MC can be started by the following Same 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 Note In some consoles such as gnome terminal 1 key strokes of function keys may be stolen by the console program You can disable these features by Edit Keyboard Shortcuts for gnome terminal If you encounter character encoding problem which displays garbage characters adding a to MC s command line may help prevent problems If this doesn t clear up your display problems with MC see Section 9 6 6 1 3 3 File manager in MC The default is two d
74. init Tip If you are looking for a light weight MTA that respects etc aliases for your laptop PC you should consider to configure exim4 8 with QUEUERUNNER nodaemon etc in etc default exim4 6 3 2 The configuration of postfix with SASL For the Internet mail via smarthost you should first read postfix documentation and key manual pages command function postfix 1 Postfix control program postconf 1 Postfix configuration utility postconf 5 Postfix configuration parameters postmap l Postfix lookup table maintenance postalias 1 Postfix alias database maintenance Table 6 5 List of important postfix manual pages You re configure post fix and sas12 bin packages as follows Debian Reference 123 265 5 sudo CEG lemibtercly ip sits exams Op sudo dpkg reconfigure postfix Chose Internet with smarthost Set SMTP relay host blank for none to smtp hostname dom 587 and configure it by the following sudo postconf e smtp_sender_dependent_authentication yes sudo postconf e smtp_sasl_auth_enable yes sudo postconf e smtp_sasl_password_maps hash etc postfix sasl_passwd sudo postconf e smtp_sasl_type cyrus sudo vim etc postfix sasl_passwd Create password entries for the smarthost S cat etc postfix sasl_passwd smtp hostname dom 587 username password sudo postmap hush etc postfix sasl_passw
75. init d klogd restart See klogd 8 You may directly change the error message level by the following dmesg n3 Debian Reference 83 265 error level value error level name meaning 0 KERN_EMERG system is unusable 1 KERN ALERT action must be taken immediately 2 KERN_CRIT critical conditions 3 KERN_ERR error conditions 4 KERN_WARNING warning conditions 5 KERN_NOTICE normal but significant condition 6 KERN_INFO informational 7 KERN_DEBUG debug level messages Table 3 4 List of kernel error levels 3 5 11 The udev system For Linux kernel 2 6 the udev system provides mechanism for the automatic hardware discovery and initialization see u dev 7 Upon discovery of each device by the kernel the udev system starts a user process which uses information from the sysfs filesystem see Section 1 2 12 loads required kernel modules supporting it using the modprobe 8 program see Section 3 5 12 and creates corresponding device nodes Tip If lib modules lt kernel version gt modules dep was not generated properly by depmod 8 for some reason modules may not be loaded as expected by the udev system Execute depmod a to fix it The name of device nodes can be configured by udev rule files in etc udev rules d Current default rules tend to create dynamically generated names resulting non static device names except for cd and network devices By adding your custom rules s
76. is an example of a crontab 5 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 LTO paul in Hour DayOfMonth Month DayOfWeek command Day are OR ed run at 00 05 every day S SHOME bin daily job gt gt SHOME tmp out 2 gt amp 1 run at 14 15 on the first of every month output mailed to paul 15 14 L SHOME bin monthly run at 22 00 on weekdays 1 5 annoy Joe for newline last for cc MA H 0 22 x 1 5 mail s It s 10pm joesJoe Where are your kids BS 2 12D echo run 23 minutes after Oam 2am 4am on Feb 1 5 4 sun echo run at 04 05 every Sunday run at 03 40 on the first Monday of each month 40 3 1 7 S date a Mon amp amp command args Tip For the system not running continuously install the anacron package to schedule periodic commands at the specified intervals as closely as machine uptime permits See anacron 8 and anacrontab 5 Tip For scheduled system maintenance scripts you can run them periodically from root account by placing such scripts in etc cron hourly etc cron daily etc cron weekly or etc cron monthly Execution timings of these scripts can be customized by etc crontab and etc anacrontab 9 5 15 Alt SysRq key Insurance against system malfunction is provided by the kernel compile option Magi
77. limit the tty for the root access by the pam_securetty 8 module etc security access conf set access limit by the pam_access 8 module etc security group conf set group based restraint by the pam_group 8 module etc security pam_env conf set environment variables by the pam_env 8 module etc environment set additional environment variables by the pam_env 8 module with the readenv 1 etc default locale set locale by pam_env 8 module with the readenv 1 envfile etc default etc security limits conf set resource restraint ulimit core by the pam_linits 8 module etc security time conf set time restraint by the pam_t ime 8 module Table 4 6 List of configuration files accessed by the PAM The limitation of the password selection is implemented by the PAM modules pam_unix 8 and pam_crack1ib 8 They can be configured by their arguments Tip PAM modules use suffix so for their filenames 4 5 2 The modern centralized system management The modern centralized system management can be deployed using the centralized Lightweight Directory Access Protocol LDAP server to administer many Unix like and non Unix like systems on the network The open source implementation of the Lightweight Directory Access Protocol is OpenLDAP Software The LDAP server provides the account information through the use of PAM and NSS with 1ibpam 1dap and libnss 1dap packages for
78. localization which correspond to M17N 118N and L10N The modern software such as GNOME and KDE are multilingualized They are internationalized by making them handle UTF 8 data and localized by providing their translated messages through the gettext 1 infrastructure Translated messages may be provided as separate localization packages They can be selected simply by setting pertinent environment variables to the appropriate locale The simplest representation of the text data is ASCII which is sufficient for English and uses less than 127 characters repre sentable with 7 bits In order to support much more characters for the international support many character encoding systems have been invented The modern and sensible encoding system is UTF 8 which can handle practically all the characters known to the human see Section 8 3 1 See Introduction to il 8n for details The international hardware support is enabled with localized hardware configuration data 8 1 The keyboard input The Debian system can be configured to work with many international keyboard arrangements environment command dpkg reconfigure priority low console data dpkg reconfigure priority low xserver xorg Linux console X Window Table 8 1 List of keyboard reconfiguration methods This supports keyboard input for accented characters of many European languages with its dead key function For Asian lan guages you need more co
79. location for local copy of Contents lt ar chitecture gt gz as default 2 5 5 The package state for APT In addition to the remotely fetched meta data the APT tool after 1enny stores its locally generated installation state information inthe var lib apt extended_states which is used by all APT tools to track all auto installed packages 2 5 6 The package state for aptitude In addition to the remotely fetched meta data the apt it ude command stores its locally generated installation state information inthe var lib aptitude pkgstates which is used only by it 2 5 7 Local copies of the fetched packages All the remotely fetched packages via APT mechanism are stored in the var cache apt packages until they are cleaned 2 5 8 Debian package file names Debian package files have particular name structures Note You can check package version order by dpkg 1 e g dpkg compare versions 7 0 gt 7 prel echo S Debian Reference 59 265 package type name structure The binary package a k a deb lt package name gt _ lt epoc gt deb n gt lt u pstream ve The binary package for the debian installer a k a udeb lt package name gt _ lt epoc gt udeb n gt lt u pstream ve The source package upstream source lt package name gt _ lt epoc n gt lt u pstream ve The source package Debian changes lt package name gt _ lt epoc n gt
80. lt commandname gt display rather long explanation on command lt commandname gt GNU style ls list contents of directory non dot files and directories ls a list contents of directory all files and directories ls A list contents of directory almost all files and directories i e skip and ls la list all contents of directory with detail information ls lai list all contents of directory with inode number and detail information ls d list all directories under the current directory tree display file tree contents lsof lt foo gt list open status of file lt foo gt lsof p lt pid gt list files opened by the process ID lt pid gt mkdir lt foo gt make a new directory lt foo gt in the current directory rmdir lt foo gt remove a directory lt foo gt in the current directory cd lt foo gt change directory to the directory lt foo gt in the current directory or in the directory cd change directory to the root directory cd change directory to the current user s home directory cd lt foo gt change directory to the absolute path directory lt foo gt Cd 3s change directory to the parent directory cd lt foo gt change directory to the home directory of the user lt foo gt cis change directory to the previous directory lt etc motd pager display contents of etc mota using the default pager touch
81. lt junkfile gt create a empty file lt junkfile gt cp lt foo gt lt bar gt copy a existing file lt foo gt to a new file lt bar gt rm lt junkfile gt remove a file lt junkfile gt mv lt foo gt lt bar gt rename an existing file lt foo gt to a new name lt bar gt lt bar gt must not exist mv lt foo gt lt bar gt move an existing file lt foo gt to a new location lt bar gt lt foo gt the directory lt 1 mv lt foo gt lt bar gt lt baz gt move an existing file lt foo gt to a new location with a new name lt bar gt lt baz gt lt bar gt lt baz gt must not exist chmod 600 lt foo gt make an existing file lt foo gt to be non readable and non writable by the other peop chmod 644 lt foo gt make an existing file lt foo gt to be readable but non writable by the other people n chmod 755 lt foo gt make an existing file lt foo gt to be readable but non writable by the other people ex find name lt pattern gt find matching filenames using shell lt pattern gt slower locate d lt pattern gt find matching filenames using shell lt pattern gt quicker using regularly generate grep e lt pattern gt x html find a lt pattern gt in all files ending with html in current directory and display th top display process information using full screen type q to quit ps aux pa
82. lt u pstream ve The source package description lt package name gt _ lt epoc n gt lt u pstream ve Table 2 15 The name structure of Debian packages name component usable characters regex existence lt package name gt la z A Z 0 9 0 9 required lt epoch gt 0 9 optional lt upstream version gt Lae AZ 0 9 ej 2 required lt debian version gt a z A Z 0 9 7 optional Table 2 16 The usable characters for each component in the Debian package names Note The debian installer d i uses udeb as the file extension for its binary package instead of normal deb An udeb package is a stripped down deb package which removes few non essential contents such as documentation to save space while relaxing the package policy requirements Both deb and udeb packages share the same package structure The u stands for micro 2 5 9 The dpkg command dpkg 1 is the lowest level tool for the Debian package management This is very powerful and needs to be used with care While installing package called lt package_name gt dpkg process it in the following order 1 Unpack the deb file ar x equivalent 2 Execute lt package_name gt preinst using debconf 1 3 Install the package content to the system tar x equivalent 4 Execute lt package_name gt postinst using debconf 1 The debconf system provides standardized user interaction with I1
83. mail user agent MUA ignore x unignore from date subject to cc unignore user agent x mailer hdr_order from subject to cc date user agent x mailer set hostname spoof example org set from First Last lt username example org gt Add the following to etc mailcap or 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 6 5 The remote mail retrieval and forward utility Although fet chmail 1 has been de facto standard for the remote mail retrieval on GNU Linux the author likes getmail 1 now If you want to reject mail before downloading to save bandwidth mailfilter or mpop may be useful Whichever mail retriever utilities are used it is good idea to configure system to deliver retrieved mails to MDA such as maildrop via pipe package popcon size description fetchmail G popconl a epsize10 mail retriever POP3 APOP IMAP old me popcon1 S getmail4 o psizel mail retriever POP3 IMAP4 and SDPS simple secure and reliable mailfilter A Spey psize1 mail retriever POP3 with with regex filtering capability mpop Pag A psizel mail retriever POP3 and MDA with filtering capability Table 6 9 List of remote mail retrieval and forward utilities 6 5 1 getmail configurati
84. may indicate that the package in the unstable release is a dummy package which installs other packages with significant contents by the dependency The dummy package enables a smooth transition or split of the package Debian Reference Note A package size followed by indicates that the package in the unstable release is missing and the package size for the experimental release is used instead Bug reports on this document Please file bug reports on the debian reference package using reportbug 1 if you find any issues on this document Please include correction suggestion by diff u to the plain text version or to the source Some quotes for new users Here are some interesting quotes from the Debian mailing list which may help enlighten new users e This is Unix It gives you enough rope to hang yourself Miquel van Smoorenburg lt miquels at cistron nl gt e Unix IS user friendly It s just selective about who its friends are Tollef Fog Heen lt tollef at add no gt Debian Reference 1 265 Chapter 1 GNU Linux tutorials I think learning a computer system is like learning a new foreign language Although tutorial books and documentation are helpful you have to practice it yourself In order to help you get started smoothly I elaborate a few basic points The powerful design of Debian GNU Linux comes from the Unix operating system i e a multiuser multitasking operating system Yo
85. modprobes d blacklist file The 1ib modules lt version gt modules dep file generated by the depmod 8 program describes module depen dencies used by the modprobe 8 program Debian Reference 84 265 Note If you experience module loading issues with boot time module loading or with modprobe 8 depmod a may resolve these issues by reconstructing modules dep The modinfo 8 program shows information about a Linux kernel module The 1smoa 8 program nicely formats the contents of the proc modules showing what kernel modules are currently loaded Tip You can identify exact hardware on your system See Section 9 6 3 Tip You may configure hardware at boot time to activate expected hardware features See Section 9 6 4 Tip You can add support for your device by recompiling kernel See Section 9 7 Debian Reference 85 265 Chapter 4 Authentication When a person or a program requests access to the system authentication confirms the identity to be a trusted one Warning l Configuration errors of PAM may lock you out of your own system You must have a rescue CD handy or setup an alternative boot partition To recover boot the system with them and correct things from there 4 1 Normal Unix authentication Normal Unix authentication is provided by the pam_unix 8 module under the PAM Pluggable Authentication Modules Its 3 important con
86. my own stupidity Personally I consider using sudo a better alternative to using the system from the root account all the time For example the following changes the owner of lt some_file gt to lt my_name gt sudo chown lt my_name gt lt some_file gt Of course if you know the root password as self installed Debian users do any command can be run under root from any user s account using su c Debian Reference 91 265 4 6 2 SELinux Security Enhanced Linux SELinux is a framework to tighten privilege model tighter than the ordinary Unix like security model with the mandatory access control MAC policies The root power may be restricted under some conditions 4 6 3 Restricting access to some server services For system security It is a good idea to disable as much server programs as possible This becomes critical for network servers Having unused servers activated either directly as daemon or via super server program are considered security risks Many programs such as ssha 8 use PAM based access control There are many ways to restrict access to some server services e configuration files etc default lt program_name gt e runlevel configuration for daemon e PAM Pluggable Authentication Modules e etc inetd conf for super server e etc hosts deny and etc hosts allow for TCP wrapper tcpd 8 e etc rpc conf for Sun RPC e etc at allow and etc at deny for at d 8 e etc cro
87. normally uses the traditional sysvinit scheme with the sysv rc package See init 8 inittab 5 and usr share doc sysv r c README runlevels gz for the exact explanation This main boot process essentially goes through the following 1 The Debian system goes into runlevel N none to initialize the system by following the etc inittab description 2 The Debian system goes into runlevel S to initialize the system under the single user mode to complete hardware initial ization etc 3 The Debian system goes into one of the specified multi user runlevels 2 to 5 to start the system services The initial runlevel used for multi user mode is specified with the init kernel boot parameter or in the initdefault line of the etc inittab The Debian system as installed starts at the runlevel 2 All actual script files executed by the init system are located in the directory etc init d Tip For alternative boot mechanism to the sysv rc package using a single configuration file etc runlevel conf see the file rc package Both mechanisms are compatible through etc init d rc etc init d rcs usr sbin update rc d and usr sbin invoke rc d scripts 3 5 1 The meaning of the runlevel Each runlevel uses a directory for its configuration and has specific meaning as the following You can change the runlevel from the console to e g 4 by the following sudo telinit 4 Debian Reference 80 265
88. not set up a repository so one must set it up manually One possible location for a repository isin srv svn project Create a directory by the following mkdir p srv svn project Create the repository database by the following svnadmin create srv svn project Debian Reference 223 265 10 8 2 Access to Subversion via Apache2 server If you only access Subversion repository via Apache2 server you just need to make the repository only writable by the WWW server by the following chown R www data www data srv svn project Add or uncomment the following in etc apache2 mods available dav_svn conf to allow access to the repos itory via user authentication lt Location project gt DAV svn SVNPath srv svn project 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 Create a user authentication file with the command by the following htpasswd2 c etc subversion passwd some username Restart Apache2 Your new Subversion repository is accessible at URL http localhost project and http example com project from svn 1 assuming your URL of web server is http example com 10 8 3 Local access to Subversion by group The following sets up Subversion repository for the local access by a group e g project chmod 2775 srv s
89. on the file location diff u file old file new gt file patch0 diff u old file new file gt file patchl 10 5 2 Merging updates for source files The diff file alternatively called patch file is used to send a program update The receiving party applies this update to another file by the following patch p0 file lt file patch0 S paren sol Elle lt wile percal 10 5 3 Updating via 3 way merge If you have three versions of a source code you can perform 3 way merge effectively using di f 3 1 by the following S diff3 m file mine file old file yours gt file 10 6 Version control systems Here is a summary of the version control systems VCS on the Debian system Note If you are new to VCS systems you should start learning with Git which is growing fast in popularity Debian Reference 215 265 command package popcon size description diff diff OS psize2 compare files line by line diff3 1 diff pa psize2 compare and merges three files line by line vimdiff 1 vim ERER psize2 compare 2 files side by side in vim patch 1 patch es ad psize2 apply a diff file to an original dpatch 1 dpatch aaa psize2 manage series of patches for Debian pac kag diffstat l diffstat li psize2 produce a histogram of changes by the diff combinediff 1 patchutil
90. on your host is connected to a Ethernet hub not to the broadband router e The Ethernet hub is connected to both the Internet and LAN network e The LAN network uses subnet 192 168 0 x 24 e Your host uses DHCP served IP address with the physical interface et hO for the Internet e Your host uses 192 168 0 1 with the virtual interface et hO 0 for the LAN The following stanzas in etc network interfaces configure your network iface eth0 inet dhcp metric 0 iface eth0 0 inet static address 192 168 0 1 PELIS 255 255 255 0 network 192 168 0 0 broadcast 19276820255 metrici ii Caution e Although this configuration example with network address translation NAT using netfilter iptables see Section 5 8 can provide cheap router for the LAN with only single interface there is no real firewall capability with such set up You should use 2 physical interfaces with NAT to secure the local network from the Internet Debian Reference 108 265 5 4 4 The advanced command syntax The ifupdown package offers advanced network configuration using the network configuration name and the network inter face name I use slightly different terminology from one used in ifup 8 and interfaces 5 manpage terminology my terminology examples in the following text physical interface name network interface name lo eth0 lt interface_name gt logical interface name network configuration name configl config2 lt config_
91. parameter meaning root use 3rd partition on the primary disk by setting it as hd0 2 in GRUB legacy or as hd0 3 in GRUB kernel use kernel located at vmlinuz with kernel parameter root dev hda3 ro initrd use initrd initramfs image located at initrd img Table 3 2 The meaning of GRUB parameters Note The value of the partition number used by GRUB legacy program is one less than normal one used by Linux kernel and utility tools GRUB 2 program fixes this problem Tip UUID see Section 9 3 2 may be used to identify a block special device instead of its file name such as dev hda3 e g root UUID 81b289d5 4341 4003 9602 e254al7ac232 ro Tip You can start a boot loader from another boot loader using techniques called chain loading See info grub and grub instal1 8 3 4 Stage 3 the mini Debian system The mini Debian system is the 3rd stage of the boot process which is started by the boot loader It runs the system kernel with 1ts root filesystem on the memory This is an optional preparatory stage of the boot process Note The term the mini Debian system is coined by the author to describe this 3rd stage boot process for this document This system is commonly referred as the initrd or initramfs system Similar system on the memory is used by the Debian Installer Debian Reference 79 265 The init script is executed as the first program in this root filesystem on
92. per1 1 and html pages provided by perl doc and perl d python G big S psizel python 1 and html pages provided by python doc tcl8 4 aoe a psizel tc1 3 and detail manual pages provided by tc18 4 doc tk8 4 Pa Er psizel tk 3 and detail manual pages provided by tk8 4 doc ruby oe a psizel ruby 1 and interactive reference provided by ri vim aX qe psizel help F1 menu provided by vim doc susv2 e es psizel fetch The Single Unix Specifications v2 susv3 aap psizel fetch The Single Unix Specifications v3 Table 12 1 List of packages to help programing Debian Reference 249 265 12 1 1 POSIX shell compatibility Many system scripts may be interpreted by any one of POSIX shells see Table 1 13 The default shell for the system is bin sh which is a symlink pointing to the actual program e bash 1 for Lenny or older e dash 1 for squeeze or newer Avoid writing a shell script with bashisms or zshisms to make it portable among all POSIX shells You can check it using checkbashisms 1 Good POSIX Avoid bashism if foo Sbar then if foo Sbar then diff u file c orig file c diff u file c orig mkdir foobar foobaz mkdir foo bar baz octal format 377 hexadecimal format xf Table 12 2 List of typical bashisms The echo command must be used with following cares since its implementation differs amo
93. proc sys contain interface to change certain kernel parameters at run time You may do the same through specialized sysct1 8 command or its preload configuration file etc sysctrl conf Note The Linux kernel may complain Too many open files You can fix this by increasing i1e max value to a larger value from the root shell e g echo 65536 gt proc sys fs file max This was needed on older kernels 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 content of your computer s memory It s used to debug the kernel It is a virtual file that points to computer memory so don t worry about its size The directory under sys contains exported kernel data structures their attributes and their linkages between them It also contains interface to change certain kernel parameters at run time n See proc txt gz sysfs txt gz and other related documents in the Linux kernel documentation usr sh are doc linux doc 2 6 Documentation filesystems x provided by the 1Linux doc 2 6 package 1 3 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 You may need to install the Midnight Commander package which is titled mc by the
94. regex c in the New Flat Package List view with 1 prompt This limits the package view only to regex matched packages i e removed but not purged All these regex matched packages can be shown by pressing at top level headings n Then you press marked to be purged by this You can exclude some packages to be purged by pressing at top level headings such as Installed Packages Only regex matched packages under the heading are interactively for each of them This technique is quite handy and works for many other command keys Debian Reference 52 265 2 3 4 Tidying auto manual install status Here is how I tidy auto manual install status for packages after using non aptitude package installer etc 1 Start aptitude in interactive mode as root Woo on 2 Type u U and g to update and upgrade package list and packages U 3 Type 1 to enter the package display limit as Packages as auto installed i R i Rrecommends i and type M over Installed n_n 4 Type 1 to enter the package display limit as prequired pimportant pstandard E and type m over Installed Packages as manual installed 5 Type 1 to enter the package display limit as i M and remove unused package by typing over each of them after exposing them by typing over Installed Packages om 6 Type 1 to enter the package display limit as i and type m over Tasks as man
95. s t es sa Re a eee ee 107 5 4 4 The advanced command syntax 2 2 ee 108 3 4 5 The mapping stanza 24 0 be eR a e Oe Ee we 108 5 4 6 The manually switchable network configuration 00000000020 eee 109 5 4 7 Scripting with the ifupdown system 2 2 0 000 pe ee 110 5 4 8 Mapping With guessnet 2 ee 111 The network configuration for desktop ee 111 5 5 1 GUI network configuration tools ooa ee 111 5 5 2 Automatic network configuration 2 2 0 e ee 112 The low level network configuration oaoa ee 113 5 6 1 Iproute2commands 2 pae aa a aa a E ee 113 5 6 2 Safe low level network operations 2 ee 113 Network optimization Pue ieee gok R aa Re Bh A A ee Se amp 113 5 7 1 Finding optimal MTU lt e e se e dR R RRR E R RR R RR ee 113 31 2 Setting MTU s su poe menka d e me eoa a a e a A eee we 115 3 1 3 WAN TCP optimization ssi ha gaea A A A che da E es 116 Netfilter infrastructure lt s s eeo R E R R R R RR R R R RRR RER RE RRR RR a 116 Debian Reference X 6 Network applications 117 6 1 Web browsers busca da dc da BA A OR a A a e A eee sde 117 6 1 1 Browser configuration s se sss e sesser esera nedre resa 117 62 The mall Ste e RO E e ee ee AOAC e we e ds 119 6 2 1 Modern mail service basics serenus eap eeki keea R RRR 119 6 2 2 The mail configuration strategy for workstation e 119 6 3 Mail transport agent MTA vocac
96. sets the metric via the SIF_METRIC variable The guessnet package see Section 5 4 8 which provides simple and powerful framework for the auto selection of the network configuration via the mapping mechanism also uses these Debian Reference 111 265 environment variable value passed SIFACE physical name interface name of the interface being processed SLOGICAL logical name configuration name of the interface being processed SADDRFAM lt address_family gt of the interface SMETHOD lt method_name gt of the interface e g static SMODE start if run from ifup stop if run from ifdown SPHASE as per SMODE but with finer granularity distinguishing the pre up post up pre down and p SVERBOSITY indicates whether verbose was used set to 1 if so 0 if not SPATH command search path usr local sbin usr local bin usr sbin usr bin s SIF_ lt OPTION gt value for the corresponding option under the iface stanza Table 5 14 List of environment variables passed by the ifupdown system Note For more specific examples of custom network configuration scripts using these environment variables you should check example scripts in usr share doc ifupdown examples and scripts used in ifscheme and ifupdown s cripts zg2 packages These additional scripts have some overlaps of functionalities with basic i fupdown extra and guessnet packages If you instal
97. single user workstation which you administer and where you are the only user Warning l Do not set up accounts of regular users on multiuser workstation like this because it would be very bad for system security Caution The password and the account of the penguin in the above example requires as much protection as the root password and the root account Caution Administrative privilege in this context belongs to someone authorized to perform the system administration task on the workstation Never give some manager in the Admin department of your company or your boss such privilege unless they are authorized and capable Note For providing access privilege to limited devices and limited files you should consider to use group to provide limited access instead of using the root privilege via sudo 8 Note With more thoughtful and careful configuration sudo 8 can grant limited administrative privileges to other users on a shared system without sharing the root password This can help with accountability with hosts with multiple administrators so you can tell who did what On the other hand you might not want anyone else to have such privileges Debian Reference 7 265 1 1 13 Play time Now you are ready to play with the Debian system without risks as long as you use the non privileged user account This is because the Debian system is even after the defa
98. 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 the last 3 digit of the numeric mode value should make sense as an octal radix 8 representation of file permissions to you For example try the following Debian Reference 11 265 touch foo bar chmod u rw go r foo chmod 644 bar lg 1 oo loa ieee 1 penguin penguin 17 2007 04 29 08 22 bar EW 18 e 1 penguin penguin 12 2007 04 29 08 22 foo UL UY Ur U Tip If you need to access information displayed by 1s 1 in shell script you should use pertinent commands such as test 1 stat 1 and readlink 1 The shell builtin such as or test may be used too 1 2 4 Control of permissions for newly created files umask What permissions are applied to a newly created file or directory is restricted by the umask shell builtin command See dash 1 bash 1 and builtins 7 file permissions requested file permissions umask value umask file permissions created directory permissions created usage 0022 rw r 4r rwxr xr x writable only by the user 0002 rw rw r IWXIWXYI X writable by the group Table 1 6 The umask value examples The Debian system uses a user private group UPG scheme as its default A UPG is created whenever a new user is added
99. specific package o o 45 Basic package management operations with commandline using apt itude 8 and apt get 8 apt cache 8 45 Notable command options for aptitude 8 2 ee 46 List of key bindings for aptitude 2 ee 47 Listof views for aptitude ss s seas BR ee ee RD Re ER Re ea eee 47 The categorization of standard package views 2 2 ee 48 List of the aptitude regex formula 2 ee 49 The log files for package activities ee 50 List of advanced package management operations 1 2 0 a 54 The content of the Debian archive metadata ooa ee 56 The name structure of Debian packages 1 ee 39 The usable characters for each component in the Debian package names o o 59 The notable files created by pk 60 List of the default Pin Priority value for each package source type o o o ee 66 List of the proxy tools specially for Debian archive a 71 Listot bont loaders pss sore 4 28545 eaka a a a e R TI The meaning of GRUB parameters 2 ee 78 List of runlevels and description of theirusage 2 ee 80 Listiof Kernel error levels x 54 K sd A om amp eR Rey eg HE ESS ee Be wed adie amp 4 83 3 important configuration files forpam_unix 8 saaa e 85 The second entry content of f etc passwd 2 ee 86 List of commands to manage account information oao ee 87 List of tools to generate password 2 1 ee 88 List of notable PAM and N
100. swapon a 9 4 3 Automatically encrypting files with eCryptfs You can encrypt files written under Private automatically using eCryptfs and the ecrypt fs utils package e Runecryptfs setup private l and set up Private by following prompts e Activate Private by running ecrypt fs mount private l e Move sensitive data files to Private and make symlinks as needed Candidates fetchmailrc ssh identity ssh id_rsa ssh id_dsa and other files with go rwx e Move sensitive data directories to a subdirectory in Private and make symlinks as needed Candidates gnupg and other directories with go rwx e Create symlink from Desktop Private to Private for easier desktop operations e Deactivate Private by running ecryptfs umount private l e Activate Private by issuing ecryptfs mount private as you need encrypted data Tip Since eCryptis selectively encrypt only the sensitive files its system cost is much less than using dm crypt on the entire root or home device It does not require any special on disk storage allocation effort but cannot keep all filesystem metadata confidential 9 4 4 Automatically mounting eCryptfs If you use your login password for wrapping encryption keys you can automate mounting eCryptfs via PAM Pluggable Authen tication Modules Insert the following line just before pam_permit so in etc pam d common auth auth re
101. system unusable The serious Debian system administrator who runs mission critical servers should use extra precautions e Do not install any packages including security updates from Debian without thoroughly testing them with your particular configuration under safe conditions You as the system administrator are responsible for your system in the end The long stability history of Debian system is no guarantee by itself 2 1 3 Life with eternal upgrades Despite my warnings above I know many readers of this document wish to run the testing or unstable suites of Debian as their main system for self administered Desktop environments This is because they work very well are updated frequently and offer the latest features Caution I For your production server the st able suite with the security updates is recommended The same can be said for desktop PCs on which you can spend limited administration efforts e g for your mother s PC It takes no more than simply setting the distribution string in the etc apt sources 1list to the suite name testi ng or unstable or the codename codename testing or codename unstable This makes you live the life of eternal upgrades The use of testing or unstable is a lot of fun but comes with some risks Even though the unstable suite of Debian system looks very stable for most of the times there have been some package problems on the testi
102. task 2 2 5 Search method options with aptitude Aptitude offers several options for you to search packages using its regex formula e Shell commandline aptitude search lt aptitude_regex gt to list installation status package name and short description of match ing packages aptitude show lt package_name gt to list detailed description of the package e Interactive full screen mode 1 to limit package view to matching packages for search to a matching package for backward search to a matching package n for find next N for find next backward Tip The string for lt package_name gt is treated as the exact string match to the package name unless it is started explicitly with to be the regex formula 2 2 6 The aptitude regex formula The aptitude regex formula is mutt like extended ERE see Section 1 6 2 and the meanings of the aptitude specific special match rule extensions are as follows e The regex part is the same ERE as the one used in typical Unix like text tools using x etc as in egrep 1 awk 1 and per1 1 e The relation lt type gt is one of depends predepends recommends suggests conflicts replaces provides e The default relation type is depends Debian Reference 49 265 description of the extended match rule regex formula match on package name n lt regex_name match on description
103. the Debian system Several actions are required to enable this I have not used this setup and the following is purely secondary information Please read this in this context e You set up a centralized LDAP server by running program such as stand alone LDAP daemon slapd 8 e You change the PAM configuration files in the etc pam d directory to use pam_ldap so instead of the default pam_unix so Debian uses etc pam_ldap conf as the configuration file for 1ibpam 1dap and etc pam_1dap secret as the file to store the password of the root e You change the NSS configuration in the etc nsswitch conf file to use 1dap instead of the default compat or file Debian uses etc libnss 1ldap contf as the configuration file for 1ibnss 1dap e You must make 1ibpam 1dap to use SSL or TLS connection for the security of password Debian Reference 90 265 e You may make libnss 1dap to use SSL or TLS connection to ensure integrity of data at the cost of the LDAP network overhead e You should run nscd 8 locally to cache any LDAP search results in order to reduce the LDAP network traffic See documentations in pam_ldap conf 5 and usr share doc libpam doc html offered by the 1ibpam d oc package and info libc Name Service Switch offered by the glibc doc package Similarly you can set up alternative centralized systems with other methods e NIS originally called YP or NIS with older Unix lik
104. the following sensible pager etc passwd A directory name is referred by the typewriter font between double quotation marks such as etc init d You are encouraged to explore its contents by typing the following S me Y erto ame sC A package name is referred by its name in the typewriter font such as vim You are encouraged to obtain information by typing the following Debian Reference S dpkg L vim apt cache show vim aptitude show vim A documentation may indicate its location by the filename in the typewriter font between double quotation marks such as usr share doc sysv rc README runlevels gz and usr share doc base passwd users and groups html or by its URL such as http www debian org You are encouraged to read the documentation by typing the following S zcat usr share doc sysv rc README runlevels gz sensible pager sensible browser usr share doc base passwd users and groups html S sensible browse http www debian org An environment variable is referred by its name with leading in the typewriter font between double quotation marks such as STERM You are encouraged to obtain its current value by typing the following Se Chou omen Mus Debian BTS Astarisk placed right after each package name is linked to Debian bug tracking system BTS of each package The popcon The popcon data is presented as the objective measure for the popularity of
105. the following RED printf xlb 31m NORMAL printf xlb 0m REVERSESS printf xlb 7m echo S RED RED TEXTS NORMAL REVERSE REVERSE UN Ur i Ur H EXTS NORMAL 9 2 7 Colorized commands Colorized commands are handy for inspecting their output in the interactive environment I include the following in my bashrc IS TERM no Asa small Y clilicicioulloses 904 alias ls ls color always alias 11 1s color always 1 alias la ls color always A alias less less R alias ls ls color always alias grep grep color always alias egrep egrep color always alias fgrep fgrep color always alias zgrep zgrep color always else alias ILS Ls i alias la ls A Ea The use of alias limits color effects to the interactive command usage It has advantage over exporting environment variable export GREP_OPTIONS color auto since color can be seen under pager programs such as less 1 If you wish to suppress color when piping to other programs use color auto instead in the above example for bashrc Tip You can turn off these colorizing aliases in the interactive environment by invoking shell with TERM dumb bash Debian Reference 9 2 8 Recording the editor activities for complex repeats You can record the editor activities for complex repe
106. the updated local source tree to Subversion by the following svn ci m Describe change Create and add file_to_ada file to Subversion by the following vi file to_add e sia ace rila to ace svn ci m Added file _to_add Merge the latest version from Subversion by the following S svn up Watch out for lines starting with C filename which indicates conflicting changes Look for unmodified code in e g filename r6 filename r9 and filename mine Search for lt lt lt lt lt lt lt and gt gt gt gt gt gt gt in files for conflicting changes Edit files to fix conflicts as needed Add a release tag Release 1 by the following svn ci m last commit for Release 1 svn cp file srv svn project modulel trunk file srv svn project modulel tags Release gt f Edit further Remove the release tag Release 1 by the following svn rm file srv svn project modulel tags Release 1 Check in changes to Subversion by the following svn ci m real last commit for Release 1 Re add the release tag Release 1 from updated Subversion HEAD of trunk by the following svn cp file srv svn project modulel trunk file srv svn project modulel tags Release gt T Create a branch with a path nodule1 branches Release initial bugfixes from the original version pointed by the path modulel tags Release initial and check it out to path to old directory by the following
107. this emergency downgrading Tip lt is good idea to remove not purge as much packages to minimize dependency problems You may need to manually remove and install some packages to get system downgraded Linux kernel bootloader udev PAM APT and networking related packages and their configuration files require special attention 2 7 8 Who uploaded the package Although the maintainer name listed in var lib dpkg available and usr share doc package_name ch angelog provide some information on who is behind the packaging activity the actual uploader of the package is somewhat obscure who uploads 1 in the devscripts package identifies the actual uploader of Debian source packages 2 7 9 The equivs package If you are to compile a program from source to replace the Debian package it is best to make it into a real local debianized package x deb and use private archive If you chose to compile a program from source and to install them under usr local instead you may need to use equivs as a last resort to satisfy the missing package dependency 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 Debian Reference 71 265 2 7 10 Porting a package to the stable system For partial upgrades of the stable system rebuilding a package within its enviro
108. to cdrom i moune E 1209660 0 ro loco chise eckeom Tip Modern desktop system mounts removable media automatically see Section 10 1 10 10 3 The binary data Here we discuss direct manipulations of the binary data on storage media See Section 9 3 too 10 3 1 Viewing and editing binary data The most basic viewing method of binary data is to use od t x1 command Tip HEX is used as an acronym for hexadecimal format with radix 16 OCTAL is for octal format with radix 8 ASCII is for American Standard Code for Information Interchange i e normal English text code EBCDIC is for Extended Binary Coded Decimal Interchange Code used on IBM mainframe operating systems 10 3 2 Manipulating files without mounting disk There are tools to read and write files without mounting disk 10 3 3 Data redundancy Software RAID systems offered by the Linux kernel provide data redundancy in the kernel filesystem level to achieve high levels of storage reliability There are tools to add data redundancy to files in application program level to achieve high levels of storage reliability too Debian Reference 207 265 package popcon size description coreutils ee O psize1 basic package which has od 1 to dump files HEX ASCI OC bsdmainutils es psizel utility package which has ha 1 to dump files HEX ASCII Ot hexedit ACA psize1 binary editor and viewer HEX
109. to install from unstable archive in my experience so far Here is another example of apt pinning technique to include specific newer upstream version packages found in experimen tal while tracking unstable You list all required archives in the etc apt sources list file as the following Debian Reference 68 265 deb http ftp us debian org debian unstable main contrib non free deb http ftp us debian org debian experimental main contrib non free deb http security debian org testing updates main contrib The default Pin Priority value for experimental archive is always 1 lt lt 100 since it is NotAutomatic archive see Sec tion 2 5 3 There is no need to set Pin Priority value explicitly in the etc apt preferences file just to use experi mental archive unless you wish to track particular packages in it automatically for next upgrading 2 7 4 Volatile and Backports org There are debian volatile project and backports org archives which provide updgrade packages for stable Warning I Do not use all packages available in the NotAutomatic archives such as codename stable backpor ts and volatile sloppy Use only selected packages which fits your needs l Caution backports org is a non Debian archive although its packages are signed by Debian developers Caution Archive level Release files see Section 2 5 3 are used for the rule of apt_preference
110. unstable Component main Origin Debian Label Debian Architecture amd64 Caution I For Archive stanza suite names stable testing unstable are used in the Debian archive while codenames dapper feisty gutsy hardy intrepid are used in the Ubuntu archive For some archives such as experimental volatile sloppy and codename stable backports which contain packages which should not be installed automatically there is an extra line e g http ftp us debian org debian dists experimental main binary amd64 Release as follows Archive experimental Component main Origin Debian Label Debian NotAutomatic yes Architecture amd64 Please note that for normal archives without NotAutomatic yes the default Pin Priority value is 500 while for special archives with NotAutomatic yes the default Pin Priority value is 1 see apt_preferences 5 and Section 2 7 3 Debian Reference 58 265 2 5 4 Fetching of the meta data for the package When APT tools such as aptitude apt get synaptic apt file auto apt are used we need to update the local copies of the meta data containing the Debian archive information These local copies have following file names corre sponding to the specified distribution component and architecture names in the etc apt sources list see Section 2 1 4 e var lib apt lists ftp us debian org_debian_dists _ lt distrib
111. we ee 219 10 7 8 Latest files from CVS 2 24054 gece a a EE do Eai bs 221 10 7 9 Administration of CVS aaau a a 222 10 7 10 Execution bit for CVS checkout ee 222 SUDVERSION 6 edad de is E E GA 222 10 8 1 Configuration of Subversion repository 222 10 8 2 Access to Subversion via Apache2 server a 223 10 8 3 Local access to Subversion by group ee 223 10 8 4 Remote access to Subversion via SSH a 223 10 8 5 Subversion directory structure ee 223 10 8 6 Importing a new source to Subversion 2 2 ee 224 10 8 7 Work flow of Subversion 9 ee 224 Gilby eroa eb a Soe Raho ee Pe ad a Sw 227 10 9 1 Configuration of Git client 2 a 227 109 2 Git referentes ir is oe ae he a BES Gel SE SE 221 10 93 Git commands s 225 Les bee pee RR a a a Sem 228 10 9 4 Git for recording configuration history 228 Debian Reference 11 Data conversion 11 1 Text data Conversion tools s ea errar A A bw we A amp 11 1 1 11 1 2 11 1 3 11 1 4 11 1 5 11 1 6 11 1 7 11 1 8 Converting a text file with icony 2 2 a Checking file to be UTF 8 with iconv 2 2 2 2 2 0 0 000000000000 Converting file names With iconv ooa EOL Conversion sorok apa be a d E ek ew ee a ad e GR a a TAB conversion sa oc a a ee eA e a A Editors with auto conversion 2 ee Plain text extraction eri ee Sa Ra o RS Bae Re ah a S Gago Oo Highlighting and formatting plain text data
112. with a group of files without typing all of them The filename expansion pattern using the shell glob sometimes referred as wildcards facilitate this need shell glob pattern description of match rule filename segment not started with ak filename segment started with exactly one character Wot el Lass exactly one character with any character enclosed in brackets a z exactly one character with any character between a and z Sore exactly one character other than any character enclosed in brackets excluding Table 1 20 Shell glob patterns For example try the following E usp cl Wiles Onen I este Bock BoC ala SEIS co Go Ere echo x txt SIG 2 ESE echo pic Asitxe Soc Lula echo he oe ola echo x SOc o6 Gate S echo s l olz TIERE 5 G ices S echo 1 3 t UR Sep E H dp U S Cel enp Tm ie ile See glob 7 Debian Reference 28 265 Note Unlike normal filename expansion by the shell the shell pattern x tested in find 1 with name test etc matches the initial of the filename New POSIX feature Note BASH can be tweaked to change its glob behavior with its shopt builtin options such as dot glob noglob nocaseg lob nullglob nocaseglob extglob etc See bash 1 1 5 7 Return value of the command Each command returns its exit status variable as the return value command exit st
113. writable directories such as tmp or in group writable directories one must not only reset the write permission 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 file permissions S ls 1 etc passwd etc shadow dev ppp usr sbin exim4 Ciy Lia oe TOS 0 2007 04 29 07 00 dev pee rw r r 1 root root 1427 2007 04 16 00 19 etc passwd rw r 1 root shadow 943 2007 04 16 00 19 etc shadow rwsr xr x 1 root root 700056 2007 04 22 05 29 usr sbin exim4 ls ld tmp var tmp usr local var mail usr srce drwxrwxrwt 10 root root 4096 2007 04 29 07 59 tmp drwxrwsr x 10 root staff 4096 2007 03 24 18 48 usr local drwxrwsr x 4 root src 4096 2007 04 27 00 31 usr sre drwxrwsr x 2 root mail 4096 2007 03 28 23 33 var mail drwxrwxrwt 2 root root 4096 2007 04 29 07 11 var tmp There is an alternative numeric mode to describe file permissions with chmod 1 This numeric mode uses 3 to 4 digit wide octal radix 8 numbers digit meaning Ist optional digit sum of set user ID 4 set group ID 2 and sticky bit 1 2nd digit sum of read 4 write 2 and execute 1 permissions for user 3rd digit ditto for group 4th digit ditto for other Table 1 5 The numeric mode for file permissions in chmod 1 commands This
114. x86_64 pc stagel Note gdb 1 may be used to disassemble code interactively 12 5 Flex a better Lex Flex is a Lex compatible fast lexical analyzer generator Tutorial for 1ex 1 can be found in info flex You need to provide your own main and yywrap Otherwise your flex program should look like this to compile without a library This is because that yywrap is a macro and Soption main turns on Soption noyywrap implic itly oe option main oe n BCHOM ae Gy Jo Alternatively you may compile with the 1 f1 linker option at the end of your cc 1 command line like AT amp T Lex with 11 No Soption is needed in this case 12 6 Bison a better Yacc Several packages provide a Yacc compatible lookahead LR parser or LALR parser generator in Debian package popcon size description bison on a psizel1 GNU LALR parser generator byacc E O popcont s psize1 Berkeley LALR parser generator btyacc ee psizel1 backtracking parser generator based on byacc Table 12 15 List of Yacc compatible LALR parser generators Tutorial for bison 1 can be found in info bison n You need to provide your own main and yyerror main calls yyparse which calls yylex usually created with Flex S oe oe o 12 7 Autoconf Autoconf is a tool for producing shell scripts that automatically configure software source code
115. you need to have root privilege 2 2 1 Basic package management operations with commandline Here are basic package management operations with commandline using apt itude 8 and apt get 8 apt cache 8 aptitude syntax apt get apt cache syntax description aptitude update apt get update update package archive metadata install foo aptitude apt get install foo install candidate version of foo package wi aptitude safe upgrade install candidate version of installed packages apt get upgrade aptitude full upgrade apt gen EOS install candidate version of installed packages lt package gt aptitude remove foo apt get remove foo remove foo package while leaving its confi N A apt get autoremove remove auto installed packages which is no lo aptitude purge foo apt get purge foo purge foo package with its configuration fil aptitude clean apt get clean clear out the local repository of retrieved pack aptitude autoclean apt get autoclean clear out the local repository of retrieved pack aptitude show foo apt cache show lt package gt display detailed information about foo pach aptitude search lt regex gt apt cache search lt regex gt search packages which match lt regex gt aptitude why lt regex gt N A explain the reason why lt regex gt matching pac aptitude why not lt regex gt N A explain the reason why lt regex gt matching pac Table
116. your menu 7 8 The X trivia 7 8 1 Keymaps and pointer button mappings in X xmodmap 1 is a utility for modifying keymaps and pointer button mappings in the X Window System To get the keycode run xev 1 in the X and press keys To get the meaning of keysym look into the MACRO definition in usr include X11 k eysymdef h file x11proto core dev package All define statements in this file are named as XK_ prepended to keysym names Debian Reference 147 265 package popcon package size type description openoffice org writer O RRR psizel1 OO word processor openoffice org calc eas psizel1 OO spreadsheet openoffice org impress oer psizel OO presentation openoffice org base E m psizel OO database management openoffice org draw o E S psizel OO vector graphics editor draw openoffice org math none S psizel1 OO mathematical equation formula editor abiword gaa sd psizel GNOME word processor gnumeric E RO Ge psizel1 GNOME spreadsheet gimp ae SE psizel1 GTK bitmap graphics editor paint inkscape P operonte psizel1 GNOME vector graphics editor draw dia gnome S S psizel1 GNOME flowchart and diagram editor planner A Es psizel1 GNOME project management kword eee al psizel1 KDE word processor kspread GR aan psizel1 KDE spreadsheet kpresent
117. 1 trace communication between X11 client and server powertop aaa Es psizel powertop 1 information about system power use on Intel based lapt cron aoe GE psizel run processes according to a schedule in background from cron 8 dae anacron G SES psizel cron like command scheduler for systems that don t run 24 hours a day at S S psizel at 1 or batch 1 run ajob at a specified time or below certain load Table 9 10 List of tools for monitoring and controlling program activities nice value scheduling priority 19 lowest priority process nice 0 very high priority process for user 20 very high priority process for root not nice Table 9 11 List of nice values for the scheduling priority style typical command feature BSD ps aux display CPU MEM System V ps efH display PPID Table 9 12 List of ps command styles Debian Reference 172 265 command key description of response hor show help E set reset display field o reorder display field F set sort key field k kill a process e renice a process q quit the t op command Table 9 13 List of commands for top 9 5 4 The top command top 1 on the Debian has rich features and helps to identify what process is acting funny dynamically 9 5 5 Listing files opened by a process You can list all files opened by a process with a process ID PID e g 1 by the fo
118. 11 4 3 Pretty print a manual page You can print a manual page in PostScript nicely by one of the following commands man Tps some_manpage lpr man Tps some_manpage mpage 2 lpr The second example prints 2 pages on one sheet 11 4 4 Creating a manual page Although writing a manual page manpage in the plain troff format is possible there are few helper packages to create it 11 5 The mail data conversion The following packages for the mail data conversion caught my eyes Tip The Internet Message Access Protocol version 4 IMAP4 server see Section 6 7 may be used to move mails out from proprietary mail systems if the mail client software can be configured to use IMAP4 server too Debian Reference 243 265 package popcon size keyword description docbook to man as er psizel1 SGML manpage converter from DocBook SGML into roff r help2man A E psizel text manpage automatic manpage generator from help info2man SE S psize1 info manpage converter from GNU info to POD or man p txt2man a SEO psize1 text manpage convert flat ASCII text to man page format Table 11 15 List of packages to help creating the manpage package popcon size keyword description sharutils inant psizel1 mail shar 1 unshar 1 uuencode 1 uudecod mpack A S psizel1 MIME encoder and decoder MIME messages mpack 1 tnef aia p
119. 2 1 4 coje sk alin se oeseP Elo aie Us aa ecomuecine Es y dio come e find 1 and xargs 1 combination find type maxdepth 1 name ext printO xargs 0 n 1 command e fina 1 with exec option with a command find type f maxdepth 1 name ext xec command e fina 1 with exec option with a short shell script find type f maxdepth 1 name x ext Se sa e Ucomnmancde 0 e Eco success ale No The above examples are written to ensure proper handling of funny file names such as ones containing spaces See Section 10 1 5 for more advance uses of find 1 9 5 10 Starting a program from GUI You can set up to start a process from graphical user interface GUI Under GNOME desktop environment a program can be started with proper argument by double clicking the launcher icon by drag and drop of a file icon to the launcher icon or by Open with menu via right clicking a file icon KDE can do the equivalent too Here is an example under GNOME to create a launcher icon for mc 1 started in gnome terminal Create an executable program mc term by the following cat gt usr local bin mc term lt lt EOF bin sh gnome terminal e mc 1 1 EOF chmod 755 usr local bin mc term Create a desktop launcher as the following 1 Right click desktop space to select Create Launcher Set Type to Application Set Name to mc Set Comman
120. 2 6 Basic package management operations with commandline using apt itude 8 and apt get 8 apt cache 8 Although it is now safe to mix different package tools on the Debian system it is best to continue using aptitude as much as possible The difference between safe upgrade upgrade and full upgrade dist upgrade only appears when new versions of packages stand in different dependency relationships from old versions of those packages The aptitude saf e upgrade command does not install new packages nor remove installed packages The aptitude why lt regex gt can list more information by aptitude v why lt regex gt Similar information can be obtained by apt cache rdepends lt package gt When aptitude command is started in the commandline mode and faces some issues such as package conflicts you can switch non to the full screen interactive mode by pressing e key later at the prompt You may provide command options right after aptitude See aptitude 8 and aptitude user s manual at usr share doc aptitude README for more Debian Reference 46 265 command option description s simulate the result of the command d download only but no install upgrade D show brief explanations before the automatic installations and removals Table 2 7 Notable command options for apt itude 8 Tip The dselect package is still available and was the preferred full screen intera
121. 265 CDPATH usr share doc Desktop src Desktop export CDPATH PATH S PATH usr sbin sbin set PATH so it includes user s private bin if it exists if d bin then PATH bin S PATH Ea export PATH EDITOR vim export EDITOR Tip You can find more bash customization tips such as Section 9 2 7 in Chapter 9 1 4 3 Special key strokes In the Unix like environment there are few key strokes which have special meanings Please note that on a normal Linux character console only the left hand Ct r1 and Alt keys work as expected Here are few notable key strokes to remember key description of key binding ctri U erase line before cursor Ctrl H erase a character before cursor Ctrl D terminate input exit shell if you are using shell Ree terminate a running program Ctrl Z temporarily stop program by moving it to the background job CELLS halt output to screen CErl 0 reactivate output to screen Ctrl Alt Del reboot halt the system see inittab 5 Left Alt key optionally Windows key meta key for Emacs and the similar UI Up arrow start command history search under bash Ctrl R start incremental command history search under bash Tab complete input of the filename to the command line under bash Ctrl V Tab input Tab without expansion to the command line under bash Table 1 14 List of key bindings for bash Tip The terminal feature of C
122. 3 steps 1 Update the list of available locales 2 Compile them into the binary form 3 Set the system wide default locale value in the etc defaults locale for use by PAM see Section 4 5 Debian Reference 154 265 The list of available locale should include en_US UTF 8 and all the interesting languages with UTF 8 The recommended default locale is en_US UTF 8 for US English For other languages please make sure to chose locale with UTF 8 Any one of these settings can handle any international characters Note Although setting locale to C uses US English message it handles only ASCII characters 8 3 4 The value of the SLANG environment variable The value of the SLANG environment variable is set and changed by many applications e Set initially by the PAM mechanism of 10gin 1 for the local Linux console programs e Set initially by the PAM mechanism of the display manager for all X programs e Set initially by the PAM mechanism of ssh 1 for the remote console programs e Changed by some display manager such as gdm 1 for all X programs e Changed by the X session startup code via xsessionrc for all X programs lenny feature e Changed by the shell startup code e g bashrc for all console programs Tip It is good idea to install system wide default locale as en_US UTF 8 for maximum compatibility 8 3 5 Specific locale only under X Window You can chose specific locale only und
123. 464 Device Boot Start End Blocks Id System dev loop0pl1 il 600 4819468 83 Linux dev loop0p2 601 652 417690 83 Linux mkdir p mnt loop0pl mount t ext3 dev loop0p1 mnt loop0pl mkdir p mnt loop0p2 mount t ext3 dev loop0p2 mnt loop0p2 Debian Reference 204 265 o 0 o MES A gt 6 MEC 5 STE umount dev loop0pl umount dev loop0p2 losetup d dev loop0 Alternatively similar effects can be done by using the device mapper devices created by kpartx 8 from the kpartx package as follows goce EL E LH HIST mkdir p mnt loop0p2 mount t ext3 dev mapper loop0p2 mnt loop0p2 CI CE umount dev mapper loop0p2 kpartx d mnt loop0 Note You can mount a single partition of such disk image with loop device using offset to skip MBR etc too But this is more error prone 10 2 4 Cleaning a disk image file A disk image file disk img can be cleaned of all removed files into clean sparse image new img by the following mkdir old mkdir new mount E SRDE OM STO SRo dd bs 1 count 0 if dev zero of new img seek 5G mount t auto o loop new img new edmond cp a sparse always new ed umount new img umount disk img If disk img is in ext2 or ext3 you can also use zerofree 8 from the zerofree package as follows losetup f v disk img Loop device is dev loop3 zerofree dev loop3 cp sparse always disk img new img 10 2 5 Making the empty dis
124. 48 155 8 3 8 Effects of the locale mt pas e Get beeen dd head wee OSS AA 4 155 9 System tips 156 9 1 The escreen prostam cs dE EDR e A a EE a de da 156 9 1 1 The use scenario for screen 1 ooa aa ee 156 9 1 2 Key bindings for the screen command 2 0 0 0 2 ee ee 157 9 2 Data recording and presentation osoo ee 157 9 2 1 Thelog daemon nos s e cederet herea Dere ee ERA ee RD A ae be a ee 157 9 2 2 Log analyzer lt s ios aeck gel eb been a a E a 157 9 2 3 Recording the shell activities cleanly o ooo o 159 9 2 4 Customized display of text data 2 2 2 ee 159 9 2 5 Customized display of time and date 000 0 2000000002022 ee 159 9 2 6 Colorized shell echo lt s ss oe ee ee ee ee ee eee ee ee ee 160 9 2 7 Colorized commands 3 60645 2 6s eee e OY RR RRR R NR RR A 160 9 2 8 Recording the editor activities for complex repeats o 00 00 0000 0002 2 ee 161 9 2 9 Recording the graphic image of an X application o o 00000000004 161 9 2 10 Recording changes in configuration files 2 2 0 0 0 0200000020 ee eee 161 9 3 Datastoragetips os toai d 0s eee ibad bo Pee oe Se be ba e ea eee ee a E 162 9 3 1 Disk partition configuration 2 2 162 9 3 2 Accessing partition using UUID 2 000 000 000002 ee 163 9 3 3 Filesystem configuration s ose se eR A AER EARS e eS 163 9 3 4 Filesystem creation and integrity check o o e 164
125. 64356455 255456 e a it ES 76 3 3 Stage 2 the boot loader mcr alee RRR A Re e bE RRR A ee a E 7I 3 4 Stage 3 the mini Debian system 78 3 5 Stage 4 the normal Debian system ee 79 3 5 1 The meaning of the runlevel 2 5c Re RR lt lt seme de 79 3 5 2 The configuration of the runlevel 80 3 5 3 The runlevel management example 2 000002 eee 81 3 5 4 The default parameter for each init script 2 2 2 2 0 0 0000000000000 200004 81 320 0 The hostnames occ a Be ee ee ee Ga Se a i ee eee GS a 81 Debian Reference 3 5 6 3 5 7 3 5 8 3 5 9 3 5 10 3 5 11 3 5 12 The les ystems jas e ER A e Ae a ee eS Network interface initialization ee Network service initialization ee The Systenmimessale susia oe a Sy ae ee Rk Se eet ee Ee es WS Ree ee 3 The kernel Message oc chop ee A RR GOS eS Se ee A A A RE Oe A ee Ae Theudev system lt a corans T E R een bau ai eeetakeaew vee eee eee baba ee ds The kernel module initialization 2 De 4 Authentication 4 1 42 43 44 4 5 4 6 4 7 Normal Unix authentication 2 a Managing account and password information oaoa a Good password oeer bb eA ee A we ee ea eae ee Creating encrypted password s ccecce p R RRR R t es RR RR NER N RRR R R RRR RRR PAM and NSS eaea 6 6 R oe Eats ee A A AE EA AR oy 4 5 1 Configuration files accessed by the PAM and NSS o e 4 5 2 The modern centralized system m
126. 7 1 Compile and install a progra 261 12 7 2 Uninstall program 2 e S E ZE E E RAE R TN E A 261 12 8 Perl short script madness o os e e e e e e R R R R R dete es RRR RRR RRR RR RR 261 1290 Web cami dd Gos a Pe See da a es Ga a da e a 262 12 10The source code translation 262 12 11Making Debian package a 262 A Appendix 264 Ad The DEDIAA Maze s pee ii BRR EE E E Ye eee so 264 A2 Copyright history se AA A R RRR KR A a ek 264 A 3 Document Tormgt gt sss so cama eera d RRR ee 265 Debian Reference xviii List of Tables 1 1 List of interesting text mode program packages o oo ee 3 1 2 List of informative documentation packages 2 2 ee 5 1 3 List of usage of key directories 8 1 4 List of the first character of Ls L output osoa 9 1 5 The numeric mode for file permissions in chmod 1 commands 00 002 eee eee 10 1 6 The umask value examples 0 0 0000 pe ee 11 1 7 List of notable system provided groups for file access o o e e 12 1 8 List of notable system provided groups for particular command executions osoo e 12 1 9 List of types of timestamps ooo 0 0 02 12 1 10 Listor special device heg p oos 43 3 earo aa a ir RRR a PE RE e 16 1 11 The Key bindings of MC esop o eee e a e a eee RR BR EP KE ee ee es 8 7 1 12 The reaction to the enter key in MC 2 20 00 0020 00000002 2 ee 19 1 13 Listof shell programs estais ee o
127. 8N and LION Chapter 8 supports The status file is also used by the tools such as dpkg 1 dselect update and apt get ade u dselect upgr The specialized search command grep dct r1 1 can search the local copies of status and available meta data Tip In the debian installer environment the udpkg command is used to open udeb packages The udpkg command is a stripped down version of the dpkg command 2 5 10 The update alternative command The Debian system has mechanism to install somewhat overlapping programs peacefully using update alternatives 8 For example you can make the vi command select to run vim while installing both vim and nvi packages Debian Reference 60 265 file description of contents A A eee list of configuration files user modifiable var lib dpkg info lt package_name gt list list of files and directories installed by the package var lib dpkg info lt package_name gt md5sums list of MDS hash values for files installed by the package var lib dpkg info lt package_name gt preinst package script run before the package installation li info lt gt in E Eee we eg E N aa package script run after the package installation var lib dpkg info lt package_name gt prerm package script run before the package removal var lib dpkg info lt package_name gt postrm package script run after the package removal var lib dpkg info lt package_name
128. 96 265 Caution e When editing the etc udev rules d 70 persistent net rules rules file you must keep each rule on a single line and the MAC address in lowercase For example if you find Firewire device and PCI device in this file you probably want to name PCI device as et hO and configure it as the primary network interface 5 1 4 The network address range for the LAN Let us be reminded of the IPv4 32 bit address ranges in each class reserved for use on the local area networks LANs by rfc1918 These addresses are guaranteed not to conflict with any addresses on the Internet proper Class network addresses net mask net mask bits of subnets A 10 x x x 255 0 0 0 8 1 B 172 16 x x 172 31 x x 255 255 0 0 16 16 C 192 168 0 x 192 168 255 x 255 255 255 0 24 256 Table 5 1 List of network address ranges Note If one of these addresses is assigned to a host then that host must not access the Internet directly but must access it through a gateway that acts as a proxy for individual services or else does Network Address Translation NAT The broadband router usually performs NAT for the consumer LAN environment 5 1 5 The network configuration infrastructure There are 2 types of low level networking programs for Linux networking system see Section 5 6 1 e Old net tools programs i fconfig 8 are from the Linux NET 3 networking system Most of these
129. AB o with set expandtab and retab command sequence You can revert this with set noexpandtab and retab command sequence 11 1 6 Editors with auto conversion Intelligent modern editors such as the vim program are quite smart and copes well with any encoding systems and any file formats You should use these editors under the UTF 8 locale in the UTF 8 capable console for the best compatibility An old western European Unix text file u file txt stored in the latin iso 8859 1 encoding can be edited simply with vim by the following S yim verile txt This is possible since the auto detection mechanism of the file encoding in vim assumes the UTF 8 encoding first and if it fails assumes it to be latin1 An old Polish Unix text file pu file txt stored in the latin2 iso 8859 2 encoding can be edited with vim by the following G vim te enc latin2 pu file txt An old Japanese unix text file ju file txt stored in the eucJP encoding can be edited with vim by the following vim e enc eucJP ju file txt An old Japanese MS Windows text file jw file txt stored in the so called shift JIS encoding more precisely CP932 can be edited with vim by the following S vim te enc CP932 ff dos jw file txt When a file is opened with enc and f f options w in the Vim command line stores it in the original format and overwrite the original file You can also specify the saving format
130. ASCII bless a C psize1 full featured hexadecimal editor GNOME okteta LO psizel full featured hexadecimal editor KDE4 ncurses hexedit popcon1 psizel binary editor and viewer HEX ASCII EBCDIC popcon1 lde psizel Linux Disk Editor popcon1 2 S 3 beav o psizel binary editor and viewer HEX ASCII EBCDIC OCTAL hex il SHE psizel hexadecimal dumping tool support Japanese 2 byte codes Table 10 7 List of packages which view and edit binary data package popcon size description mtools ne porous psize1 utilities for MSDOS files without mounting them hfsutils S Kalos psize1 utilities for HFS and HFS files without mounting them Table 10 8 List of packages to manipulate files without mounting disk package popcon size description par2 DG Gang psizel Parity Archive Volume Set for checking and repair of files dvdisaster ER pa psizel data loss scratch aging protection for CD DVD media dvbackup te GS psizel backup tool using MiniDV camcorders providing rsbep 1 vdmfec cP Gui psizel recover lost blocks using Forward Error Correction Table 10 9 List of tools to add data redundancy to files Debian Reference 208 265 package popcon size description testdisk ES ES psize1 utilities for p
131. Bn psize2 create a cumulative patch from two incremel dehtmldiff 1 patchutil ae psize2 extract a diff from an HTML page filterdiff l patchutil O PE psize2 extract or excludes diffs from a diff file fixcvsdif l patchutil a ciate psize2 fix diff files created by CVS that pat ch 1 flipdif l patchutil ae psize2 exchange the order of two patches grepdiff 1 patchutil E ANa psize2 show which files are modified by a patch ma interdiff patchutil te ae psize2 show differences between two unified diff fil 1sdif 1 patchutil ha a aed psize2 show which files are modified by a patch recountdiff 1 patchutil ee psize2 recompute counts and offsets in unified cont rediff 1 patchutil a ae psize2 fix offsets and counts of a hand edited diff splitdiff d patchutil i a aka psize2 separate out incremental patches unwrapdiff 1 patchutil le ae psize2 demangle patches that have been word wrap wiggle l wiggle AS psize2 apply rejected patches quilt 1 quilt Sn psize2 manage series of patches mela 1 meld A psize2 compare and merge files GTK xxdif 1 xxdiff DO nai psize2 compare and merge files plain X dirdiff 1 dirdiff E psize2 display differences and merge changes betw docdiff 1 docdiff a psize2 compare two files word by word char by ck imediff2 1 imediff2 ci psize2 interactive full screen 2 way merge
132. C Apache Ghostscript Common Unix Printing System Samba GNOME KDE Mozilla OpenOffice org Vim TeX LaTeX DocBook Perl Python Tcl Java Ruby PHP Berkeley DB MySQL PostgreSQL Exim Postfix Mutt FreeBSD OpenBSD Plan 9 and many more independent free software projects Debian integrates this diversity of Free Software into one system Debian Reference About this document Guiding rules Following guiding rules are followed while compiling this document Provide overview and skip corner cases Big Picture Keep It Short and Simple KISS Do not reinvent the wheel Use pointers to the existing references Focus on non GUI tools and consoles Use shell examples Be objective Use popcon etc Tip tried to elucidate hierarchical aspects and lower levels of the system Prerequisites Warning l You are expected to make good efforts to seek answers by yourself beyond this documentation This document only gives efficient starting points You must seek solution by yourself from primary sources The Debian site at http www debian org for the general information The documentation under the usr share doc lt package_name gt directory The Unix style manpage dpkg L lt package_name gt grep man man x The GNU style info page dpkg L lt package_name gt grep info The bug report http bugs debian org lt package_name gt The Debian Wiki at http wiki debian or
133. CREER G psizel highlight convert many source codes to TeX C lang source highlight a eprecon vos psizel highlight SR ad Ce A highlight et S psizel1 highlight convert many source codes to HTML XH gre E ia psizel text color generic colouriser for everything Python txt2html ES GA psizel text gt html text to HTML converter Perl markdown S G e psizel text gt html markdown text document formatter to X I asciidoc E SHOES psizel text any AsciiDoc text document formatter to XML python docutils oe SED psizel text any ReStructured Text document formatter to gt LD pags me psize1 text any ade qe from text to HTML udo G SET psizel text any universal document text processing utility stx2any Re SE psizel text any document converter from structured plain t rest2web CPOP psizel text html document converter from ReStructured Te aft Prope onte psizel text any free form document preparation system yodl E R EE psizel text any pre document language and tools to proces sdf S SE psizel text any simple document parser Perl sisu Gee LE psizel text any document structuring publishing and searc Table 11 6 List of tools to highlight plain text data Debian Reference 236 265 lt name attribute value gt content lt name gt XML element with empty content is marked up in the follo
134. D Wt WH FH Ur make kpkg clean fakeroot make kpkg append_to_version amd64 initrd revision rev 01 kernel_imag e modules_image S l s dpkg i linux imagex deb Reboot to new kernel with shutdown r now Caution When you intend to create a non modularized kernel compiled only for one machine invoke make kpkg without initrd option since initrd is not used Invocation of make oldconfig and make dep are not required since make kpkg kernel_image invokes them 9 7 6 Compiling the module source Debian standard method The Debian standard method for creating and installing a custom module package for a custom kernel package uses modul e assistant 8 and module source packages For example the following builds the unionfs kernel module package and installs it sudo aptitude install module assistant sudo aptitude install unionfs source unionfs tools unionfs utils sudo m a update sudo m a prepare sudo m a auto install unionfs UY UY UF Uz e sudo apt get autoremove 9 7 7 Compiling the kernel source classic method You can still build Linux kernel from the pristine sources with the classic method You must take care the details of the system configuration manually ede usia sre wget http www kernel org pub linux kernel v2 6 linux lt version gt tar bz2 ieee xve aa Version y Eva paz cd linux lt version gt cp boot config lt version gt config make menuconfig M
135. Debian Reference Debian Reference Debian Reference Copyright O 2007 2009 Osamu Aoki This Debian Reference v2 build date 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 for non developers Debian Reference COLLABORATORS TITLE Debian Reference ACTION NAME DATE SIGNATURE WRITTEN BY Osamu Aoki February 23 2010 REVISION HISTORY NUMBER DATE DESCRIPTION NAME Debian Reference iv Contents 1 GNU Linux tutorials 1 1 1 Console basics sss e a A e SR ac eA GR a a BR ala oe e 1 1 1 1 Theshel prompt 1 1 1 2 The shell prompt under X oaaae 2 1 13 ThE TOOL account a accen i 64 ER A E E a 2 1 1 4 Therootshell prompt s lt 24 si 24 5 g e A E 3 1 1 5 GUI system administration tools oaa ee 3 1 1 6 Virtual cONSOlES op cocos ca dd A 3 1 1 7 Howto leave the command prompt 2 2 0 0 ee ee 4 1 1 8 Howto shutdown the system 0 00002 ee ee 4 1 1 9 Recovering asaneconsole es R RER ee ee ee ee 4 1 1 10 Additional package suggestions for the newbie 0 000002 0 ee eee 4 1 1 11 An extra user account 2 cree d R RARE R RRR ee D 1 1 12 sudo configuration 2 2 ee 6 11 13 Play Ume se fa ee a a A ie a a Oa Bee eae ae a E 12 Unix like filesystems x doh dae deck he earch e eect
136. Debian Reference 247 265 Chapter 12 Programming I provide some pointers for people to learn programming on the Debian system enough to trace the packaged source code Here are notable packages and corresponding documentation packages for programing Online references are available by typing man name after installing manpages and manpages dev packages Online references for the GNU tools are available by typing info program_name after installing the pertinent documentation packages You may need to include the cont rib and non free archives in addition to the main archive since some GFDL documentations are not considered to be DSFG compliant e Warning Do not use test as the name of an executable test file test is a shell builtin Caution tI You should install software programs directly compiled from source into usr local or opt to avoid collision with system programs Tip Code examples of creating Song 99 Bottles of Beer should give you good idea of practically all the programming languages 12 1 The shell script The shell script is a text file with the execution bit set and contains the commands in the following format bin sh command lines The first line specifies the shell interpreter which read and execute this file contents Reading shell scripts is the best way to understand how a Unix like system works Here L give some pointers and reminders for shell progra
137. FLAGS G Wa11 for compiling binaries 12 4 3 Obtaining backtrace When you encounter program crash reporting bug report with cut and pasted backtrace information is a good idea The backtrace can be obtained by the following steps Debian Reference 258 265 e Run the program under gdb 1 e Reproduce crash It causes you to be dropped back to the gdb prompt e Type bt at the gdb prompt In case of program freeze you can crash the program by pressing Ct r1 C in the terminal running gdb to obtain gdb prompt Tip Often you see a backtrace where one or more of the top lines are in malloc or g_malloc When this happens chances are your backtrace isn t very useful The easiest way to find some useful information is to set the environment variable SMALLOC_CHECK_ to a value of 2 mal loc 8 You can do this while running gdb by doing the following MALLOC_CHECK_ 2 gdb hello 12 4 4 Advanced gdb commands command description for command objectives gdb thread apply all bt get a backtrace for all threads for multi threaded program gdb bt full get parameters came on the stack of function calls gdb thread apply all bt full get a backtrace and parameters as the combination of the preceding options S E T paread APRSY A pe tu get a backtrace and parameters for top 10 calls to cut off irrelevant output gdb set logging on write log of gdb out
138. IMAP4 server you may be able to move them out by running your own IMAP4 server see Section 6 7 Note If you use other mail storage formats moving them to mbox format is the good first step The versatile client program such as mutt 1 may be handy for this You can split mailbox contents to each message using procmail 1 and formai1 1 Each mail message can be unpacked using munpack 1 from the mpack package or other specialized tools to obtain the MIME encoded contents Debian Reference 244 265 11 6 Graphic data tools The following packages for the graphic data conversion editing and organization tools caught my eyes Tip Search more image tools using regex gt Gworks with image in apt itude 8 see Section 2 2 5 Although GUI programs such as gimp 1 are very powerful command line tools such as imagemagick 1 are quite useful for automating image manipulation with the script The de facto image file format of the digital camera is the Exchangeable Image File Format EXIF which is the JPEG image file format with additional metadata tags It can hold information such as date time and camera settings The Lempel Ziv Welch LZW lossless data compression patent has been expired Graphics Interchange Format GIF utilities which use the LZW compression method are now freely available on the Debian system Tip Any digital camera or scanner with removable recording media works with Linux throug
139. If you are really interested see usr include linux fs h for the exact definition of struct inode in the Debian GNU Linux system The idea of representing just about everything in the filesystem was a Unix innovation and modern Linux kernels have developed this idea ever further Now even information about processes running in the computer can be found in the filesystem This abstract and unified representation of physical entities and internal processes is very powerful since this allows us to use the same command for the same kind of operation on many totally different devices It is even possible to change the way the kernel works by writing data to special files that are linked to running processes Tip If you need to identify the correspondence between the file tree and the physical entity execute mount 8 with no arguments Debian Reference 1 2 3 Filesystem permissions Filesystem permissions of Unix like system are defined for three categories of affected users s The user who owns the file u e Other users in the group which the file belongs to g All other users 0 also referred to as world and everyone For the file each corresponding permission allows following actions s The read r permission allows owner to examine contents of the file s The write w permission allows owner to modify the file s The execute x permission allows owner to run the file as a command For the directory each correspon
140. Import it to CVS with the following parameters Module name modulel Vendor tag Main branch tag for the entire branch Release tag Release initial tag for a specific release cd path to modulel cvs import m Start modulel modulel Main branch Release initial S im IME o Op PEO mani 10 7 6 File permissions in CVS repository CVS does not overwrite the current repository file but replaces it with another one Thus write permission to the repository directory is critical For every new module for module in repository at srv cvs project run the following to ensure this condition if needed cd srv cvs project chown R root src modulel chmod R ug rwX modulel chmod ZU TS modulel 10 7 7 Work flow of CVS Here is an example of typical work flow using CVS Check all available modules from CVS project pointed by CVSROOT by the following S Crys sells CVSROOT modulel module2 Checkout module to its default directory module1 by the following cd path to cvs co modulel cd modulel Make changes to the content as needed Check changes by making diff u repository local equivalent by the following S mys Cri u You find that you broke some file file_to_undo severely but other files are fine Overwrite file_to_undo file with the clean copy from CVS by the following Debian Reference 220 265 Ss eva us 0 file to undo Save the updated local source tre
141. Linux system btr s filesystem is expected to be the next default filesystem after ext4 filesystem for the Linux system Warning S You might face some limitations with ext4 since it is new For example you must have Linux kernel 2 6 30 or later if you wish to resize an ext4 partition Tip Some tools allow access to filesystem without Linux kernel support see Section 10 3 2 Debian Reference 164 265 package popcon size description e2fsprogs D n En psize1 utilities for the ext2 ext3 ext4 filesystems reiserfsprogs ees psize1 utilities for the Reiserfs filesystem dosfstools a aaae psize1 utilities for the FAT filesystem Microsoft MS DOS Windows xfsprogs E nng psize1 utilities for the XFS filesystem SGI IRIX ntfsprogs ae S psizel1 utilities for the NTFS filesystem Microsoft Windows NT jfsutils ee psize1 utilities for the JFS filesystem IBM AIX OS 2 reiser4progs Gaana psize1 utilities for the Reiser4 filesystem nfsprogs popconl _ psize1 utilities for HFS and HFS Plus filesystem Apple Mac OS btrfs tools popcon psize1 utilities for the btrfs filesystem zerofree popcon psize1 program to zero free blocks from ext2 3 filesystems Table 9 8 List of filesystem management packages 9 3 4 Filesystem creation and integ
142. MM WM Ur make dep make bzImage make modules cp arch x86_64 boot bzImage boot vmlinuz lt version gt make modules_install depmod a update initramfs c k lt version gt He de e OE LH Set up bootloader by the following Debian Reference 185 265 e Edit etc lilo conf and run sbin lilo if you use lilo e Edit boot grub menu 1st if you use grub Reboot to new kernel with shutdown r now 9 7 8 Non free hardware drivers Although most of hardware drivers are available as free software and as a part of the Debian system you may need to load some non free external drivers to support some hardwares such as Winmodem on your system Check pertinent resources e http en wikipedia org wiki Softmodem e http en wikipedia org wiki Comparison_of_open_source_wireless_drivers e Google or other search engines with keyword Linmodem e http ndiswrapper sourceforge net s http linuxwireless org e http madwifi project org there is ath5k which contains free drivers 9 8 Virtualized system Use of virtualized system enables us to run multiple instances of system simultaneously on a single hardware Tip See http wiki debian org SystemVirtualization 9 8 1 Virtualization tools There are several system virtualization and emulation related packages in Debian beyond simple chroot Some packages also help you to setup such system See Wikipedia article Comparison of platform virtual m
143. Make all VCS archive files belonging to a pertinent group e Enable set group ID on all VCS archive directories BSD like file creation scheme see Section 1 2 3 e Make user sharing the VCS archive belonging to the group 10 6 1 Comparison of VCS commands Here is an oversimplified comparison of native VCS commands to provide the big picture The typical command sequence may require options and arguments Debian Reference 217 265 CVS Subversion Git function cvs init svn create git init create the local repository cvs login login to the remote repository cvs co svn co git clone check out the remote repository as the working ti cvs up svn up git pull update the working tree by merging the remote re cvs add svn add git add add file s in the working tree to the VCS cvs rm svn rm git rm remove file s in working tree from the VCS cvs ci svn ci commit changes to the remote repository git commit a commit changes to the local repository git push update the remote repository by the local reposit cvs status svn status git status display the working tree status from the VCS cvs diff svn diff git diff diff lt reference_repository gt lt working_tree gt git repack a d git prune repack the local repository into single pack tkcvs tkcvs gitk GUI display of VCS repository tree Table 10 17 Comparison of native VCS commands Caution Invokin
144. Places gt CD DVD Creator Note You may wish to stop some application daemons such as MTA see Section 6 3 while backing up data Note You should pay extra care to the backup and restoration of identity related data files such as etc ssh ssh_host_ dsa_key etc ssh ssh_host_rsa_key gnupg x ssh x etc passwd etc shadow Jetc fetchmailrc popularity contest conf etc ppp pap secrets and etc exim4 pas swd client Some of these data can not be regenerated by entering the same input string to the system Note If you run a cron job as a user process you must restore files in var spool cron crontabs directory and restart cron 8 See Section 9 5 14 for cron 8 and crontab 1 Debian Reference 10 1 7 Backup utility suites 196 265 Here is a select list of notable backup utility suites available on the Debian system package popcon size description rdiff backup popcon1 psize1 remote incremental backup popcon1 dump psizel 4 4 BSD dump 8 and restore 8 for ext2 ext3 filesystems popcon1 a S xfsdump o psize1 dump and restore with xfsdump 8 and xfsrestore 8 for X backupninja a sl psize1 lightweight extensible meta backup system mondo oe psize1 Mondo Rescue disaster recovery backup suite sbackup hts psize1 simple backup suite for GNOME desktop keep eG pon
145. Precedence xlist x 1 0 Precedence xbulk 2 LAO 2 AS AS O O lo A 10 x 1 0 Return path debian devel admintdebian or Jp jp debian devel s0 x Resent Sender debian user requestflists debian org debian user 310 Resent Sender debian devel requestfilists debian org debian devel 0 x Resent Sender xdebian announce requestflists debian org debian announce 30 mailing list Inbox Debian Reference 6 6 3 Redeliver mbox contents 129 265 You need to manually deliver mails to the sorted mailboxes in your home directory from var mail lt username gt if your home directory became full and procmail 1 failed After making disk space in the home directory run the following etc init d MAI DAEMON stop formail s procmail lt var mail lt username gt etc init d MAI DAEMON start 6 7 POP3 IMAP4 server If you are to run a private server on LAN you may consider to run POP3 IMAP4 server for delivering mail to LAN clients package popcon size type description apopper ns S psizel POP3 Qualcomm enhanced BSD POP3 server courier pop E qe psizel POP3 Courier mail server POP3 server maildir format onl ipopd S ase psizel POP3 The University of Washington POP2 and POP3 server cyrus pop3d 2 2 a qe psizel POP3 Cyrus mail system POP3 support xmail ae psizel POP3 ESMTP
146. R RN a aa E R REAR EE a 19 1 14 List of key bindings for bash 0000002 ee 20 1 15 List of Unix style mouse operations 2 ee 21 1 16 Listof basic Unix commands ss se e e s e c eK RR KRK 23 1 17 3 parts of locale value lt s ee be Re RR eR RRR RR ee RE ae N 25 1 18 List of locale recommendations 25 1 19 Listor SHOME Valles ep wR RN e OR OR Ew Sk be ee eee eee oS 21 1 20 Shell glob patterdsS 2 cosa caora a epa resis RR a a RD eR ae N 21 1 21 Command exit codes s ar Sede GS e A A A A AS oa 28 1 22 Shellcommandidioms lt s os perd N E R KRN E RL EE RE ee 29 1 23 Predefined file descriptors e e a ee RR RRR RRR KR RRR RRR KR 29 1 24 Metacharacters for BRE and ERE soro eati R K paa ee RRR ee R RRR RE L 31 1 25 The replacement expression 2 lt lt o sere rss e e eR RRR a Oe 32 1 26 List of script snippets for piping commands soo 2 0 ee 35 2 1 List of Debian package management tools 2 2 2 2 0 00 ee ee 37 22 Listof Debian archive Sites s s s caora eea e 4G 4420 e e ia ee eee E 40 2 3 List of Debian archive components osoa a ee 41 Debian Reference 2 4 2 5 2 6 2 7 2 8 2 9 2 10 2 11 2 12 2 13 2 14 2 15 2 16 2 17 2 18 2 19 3 1 3 2 3 3 3 4 4 1 42 43 44 4 5 4 6 4 7 4 8 5 1 5 2 5 3 5 4 5 5 5 6 5 7 5 8 5 9 xix The relationship between suite and codename 2 a 41 List of key web site to resolving problems with a
147. R RRR 249 12 3 List of shell parameters 5 eR ee AD RR RR ERR ED pA RR aa eo 250 12 4 List of shell parameter expansions 2 lt e esere re e 250 12 5 List of key shell parameter substitutions o ooa ee 250 12 6 List of file comparison operators in the conditional expression 0 0 0 0 0000004 251 12 7 List of string comparison operators in the conditional expression o e 232 12 8 List of packages containing small utility programs for shell scripts o 253 Debian Reference xxiii 12 9 List of user interface programs lt ss s e e css ORR Re eters arr De ee ed ER wee OB 254 12 10List of make automatic variables 2 oaa 253 12 11List of make variable expansions ooa 255 12 12List of advanced gdb commands oaoa 258 12 13List of memory leak detection tools 0 0 0 0 22 ee 259 12 14List of tools for static code analysis 259 12 15List of Yacc compatible LALR parser generators 0 2 0 eee ee 260 12 16List of source code translation tools ea e a 262 Abstract This book is free you may redistribute it and or modify it under the terms of the GNU General Public License of any version compliant to the Debian Free Software Guidelines DFSG Debian Reference Preface This Debian Reference version 2 build date is intended to provide a broad overview of Debian system administra tion as a post installation user guide
148. SS Name Service Switch mechanism too The flow of this resolution is the following 1 The etc nsswitch conf file with stanza like hosts files dns dictates the hostname resolution order This replaces the old functionality of the order stanza in etc host conf 2 The files method is invoked first If the hostname is found in the etc hosts file it returns all valid addresses for it and exits The etc host conf file contains multi on 3 The dns method is invoked If the hostname is found by the query to the Internet Domain Name System DNS identified by the etc resolv conf file it returns all valid addresses for it and exits The etc hosts file associates IP addresses with hostnames contains the following 1270 01 localhost 127 0 1 1 lt host_name gt lt domain_name gt lt host_name gt The following lines are desirable for IPv6 capable hosts seems ip6 localhost ip6 loopback fe00 0 ip6 localnet ff00 0 ip6 mcastprefix ff02 1 ipo allnodes PTOZ iZ o6 l le outers EO2223 TIE Here the lt host_name gt in this matches the own hostname defined in the etc hostname The lt domain_name gt in this is the fully qualified domain name FQDN of this host Tip For lt domain_name gt of the mobile PC without the real FQDN you may pick a bogus and safe TLD such as lan home invalid localdomain none and private The etc resolv conf is a static file if the resolvco
149. SS systems oana 88 List of configuration files accessed by the PAM 2 2 2 ee 89 List of insecure and secure services and ports 92 List of tools to provide extra security measures ee 92 List of network address ranges RRR RRR RRR RRR NR RRR RRR RRR RRR RRR 96 List of network configuration tools ee 97 List of network connection methods and connection paths o o e ee 98 List of network connection configurations 2 ee 98 List of network connection acronyms 2 ee 98 List of configuration files for the PPP connection with pppconfig e 99 List of configuration files for the PPP connection with wvdialconf oao aoaaa a 100 List of configuration files for the PPPoE connection with pppoeconf oao sooo a 101 List of basic network configuration commands with ifapdown aooaa ea a 101 Debian Reference 5 10 5 11 5 12 5 13 5 14 5 15 5 16 5 17 5 18 5 19 6 1 6 2 6 3 6 4 6 5 6 6 6 7 6 8 6 9 6 10 6 11 6 12 6 13 6 14 6 15 6 16 6 17 6 18 6 19 6 20 7 1 7 2 73 7 4 7 5 7 6 7 1 XX List of stanzas in etc network interfaces e ee 101 List of acronyms for WLAN 5 sacri R REG A RR RS A GA RE a A Bao a 103 List of terminology for network devices ee 108 List of advanced network configuration commands withifupdown 000004 108 List of environment variables passed by the ifupdown system nooo e e
150. Si LOs SlO0Sial arger y Wy ame return 0 EOF gcc Wall g o run_exampl xample c lm S run_example eo 2 OS PUNO Em null run_example 1234567890qwerty 273 082 s runeexam U234 567 890qwerty Here 1m is needed to link library usr lib libm so from the 1ibc package for sqrt 3 The actual library is in 1ib with filename libm so 6 which is a symlink to 1ibm 2 7 so Look at the last parameter in the output text There are more than 10 characters even though 310s is specified The use of pointer memory operation functions without boundary checks such as sprint 3 and st rcpy 3 is deprecated to prevent buffer overflow exploits that leverage the above overrun effects Instead use snprint 3 and strncpy 3 12 4 Debug Debug is important part of programing activities Knowing how to debug programs makes you a good Debian user who can produce meaningful bug reports 12 4 1 Basic gdb execution Primary debugger on Debian is gdb 1 which enables you to inspect a program while it executes Let s install gdb and related programs by the following aptitude install gdb gdb doc build essential devscripts Debian Reference 257 265 Good tutorial of gdb is provided by info gdb or found elsewhere on the web Here is a simple example of using gdb 1 on a program compiled with the g option to produce debugging information gdb program gals Io i set break point at l
151. The target reader is someone who is willing to learn shell scripts but who is not ready to read all the C sources to figure out how the GNU Linux system works Disclaimer All warranties are disclaimed All trademarks are property of their respective trademark owners The Debian system itself is a moving target This makes its documentation difficult to be current and correct Although the current unstable version of Debian system was used as the basis for writing this some contents may be already outdated by the time you read this Please treat this document as the secondary reference This document does not replace any authoritative guides The author and contributors do not take responsibility for consequences of errors omissions or ambiguity in this document What is Debian The Debian Project is an association of individuals who have made common cause to create a free operating system It s distribution is characterized by the following e Commitment to the software freedom Debian Social Contract and Debian Free Software Guidelines DFSG e Internet based distributed unpaid volunteer effort http www debian org e Large number of pre compiled high quality softwares e Focus on stability and security with easy access to the security updates e Focus on smooth upgrade to latest softwares with unstable and testing archives e Large number of supported hardware architectures Free Software pieces in Debian come from GNU Linux BSD X IS
152. X oriented programs with update menus 1 from the menu package Each package installs its menu data in the usr share menu directory See usr share menu R EADME 7 2 2 Freedesktop org menu Each package which is compliant to Freedesktop org s xdg menu system installs its menu data provided by desktop under usr share applications Modern desktop environments which are compliant to Freedesktop org standard use these data to generate their menu using the xdg utils package See usr share doc xdg utils README Debian Reference 138 265 meta package popcon size description xorg popcon psize1 X libraries an X server a set of fonts and a grout XSeYrver xorg popcon psize1 full suits of the X server and its configuration xbase clients popcon psize1 miscellaneous assortment of X clients x11 common popcon psize1 filesystem infrastructure for the X Window Syster xorg docs popcon psize1 miscellaneous documentation for the X Org softw popcon xspecs o psize1 X protocol extension and library technical specif menu ioe O psize1 generate the Debian menu for all menu aware app gksu popcoul naeei Giros menu xdg popcon psize1 convert the Debian menu structur
153. a pdf f fool pdf foo2 pdf Note The PDF which is widely used cross platform printable data format is essentially the compressed PS format with few additional features and extensions Tip For command line psmerge 1 and other commands from the psutils package are useful for manipulating PostScript documents Commands in the pdf jam package work similarly for manipulating PDF documents pdftk 1 from the pdftk package is useful for manipulating PDF documents too 11 3 3 Printable data utilities The following packages for the printable data utilities caught my eyes Debian Reference 240 265 package popcon size keyword description poppler utils ae psizel pdf ps text PDF utilities pdftops pdfinfo psutils a Kanai psize1 ps ps PostScript document conversion too poster e S psize1 ps ps create large posters out of PostScript xpdf utils ea ag psize1 pdf ps text PDF utilities pdftops pdfinfo enscript apena psize1 text gt ps html rtf convert ASCII text to PostScript HT a2ps Pi opena psizel1 text ps Anything to PostScript converter a pdftk a eee Se psizel1 pdf pdf PDF document conversion tool pdi mpage oo GR psizel1 text ps ps print multiple pages per sheet html2ps open psize1 html ps converter from HTML to PostScript pdfjam SOn psizel1 pdf pdf
154. above Debian provides unified access to the system default editor via command usr bin editor so other programs e g re portbug 1 can invoke it You can change it by the following sudo update alternatives config editor Debian Reference 22 265 The choice usr bin vim basic over usr bin vim tiny is my recommendation for newbies since it supports syntax highlighting Tip Many programs use the environment variables SEDITOR or SVISUAL to decide which editor to use see Section 1 3 5 and Section 9 5 11 For the consistency on Debian system set these to usr bin editor Historically SEDITOR was ed and SVISUAL was vi 1 4 8 Customizing vim You can customize vim 1 behavior by vimrc For example try the following Eo cacon Er qurataon set nocompatible set nopaste set pastetoggle lt f2 gt syn on if SUSER root set nomodeline set noswapfile else set modeline set swapfile endif filler to avoid the line above being recognized as a modeline filler Y seat iL ibewe 1 4 9 Recording the shell activities The output of the shell command may roll off your screen and may be lost forever It is good practice to log shell activities into the file for you to review them later This kind of record is essential when you perform any system administration tasks The basic method of recording the shell activity is to run it under script 1 For example try the follo
155. accented equivalen tofrodos a age ee psizel1 eol text format converter between DOS and Unix romc macutils S POPC psize1 eol text format converter between Macintosh and Unix f Table 11 1 List of text data conversion tools 11 1 1 Converting a text file with iconv Tip iconv 1 is provided as a part of the 1ibc6 package and it is always available on practically all systems to convert the encoding of characters You can convert encodings of a text file with i conv 1 by the following Debian Reference S iconv f encodingl t encoding2 input txt gt output txt Encoding values are case insensitive and ignore 1 command wom 231 265 and _ for matching Supported encodings can be checked by the iconv encoding value usage ASCII American Standard Code for Information Interchang UTF 8 current multilingual standard for all modern OSs ISO 8859 1 old standard for western European languages ASCI ISO 8859 2 old standard for eastern European languages ASCII ISO 8859 15 old standard for western European languages SO 8 CP850 code page 850 Microsoft DOS characters with grap CP932 code page 932 Microsoft Windows style Shift JIS v CP936 code page 936 Microsoft Windows style GB23 12 CP949 code page 949 Microsoft Windows style EUC KR CP950 code page 950 Microsoft Windows style Big5 varia CP1251 code page 1251
156. aces b ethtool Ga aia psizel display or change Ethernet iputils ping popcon1 psizel test iproute2 test network reachability of iputils arping popcon1 psizel test network reachability of iputils tracepath popcon1 psizel 2 trace the network path to ar net tools popcon1 psizel config net tools NET 3 networking toolkit r inetutils ping popcon1 psizel test net tools test network reachability of arping popcon1 psizel test network reachability of traceroute popcon1 psizel 29 trace the network path to ar dhcp3 client popcon1 psizel config low level DHCP client wpasupplicant popcon1 psizel client support for WPA and wireless tools popcon1 psizel tools for manipulating Linu popcon1 ppp psizel PPP PPPoE connection wit pppoeconf Gin S psizel config helper configuration helper for PPE pppconfig E SS psize1 configuration helper for PPE wvdial re S psizel configuration helper for PPE mbe tins q popcont C Q OpsizeLO O testulow level trace the network path to ar mtr Ge aia psizel trace the network path to ar
157. achines for detail comparison of different platform virtualization solu tions 9 8 2 Virtualization work flow Note Some functionalities described here are only available in squeeze Note Default Debian kernels support KVM since Lenny Typical work flow for virtualization involves several steps e Create an empty filesystem a file tree or a disk image Debian Reference 186 265 package popcon size description schroot a Gianni psizel specialized tool for executing Debian binary packages in chroot sbuild ig opens psizel tool for building Debian binary packages from Debian sources pbuilder ara a psizel personal package builder for Debian packages debootstrap a Es psizel bootstrap a basic Debian system written in sh cdebootstrap a aaa En psizel bootstrap a Debian system written in C rootstrap Deron psizel tool for building complete Linux filesystem images virt manager popcon1 psizel Virtual Machine Manager desktop application for managing vi libvirt bin popcon1 psizel programs for the libvirt library user mode linux popcon1 psizel User mode Linux kernel bochs popcon1 psizel Bochs IA 32 PC emulator qemu popcon1 psizel QEMU fast generic processor emulator qemu system popcon1
158. ackage_name gt download a source from standard archive dget lt URL for dsc file gt download a source packages from other arct ESA TN l f build a source tree from a set of source packa lt package_name gt _ lt version gt lt debian_version gt dsc debuild binary build package s from a local source tree make kpkg kernel_image build a kernel package from a kernel source t make kpkg initrd kernel_image build a kernel package from a kernel source t dpkg i c lt package_name gt lt version gt lt debian_version gt lt arch gt deb pas OPA pArA O a debi lt package_name gt lt version gt lt debian_version gt lt arch gt dsc install local package s to the system dpkg get selection gt selection txt save dpkg level package selection state infor dpkg set selection lt selection txt set dpkg level package selection state inforn Table 2 13 List of advanced package management operations Debian Reference 55 265 e configure debian 8 provided by the configure debian package runs dpkg reconfigure 8S as its backend e dpkg reconfigure 8 runs package scripts using debconf 1 as its backend e apt get build dep apt get source and apt cache showsrc commands require deb src entry in etc apt sources list e dget 1 debuila 1 and debi 1 require devscripts package e See re packaging procedure using apt get source in Section 2 7 10 e make kpkg command requires the kernel package package see Section 9
159. ackages listed in tasks such as Desktop environment e Packages selected by the dependency package e g python2 4 by python e Popcon higher in the vote and install number e Changelog regular updates by the maintainer e BTS No RC bugs no critical no grave and no serious bugs e BTS responsive maintainer to bug reports e BTS higher number of the recently fixed bugs e BTS lower number of remaining non wishlist bugs Debian being a volunteer project with distributed development model its archive contains many packages with different focus and quality You must make your own decision what to do with them Debian Reference 64 265 2 7 2 Packages from mixed source of archives I Caution I Installing packages from mixed source of archives is not supported by the official Debian distribution except for officially supported particular combinations of archives such as stable with security updates and volatile updates Here is an example of operations to include specific newer upstream version packages found in unstable while tracking testing for single occasion 1 Change the etc apt sources 1list file temporarily to single unstable entry Run aptitude update Run aptitude install lt package name gt 2 3 4 Recover the original etc apt sources list file for testing 5 Run aptitude update You do not create the etc apt preferences file nor need to worry about apt pinning
160. ackup suite Utilities e eR RRR RR RRR RRR RRR RR RR RRR KR 196 List of packages which permit normal users to mount removable devices without a matching etc fstab A NN 200 List of filesystem choices for removable storage devices with typical usage scenarios 200 List of the network service to chose with the typical usage scenario o e e 201 List of packages which view and edit binary data e 207 List of packages to manipulate files without mounting disk o e 207 List of tools to add data redundancy to files o o 207 Debian Reference xxii 10 10List of packages for data file recovery and forensic analysis 2 2 ee ee 208 10 11List of data security infrastructure tools 2 ee 212 10 12List of GNU Privacy Guard commands for the key management o 212 10 13List of the meaning of the trust code 2 2 ee 212 10 14List of GNU Privacy Guard commands on files e 218 10 15List of source code merge tools crude ro nea kn 213 10 16List of version control system tools 2 216 10 17Comparison of native VCS commands 2 2 ee 217 10 18Notable options for CVS commands use as first argument s to cvs 1 o o 221 10 19Notable options for Subversion commands use as first argument s to svn 1 o 227 10 20List of git related packa
161. ad devices setcd Pans S psizel compact disc drive access optimization big cursor ie ame psizel larger mouse cursors for X Table 9 17 List of hardware configuration tools Debian Reference 178 265 9 6 4 Hardware configuration Although most of the hardware configuration on modern GUI desktop systems such as GNOME and KDE can be managed through accompanying GUI configuration tools it is a good idea to know some basics methods to configure them Here ACPI is a newer framework for the power management system than APM Tip CPU frequency scaling on modern system is governed by kernel modules such as acpi_cpufreq 9 6 5 System and hardware time The following sets system and hardware time to MM DD hh mm CCYY date MMDDhhmmCCYY hwclock utc systohc hwclock show Times are normally displayed in the local time on the Debian system but the hardware and system time usually use UT GMT If the hardware BIOS time is set to UT change the setting to UTC yes in the etc default rcs If you wish to update system time via network consider to use the NTP service with the packages such as ntp ntpdate and chrony See the following e Managing Accurate Date and Time HOWTO e NTP Public Services Project e The ntp doc package Tip ntpt race 8 in the ntp package can trace a chain of NTP servers back to the primary source 9 6 6 The terminal configuration There are several com
162. aintained by Josip Rodin The other contents can trace some of their origin and their inspiration in following e Debian Reference version 1 by Osamu Aoki 2001 2007 obsoleted by this new Debian Reference version 2 The previous Debian Reference version 1 was created with many contributors the major contents contribution on network configuration topics by Thomas Hood significant contents contribution on X and VCS related topics by Brian Nelson the help on the build scripts and many content corrections by Jens Seidel extensive proofreading by David Sewell many contributions by the translators contributors and bug reporters Many manual pages and info pages on the Debian system were used as the primary references to write this document To the extent Osamu Aoki considered within the fair use 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 The gdb debugger description was expanded using Debian wiki contents on backtrace with consent by Ari Pollak Loic Minier and Dafydd Harries Contents of Debian Reference version 2 are mostly my own work except as mentioned above These has been updated by the contributors too The author Osamu Aoki thanks all those who helped make this document possible A 3 Document format The source of the English original document is currently written in AsciiD
163. al source tree having the sticky tag Release initial bugfixes which is based on the original version Work on this branch by yourself until someone else joins to this Release initial bugfixes branch Sync with files modified by others on this branch while creating new directories as needed by the following Debian Reference 221 265 cvs up d Edit files to fix conflicts as needed Check in changes to CVS by the following S cvs ci m checked into this branch Update the local tree by HEAD of main while removing sticky tag A and without keyword expansion kk by the following cvs up d kk A Update the local tree content HEAD of main by merging from the Release initial bugfixes branch and without keyword expansion by the following cvs up d kk J Release initial bugfixes Fix conflicts with editor Check in changes to CVS by the following cvs ci m merged Release initial bugfixes Make archive by the following clare mv old old modulel bugfixes tar cvzf old modulel bugfixes tar gz old modulel bugfixes rm rf old modulel bugfixes UL UD UL UY Tip cvs up command can take d option to create new directories and P option to prune empty directories Tip You can checkout only a sub directory of nodule1 by providing its name as cvs co modulel subdir option meaning n dry run no effect E display messages showi
164. also supports LSB packages Warning alien 1 should not be used to replace essential system packages such as sysvinit libc6 libpam mo dules etc Practically alien 1 should only used for non free binary only packages which are LSB compliant or statically linked For free softwares you should use their source packages to make real Debian packages 2 7 15 Extracting package without dpkg The current x deb package contents can be extracted without using dpkg 1 on any Unix like environment using standard ar 1 and tar 1 ar x path to dpkg_ lt version gt _ lt arch gt deb ls total 24 SEW Ga el OZ Om OZ Om 1520 2007 05 07 0041 GRE Eel ce ez 9 20 1 loz bozo 12697 2007 05 07 OS clara ices oy p 2 IL 1900 Doza 4 2007 05 07 00 11 debian binary mkdir control mkdir data E tar ZAS O Mites Olean Zui Control i ele ae Cre ieee ITR 0 clita You can also browse package content using the mc command Debian Reference 75 265 2 7 16 More readings for the package management You can learn more on the package management from following documentations e Primary documentations on the package management aptitude 8 dpkg 1 tasksel 8 apt get 8 apt config 8 apt key 8 sources 1list 5 apt con 5 and apt_preferences 5 usr share doc apt doc guide html index html and usr share doc apt doc offline h tml index html from the apt doc package and usr s
165. alternative measure of packet size The relationship between MSS and MTU are the following e MSS MTU 40 for IPv4 e MSS MTU 60 for IPv6 Note The iptables 8 see Section 5 8 based optimization can clamp packet size by the MSS and is useful for the router See TCPMSS in iptables 8 5 7 3 WAN TCP optimization The TCP throughput can be maximized by adjusting TCP buffer size parameters as described in TCP Tuning Guide and TCP tuning for the modern high bandwidth and high latency WAN So far the current Debian default settings serve well even for my LAN connected by the fast 1G bps FTTP service 5 8 Netfilter infrastructure Netfilter provides infrastructure for stateful firewall and network address translation NAT with Linux kernel modules see Section 3 5 12 packages popcon size description iptables a Rania psizel administration tools for netfilter iptstate E SEE psizel continuously monitor netfilter state similar to top 1 shorewall per ee psizel Shoreline Firewall netfilter configuration file generator Perl b ae l Opopconl 2 3 lt shorewall shell o psizel Shoreline Firewall netfilter configuration file generator shell b Table 5 19 List of firewall tools Main user space program of netfilter is iptables 8 You can manually configure netfilter interactively from shell save its state with iptables save 8 and rest
166. always set to UTF 8 Table 1 17 3 parts of locale value For language codes and country codes see pertinent description in the info gettext For the codeset on the modern Debian system you should always set it to UTF 8 unless you specifically want to use the historic one with good reason and background knowledge For fine details of the locale configuration see Section 8 3 Note The LANG en_US is not LANG C nor LANG en_US UTF 8 It is LANG en_US ISO 8859 1 see Sec tion 8 3 1 locale recommendation Language area en_US UTF 8 English USA en_GB UTF 8 English Great_Britain fr_FR UTF 8 French France de_DE UTF 8 German Germany it_IT UTF 8 Italian Italy es_ES UTF 8 Spanish Spain ca_ES UTF 8 Catalan Spain sv_SE UTF 8 Swedish Sweden pt_BR UTF 8 Portuguese Brazil ru_RU UTF 8 Russian Russia zh_CN UTF 8 Chinese P R _of China zh_TW UTF 8 Chinese Taiwan_R O C ja_JP UTF 8 Japanese Japan ko_KR UTF 8 Korean Republic_of_Korea vi_VN UTF 8 Vietnamese Vietnam Table 1 18 List of locale recommendations Typical command execution uses a shell line sequence as the following Debian Reference 26 265 S date Sum vein FS 10227839 IST 2007 LANG fr_FR UTF 8 date dimanche se ain OOO SS AHE HE 0190 01 Here the program dat e 1 is executed with different values of the environment variable SLANG e For the first comma
167. an be written to an unmounted partition e g the first partition of the second SCSI drive dev sdb1 with matching size by the following dd if partition img of dev sdb1 10 2 3 Mounting the disk image file 1 The disk image partition img containing a single partition image can be mounted and unmounted by using the loop device as follows losetup v f partition img Loop device is dev loop0 mkdir p mnt loop0 mount t auto dev loop0 mnt loop0 a o DEEI a o o MECA sIOZICIE umount dev loop0 losetup d dev loop0 This can be simplified as follows mkdir p mnt loop0 mount t auto o loop partition img mnt loop0 a6 o MENS E a 0 a ANE S y 0 HEES umount partition img Each partition of the disk image disk img containing multiple partitions can be mounted by using the loop device Since the loop device does not manage partitions by default we need to reset it as follows modinfo p loop verify kernel capability max_part Maximum number of partitions per loop device max_loop Maximum number of loop devices losetup a verify nothing using the loop device rmmod loop modprobe loop max_part 16 Now the loop device can manage up to 16 partitions losetup v f disk img Loop device is dev loop0 fdisk 1 dev loop0 Disk dev loop0 5368 MB 5368709120 bytes 255 heads 63 sectors track 652 cylanders Units cylinders of 16065 x 512 8225280 bytes Disk identifier 0x452b6
168. an idiomatic style as the following find path to xdev regextype posix extended Senior E edge WU socio Y Hg as o e e recen Voe oque prume o Y type f size 99M prun ON type f newer path to timestamp print0 This means to do following actions 1 Search all files starting from path to Globally limit its search within its starting filesystem and uses ERE see Section 1 6 2 instead Exclude files matching regex of x afio or x from search by stop processing Exclude directories matching regex of git from search by stop processing Exclude files larger than 99 Megabytes units of 1048576 bytes from search by stop processing Aua A ug N Print filenames which satisfy above search conditions and newer than path to timestamp Please note the idiomatic use of prune o to exclude files in the above example Note For non Debian Unix like system some options may not be supported by find 1 In such a case please consider to adjust matching methods and replace print 0 with print You may need to adjust related commands too Debian Reference 195 265 10 1 6 Backup and recovery We all know that computers fail sometime or human errors cause system and data damages Backup and recovery operations are the essential part of successful system administration All possible failure modes hit you some day Tip Keep your backup system simple and backup your syste
169. anagement 0 0 00 00000022 eee ee 4 5 3 Why GNU su does not support the wheel group 2 ee 4 5 4 Stricter password rule Other access controls erro A A A dE RRR R LR 9 ALO SUIA i REG e AA Ra BER le oe RRS Bee ee 4 62 SELINUX seoce Pbae beta dbbiaveds Hobie bbe bbe hb Cea ee PEE Chee e 4 6 3 Restricting access to SOME server services ee Security of authentication i s soa ee AR eG eR Rak a AS BS be A wb ee N 4 7 1 Secure password over the Internet ee ee 4 7 2 Secure Shelli lt dace R A BRR oR ee Oe ee Bow Bee amp eS 4 7 3 Extra security measures for the Internet 0 2 0 00000000000 000 4 7 4 Securing the root password 2 a 5 Network setup 5 1 5 2 The basic network infrastructure 3 1 1 The domainname oo a o e E R we apa R A es ada a hk Be ae 5 1 2 The hostname resolution e oe a i e K a ee 5 1 3 The network interface name a 5 1 4 The network address range for the LAN naana aaa ee 5 1 5 The network configuration infrastructure ooo ee 5 1 6 The network device support ooa ee The network connection method 5 2 1 The DHCP connection with the Ethernet ee 5 2 2 The static IP connection with the Ethernet 2 2 ee viii 81 82 82 82 82 83 83 85 85 87 87 87 88 89 89 90 90 90 90 91 91 91 91 92 92 92 Debian Reference 5 3 5 4 5 5 5 6 5 7 5 8 ix 5 2 3 The PPP c
170. and aptitude full upgrade or apt get upgrade and apt g et dist upgrade 1 Chose candidate version which is usually the latest available version for all installed packages see Section 2 7 3 for exception Make package dependency resolution Fetch selected binary packages from remote archive if candidate version is different from installed version Unpack fetched binary packages Lh AeA U N Run preinst script Debian Reference 44 265 6 Install binary files 7 Run postinst script e Install aptitude install or apt get install 1 Chose packages listed on the command line 2 Make package dependency resolution 3 Fetch selected binary packages from remote archive 4 Unpack fetched binary packages 5 Run preinst script 6 Install binary files 7 Run postinst script e Remove aptitude remove or apt get remove 1 Chose packages listed on the command line 2 Make package dependency resolution 3 Run prerm script 4 Remove installed files except configuration files 5 Run postrm script s Purge aptitude purge or apt get purge 1 Chose packages listed on the command line 2 Make package dependency resolution 3 Run prerm script 4 Remove installed files including configuration files 5 Run postrm script Here I intentionally skipped technical details for the sake of big picture 2 1 7 First response to package management troubles You should read the fine official documen
171. apt sources list file to comment out unstable archive entry right after above operation This avoids slow update process of having too many entries in the etc apt sources list file although this prevents upgrading packages which were installed from unstable archive using current unstable archive Tip If Pin Priority 20 is used instead of Pin Priority 200 for the etc apt preferences file al ready installed packages having Pin Priority value of 100 are not upgraded by unstable archive even if test ing entry in the etc apt sources list file is removed If you wish to track particular packages in unstable automatically without initial t unstable installation you must create the etc apt preferences file and explicitly list all those packages at the top of it as the following Package lt package 1 gt Pin release a unstable Bineet LOO Package lt package 2 gt Pin release a unstable Piar 00 These set Pin Priority value for each specific package For example in order to track the latest unstable version of this Debian Reference in English you should have following entries in the etc apt preferences file Package debian referenc n Pin release a unstable Pacos ADO Package debian reference common Pin release a unstable Palin IPieakouedicwys ADO Tip This apt pinning technique is valid even when you are tracking stable archive Documentation packages have been always safe
172. ar bz2 archive Debian Reference 24 265 Note Unix has a tradition to hide filenames which start with They are traditionally files that contain configuration information and user preferences Note For cd command see builtins 7 Note The default pager of the bare bone Debian system is more 1 which cannot scroll back By installing the less package using command line aptitude install less less 1 becomes default pager and you can scroll back with cursor keys Note The and in the regular expression of the ps aux grep e e xim4x command above enable grep to avoid matching itself The 4x in the regular expression means 0 or more repeats of character 4 thus enables grep to match both exim and exim4 Although x is used in the shell filename glob and the regular expression their meanings are different Learn the regular expression from grep 1 Please traverse directories and peek into the system using the above commands as training If you have questions on any of console commands please make sure to read the manual page For example try the following man man man bash man builtins man grep man ls UD UY UY UU The style of man pages may be a little hard to get used to because they are rather terse particularly the older very traditional ones But once you get used to it you come to appreciate their succinctness Please note that many Unix like commands including
173. arameter see Section 3 3 e g root flags data journal to deploy a non default journaling mode for the root filesystem For Lenny the default jounaling mode is root flags data ordered For squeeze itis root flags data writeback 9 3 6 Optimization of filesystem via superblock Characteristics of a filesystem can be optimized via its superblock using the tune2fs 8 command e Execution of sudo tune2fs 1 dev hdal displays the contents of the filesystem superblock on dev hdal e Execution of sudo tune2fs c 50 dev hdal changes frequency of filesystem checks fsck execution during boot up to every 50 boots on dev hdal e Execution of sudo tune2fs j dev hdal adds journaling capability to the filesystem i e filesystem conversion from ext2 to ext3 on dev hda1 Do this on the unmounted filesystem s Execution of sudo tune2fs O extents uninit_bg dir_index dev hdal amp amp fsck pf dev hd al converts it from ext3 to ext4 on dev hda1 Do this on the unmounted filesystem Warning T Filesystem conversion for the boot device to the ext4 filesystem should be avoided until GRUB boot loader supports the ext4 filesystem well and installed Linux Kernel version is newer than 2 6 30 Tip Despite its name tune2f s 8 works not only on the ext2 filesystem but also on the ext3 and ext4 filesystems 9 3 7 Optimization of hard disk Warning tI Please check your hardware and
174. are obsolete now e New Linux iproute2 programs ip 8 are the current Linux networking system Although these low level networking programs are powerful they are cumbersome to use So high level network configuration systems have been created The ifupdown package is the de facto standard for such high level network configuration system on Debian It enables you to bring up network simply by doing e g ifup eth0 Its configuration file is the etc network interfaces file and its typical contents are the following auto lo iface lo inet loopback auto eth0 iface eth0 inet dhcp The resolvconf package was created to supplement i fupdown system to support smooth reconfiguration of network address resolution by automating rewrite of resolver configuration file etc resolv conf Now most Debian network configura tion packages are modified to use resolvconf package see usr share doc resolvconf README Debian Helper scripts to the ifupdown package such as ifplugd guessnet ifscheme etc are created to automate dynamic configuration of network environment such as one for mobile PC on wired LAN These are relatively difficult to use but play well with existing i fupdown system Alternative high level network configuration systems independent of i fupdown system such as network manager wicd etc are created to ease configuration of network environment even for mobile PC on wireless network Since these are rel
175. artition scan and disk recovery magicrescue S G psize1 utility to recover files by looking for magic bytes scalpel Kaan psize1 frugal high performance file carver myrescue S S psize1 rescue data from damaged harddisks recover iO oe psize1 utility to undelete files on the ext2 filesystem e2undel RNG es psize1 utility to undelete files on the ext2 filesystem ext3grep S epopeon Me psize1 tool to help recover deleted files on the ext3 filesystem o scrounge nt s popcon psize1 data recovery program for NTFS filesystems popcon gzrt psize1 gzip recovery toolkit sleuthkit O psize1 tools for forensics analysis Sleuthkit autopsy di S psize1 graphical interface to SleuthKit foremost ER a E psize1 forensics application to recover data guymager EATE ee psizel forensic imaging tool based on Qt tet ee aoe Ga psize1 forensics related utilities dcfldd E conn psize1 enhanced version of dd for forensics and security rdd er Sporn he psize1 forensic copy program Table 10 10 List of packages for data file recovery and forensic analysis Debian Reference 209 265 10 3 4 Data file recovery and forensic analysis There are tools for data file recovery and forensic analysis 10 3 5 Splitting a large file into small files When a data is too big to back
176. atively new system and their integration to Debian system is in progress you may still need to disable the corresponding network interface configuration manually in etc network interfaces to avoid conflicts between these and i fupdown see Section 5 5 2 Debian Reference 97 265 packages popcon size type description ifupdown i a en psizel config ifupdown standardized tool to bring yy ifplugd AS psizel manage the wired network a ifupdown extra popcon1 psizel network testing script to enh popcon1 ifmetric psizel set routing metrics for a net SAT popcon1 psize1 mapping script to enhance file ifscheme e apaneal psizel mapping scripts to enhance ifupdown scripts zg2 popcon1 psizel Zugschlus interface scripts network manager popcon1 psizel NetworkManager daemon network manager gnom popcon1 psizel NetworkManager GNOME network manager kd popcon1 psizel NetworkManager KDE fro popcon1 29 wicd psizel config wicd wired and wireless network iptables oo SS psizel config Netfilter administration tools for pac iproute E aponle psizel config iproute2 iproute2 IPv6 and other adi ifrename oe psizel rename network interf
177. ats For Vim as follows e ga start recording typed characters into named register a e editor activities Woo e q end recording typed characters e Qa execute the contents of register a For Emacs as follows a C x e editor activities e C x end defining a keyboard macro start defining a keyboard macro e C x e execute a keyboard macro 9 2 9 Recording the graphic image of an X application 161 265 There are few ways to record the graphic image of an X application including an xt erm display package popcon size command l popcon1 xbase clients psizel xwd 1 gimp oe psize1 GUI menu imagemagick oe psizel import 1 scrot popconl psizel scrot 1 Table 9 5 List of graphic image manipulation tools 9 2 10 Recording changes in configuration files There are specialized tools to record changes in configuration files with help of DVCS system package popcon size description etckeeper ar appeal psizel store configuration files and their metadata with Git default Mercu changetrack i aia psizel store configuration files with RCS old Table 9 6 List of packages to record configuration history in VCS I recommend to use the et ckeeper package with git 1 which put entire etc under VCS control Its installation guide and tutorial are found in
178. atus numeric return value logical return value success zero 0 TRUE error non zero 1 FALSE Table 1 21 Command exit codes For example try the following s l i cm se 0 slis 6 eno SP ii Note Please note that in the logical context for the shell success is treated as the logical TRUE which has 0 zero as its value This is somewhat non intuitive and needs to be reminded here 1 5 8 Typical command sequences and shell redirection Let s try to remember following shell command idioms typed in one line as a part of shell command The Debian system is a multi tasking system Background jobs allow users to run multiple programs in a single shell The management of the background process involves the shell builtins jobs fg bg and kill Please read sections of bash 1 under SIGNALS and JOB CONTROL and builtins 1 For example try the following lt etc motd pager pager lt etc motd S pager etc motd cat etc motd pager Although all 4 examples of shell redirections display the same thing the last example runs an extra cat command and wastes resources with no reason The shell allows you to open files using the exec builtin with an arbitrary file descriptor Debian Reference 29 265 command idiom description command amp background execution of command in the subshell commandl command2 pipe the standard output of co
179. bian archive key e The public Debian archive key can be seeded into etc apt trusted gpg automatically by installing the keyring with the latest base files package or manually by gpg or apt key tool with the latest public archive key posted on the ftp master debian org s The secure APT system verifies the integrity of the downloaded top level Release file cryptographically by this Rele ase gpg file and the public Debian archive key in etc apt trusted gpg The integrity of all the Packages and Sources files are verified by using MD5sum values in its top level Release file The integrity of all package files are verified by using MD5sum values in the Packages and Sources files See debsums 1 and Section 2 4 2 Since the cryptographic signature verification is very CPU intensive process than the MD5sum value calculation use of MD3sum value for each package while using cryptographic signature for the top level Release file provides the good security with the performance see Section 10 4 2 5 3 Archive level Release files Tip The archive level Release files are used for the rule of apt_preferences 5 There are archive level Release files for all archive locations specified by deb line in etc apt sources list such as http ftp us debian org debian dists unstable main binary amd64 Release or htt p ftp us debian org debian dists sid main binary amd64 Release as follows Archive
180. bian system used to set the locale as LANG C or LANG xx_YY without UTF 8 s The ASCII character set is used for LANG C or LANG POSIX Debian Reference 153 265 e The traditional encoding system in Unix is used for LANG xx_YY Actual traditional encoding system used for LANG xx_YY can be identified by checking usr share i18n SUPPOR TED For example en_US uses ISO 8859 1 encoding and fr_FR euro uses ISO 8859 15 encoding Tip For meaning of encoding values see Table 11 2 8 3 2 Rationale for UTF 8 locale The UTF 8 encoding is the modern and sensible text encoding system for 118N and enables to represent Unicode characters i e practically all characters known to human UTF stands for Unicode Transformation Format UTF schemes I recommend to use UTF 8 locale for your desktop e g LANG en_US UTF 8 The first part of the locale determines messages presented by applications For example gedit 1 text editor for the GNOME Desktop under LANG fr_FR U TF 8 locale can display and edit Chinese character text data while presenting menus in French as long as required fonts and input methods are installed I also recommend to set the locale only using the SLANG environment variable I do not see much benefit of setting a compli cated combination of LC_x variables see Locale 1 under UTF 8 locale Even plain English text may contain non ASCII characters e g left and right quotatio
181. by some application read or write mode it is possible to recover such a file For example try the following echo foo gt bar less bar S jos eve cress iess1 11 bozo ATS O20 O20 Y2200 884 pts 8 SE 00 18 0 00 less bar So als Ss ls l fas 21139 30 Grao ber lr x 1 bozo bozo 64 2008 05 09 00 19 4 gt home bozo bar deleted E car PELOS Ai Stas am ls 1 ET EE 1 o2 loxo4 4 ZOOS WH OS 00323 Joe cat bar foo Execute on another terminal when you have the 1sof package installed as follows Debian Reference 211 265 S ie O MAD miner UL booz loove A 2006 05 11 11 02 Ioa lsof grep bar grep less less 4775 bozo 4r REG 8 3 4 2228329 home bozo bar S rm bar S lsof grep bar grep less less 4775 bozo 4r REG 8 3 4 2228329 home bozo bar deleted S car poroe Ay mol Aovar S ie Silat cl LAAs ii 1 lore lara 4 2OMS OS i1il M05 lose eat ber foo 10 3 11 Searching all hardlinks Files with hardlinks can be identified by ls 1i S le li torals AUSSAOS gt l root Oor O 2006 09 15 20821 bar AISSA rye 2 ido oor 0 2006 09115 20821 oar ANSIA cry 2 ioe moos 0 2006 09 15 20821 Too Both baz and foo have link counts of 2 gt 1 showing them to have hardlinks Their inode numbers are common 2738404 This means they are the same hardlinked file If you do not happen to find all hardlinked files by chance you can search it by the inode e g 2738404 as the foll
182. byte characters In order to save space for TrueType font files TrueType font collection file with file extension ttc may be used In order to cover complicated code space of characters CID keyed PostScript Type 1 font is used with CMap files starting themselves with 3 PS Adobe 3 0 Resource CMap This is rarely used for normal X display but used for PDF rendering etc see Section 7 7 2 Tip The multiple glyphs are expected for some Unicode code points due to Han unification One of the most annoying ones are U 3001 IDEOGRAPHIC COMMA and U 3002 IDEOGRAPHIC FULL STOP whose character positions differ among CJK countries Configuring priority of Japanese centric fonts over Chinese ones using fonts conf should give peace of minds to Japanese 7 7 X applications 7 7 1 X office applications Here is a list of basic office applications OO is OpenOffice org 7 7 2 X utility applications Here is a list of basic utility applications which caught my eyes Caution I The poppler data package previously non free see Section 11 3 1 needs to be installed for evince and oku lar to display CJK PDF documents using Cmap data Section 7 6 3 Note Installing softwares such as scribus KDE on GNOME desktop environment are quite acceptable since corresponding func tionality is not available under GNOME desktop environment But installing too many packages with duplicated functionalities clutter
183. c OS X OpenSSH use ssh in the Terminal application GPL Table 6 17 List of free SSH clients for other platforms 6 9 5 Setting up ssh agent It is safer to protect your SSH authentication secret keys with a pass phrase If a pass phrase was not set use ssh keygen p to set it Place your public SSH 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 described above ssh agent bash ssh add ssh id_rsa Enter passphrase for home lt username gt ssh id_rsa Identity added home lt username gt ssh id_rsa home lt username gt ssh id_rsa No remote password needed from here on for the next command scp foo lt username gt remote host foo Press D to terminating ssh agent session For the X server the normal Debian startup script executes ssh agent as the parent process So you only need to execute ssh add once For more read ssh agent l and ssh ada 1 6 9 6 How to shutdown the remote system on SSH You need to protect the process doing shutdown h now see Section 1 1 8 from the termination of SSH using the at 1 command see Section 9 5 13 by the following echo shutdown h now at now Running shutdown h now in screen 1 see Section 9 1 session is another way to do the same Debian Reference 6 9 7 Troubleshooting SSH 134 265 If you have problems check the permissions of configurati
184. c SysRq key SAK key which is now the default for the Debian kernel Pressing Alt SysRq followed by one of the following keys does the magic of rescuing control of the system The combination of Alt SysRq s Alt SysRq u and Alt SysRq r is good for getting out of really bad situations See usr share doc linux doc 2 6 Documentation sysrq txt gz Caution The Alt SysRq feature may be considered a security risk by allowing users access to root privileged functions Placing echo 0 gt proc sys kernel sysraq in etc rc local or kernel sysrq 0 in etc sys ct1 conf disables the Alt SysRq feature Debian Reference 176 265 key following Alt SysRq description of action restore the keyboard from raw mode after X crashes change the console loglevel to 0 to reduce error messages kill all processes on the current virtual console send a SIGTERM to all processes except for init 8 send a SIGKILL to all processes except for init 8 sync all mounted filesystems remount all mounted filesystems read only umount olcjajlel ol Ol H reboot the system without syncing or unmounting Table 9 15 List of SAK command keys Tip From SSH terminal etc you can use the Alt SysRq feature by writing to the proc sysrq trigger For example e cho s gt proc sysrq trigger echo u gt proc sysrq trigger from the root shell prompt syncs and umounts all mounted
185. cd etc apt sudo git commit a Commit configuration with description and continue your life cd etc apt sudo gitk all You have full configuration history with you Note sudo 8 is needed to work with any file permissions of configuration data For user configuration data you may skip sudo Note The chmod 700 git command in the above example is needed to protect archive data from unauthorized read access Tip For more complete setup for recording configuration history please look for the et ckeeper package Section 9 2 10 Debian Reference Chapter 11 Data conversion Tools and tips for converting data formats on the Debian system are described 230 265 Standard based tools are in very good shape but support for proprietary data formats are limited 11 1 Text data conversion tools Following packages for the text data conversion caught my eyes package popcon size keyword description libc 6 casi il psize1 charset text encoding converter between locales by iconv 1 recode STO psize1 charset eol text encoding converter between locales versatile mc konwert i Kagne psize1 charset text encoding converter between locales fancy nK T E SHENDE psize1 charset character set translator for Japanese tcs ae dd psize1 charset character set translator unaccent ore clean psize1 charset replace accented letters by their un
186. cen lee psize1 backup system for KDE bacula common popcon1 psize1 Bacula network backup recovery and verification common Sur bacula client popcon1 psize1 Bacula network backup recovery and verification client meta bacula console popcon1 psize1 Bacula network backup recovery and verification text console bacula server popcon1 psize1 Bacula network backup recovery and verification server meta amanda common popcon1 psize1 Amanda Advanced Maryland Automatic Network Disk Archive amanda client popcon1 psize1 Amanda Advanced Maryland Automatic Network Disk Archive amanda server popcon1 psize1 Amanda Advanced Maryland Automatic Network Disk Archive backuppc popcon1 psize1 BackupPC is a high performance enterprise grade system for ba backup manager popcon1 psize1 command line backup tool backup21 popcon1 psize1 low maintenance backup restore tool for mountable media disk faubackup popcon1 psize1 backup system using a filesystem for storage disk based Table 10 3 List of backup suite utilities Backup tools have their specialized focuses e Mondo Rescue is a backup system to facilitate restoratio
187. cient for saving bandwidth than use of local mirror server with the full Debian archive contents Debian Reference 6 11 Here are other network application clients Other network application clients 135 265 package popcon size protocol netcat A psizel TCP IP stunnel4 pi laa psizel SSL telnet A psizel TELNET telnet ssl e A psizel1 nfs common ae kal psizel1 NFS smbclient a aa psizel1 SMB smbfs O IAS psize1 ftp e en psize1 FTP lftp a alll psizel1 neftp a psizel1 wget ad aia psizel HTTP and FTP curl a ra psizel1 bind9 host IA psizel DNS dnsutils ee psize1 dhep3 client ec cell psizel DHCP ldap utils popconl _ psize1 LDAP Table 6 19 List of network application clients 6 12 The diagnosis of the system daemons The telnet program enables manual connection to the system daemons and its diagnosis For example try the following telnet mail ispname net pop3 The following RFCs provide required knowledge to each system daemon The port usage is described in etc services Note For testing TLS SSL services such as HTTPS you need TLS SSL enabled telnet program Debian Reference 136 265 RFC descr rfc1939 and rfc2449 POP3 rfc3501 IMAF rfc2821 rfc821
188. ckage provides sensible browser 1 sensibl ditor 1 and sensible pager 1 which make sensible decisions on which editor pager and web browser to call respectively recommend you to read these shell scripts Tip In order to run a console application such as mutt under X as your preferred application you should create an X application as following and set usr local bin mutt term as your preferred application to be started as described cat usr local bin mutt term lt lt EOF bin sh gnome terminal e mutt EOF chmod 755 usr local bin mutt term 9 5 12 Killing a process Use ki 11 1 to kill or send a signal to a process by the process ID Use ki11a11 1 or pki11 1 to do the same by the process command name and other attributes 9 5 13 Scheduling tasks once Run the at 1 command to schedule a one time job by the following echo command args at 3 40 monday Debian Reference 175 265 signal value signal name function 1 HUP restart daemon 15 TERM normal kill 9 KILL kill hard Table 9 14 List of frequently used signals for kill command 9 5 14 Scheduling tasks regularly Use cron 8 to schedule tasks regularly See cront ab 1 and crontab 5 If you are a member of cront ab group you can schedule to run processes as a normal user e g foo by creating a crontab 5 file as var spool cron crontabs foo with crontab e command Here
189. ckage selection data and suffers severely Look for the old var lib dpkg status file at var lib dpkg status old or var backups dpkg status x Keeping var backups in a separate partition may be a good idea since this directory contains lots of important system data For serious breakage I recommend to make fresh re install after making backup of the system Even if everything in var is gone you can still recover some information from directories in usr share doc to guide your new installation Reinstall minimal desktop system mkdir p path to old system Mount old system at path to old system cd path to old system usr share doc Is l A cd usr share doc le 1 55 MsSd tzr cd sos lsk we ale Tess He de de e Se Se Then you are presented with package names to install There may be some non package names such as texm 2 7 Tips for the package management 2 7 1 How to pick Debian packages You can seek packages which satisfy your needs with aptitude from the package description or from the list under Tasks When you encounter more than 2 similar packages and wonder which one to install without trial and error efforts you should use some common sense I consider following points are good indications of preferred packages e Essential yes gt no e Component main gt contrib gt non free e Priority required gt important gt standard gt optional gt extra e Tasks p
190. clude specific newer upstream version packages found in unstable regularly upgraded while tracking testing You list all required archives in the etc apt sources list file as the following deb http ftp us debian org debian testing main contrib non free deb http ftp us debian org debian unstable main contrib non free deb http security debian org testing updates main contrib Set the etc apt preferences file as as the following Package Pin release a testing STREO E S00 Package Pin release a unstable aloe 7210 0 When you wish to install a package named lt package name gt with its dependencies from unstable archive under this configuration you issue the following command which switches target release with t option Pin Priority of unstable becomes 990 Debian Reference 67 265 sudo apt get install t unstable lt package name gt With this configuration usual execution of apt get upgrade and apt get dist upgrade or aptitude sa fe upgrade and aptitude full upgrade for squeeze upgrades packages which were installed from test ing archive using current testing archive and packages which were installed from unstable archive using current unstable archive Caution l Be careful not to remove testing entry from the etc apt sources list file Without testing entry in it APT system upgrades packages using newer unstable archive Tip usually edit the etc
191. combined Be careful about using this shell IFS tricks Strange things may happen when shell interprets some parts of the script as its input SES u use 3 and as IES echo IFS SIFS IFS SIFS echo is a Bash builtin IFS IFS date R just a command output Sawy 23 IWE 2003 0591590315 POZNO echo date R sub shell gt input to main shell Sar 23 Aue 2005 06 S0 36 02 010 unset IFS reset IFS to the default echo date R Sicilia 2S AUR OSOS ES Ono Ole O00 1 6 6 Script snippets for piping commands The following scripts do nice things as a part of a pipe Debian Reference 35 265 script snippet type in one line effect of command find usr print find all files under usr seg 1 100 print to 100 xargs n 1 lt command gt run command repeatedly with each item from pipe as its argument xargs n 1 echo split white space separated items from pipe into lines xargs echo merge all lines from pipe into a line grep e lt regex_pattern gt extract lines from pipe containing lt regex_pattern gt grep v lt regex_pattern gt extract lines from pipe not containing lt regex_pattern gt cut d 3 wow extract third field from pipe separated by passwd file etc awk print 3 extract third field from pipe separated by whitespaces awk F t print 3 extract third field fro
192. command tool chain is used as the backend tool for most translation activities apt itude 8 lists under Tasks Localization provide extensive list of useful binary packages which add localized mes sages to applications and provide translated documentation For example you can obtain the localized message for manpage by installing the manpages lt LANG gt package To read the Italian language manpage for lt programname gt from usr share man it execute as the following LANG it_IT UTF 8 man lt programname gt 8 3 8 Effects of the locale The sort order of characters with sort 1 is affected by the language choice of the locale Spanish and English locale sort differently The date format of 1s 1 is affected by the locale The date format of LANG C 1s 1 and LANG en_US UTF 8 are different see Section 9 2 5 Number punctuation are different for locales For example in English locale one thousand one point one is displayed as 1 0 00 1 while in German locale it is displayed as 1 000 1 You may see this difference in spreadsheet program Debian Reference Chapter 9 System tips 156 265 Here I describe basic tips to configure and manage systems mostly from the console 9 1 The screen program screen 1 is a very useful tool for people to access remote sites via unreliable or intermittent connections since it support interrupted network connections package popcon size description
193. con1 psizel GStreamer GNOME sound engine popconl libxinel psizel xine KDE older sound engine libphonon4 E psizel Phonon KDE new sound engine Table 9 18 List of sound packages environment command The Linux console setterm powersave off The X Window turning off screensaver xset s off The X Window disabling dpms xset dpms The X Window GUI configuration of screen saver xscreensaver command prefs Table 9 19 List of commands for disabling the screen saver Debian Reference 9 6 11 181 265 report size Total size in dmesg 1016784k 1GB 31792k Free in dmesg 990528k Total under shell 997184k 20256k but effectively Free under shell 321780k Table 9 20 List of memory sizes reported System security and integrity check Poor system maintenance may expose your system to external exploitation For system security and integrity check you should start with the following e The debsums package See debsums 1 and Section 2 5 2 e The chkrootkit package See chkrootkit 1 s The clamav package family See clamscan 1 and freahclam 1 e Debian security FAQ e Securing Debian Manual package popcon size description logcheck Ep guano psizel daemon to mail anomalies in the system logfiles to the administrator debsums le SES psizel uti
194. cription of configuration file etc ssh ssh_config SSH client defaults see ssh_config 5 etc ssh sshd_config SSH server defaults see sshd_config 5 ssh authorized_keys default public SSH keys that clients use to connect to this account on this SSH server ssh identity secret SSH 1 RSA key of the user ssh id_rsa secret SSH 2 RSA key of the user ssh id_dsa secret SSH 2 DSA key of the user Table 6 15 List of SSH configuration files Tip See ssh keygen 1 ssh add 1 and ssh agent 1 for how to use public and secret SSH keys Tip Make sure to verify settings by testing the connection In case of any problem use ssh v Tip You can change the pass phrase to encrypt local secret SSH keys later with ssh keygen p Tip You can add options to the entries in gt ssh authorized_keys to limit hosts and to run specific commands See ssha 8 for details Debian Reference 132 265 command description ssh username hostname domain ext connect with default mode ssh v username hostname domain ext connect with default mode w ssh 1 username hostname domain ext force to connect with SSH ve ssh 1 o RSAAuthentication no 1 username hostname domain ext force to use password with S ssh o PreferredAuthentications password 1 username hostname domain ext force to use password with S Table 6 16 List of SSH client startup exampl
195. ctive package management tool in previous releases 2 2 2 Interactive use of aptitude For the interactive package management you start apt itude in interactive mode from the console shell prompt as follows sudo aptitude u Password This updates the local copy of the archive information and display the package list in the full screen with menu Aptitude places its configuration at aptitude config Tip If you want to use root s configuration instead of user s one use sudo H aptitude insteadof sudo aptitude in the above expression Tip Aptitude automatically sets pending actions as it is started interactively If you do not like it you can reset it from menu Action Cancel pending actions 2 2 3 Key bindings of aptitude Notable key strokes to browse status of packages and to set planned action on them in this full screen mode are the following The file name specification of the command line and the menu prompt after pressing 1 and take the aptitude regex as described below Aptitude regex can explicitly match a package name using a string started by n and followed by the package name Tip You need to press U to get all the installed packages upgraded to the candidate version in the visual interface Otherwise only the selected packages and certain packages with versioned dependency to them are upgraded to the candidate version 2 2 4 Package views under aptitude
196. d Start the post fix by the following sudo etc init d postfix start Here the use of and in the dpkg reconfigure dialog and etc postfix sasl_passwd ensures not to check MX record but directly use exact hostname specified See Enabling SASL authentication in the Postfix SMTP client in usr share doc postfix html SASL_README htm1 6 3 3 The mail address configuration There are a few mail address configuration files for mail transport delivery and user agents file function application etc mailname default host name for outgoing mail Debian specific nai lname 5 etc email addresses host name spoofing for outgoing mail exim 8 specific exim4 config_files etc postfix generic host name spoofing for outgoing mail post fix 1 specific activated after postm etc aliases account name alias for incoming mail general activated after newaliases 1 cor Table 6 6 List of mail address related configuration files The mailname in the etc mailname file is usually a fully qualified domain name FQDN that resolves to one of the host s IP addresses For the mobile workstation which does not have a hostname with resolvable IP address set this mailname to the value of hostname f This is safe choice and works for both exim4 x and post fix Tip The contents of etc mailname is used by many non MTA programs for their default behavior For mutt set hostn ame and from var
197. d to mc term f Click OK wk YN Create an open with association as as the following 1 Right click folder to select Open with Other Application 2 Click open Use a custom command dialog and enter mc term f 3 Click Open Tip Launcher is a file at Desktop with desktop as its extension Debian Reference 174 265 9 5 11 Customizing program to be started Some programs start another program automatically Here are check points for customizing this process e Application configuration menu GNOME desktop System Preferences Preferred Application KDE desktop K Control Center KDE Components Component Chooser Iceweasle browser Edit Preferences Applications mc 1 etc mc mc ext e Environment variables such as SBROWSER SEDITOR S VISUAL and SPAGER see eviron 7 momo n on e The update alternat ives 8 system for programs such as editor view x www browser gnome www browser and www browser see Section 1 4 7 e the mailcap and etc mailcap file contents which associate MIME type with program see mailcap 5 e The mime types and etc mime types file contents which associate file name extension with MIME type see run mailcap 1 Tip update mime 8 updates the etc mailcap file using etc mailcap order file see mailcap order 5 Tip The debianutils pa
198. d by the moreutils package This is quite useful when you wish to overwrite original file The vim 1 command can replace all instances of F ROM_REGEX with TO_TEXT in file by using ex 1 commands vim s FROM_REGEX TO_TEXT gc w q file Tip The c flag in the above ensures interactive confirmation for each substitution Multiple files file1 file2 and file3 can be processed with regular expressions similarly with vim 1 or per1 1 vim argdo s FROM_REGEX TO_TEXT ge lupdate q filel file2 file3 Tip The e flag in the above prevents the No match error from breaking a mapping perl i p e s FROM_REGEX TO_TEXT g filel file2 file3 In the perl 1 example i is for in place editing p is for implicit loop over files Tip Use of argument i bak instead of i keeps each original file by adding bak to its filename This makes recovery from errors easier for complex substitutions Note ed 1 and vim 1 are BRE per1 1 is ERE 1 6 5 Extracting data from text file table Let s consider a text file called DPL in which some pre 2004 Debian project leader s names and their initiation days are listed in a space separated format Tan Murdock GT T Bruce Perens April 1996 Tan Jackson January 1998 Wichert Akkerman January 1999 Ben Collins April 2001 Bdale Garbee April 2002 Martin M
199. d crypt_file gpg r name decryption gpg o file decrypt crypt_file gpg pe Table 10 14 List of GNU Privacy Guard commands on files 10 4 3 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 mce Asia to gg lle Dea verity sio set pgp_verify_sig no 10 4 4 Using GnuPG with Vim won The gnupg plugin let you run GnuPG transparently for files with extension gpg asc and ppg aptitude install vim scripts vim addon manager vim addons install gnupg Debian Reference 214 265 10 4 5 The MDS sum md5sum 1 provides utility to make a digest file using the method in rfc1321 and verifying each file with it S md5sum foo bar gt baz md5 G ear bez meS d3b07384d113edec49eaab238ad5ff00 foo celora OSSLA ISS Sa Oe md5sum c baz md5 oo OK bar TOR Note The computation for the MD5 sum is less CPU intensive than the one for the cryptographic signature by GNU Privacy Guard GnuPG Usually only the top level digest file is cryptographically signed to ensure data integrity 10 5 Source code merge tools There are many merge tools for the source code Following commands caught my eyes 10 5 1 Extracting differences for source files One of following procedures extract differences between two source files and create unified diff files file patch0 or fi le patch1 depending
200. d lt regex_desc match on task name t lt regex_task match on debtag G lt regex_debt match on maintainer m lt regex_main match on package section s lt regex_sect match on package version V lt regex_vers match archive A sarge etch match origin O debian match priority p extra impo match essential packages match virtual packages match new packages match with pending action a install up ep match installed packages SI match installed packages with A mark auto installed package M match installed packages without A mark administrator selected package i M match installed and upgradable packages U match removed but not purged packages C match removed purged or can be removed packages g match packages with broken relation b match packages with broken depends predepends conflict B lt type gt match packages from which relation lt type gt is defined to lt term gt package D lt type gt lt t match packages from which broken relation lt type gt is defined to lt term gt package DB lt type gt lt match packages to which the lt term gt package defines relation lt type gt R lt type gt lt t match packages to which the lt term gt package defines broken relation lt type gt RB lt type gt lt match packages to which some other installed packages depend o
201. data backup a 198 10 1 10 Removable storage device a 199 10 11 1 Sharng dat via network e 5 perra e Boe a a o E e GAYS ES 201 10 1 12 Archive media s spp Sake pee eb a ET EE ERR EO EEE ee ee Lee E 201 10 2 The disk image lt S Seah ee eee a ee he e A E a 202 10 2 1 Making the disk image file ee 202 10 2 2 Writing directly to the disk nunne e ror 203 10 2 3 Mounting the disk image file 000000000000 000 203 10 2 4 Cleaning a disk image file a e RR RR R R R RR RR eG a RE eee N 204 10 2 5 Making the empty disk image file e 204 10 2 6 Making the ISO9660 image file e 205 10 2 7 Writing directly to the CD DVD R RW 0 000 0 0 2 ee ee 205 10 2 8 Mounting the ISO9660 image file 2 2 2 020 0 2 00 00 0000000000 206 10 3 The binary datas ss c eG a ge SR A Re Re Re ER A ae be RR ee ee we e de 206 10 3 1 Viewing and editing binary data ee 206 10 3 2 Manipulating files without mounting disk 2 2 2 ee 206 10 3 3 Data redundancy 2 e R R RR RR RRR RRR ee 206 10 3 4 Data file recovery and forensic analysis e 209 10 3 5 Splitting a large file into small files o o e e 209 10 3 6 Clearing file cONteMtS ee AR R EA R ee 209 10 3 7 Dummy files cae tae PA ee EL eae Aa ed ee Ae eae ee 209 10 3 8 Erasing an entire hard disk ee 209 10 3 9 Erasing unused
202. dband router The LAN behind this router is usually served by the dynamic host configuration protocol DHCP server running on the router Just install the dhcp3 client package for the Ethernet served by the dynamic host configuration protocol DHCP 5 2 2 The static IP connection with the Ethernet No special action is needed for the Ethernet served by the static IP 5 2 3 The PPP connection with pppconfig The configuration script pepconf ig configures the PPP connection interactively just by selecting the following e The telephone number s The ISP user name The ISP password s The port speed s The modem communication port s The authentication method file function etc ppp peers lt isp_name gt The pppconfig generated configuration file for pppd specific to lt isp_name gt etc chatscripts lt isp_name gt The pppconfig generated configuration file for chat specific to lt isp_name gt etc ppp options The general execution parameter for pppd etc ppp pap secret Authentication data for the PAP security risk etc ppp chap secret Authentication data for the CHAP more secure Table 5 6 List of configuration files for the PPP connection with pppconfig e Caution The lt isp_name gt value of provider is assumed if pon and poff commands are invoked without arguments Debian Reference 100 265 You can test configuration using low level network configuration tools as the fo
203. dea to read some informative documentations You can install some of these packages by the following aptitude install package_name Debian Reference 5 265 package popcon size description popcon mc psize1 A text mode full screen file manager sudo ae SE psize1 A program to allow limited root privileges to users popcon1 2 3 E E E vim psize1 Unix text editor Vi IMproved a programmers text editor standard versio vim tiny popcon psize1 Unix text editor Vi IMproved a programmers text editor compact versio emacs22 popcon psize1 GNU project Emacs the Lisp based extensible text editor version 22 emacs23 a SEU psize1 GNU project Emacs the Lisp based extensible text editor version 23 w3m A SOD M psize1 Text mode WWW browsers gpm oe Opens psize1 The Unix style cut and paste on the text console daemon Table 1 1 List of interesting text mode program packages package popcon size description doc debian popcon1 psizel Debian Project documentation Debian FAQ and other debian policy popcon1 psizel Debian Policy Manual and related documents developers referenc popcon1 psizel Guidelines and information for Debian developers maint guide popcon1 psizel Debian
204. ding permission allows following actions e The read r permission allows owner to list contents of the directory s The write w permission allows owner to add or remove files in the directory e The execute x permission allows owner to access files in the directory 9 265 Here the execute permission on a directory means not only to allow reading of files in that directory but also to allow viewing their attributes such as the size and the modification time 1s 1 is used to display permission information and more for files and directories When it is invoked with the 1 option it displays the following information in the order given Type of file first character e Access permission of the file nine characters consisting of three characters each for user group and other in this order s Number of hard links to the file s Name of the user who owns the file e Name of the group which the file belongs to Size of the file in characters bytes Date and time of the file mtime s Name of the file character meaning normal file directory symlink character device node block device node named pipe socket HIT 1 Ol Kol a Table 1 4 List of the first character of 1s 1 output chown 1 is used from the root account to change the owner of the file chgrp 1 is used from the file s owner or root account to change the group of the file chmod 1 is used from the file
205. dists or pool The distribution is referred by two ways the suite or codename The word distribution is alternatively used as the synonym to the suite in many documentations The relationship between the suite and the codename can be summarized as the following Timing suite stable suite testing after the codename stable release codename codename stable codename co after the codename testing release codename codename testing codename co Table 2 4 The relationship between suite and codename The history of codenames are described in Debian FAQ 6 3 1 Which other codenames have been used in the past In the stricter Debian archive terminology the word section is specifically used for the categorization of packages by the application area Although the word main section may sometimes be used to describe the Debian archive section which provides the main component Every time a new upload is done by the Debian developer DD to the unstable archive via incoming processing DD is required to ensure uploaded packages to be compatible with the latest set of packages in the latest unstable archive Debian Reference 42 265 If DD breaks this compatibility intentionally for important library upgrade etc there is usually announcement to the debian devel mailing list etc Before a set of packages are moved by the Debian archive maintenance script from the uns
206. dness 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 Let s think following AWK script snippet AS AA priat Ss e This is equivalent to any one of the following lines perl me HQr splirp e S es 19570 prime Sie Ay yal perl sae lir CieSsjolaic 1 ee 19570 prime Veral perl ne f split print f 2 if f 1 1957 ere leame Gorbea 2 ase Su es 195 qwe Pere lance pra test ec ase The last one is a riddle It took advantage of following Perl features e The whitespace is optional e The automatic conversion exists from number to the string See perlrun 1 for the command line options For more crazy Perl scripts Perl Golf may be interesting Debian Reference 262 265 12 9 Web Basic interactive dynamic web pages can be made as follows e Queries are presented to the browser user using HTML forms Filling and clicking on the form entries sends one of the following URL string with encoded parameters from the browser to the web server http www foo dom cgi bin program pl VAR1 VAL18VAR2 VAL28VAR3 VAL3 http www foo dom cgi bin program py VAR1 VAL18VAR2 VAL28VAR3 VAL3 http www foo dom program php VAR1 VAL18VAR2 VAL28VAR3 VAL3 gnn in URL is replaced with a character with hexadecimal nn value The environment variable is set as
207. ds here The device pointed by dev sda may be SCSI hard disk or serial ATA hard disk where your entire system resides Debian Reference 210 265 Erase all the disk content by resetting data to O with the following dd if dev zero of dev sda Erase all by overwriting random data with the following dd if dev urandom of dev sda Erase all by overwriting random data very efficiently with the following shred v n 1 dev sda Since dd 1 is available from the shell of many bootable Linux CDs such as Debian installer CD you can erase your installed system completely by running an erase command from such media on the system hard disk e g dev hda dev sda etc 10 3 9 Erasing unused area of an hard disk Unused area on an hard disk or USB memory stick e g dev sdb1 may still contain erased data themselves since they are only unlinked from the filesystem These can be cleaned by overwriting them mount t auto dev sdb1 mnt foo cd mnt foo dd if dev zero of junk dd writing to junk No space left on device sync umount dev sdbl Warning l This is usually a good enough for your USB memory stick But this is not perfect Most parts of erased filenames and their attributes may be hidden and remain in the filesystem 10 3 10 Undeleting deleted but still open files Even if you have accidentally deleted a file as long as that file is still being used
208. e SLANG variable is referred first and it can be overridden by the LC_TIME variable The actual default display format for each locale depends on the version of the standard C library the 1ibc6 package used Le different releases of Debian had different defaults If you really wish to customize this display format of time and date beyond the locale you should set the time style value by the time style argument or by the STIME_STYLE value see 1s 1 date 1 info coreutils ls invoca tion Tip You can eliminate typing long option on commandline using command alias e g alias 1s 1s time style d sm y H M see Section 1 5 9 Tip ISO 8601 is followed for these iso formats Debian Reference 160 265 time style value locale display of time and date iso any 01 19 00 15 long iso any 2009 01 19 00 15 Cisse P 2009 01 19 00 15 16 000000000 0900 locale E Jan 19 00 15 locale en_US UTF 8 2009 01 19 00 15 locale es_ES UTF 8 ene 19 00 15 5d Sm Sy SH SM any 19 01 09 00 15 5d Sb Sy SH SM C or en_US UTF 8 19 Jan 09 00 15 5d Sb Sy SH 5M es_ES UTF 8 19 ene 09 00 15 Table 9 4 Display examples of time and date for the 1s 1 command for lenny 9 2 6 Colorized shell echo Shell echo to most modern terminals can be colorized using ANSI escape code see usr share doc xterm ctlseq s txt gz For example try
209. e Debian system has some notable packages for the print servers and utilities Tip You can configure CUPS system by pointing your web browser to http localhost 631 Debian Reference 130 265 package popcon size port description lpr Gia bii psize1 printer 515 BSD Ipr Ipd Line printer daen lprng eee psizel Enhanced cups oo kE psizel IPP 631 Internet Printing CUPS server ae popcon1 System V printer commands fc cups client o psizel Ipmove 8 1pinfo 8 ipa cups bsd e SS psizel1 BSD printer commands for CL cups driver gutenprint Pang ad psizel1 Not applicable printer drivers for CUPS Table 6 12 List of print servers and utilities 6 9 The remote access server and utility SSH The Secure SHell SSH is the secure way to connect over the Internet A free version of SSH called OpenSSH is available as openssh client and openssh server packages in Debian package popcon size tool description openssh client ia psizel ssh 1 Secure shell openssh server A psizel sshd 8 Secure shell ssh askpass fullscreen da psizel ssh askpass fullscreen l asks user for ssh askpass A psizel ssh askpass l asks user for Table 6 13 List of remote access server and utilities l Caution See Section 4 7 3 if your SSH is accessible from the Internet
210. e default installation The typical boot strap process is like a four stage rocket Each stage rocket hands over the system control to the next stage one e Section 3 2 e Section 3 3 e Section 3 4 e Section 3 5 Of course these can be configured differently For example if you compiled your own kernel you may be skipping the step with the mini Debian system So please do not assume this is the case for your system until you check it yourself Note For non legacy PC platform such as the SUN or the Macintosh system the BIOS on ROM and the partition on the disk may be quite different Section 9 3 1 Please seek the platform specific documentations elsewhere for such a case 3 2 Stage 1 the BIOS The BIOS is the 1st stage of the boot process which is started by the power on event The BIOS residing on the read only memory ROM is executed from the particular memory address to which the program counter of CPU is initialized by the power on event This BIOS performs the basic initialization of the hardware POST power on self test and hands the system control to the next step which you provide The BIOS is usually provided with the hardware Debian Reference 77 265 The BIOS startup screen usually indicates what key s to press to enter the BIOS setup screen to configure the BIOS behavior Popular keys used are Fl F2 F10 Esc Ins and Del If your BIOS startup screen is hidden by a nice graphics screen you may press some ke
211. e file mount it as loop device or device mapper devices see Section 10 2 3 For disk images supported by QEMU mount them as network block device see Section 9 8 3 e Populate the target filesystem with required system data Use programs such as deboot strap and cdeboot st rap help this process see Section 9 8 4 Use installers of OSs under the full system emulation e Run a program under a virtualized environment chroot provides basic virtualized environment enough to compile programs run console applications and run daemons in it QEMU provides cross platform CPU emulation QEMU with KVM provides full system emulation by the hardware assisted virtualization VirtualBox provides full system emulation on 1386 and amd64 with or without the hardware assisted virtualization 9 8 3 Mounting the virtual disk image file For the raw disk image file see Section 10 2 For other virtual disk image files you can use qemu nba 8 to export them using network block device protocol and mount them using the nbd kernel module qemu nba 8 supports disk formats supported by QEMU QEMU supports following disk formats raw qcow2 qcow vmdk vdi bochs cow user mode Linux copy on write parallels dmg cloop vpc vvfat virtual VFAT and host_device The network block device can support partitions in the same way as the loop device see Section 10 2 3 You can mount the first partition of disk img as follows
212. e 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 mathematica4 1 e ttf mscorefonts installer You ll have a really good selection of TrueType fonts at the expense of contaminating your Free system with non Free fonts 7 6 3 CJK fonts Here are some key points focused on fonts of CJK characters font type Japanese font name Chinese font name Korean font name gothic sans serif amp X30b4 8 amp x30c 1 amp x30c3 SeotBOatodu m gulim gothic hei mincho serif ng ming ba tang amp x660e amp x671d so Table 7 7 Table of key words used in CJK font names to indicate font types Font name such as VL PGothic with P is a proportional font which corresponds to the fixed width VL Gothic font For example Shift_JIS code table comprises 7070 characters They can be grouped as the following Debian Reference 146 265 e JIS X 0201 single byte characters 191 characters a k a half width characters e JIS X 0208 double byte characters 6879 characters a k a full width characters Double byte characters occupy double width on console terminals which uses CJK fixed width fonts In order to cope with such situation Hanzi Bitmap Font HBF File with file extension hbf may be deployed for fonts containing single byte and double
213. e g path to emp dir in another partition with usable space you can create a symlink to the directory with 1n 8 S sudo mv work dir old dir S sudo mkdir p path to emp dir sudo ln sf path to emp dir work dir sudo cp a old dir x work dir SMsud o en folic casa e Caution Some software may not function well with symlink to a directory 9 3 12 Expansion of usable storage space using aufs If you have usable space in another partition e g path to you can create a directory in it and stack that on to a directory where you need space with aufs sudo mv work dir old dir sudo mkdir work dir S sudo mkdir p path to emp dir sudo mount t aufs o br path to emp dir old dir none work dir Caution l Use of aufs for long term data storage is not good idea since it is under development and its design change may introduce issues Tip In order to use aufs its utility package aufs tools and kernel module package for aufs such as aufs modules 2 6 amd64 need to be installed Tip aufs is used to provide writable root filesystem by many modern live CD projects 9 4 Data encryption tips With physical access to your PC anyone can easily gain root privilege and access all the files on your PC see Section 4 7 4 This means that login password system can not secure your private and sensitive data against possible theft of your PC You must deploy data encrypti
214. e internal 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 is moved to the cursor location If you press F5 the selected area is copied and inserted at the cursor location F2 saves the file F10 gets you out Most cursor keys work intuitively This editor can be directly started on a file using one of the following commands me filename_to_edit mcedit filename_to_edit This is not a multi window editor but one can use multiple Linux consoles to achieve the same effect To copy between windows use Alt F lt n gt keys to switch virtual consoles and use File Insert file or File 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 the environment variables SEDITOR or SVISUAL to decide which editor to use If you are uncomfortable with vim 1 or nano 1 initially you may set these to mcedit by adding the following lines to bash rC x export EDITOR mcedit export VISUAL mcedit I do recommend setting these to vim if possible If you are uncomfortable with vim 1 you can keep using mcedit 1 for most system maintenance tasks 1 3 6 The internal viewer in MC MC is a very smart viewer This is a gr
215. e systems e Winbind with Windows NT and SAMBA 4 5 3 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 s u command in Debian uses PAM so that one can restrict the ability to use su to the root group by enabling the line with pam_wheel so in etc pam d su 4 5 4 Stricter password rule Installing the 1libpam cracklib package enables you to force stricter password rule for example by having active lines in etc pam d common password as the following For lenny password required pam_cracklib so retry 3 minlen 9 difok 3 password required pam_unix so use_authtok nullok md5 For squeeze password required pam_cracklib so retry 3 minlen 9 difok 3 password success 1 default ignore pam_unix so use_authtok nullok md5 password requisite pam_deny so password required pam_permit so 4 6 Other access controls Note See Section 9 5 15 for restricting the kernel secure attention key SAK feature 4 6 1 sudo sudo 8 is a program designed to allow a sysadmin to give limited root privileges to users and log root activity sudo re quires only an ordinary user s password Install sudo package and activate it by setting options in etc sudoers See configuration example at usr share doc sudo examples sudoers My usage of sudo for the single user system see Section 1 1 12 is aimed to protect myself from
216. e terminal 1 r xvt 1 or xterm 1 Under the GNOME Desktop environment clicking Applications Accessories Terminal does the trick You can also see the section below Section 1 1 6 Under some other Desktop systems like 1uxbox there may be no obvious starting point for the menu If this happens just try right clicking the center of the screen and hope for a menu to pop up 1 1 3 The root account The root account is also called superuser or privileged user From this account you can perform the following system adminis tration tasks e Read write and remove any files on the system irrespective of their file permissions e Set file ownership and permissions 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 This unlimited power of root account requires you to be considerate and responsible when using it Warning Never share the root password with others Debian Reference 3 265 Note File permissions of a file including hardware devices such as CD ROM etc which are just another file for the Debian sys tem may render it unusable or inaccessible by non root users Although the use of root account is a quick way to test this kind of situation its resolution should be done through proper setting of file permissions and user s group membership see Section 1 2 3 1 1 4 The root shell prompt
217. e to CVS by the following cvs ci m Describe change Create and add file_to_ada file to CVS by the following S wal raile co ack S hws Exelol ale 20 grelol Ss eL u olle illes ada Merge the latest version from CVS by the following cvs up d Watch out for lines starting with C filename which indicates conflicting changes Look for unmodified code in filename version Search for lt lt lt lt lt lt lt and gt gt gt gt gt gt gt in files for conflicting changes Edit files to fix conflicts as needed Add a release tag Release 1 by the following cvs ci m last commit for Release 1 cvs tag Release 1 Edit further Remove the release tag Release 1 by the following S cvs tag d Release 1 Check in changes to CVS by the following Ss eya el aco last combo or Release Re add the release tag Release 1 to updated CVS HEAD of main by the following cvs tag Release 1 Create a branch with a sticky branch tag Release initial bugfixes from the original version pointed by the tag Release initial and check it out to path to old directory by the following cvs rtag b r Release initial Release initial bugfixes modulel cd path to S cvs co r Release initial bugfixes d old modulel Se co ll Tip Use D 2005 12 20 ISO 8601 date format instead of r Release initial to specify particular date as the branch point Work on this loc
218. e to the freedesk xdg utils popcon psize1 utilities to integrate desktop environment providec gnome desktop environment popcon1 psize1 standard GNOME desktop environment metapac kde core popcon psize1 core KDE desktop environment metapackage xfce4 popcon psize1 Xfce lightweight desktop environment metapack lxde core popcon psize1 LXDE lightweight desktop environment metapac fluxbox popcon psize1 Fluxbox package for highly configurable and low Table 7 1 List of key meta packages for X Window Debian Reference 139 265 7 2 3 Debian menu under GNOME desktop environment In order to obtain access to the traditional Debian menu under GNOME desktop environment you must install the menu xdg package click System Preference Main Menu and check the box for Debian Tip You may need to do the similar for other modern desktop environments which are compliant to Freedesktop org standard 7 3 The server client relationship The X Window System is activated as a combination of the server and client programs The meaning for the words server and client with respect to the words local and remote requires attention here type description X server a program run on a local host connected to the user s display and inpu
219. e vector PostScript and PI libwmf bin oponi psize1 Windows image vector Windows metafil fig2sxd A psize1 fig sxd vector convert XFig file unpaper ag Sopol psize1 image image post processing t tesseract ocr ea psizel1 image text free OCR softwat tesseract ocr eng Piano psize1 image text OCR engine data gocr E binanudie psize1 image text free OCR softwas ocrad G popon psize1 image text free OCR softwai gtkam oo ag psizel1 image Exif manipulate digita gphoto2 a SS psize1 image Exif manipulate digita kamera Gan S psize1 image Exif manipulate digita jhead Din psizel1 image Exif manipulate the nc exif gc S psize1 image Exif command line uti exiftags a SOD psize1 image Exif utility to read Ex exiftran a adie psizel1 image Exif transform digital exifprobe E psizel image Exif read metadata fro deraw q popcont psizel imageRaw ppm decede raw digits findimagedupes aiie psize1 image fingerprint find visually simi 7 et T Debian Reference 246 265 package popcon size keyword description alien a Opeon nOs psizel rpm tgz deb converter for the foreign package into the Debian p freepwing a opent E psizel EB EPWING converter from Electric Book popular in Japan 1 Table 11 18 List of miscellaneous data conversion tools
220. e when a package is installed If update is specified and file exists it is immediately set to the new owner and mode Caution l The direct alteration of owner or mode for a file owned by the package using chmod or chown commands by the system administrator is reset by the next upgrade of the package Note use the word file here but in reality this can be any filesystem object that dpkg handles including directories devices etc Debian Reference 61 265 2 5 12 The dpkg divert command File diversions provided by the dpkg divert 8 command are a way of forcing dpkg 1 not to install a file into its default location but to a diverted location The use of dpkg divert is meant for the package maintenance scripts Its casual use by the system administrator is deprecated 2 6 Recovery from a broken system When running unstable system the administrator is expected to recover from broken package management situation e Caution Some methods described here are high risk actions You have been warned 2 6 1 Incompatibility with old user configuration If a desktop GUI program experienced instability after significant upstream version upgrade you should suspect interferences with old local configuration files created by it If it is stable under newly created user account this hypothesis is confirmed This is a bug of packaging and usually avoided by the packager To recov
221. e while disconnected and then re attach it later when you connect again 9 1 2 Key bindings for the screen command In a screen session all keyboard inputs are sent to your current window except for the command keystroke All screen command keystrokes are entered by typing A Control A plus a single key plus any parameters Here are important ones to remember key binding meaning A show a help screen display key bindings y create a new window and switch to it gt go to next window gt go to previous window gt go to window number 0 gt go to window number 1 gt show a list of windows gt send a Ctrl A to current window as keyboard input gt write a hardcopy of current window to file gt begin end logging current window to file o a oa sf e omina gt lock the terminal password protected gt Q detach screen session from the terminal gt gt gt p gt gt gt gt P P a D gt detach screen session and log out See screen 1 for details Table 9 2 List of key bindings for screen 9 2 Data recording and presentation 9 2 1 The log daemon Many programs record their activities under the var log directory s The kernel log daemon klogd 8 e The system log daemon syslogd 8 See Section 3 5 9 and Section 3 5 10 9 2 2 Log analyzer Here are notable log analyzers
222. each package It was downloaded on pop date and contains the total submission of pop submissions reports over pop packages binary packages and pop architectures architectures Note Please note that the arch unstable archive contains only all packages packages currently The popcon data contains reports from many old system installations The popcon number preceded with V for votes is calculated by 100 the popcon submissions for the package executed recently on the PC the total popcon submissions The popcon number preceded with I for installs is calculated by 100 the popcon submissions for the package installed on the PC the total popcon submissions Note The popcon figures should not be considered as absolute measures of the importance of packages There are many factors which can skew statistics For example some system participating popcon may have mounted directories such as bin with noatime option for system performance improvement and effectively disabled vote from such system The package size The package size data is also presented as the objective measure for each package It is based on the Installed Size reported by apt cache show or aptitude show command currently on arch architecture for the unst able release The reported size is in KiB Kibibyte unit for 1024 bytes Note A package with a small numerical package size
223. eat tool for searching words in documents I always use this for files in the usr sha re doc directory This is the fastest way to browse through masses of Linux information This viewer can be directly started using one of the following commands S mc v path to filename_to_view mcview path to filename_to_view 1 3 7 Auto start features of MC Press Enter on a file and the appropriate program handles the content of the file see Section 9 5 11 This is a very convenient MC feature In order to allow these viewer and virtual file features to function viewable files should not be set as executable Change their status using chmod 1 or via the MC file menu Debian Reference 19 265 file type reaction to enter key executable file execute command man file pipe content to viewer software html file pipe content to web browser x tar gz and x deb file browse its contents as if subdirectory Table 1 12 The reaction to the enter key in MC 1 3 8 FTP virtual filesystem of MC MC can be used to access files over the Internet using FTP Go to the menu by pressing F9 then type p to activate the FTP virtual filesystem Enter a URL in the form username passwdthostname domainname which retrieves a remote directory that appears like a local one Try http us debian org debian as the URL and browse the Debian archive 1 4 The basic Unix like work environment Although MC enables you to do almos
224. eb Tip If system breakage is minor you may alternatively downgrade the whole system as Section 2 7 7 using the higher level APT system If your system is unbootable from hard disk you should seek other ways to boot it 1 Boot the system using the debian installer CD in rescue mode 2 Mount the unbootable system on the hard disk to target 3 Install older version of foo package by the following ii ells root carge 1 crac olle loas E areh ollo This example works even if the dpkg command on the hard disk is broken Tip Any GNU Linux system started by another system on hard disk live GNU Linux CD bootable USB key drive or netboot can be used similarly to rescue broken system If attempting to install a package this way fails due to some dependency violations and you really need to do this as the last resort you can override dependency using dpkg s ignore depends force depends and other options If you do this you need to make serious effort to restore proper dependency later See dpkg 8 for details Note When your system is seriously broken you should make a full backup of system to a safe place see Section 10 1 6 and should perform a clean installation This is less time consuming and produces better results in the end Debian Reference 63 265 2 6 5 Recovering package selection data If var lib dpkg status becomes corrupt for any reason the Debian system loses pa
225. ee Shell conditionals 2 5 44 44 ep 4008 48 e ba ee ea eed ded ee ea eae R SB ll loops hs wees ESE eM RR we Re R oe E od YEW ee ee wo The shell command line processing sequence 1 Utility programs for shell script ee Shell scnnpr dialog s s secs a R R R EE RS ae eR RRR ERR Ree a eR a eS Shell script example with zenity 2 2 a xvi 230 230 230 232 232 232 233 233 233 234 234 234 236 238 238 238 239 239 241 241 241 241 242 242 242 243 244 244 Debian Reference xvii 12 2 Make eii E Fa RA ee E A eee eed E a a E 253 AS AA oa Guth Aces E ES a R Re Aa RE E be RE hee ee 253 12 31 Simple C program gcc e a chee wba A A eee N E bs 256 124 DeDUS sar se aroe ae aa e e A SR ee ee a e 256 12 4 1 Basicgdb execution 222 2 ora a a R A a Aa e 256 12 4 2 Debugging the Debian package 2 ee 257 124 3 Obtaining backtrac 0 soe wb Ae ee SR Se ee ee 2 Oe ea sy E N e ee e 257 12 4 4 Advanced gdb commands e se e e e eR 258 124 5 Debueging X EMOS X E e e de a bh E A A ES 258 12 4 6 Check dependency on libraries a 258 12 4 7 Memory leak detection tools erana ee 259 12 4 8 Static code analysis tools e 259 12 4 9 Disassemble binay s gt o ss acad R e R E dee e E RR RRR RRR e e N RRR 250 125 L a better TTT 260 12 6 Bison a better Yace 2 R Rd RR RRR RR RRR RE 0 260 12 7 AUtOCODE tur a e R haa ea a ea Oh RRR a R 260 12
226. efault Pin Priority package source type 990 target release archive 500 normal archive 100 installed package 1 NotAutomatic archive Table 2 18 List of the default Pin Priority value for each package source type The target release archive can be set by several methods e etc apt apt conf configuration file with APT Default Release stable line e command line option e g apt get install t testing some package The NotAutomatic archive is set by archive server having its archive level Release file see Section 2 5 3 containing NotAu U tomatic yes The apt pinning situation of lt package gt from multiple archive sources is displayed by apt cache policy lt package gt e A line started with Package pin lists the package version of pin if association just with lt package gt is defined e g Package pin 0 190 e No line with Package pin exists if no association just with lt package gt is defined e The Pin Priority value associated just with lt package gt is listed right side of all version strings e g 0 181 700 e 0 is listed right side of all version strings if no association just with lt package gt is defined e g 0 181 0 e The Pin Priority values of archives defined as Package in the etc apt preferences file are listed left side of all archive paths e g 200 http backports org etch backports main Packages Here is an example of apt pinning technique to in
227. endency Most users would not want the package unless all of the packages listed in this field are installed Suggests This declares a weak dependency Many users of this package may benefit from installing packages listed in this field but can have reasonable functions without them Enhances This declares a week dependency like Suggests but works in the opposite direction Conflicts This declares an absolute incompatibility All of the packages listed in this field must be removed to install this package Replaces This is declared when files installed by this package replace files in the listed packages Provides This is declared when this package provide all of the files and functionality in the listed packages Note Please note that defining Provides Conflicts and Replaces simultaneously to an virtual package is the sane configuration This ensures that only one real package providing this virtual package can be installed at any one time The official definition including source dependency can be found in the Policy Manual Chapter 7 Declaring relationships between packages 2 1 6 The event flow of the package management Here is a summary of the simplified event flow of the package management by APT Update aptitude update or apt get update 1 Fetch archive metadata from remote archive 2 Reconstruct and update local metadata for use by APT Upgrade aptitude safe upgrade
228. er DATA_ISO e dvdisaster i DATA_ISO mRS02 c zenity info title Dvdisaster RS02 width 640 height 400 text ISO RS02 data SSIZE MB n created at SDATA_ISO EOF You may wish to create launcher on the desktop with command set something like usr local bin gmkrs02 d 12 2 Make Make is a utility to maintain groups of programs Upon execution of make 1 make read the rule file Makefile and updates a target if it depends on prerequisite files that have been modified since the target was last modified or if the target does not exist The execution of these updates may occur concurrently The rule file syntax is the following target prerequisites TAB commandl TAB command2 ignore errors TAB command3 suppress echoing Here TAB is a 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 by the following 0 c header h Here the target contains the character 3 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 automatic variable value se target S lt first prerequisite all newer prerequis
229. er RA psizel KDE presentation kexi as e psizel KDE database management kivio oe RA psizel KDE flowchart and diagram editor karbon S a S psizel1 KDE vector graphics editor draw krita aor open ie psizel KDE bitmap graphics editor paint kplato i kE psizel KDE project management kchart ease G psizel1 KDE graph and chart drawing program kformula G Pron Ia psizel KDE mathematical equation formula editor kugar G le psizel1 KDE business quality report generator Table 7 8 List of basic X office applications Debian Reference 148 265 package popcon package size type description evince G G psizel GNOME document pdf viewer kpdf ie G psizel KDE3 document pdf viewer okular Gpopcent a psizel KDE4 document pdf viewer Opopconl lt 2 y evolution o psizel GNOME Personal information Management groupware and email popcon lt y kontact o psizel1 KDE Personal information Management groupware and email scribus a ani psizel KDE desktop page layout editor glabels ca psizel GNOME label editor kbarcode S S psizel KDE barcode and label printing application gnucash SE psizel GNOME personal accounting homebank a Goaien psizel GTK personal accounting kmymoney2 A C popcont g psizel KDE personal accoun
230. er X Window irrespective of your system wide default locale using PAM customization see Section 4 5 as follows This environment should provide you with your best desktop experience with stability You have access to the functioning character terminal with readable messages even when the X Window System is not working This becomes essential for languages which use non roman characters such as Chinese Japanese and Korean Note There may be another way available as the improvement of X session manager package but please read following as the generic and basic method of setting the locale For gdm 1 know you can select the locale of X session via its memu The following line defines file location of the language environment in the PAM configuration file such as etc pam d gdm auth required pam_env so read_env 1 envfile etc default locale Change this to the following auth required pam_env so read_env 1 envfile etc default locale x For Japanese create a etc defaults locale gdm file with rw r r 1 root root permission containing the following LANG 4ja_JP UTF 8 Keep the default etc defaults locale file for other programs as the the following TANG KenMUS MUNET ET This is the most generic technique to customize locale and makes the menu selection dialog of gdm 1 itself to be localized Alternatively for this case you may simply change locale using the xsessionrc file Debian Reference 155
231. er stability you should move corresponding local configuration files and restart the GUI program You may need to read old configuration file contents to recover configuration information later Do not erase them too quickly 2 6 2 Different packages with overlapped files Archive level package management systems such as apt itude 8 or apt get 1 do not even try to install packages with overlapped files using package dependencies see Section 2 1 5 Errors by the package maintainer or deployment of inconsistently mixed source of archives see Section 2 7 2 by the system administrator may create situation with incorrectly defined package dependencies When you install a package with overlapped files using apt itude 8 or apt get 1 under such situation dpkg 1 which unpacks package ensures to return error to the calling program without overwriting existing files Caution I The use of third party packages introduces significant system risks via maintainer scripts which are run with root privi lege and can do anything to your system The dpkg 1 command only protects against overwriting by the unpacking You can work around such broken installation by removing the old offending package lt old package gt first sudo dpkg PB lt old package gt 2 6 3 Fixing broken package script When a command in the package script returns error for some reason and the script exits with error the package management system abort
232. erfaces contents as needed to reconfigure the network interface etho Then you can reactivate lt t h O with the sudo ifup eth0 command Tip You can re initialize the network interface simply by sudo ifdown eth0 sudo ifup etho 5 3 14 The ifupdown extra package The ifupdown extra package provides easy network connection tests for use with the i fupdown package s The network test 1 command can be used from the shell e The automatic scripts are run for each i fup command execution The network test command frees you from the execution of cumbersome low level commands to analyze the network problem The automatic scripts are installed in etc network x and performs the following Debian Reference 106 265 e Check the network cable connection Check duplicate use of IP address e Setup system s static routes based on the etc network routes definition e Check if network gateway is reachable e Record results in the var log syslog file This syslog record is quite useful for administration of the network problem on the remote system Tip The automatic behavior of the i fupdown ext ra package is configurable with the etc default network test Some of these automatic checks slow down the system boot up a little bit since it takes some time to listen for ARP replies 5 4 The advanced network configuration with ifupdown The functionality of the ifupdown package can be improved beyond what was
233. es The following starts an ssh 1 connection from a client If you use the same user name on the local and the remote host you can eliminate typing username Even if you use different user name on the local and the remote host you can eliminate it using ssh config For Debian Alioth service with account name foo guest you set ssh config to contain the following Host alioth debian org svn debian org git debian org User foo guest For the user ssh 1 functions as a smarter and more secure telnet 1 Unlike telnet command ssh command does not bomb on the telnet escape character initial default CTRL 6 9 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 host as the following 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 A11owTcpForwarding entry to yes in etc ssh sshd_config of the remote host 6 9 3 Connecting without remote passwords One can avoid having to remember passwords for remote systems by using RSAAuthentication SSH 1 protocol or PubkeyAuthentication SSH 2 protocol On the remote system set the respective entries RSAAuthentication yes or PubkeyAuthentication yes in etc ssh sshd_conf
234. es mostly due to package dependencies The larger the difference of the upgrade the more likely you face larger troubles For the transition from the old stable to the new stable after its release you can read its new Release Notes and follow the exact procedure described in it to minimize troubles When you decide to move from stable to testing before its formal release there are no Release Notes to help you The difference between stable and testing could have grown quite large after the previous stable release and makes upgrade situation complicated You should make precautionary moves for the full upgrade while gathering latest information from mailing list and using common senses 1 Read previous Release Notes 2 Backup entire system especially data and configuration information Debian Reference 53 265 NI DA 4 A U GO Have bootable media handy for broken bootloader Inform users on the system well in advance Record upgrade activity with script 1 Apply unmarkauto to required packages e g aptitude unmarkauto vim to prevent removal Minimize installed packages to reduce chance of package conflicts e g remove desktop task packages Remove the etc apt preferences file disable apt pinning 9 Try to upgrade step wise oldstable stable testing unstable 10 Update the etc apt sources 1list file to point to new archive only and run aptitude update 11 Install opt
235. ess status of active interfaces route n display all the routing table in numerical addresses ip route show display all the routing table in numerical addresses arp display the current content of the ARP cache tables ip neigh display the current content of the ARP cache tables plog display ppp daemon log ping yahoo com check the Internet connection to yahoo com whois yahoo com check who registered yahoo com in the domains database traceroute yahoo com trace the Internet connection to yahoo com tracepath yahoo com trace the Internet connection to yahoo com mtr yahoo com trace the Internet connection to yahoo com repeatedly dig dns server com a mx any example com check DNS records of example com by dns server c iptables L n check packet filter netstat a find all open ports netstat 1 inet find listening ports netstat 1n tcp find listening TCP ports numeric dlint example com check DNS zone information of example com Table 5 16 List of low level network commands packages popcon size description iftop o popon psizel display bandwidth usage information on an network interface iperf E SHO psizel Internet Protocol bandwidth measuring tool apt spy GR nana psizel write a etc apt sources list file based on bandwidth tests ifstat 7 Ppepeon
236. essential popcon psizel essential packages for building Debian packages make gc bzip2 popcon psizel compress and decompress utilities for bz2 files libncurses5 dev popcon psizel developer s libraries and docs for ncurses git core popcon psizel git distributed revision control system used by the Linux ker fakeroot popcon psizel provide fakeroot environment for building package as non ro initramfs tools popcon psizel tool to build an initramfs Debian specific kernel package popcon psizel tool to build Linux kernel packages Debian specific module assistant popcon psizel tool to help build module packages Debian specific dkms popcon psizel dynamic kernel module support DKMS generic devscripts popcon psizel helper scripts for a Debian Package maintainer Debian spec linux tree 2 6 x N A N A Linux kernel source tree meta package Debian specific Table 9 22 List of key packages to be installed for the kernel recompilation on the Debian system 9 7 4 Compiling the kernel and related modules Debian has its own method of compiling the kernel and related modules If you use initrd in Section 3 3 make sure to read the rela
237. etwork hosts except ISP s own outgoing mail server to the Internet are blocked e The SMTP port 25 connection to the ISP s incoming mail server from some suspicious external network hosts are blocked The connection from hosts on the dynamic IP address range used by the dial up and other consumer grade Internet connections are the first ones to be blocked When configuring your mail system or resolving mail delivery problems you must consider these new limitations In light of these hostile Internet situation and limitations some independent Internet mail ISPs such as Yahoo com and Gmail com offer the secure mail service which can be connected from anywhere on the Internet using Transport Layer Security TLS and its predecessor Secure Sockets Layer SSL e The smarthost service for their customers to send message uses the SMTP SSL port 465 or the message submission port 587 with the password SMTP AUTH service e The incoming mail is accessible at the TLS POP3 port 995 with POP3 Caution It is not realistic to run SMTP server on consumer grade network to send mail directly to the remote host reliably They o are very likely to be rejected You must use some smarthost services offered by your connection ISP or independent mail ISPs For the simplicity assume that the smarthost is located at smtp hostname dom requires SMTP AUTH and uses the message submission port 587 in the following text
238. evice Accessed one character at a time character 1 byte E g keyboard device serial port s Block device accessed in larger units called blocks block gt 1 byte E g hard disk 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 t tyS0 But unless this is done carefully it may cause a major disaster So be cautious Note For the normal access to a printer use 1p 1 The device node number are displayed by executing 1s 1 as the following ls 1 dev hda dev ttyS0 dev zero brw ew 1 root caro 3 0 2007 04 29 07 00 dev hda crw rw 1 root dialout 4 64 2007 04 29 07 00 dev ttyS0 CEW EWE EU 1 Foot root I 5 2007 04 29 07 00 dev zero 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 cdrom 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 e dev zero has the major device number 1 and the minor device number 5 This is read write accessible by anyone In the Linux 2
239. f new project by changing the owner of SCVSROOT directory to root staff and its permission to 3775 10 7 2 Local access to CVS The default CVS repository is pointed by CVSROOT The following sets up SCVSROOT for the local access export CVSROOT srv cvs project 10 7 3 Remote access to CVS with pserver Many public CVS servers provide read only remote access to them with account name anonymous via pserver service For example Debian web site contents are maintained by webwml project via CVS at Debian alioth service The following sets up SCVSROOT for the remote access to this CVS repository export CVSROOT pserver anonymous cvs alioth debian org cvsroot webwml cvs login Note Since pserver is prone to eavesdropping attack and insecure write access is usually disable by server administrators 10 7 4 Remote access to CVS with ssh The following sets up CVS_RSH and CVSROOT for the remote access to the CVS repository by webwml project with SSH export CVS_RSH ssh export CVSROOT ext account cvs alioth debian org cvs webwml You can also use public key authentication for SSH which eliminates the remote password prompt Debian Reference 219 265 10 7 5 Importing a new source to CVS Create a new local source tree location at path to modulel1 by the following mkdir p path to modulel cd path to modulel Populate a new local source tree under path to modulel1 with files
240. ference 213 265 The following obtains unknown keys from the keyserver gpg list sigs sedl n SA SEI ID mot E OUNAE w we W 1 p IN sort uniq xargs gpg recv keys There was a bug in OpenPGP Public Key Server pre version 0 9 6 which corrupted key with more than 2 sub keys The newer gnupg gt 1 2 1 2 package can handle these corrupted subkeys See gpg 1 under repair pks subkey bug option 10 4 2 Using GnuPG on files Here are examples for using GNU Privacy Guard commands on files command description gpg a s file sign file into ASCII armored file asc gpg armor sign file as gpg clearsign file clear sign message gpg clearsign not dash escaped patchfile clear sign patchfile gpg verify file verify clear signed file gpg o file sig b file create detached signature gpg o file sig detach sig file gpg verify file sig file verify file with file sig gpg o crypt_file gpg r nam fil public key encryption intended for name from file to b gpg o crypt_file gpg recipient name encrypt file as gpg o crypt_file asc a r nam fil public key encryption intended for name from file to A gpg o crypt_file gpg c file symmetric encryption from file to crypt_file gpg gpg o crypt_file gpg symmetric file 3 gpg o crypt_file asc a c file symmetric encryption intended for name from file to A gpg o file
241. fferent packages with overlapped files 2 2 2 2 ee 61 2 6 3 Fixing broken package SCrIpt 61 2 6 4 Rescue With the dpkg command 0 00022 ee 62 2 6 5 Recovering package selection data ee 63 2 7 Tips for the package management ooa 63 2 7 1 How to pick Debian packages sac oaceae E R ahi doa i Ee ee 63 2 7 2 Packages from mixed source of archives ee 64 2 7 3 Tweaking candidate version o oo 65 2 7 4 Volatile and Backports org ee 68 2 7 5 Automatic download and upgrade of packages 1 2 2 2 0 2 0 0 0002p eee eee 69 2 7 6 Limiting download bandwidth for APT 0 0 020000020000 22 69 2 7 7 Emergency downgrading o ee RRR ee ee ee 70 2 7 8 Who uploaded the package ee 70 2 1 9 Theequivs package e e be Ee ee eee ee ee ee eee 70 2 7 10 Porting a package to the stable system 2 2 oo 7I 2111 Proxy servertor APT 6 24604 e404 RT amp A SERED ERED SG Ee RE ede a 71 2 7 12 Small public package archive ee T2 2 7 13 Recording and copying system configuration 2 2 0 0000 2 eee eee 74 2 7 14 Converting or installing an alien binary package e 74 2 7 15 Extracting package without dpkg oaoa ee 74 2 7 16 More readings for the package management 2 2 0 0000 pee ee ee FE 3 The system initialization 76 3 1 An overview of the boot strap process ee 76 32 Stave ithe BIOS 424 24554445554 64 58
242. fice applications sea eo 4 ees Sedo Ge BHR REESE ENED ERED SG HORE Ede ee TAQ R tihty applications ssop ee aca OS a Oe ee eS eS GTO Sea BS eb hw wide a Sw ee BR EO Sha te See edo oe EG Sk A ee a 7 8 1 Keymaps and pointer button mappings MX V8 2 Classic X chents e po pue pew Ge ce Gace Ue a aS Ge FOE ee ROR Be ee es GS Babe os 7 8 3 The X terminal emulator xterm aoaaa ee 784 Running X clients AS To te se 424 he cee A as Es e The keyboard input 2 se s a cota SE RR E a e Ee ee 8 1 1 The input method support withSCIM 2 0 0 0 000000000000 00004 8 1 2 An example for Japanese e c oey ew A a ee a 8 1 3 Disabling the input method 02 0 0 0 00000 0000000000 000004 The display Output cel et A eR eee ee oo Ae eta od a Whe locale seire toa ee aie Heth Sa ES BAR SG OS HES Sees oe ae Behe y 8 3 1 Basics of encoding 5 54 ee Bo Re PY eR ORE MH SR A bee E Ee ee me eee 8 8 3 2 Rationale for UTF 8 locale 2 aae 8 3 3 The reconfiguration of thelocale 2 2 ee xi 137 137 137 137 137 139 139 139 139 140 140 141 141 141 142 142 143 144 145 145 146 146 146 146 146 149 149 149 150 Debian Reference xii 8 3 4 The value of the SLANG environment variable e o 154 8 3 5 Specific locale only under X Window 000 2 ee 154 8 3 6 Filename encoding lt e e ee eae 155 8 3 7 Localized messages and translated documentation 0 00000 0000
243. figuration files with separated entries are the following file permission user group description etc passwd rw r r root root sanitized user account information etc shadow K H r root shadow secure user account information etc group rw r Lr root root group information Table 4 1 3 important configuration files for pam_unix 8 etc passwd contains the following userl x 1000 1000 Userl Name home userl bin bash user2 x 1001 1001 User2 Name home user2 bin bash As explained in passwd 5 each separated entry of this file means the following s Login name e Password specification entry e Numerical user ID e Numerical group ID s User name or comment field Debian Reference e User home directory e Optional user command interpreter 86 265 The second entry of etc passwd was used for the encrypted password entry After the introduction of etc shadow this entry is used for the password specification entry content meaning empty passwordless account X the encrypted password is in etc shadow x no login for this account no login for this account Table 4 2 The second entry content of etc passwd etc shadow contains the following userl S1SXop0FYH9OSTfxyQwBe 9b8tiylkt2P4F 13262 0 99999 7 user2 1 vXGZLVbS ElyErNf agUDsmlDehJMS 13261 0 99999 7 As explained in shadow 5 each separated en
244. filesystems 9 6 System maintenance tips 9 6 1 Who is on the system You can check who is on the system by the following who 1 shows who is logged on w 1 shows who is logged on and what they are doing e last 1 shows listing of last logged in user e lastb 1 shows listing of last bad logged in users Tip var run utmp var log wtmp and var run utmp hold such user information See Login 1 and utm p 5 9 6 2 Warning everyone You can send message to everyone who is logged on to the system with wa11 1 by the following echo We are shutting down in 1 hour wall 9 6 3 Hardware identification For the PCI like devices AGP PCI Express CardBus ExpressCard etc 1spci 8 probably with nn option is a good start for the hardware identification Alternatively you can identify the hardware by reading contents of proc bus pci devices or browsing directory tree under sys bus pci see Section 1 2 12 Debian Reference 177 265 package popcon size description pciutils popcon1 psizel Linux PCI Utilities 1spci 8 usbutils popcon1 psizel Linux USB utilities 1 susb 8 popcon1 pemciautils psizel PCMCIA utilities for Linux 2 6 pecardct1 8 scsitools PR S psizel collection of tools for SCSI hardware manage
245. fine due to its slow response Note Be careful not to use too high refresh rate which may cause fatal hardware failure of your monitor system Debian Reference 140 265 7 4 2 The connection methods to the X server There are several ways of getting the X server display side to accept connections from an X client application side method package popcon size user encryp xhost command xbase clients eee psize2 unchecked no xauth command xbase clients ae psize2 checked no ssh X command openssh client Gnat psize2 checked yes GNOME display manager gdm oF OTENE psize2 checked no XD KDE display manager kdm ae nous psize2 checked no XD X display manager xdm oppna psize2 checked no XD WindowMaker display manager wdm E Roa analat psize2 checked no XD LTSP display manager ldm ees psize2 checked yes Table 7 3 List of connection methods to the X server Warning s Do not use remote TCP IP connection over unsecured network for X connection unless you have very good reason such as use of encryption A remote TCP IP socket connection without encryption is prone to the eavesdropping attack and is disabled by default on the Debian system Use ssh X Warning T Do not use XDMCP connection over unsecured network either lt sends data via UDP IP without encryption and is prone to the ea
246. g for the moving and specific topics The HOWTOs from The Linux Documentation Project TLDP at http tldp org The Single UNIX Specification from the Open Group s The UNIX System Home Page at http www unix org The free encyclopedia from Wikipedia at http wikipedia org Note For detailed documentation you may need to install the corresponding documentation package named with doc as its suffix Debian Reference iii Conventions This document provides information through the following simplified presentation style with bash 1 shell command examples lt command in root account gt lt command in user account gt These shell prompts distinguish account used and correspond to set environment variables as PS1 X and PS2 These values are chosen for the sake of readability of this document and are not typical on actual installed system Note See the meaning of the SPS1 and SPS2 environment variables in bash 1 Action required by the system administrator is written in the imperative sentence e g Type Enter key after typing each com mand string to the shell The description column and similar ones in the table may contain a noun phrase following the package short description convention which drops leading articles such as a and the They may alternatively contain an infinitive phrase as a noun phrase without leading to following the short command description convention in manpages
247. g a git subcommand directly as git xyz from the command line has been deprecated since early 2006 Tip GUI tools such as tkcvs 1 and gitk 1 really help you with tracking revision history of files The web interface provided by many public archives for browsing their repositories is also quite useful too Tip Git can work directly with different VCS repositories such as ones provided by CVS and Subversion and provides the local repository for local changes with git cvs and git svn packages See git for CVS users Git for GNOME developers and Section 10 9 Tip Git has commands which have no equivalents in CVS and Subversion fetch rebase cherry pick 10 7 CVS See the following e cvs l e usr share doc cvs html cvsclient e usr share doc cvs html info s usr share doc cvsbook e info cvs Debian Reference 218 265 10 7 1 Configuration of CVS repository The following configuration allows commits to the CVS repository only by a member of the src group and administration of CVS only by a member of the st aff group thus reducing the chance of shooting oneself cd var lib umask 002 mkdir cvs export CVSROOT srv cvs project cd CVSROOT chown root src chmod 2775 cvs d CVSROOT init cd CVSROOT HGG Ramco osito lala chmod 27 75 touch val tags chmod 664 history val tags chown root src history val tags Tip You may restrict creation o
248. ger display information on all the running processes using BSD style output ps ef pager display information on all the running processes using Unix system V style output ps aux grep e e xim4x display all processes running exim and exim4 ps axf pager display information on all the running processes with ASCII art output kill lt 1234 gt kill a process identified by the process ID lt 1234 gt gzip lt foo gt compress lt foo gt to create lt foo gt gz using the Lempel Ziv coding LZ77 gunzip lt foo gt gz decompress lt foo gt gz to create lt foo gt bzip2 lt foo gt compress lt foo gt to create lt foo gt bz2 using the Burrows Wheeler block sortin better compression than gzip bunzip2 lt foo gt bz2 decompress lt foo gt bz2 to create lt foo gt tar xvf lt foo gt tar extract files from lt foo gt tar archive tar xvzf lt foo gt tar gz extract files from gzipped lt foo gt tar gz archive tar xvf J lt foo gt tar bz2 extract files from lt foo gt tar bz2 archive tar eytf foo gt tar shar archive contents of folder lt bar gt im lt foo gt tar archive __ tar cvzf lt foo gt tar gz lt bar gt archive contents of folder lt bar gt in compressed lt foo gt tar gz archive tar cvjf lt foo gt tar bz2 lt bar gt archive contents of folder lt bar gt in lt foo gt t
249. ges and commands no o 000 eee ee 228 11 1 List of text data conversion tools oaoa 230 11 2 List of encoding values and their usage ee 231 11 3 List of EOL styles for different platforms 2 0 200 0000 0000000000 00004 232 11 4 List of TAB conversion commands from bsdmainutils and coreutils packages 233 11 5 List of tools to extract plain text data ee 234 11 6 List of tools to highlight plain text data ee 235 11 7 List of predefined entities for XML ouaaa 00000000022 22 eee 236 11 8 Listof XML tO0 S 0020 ac A A a a BRS be a 237 11 9 Listof DSSL tools s e pedeo ri a we bk bbe ee dea PRAM bao 237 11 10List of XML data extraction tools 1 2 0 000000 ee 238 11 11Listof XML pretty print tools sse e e eeg RR ek RG RE ee A we ee 238 11 12List of Ghostscript PostScript interpreters o oo ee 239 11 13List of printable data utilities 2 RRR 240 11 14Listof typesetting tools lt aos iora Se ARR GS SE Ra REE ARS BEG be AA Bea eo 241 11 15List of packages to help creating the manpage 2 2 2 2 e 243 11 16List of packages to help mail data conversion 2 2 2 00000 2 ee ee 243 11 17Listof graphic data tools x e ee AR Re AG EA Ra ee Bae eo 245 11 18List of miscellaneous data conversion tools ee 246 12 1 List of packages to help programing 2 0 2 0 248 12 2 List of typical bashisms e a e e R 0 RR RRR RRR RRR RR
250. ght C 2007 Osamu Aoki lt osamu debian org gt Public Domain gt amp 2 variables DATA_ISO SHOME Desktop iso img LABEL date if S 0 DATA_SRC else SYSmSd SHEMSS Z es Sel Vie 2 Tlasa S10 Select directory for creating ISO image from folder on desktop DATA_SRC zenity file selection directory title Select the directory tree root to create ISO image error_exit Exit on directory selection 024 th 640 height 400 ein Sica ME th 640 height 400 th 640 height 400 ie aL Check size of archive xterm T Check size DATA_SRC e du s DATA_SRC x SIZE du s DATA_SRC awk print 1 1 ase SS le S20 J then zenity info title Dvdisaster RS02 wid text The data size is good for CD backup elif SIZE le 3500 then zenity INTO title Dvdisaster RS02 wid text The data size is good for DVD backup Min SIZE MB else zenity info title Dvdisaster RS02 wid text The data size is too big to backup error_exit e SSIZE MB The data size is too big to backup Min SSIZE MB only xterm is sure to have working e option Create raw ISO image H DARAS O eS xterm T ge e genisoi Create RSO nisoimage DATA_ISO MATE SABE OS IATA ISO US DARAS REU 2 supplemental redundancy Debian Reference 255 265 xterm T dvdisast
251. ginal vi or new nvi are 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 If you chose either Emacs or XEmacs instead as your choice of the editor that is another good choice indeed particularly for programming Emacs has a plethora of other features as well including functioning as a newsreader directory editor mail program etc When used for programming or editing shell scripts it intelligently recognizes the format of what you are working on and tries to provide assistance Some people maintain that the only program they need on Linux is Emacs Ten minutes learning Emacs now can save hours later Having the GNU Emacs manual for reference when learning Emacs is highly recommended All these programs usually come with tutoring program for you to learn them by practice Start Vim by typing vim and press Fl key You should at least read the first 35 lines Then do the online training course by moving cursor to tutor and pressing Ctrl Note Good editors such as Vim and Emacs can be used to handle UTF 8 and other exotic encoding texts correctly with proper option in the x terminal emulator on X under UTF 8 locale with proper font settings Please refer to their documentation on multibyte text 1 4 7 Setting a default text editor Debian comes with a number of different editors We recommend to install the vim package as mentioned
252. gins can be still manually enabled by installing so into plugin directories e g usr lib iceweasel plugins and restarting browsers Some web sites refuse to be connected based on the user agent string of your browser You can work around this situation by spoofing the user agent string For example you can do this by adding following line into user configuration files such as gnome2 epiphany mozilla epiphany user js or mozilla firefox x default user js user_pref general useragent override Mozilla 4 0 compatible MSIE 7 0 Windows NT 6 0 a Alternatively you can add and reset this variable by typing about config into URL and right clicking its display contents e Caution Spoofed user agent string may cause bad side effects with Java Debian Reference 119 265 6 2 The mail system Caution I If you are to set up the mail server to exchange mail directly with the Internet you should be better than reading this elementary document 6 2 1 Modern mail service basics In order to contain spam unwanted and unsolicited e mail problems many ISPs which provide consumer grade Internet con nection are implementing counter measures e The smarthost service for their customers to send message uses the message submission port 587 specified in rfc4409 with the password SMTP AUTH service specified in rfc4954 e The SMTP port 25 connection from their internal n
253. gt config package script for debconf system var lib dp kg alternatives lt package_name gt the alternative information used by the update alternatives var lib dp kg available the availability information for all the package var lib dp kg diversions the diversions information used by dpkg 1 and set by dpkg divert var lib dp kg statoverride the stat override information used by dpkg 1 and set by dpkg stato var lib dp kg status the status information for all the packages var lib dp kg status old the first generation backup of the Var lib dpkg status file var backups dpkg status the second generation backup and older ones of the var lib dp S le Sl Sewers 9 vi lrwxrwxrwx 1 root Table 2 17 The notable files created by dpkg sudo updat alternatives display vi sudo updat alternatives CONTO Selection Command Te usr bin vim 2 usr bin nvi Enter to keep the default root 20 2007 03 24 19 05 usr bin vi gt etc alternatives vi or type selection number 1 The Debian alternatives system keeps its selection as symlinks in etc alternatives The selection process uses corresponding file in var lib dpkg alternatives 2 5 11 The dpkg statoverride command Stat overrides provided by the dpkg statoverride 8 command are a way to tell dpkg 1 to use a different owner or mode for a fil
254. h USB storage readers since it follows the Design rule for Camera Filesystem and uses FAT filesystem See Section 10 1 10 11 7 Miscellaneous data conversion There are many other programs for converting data Following packages caught my eyes using regex Guse gt converting in apt itude 8 see Section 2 2 5 You can also extract data from RPM format with the following S ioMAcioe ile sie man culo ert ract Debian Reference 245 265 package popcon size keyword description gimp Paane psize1 image bitmap GNU Image Man imagemagick A aia psize1 image bitmap image manipulati graphicsmagick aiia psize1 image bitmap image manipulati xsane a diet psize1 image bitmap GTK based X1 netpbm oo qpel psize1 image bitmap graphics conversi icoutils Piani psize1 pnge gt ico bitmap convert MS Winc xpm2wico oo on psize1 xpm gt ico bitmap convert XPM to 1 scribus nn psizel1 ps pdf SVG Scribus DTP edit openoffice org draw one psizel1 image vector OpenOffice org o inkscape AA psizel image vector SVG Scalable Vi dia gnome a COPIE psizel image vector diagram editor C dia aoe SS psizel1 image vector diagram editor C xfig a Greenlee psizel1 image vector facility for Intera pstoedit agni psizel1 ps pdf imag
255. hare doc aptitude html en index html from the aptitude doc en package e Official and detailed documentations on the Debian archive Debian Policy Manual Chapter 2 The Debian Archive Debian Developer s Reference Chapter 4 Resources for Debian Developers 4 6 The Debian archive and The Debian GNU Linux FAQ Chapter 5 The Debian FTP archives e Tutorial for building of a Debian package for Debian users Debian New Maintainers Guide Debian Reference 76 265 Chapter 3 The system initialization It is wise for you as the system administrator to know roughly how the Debian system is started and configured Although the exact details are in the source files of the packages installed and their documentations it is a bit overwhelming for most of us I did my best to provide a quick overview of the key points of the Debian system and their configuration for your reference based on the current and previous knowledge of mine and others Since the Debian system is a moving target the situation over the system may have been changed Before making any changes to the system you should refer to the latest documentation for each package 3 1 An overview of the boot strap process The computer system undergoes several phases of boot strap processes from the power on event until it offers the fully functional operating system OS to the user For simplicity I limit discussion to the typical PC platform with th
256. he psizel InterFace STATistics Monitoring bmon a Epopconto psizel portable bandwidth monitor and rate estimator ethstatus a epconti s psizel script that quickly measures network device throughput bing Pie SEE psizel empirical stochastic bandwidth tester bwm ng a Papot psizel small and simple console based bandwidth monitor ethstats ao da psizel console based Ethernet statistics monitor ipfm o Epapesnios psizel bandwidth analysis tool Table 5 17 List of network optimization tools Debian Reference 115 265 ping c 1 s 1500 28 M do www debian org PING www debian org 194 109 137 218 1472 1500 bytes of data From 192 168 11 2 icmp_seq l Frag needed and DF set mtu 1454 www debian org ping statistics 0 packets transmitted 0 received 1 errors Try 1454 instead of 1500 You see ping 8 succeed with 1454 This process is Path MTU PMTU discovery RFC1191 and the t racepath 8 command can automate this Tip The above example with PMTU value of 1454 is for my previous FTTP provider which used Asynchronous Transfer Mode ATM as its backbone network and served its clients with the PPPoE The actual PMTU value depends on your environment e g 1500 for the my new FTTP provider network environment MTU rationale Dial up link IP PPP 576 standard Ethernet link IP DHCP or fixed 1500 standard and Ethernet link
257. he apt package comes with its own cron script etc cron daily apt to support the automatic download of packages This script can be enhanced to perform the automatic upgrade of packages by installing the unattended upgrades package These can be customized by parameters in etc apt apt conf d 02backup and etc apt apt conf d 50 unattended upgrades as described in usr share doc unattended upgrades README The unattended upgrades package is mainly intended for the security upgrade for the stable system If the risk of breaking an existing stable system by the automatic upgrade is smaller than that of the system broken by the intruder using its security hole which has been closed by the security update you should consider using this automatic upgrade with configuration parameters as the following APT Periodic Update Package Lists 1 APT Periodic Download Upgradeable Packages 1 APT Periodic Unattended Upgrade 1 If you are running an unstable system you do not want to use the automatic upgrade since it certainly breaks system some day Even for such unstable case you may still want to download packages in advance to save time for the interactive upgrade with configuration parameters as the following APT Periodic Update Package Lists 1 APT Periodic Download Upgradeable Packages 1 APT Periodic Unattended Upgrade 0 2 7 6 Limiting download bandwidth for APT If you want to
258. his Debian Reference version 2 provides a good starting direction for people in the Debian maze A 2 Copyright history Debian Reference was initiated by Osamu Aoki lt osamu at debian dot org gt as a personal system administration memo Many contents came from the knowledge I gained from the debian user mailing list and other Debian resources Following a suggestion from Josip Rodin who was very active with the Debian Documentation Project DDP Debian Refer ence version 1 2001 2007 was created as a part of DDP documents After 6 years Osamu realized that the original Debian Reference version 1 was outdated and started to rewrite many contents New Debian Reference version 2 is released in 2008 The tutorial contents can trace its origin and its inspiration in followings e Linux User s Guide by Larry Greenfield December 1996 obsoleted by Debian Tutorial e Debian Tutorial by Havoc Pennington 11 December 1998 partially written by Oliver Elphick Ole Tetlie James Treacy Craig Sawyer and Ivan E Moore II obsoleted by Debian GNU Linux Guide to Installation and Usage e Debian GNU Linux Guide to Installation and Usage by John Goerzen and Ossama Othman 1999 obsoleted by Debian Reference version 1 Debian Reference 265 265 The package and archive description can trace some of their origin and their inspiration in following e Debian FAQ March 2002 version when this was m
259. iables in muttrc file to override the mailname value For programs in the devscripts package such as bt s 1 and dch 1 export environment variables SDEBFULLNAME and SDEBEMAIL to override it When setting the mailname to hostname f the spoofing of the source mail address via MTA can be realized by the following s etc email addresses file for exim4 8 as explained in the exim4 config_files 5 e etc postfix generic file for post ix 1 as explained in the generic 5 Debian Reference 124 265 For post fix the following extra steps are needed postmap hash etc postfix generic postconf e smtp_generic_ maps hash postfix reload You check filters using the following exim 8 with brw bf postmap 1 with q option bF bV etc postfix generic options Tip Exim comes with several utility programs such as exiqgrep 8 and exipick 8 See dpkg L exim4 basel grep man8g for available commands 6 3 4 Basic MTA operations There are several basic MTA operations Some may be performed via sendmail 1 compatibility interface exim command postfix command description sendmail sendmail read mails from standard input and arran mailg mailq list the mail queue with status and queue newaliases newaliases initialize alias database 1 exim4 q postqueue f flush waiting mails q eximi
260. ibnss mdns popcon psize1 NSS module for Multicast DNS name resolution libnss 1dap popcon psize1 NSS module for using LDAP as a naming service libnss 1dapd popcon psize1 NSS module for using LDAP as a naming service new fo tion Table 4 5 List of notable PAM and NSS systems The Linux PAM System Administrators Guide in 1ibpam doc is essential for learning PAM configuration System Databases and Name Service Switch section in glibc doc referenc is essential for learning NSS configura Note You can see more extensive and current list by aptitude search libpam libnss command The acronym NSS may also mean Network Security Service which is different from Name Service Switch Debian Reference 89 265 Note PAM is the most basic way to initialize environment variables for each program with the system wide default value 4 5 1 Configuration files accessed by the PAM and NSS Here are few notable configuration files accessed by the PAM configuration file function etc pam d lt program_name gt set up PAM configuration for the lt program_name gt program see pam 7 and pam d etc nsswitch conf set up NSS configuration with the entry for each service See nsswitch conf 5 etc nologin limit the user login by the pam_nologin 8 module etc securetty
261. ibxft2 o psizel1 Xft a library that connects X applications with the FreeType libfreetype6 Gan S psizel FreeType 2 0 font rasterization library fontconfig Ce aniia psizel Fontconfig a generic font configuration library support bi fontconfig config popcon psizel Fontconfig a generic font configuration library configurat defoma popcon psizel Debian Font Manager automatic font configuration frame x ttcidfont conf popcon psizel TrueType and CID fonts configuration for X with CJK supp 7 6 1 Basic fonts Table 7 4 Table of packages to support X Window font systems There are 2 major types of computer fonts e Bitmap fonts good for low resolution rasterization e Outline stroke fonts good for high resolution rasterization While scaling of bitmap fonts causes jugged image scaling of outline stroke fonts produces smooth image Bitmap fonts on the Debian system are usually provided by compressed X11 pcf bitmap font files having their file extension pef gz Outline fonts on the Debian system are provided by the following e PostScript Type 1 font files having their file extension pb binary font file and afm font metrics file e TrueType or OpenType font files usually having their file extension tt f Tip OpenType is intended to supersede both TrueType and PostScript Ty
262. ichlmayr March 2003 Tip See A Brief History of Debian for the latest Debian leadership history Debian Reference 34 265 Awk is frequently used to extract data from these types of files For example try the following S ewe 1 Dice T EIR month started August April January January Ap April March S awk 1 Tan print lt DPL DPL called Ian Ian Murdock AQUA OS 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 kind of file For example try the following while read first last month year do echo month done lt DPL same output as the first Awk example Here the read builtin command uses characters in IFS internal field separators to split lines into words If you change STFS to you can parse etc passwa with shell nicely S oldiFS SIFS save old value SS oe while read user password uid gid rest_of_line do NS US Uo P EREN Scho YSuser S ID te uct FI done lt etc passwd DOZO AS IDAS 0010 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
263. icular packages and limiting the package display e aptitude in the full screen mode has su functionality embedded and can be run from normal user until you really need administrative privileges For the old etch release version synaptic also gives you the history log apt get did not but you can rely on the log of dpkg Anyway aptitude is nice for interactive console use 2 3 Examples of aptitude operations Here are few examples of apt itude 8 operations 2 3 1 Listing packages with regex matching on package names The following command lists packages with regex matching on package names aptitude search n pam nss 1dap p libnss 1dap NSS module for using LDAP as a naming service p libpam ldap Pluggable Authentication Module allowing LDAP interfaces This is quite handy for you to find the exact name of a package 2 3 2 Browsing with the regex matching The regex dipv6 in the New Flat Package List view with 1 prompt limits view to packages with the matching description and let you browse their information interactively 2 3 3 Purging removed packages for good You can purge all remaining configuration files of removed packages Check results of the following command aptitude search c If you think listed packages are OK to be purged execute the following command aptitude purge c You may want to do the similar in the interactive mode for fine grained control You provide the
264. ig Generate authentication keys locally and install the public key on the remote system by the following RSAAuthentication RSA key for SSH 1 deprecated because it is superseded ssh keygen S cat ssh identity pub ssh userl remote cat gt gt ssh authorized_keys PubkeyAuthentication RSA key for SSH 2 ssh keygen t rsa cat ssh id_rsa pub ssh userl remote cat gt gt ssh authorized_keys PubkeyAuthentication DSA key for SSH 2 deprecated because it is slow Debian Reference 133 265 ssh keygen t dsa S cat ssh id_dsa pub ssh userl remote cat gt gt ssh authorized_keys Tip Use of DSA key for SSH 2 is deprecated because key is smaller and slow There are no more reasons to work around RSA patent using DSA since it has been expired DSA stands for Digital Signature Algorithm and slow Also see DSA 1571 1 Note For HostbasedAuthent ication to work in SSH 2 you must adjust the settings of HostbasedAuthentication to yes inboth etc ssh sshd_config onthe server host and etc ssh ssh_config or ssh config on the client host 6 9 4 Dealing with alien SSH clients There are some free SSH clients available for other platforms environment free SSH program 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 Ma
265. image manipulation tools a 161 List of packages to record configuration history in VCS aoaaa 2eee ee 161 List of disk partition management packages 2 ee 162 List of filesystem management packages a 164 List of data encryption utilities ee 168 List of tools for monitoring and controlling program activities 0 0 0 00 eee eee eee 171 List of nice values for the scheduling priority 0 2 2 0000000000 0000 171 List of ps Command styl s s pisao ta oe REN RE SEE ER we RS a ee ea a ee 9 171 List of commands for top oaoa a 172 List of frequently used signals for kill command 22 0000000000000 000 175 Listof SAK command keys c0 2 1 e ss e RER ER ee 176 List of hardware identification tools ee 177 List of hardware configuration tools ee 177 Listof sound Packages s sos so G45 e eb OR eR OR ee Soe Fp Se eRe SR oe 180 List of commands for disabling the screen saver ee 180 List of memory sizes reported secere ewa ee ee ee R R ee eee ees 181 List of tools for system security and integrity check oaoa ee 181 List of key packages to be installed for the kernel recompilation on the Debian system 183 List of virtualization tools e ded oop e a ERY ES He BRE Rete ee Oe ES Os Pee ee eee ex 186 List of archive and compression tools 2 2 ee 191 List of copy and synchronization tools 2 a 192 List of b
266. imilar to what cd and network devices do you can generate static device names for other devices such as USB memory sticks too See Writing udev rules or usr share doc udev writing_udev_rules index htmlL Since the udev system is somewhat a moving target I leave details to other documentations and describe the minimum informa tion here Tip For mounting rules in etc fstab device nodes do not need to be static ones You can use UUID to mount devices instead of device names such as dev sda See Section 9 3 2 3 5 12 The kernel module initialization The modprobe 8 program enables us to configure running Linux kernel from user process by adding and removing kernel modules The udev system see Section 3 5 11 automates its invocation to help the kernel module initialization There are non hardware modules and special hardware driver modules as the following which need to be pre loaded by listing them in the etc modules file see modules 5 e TUN TAP modules providing virtual Point to Point network device TUN and virtual Ethernet network device TAP e netfilter modules providing netfilter firewall capabilities ipt ables 8 Section 5 8 and e watchdog timer driver modules The configuration files for the modprobe 8 program are located under the etc modprobes d directory as explained in modprobe con 5 If you want to avoid some kernel modules to be auto loaded consider to blacklist them in the et c
267. in the root filesystem The default install of the Debian system places first stage GRUB boot loader code into the MBR for the PC platform There are many boot loaders and configuration options available bootloader package popcon GRUB Legacy grub o popcon2 GRUB 2 grub pc Gaan GRUB 2 grub rescue pc o Lilo lilo A Isolinux syslinux a popcon2 Syslinux syslinux eee Loadlin loadlin a popcon2 MBR by Neil Turton mbr oe Table 3 1 List of boot loaders Warning I Do not play with boot loaders without having bootable rescue media CD or floppy created from images in the grub rescue pc package lt makes you boot your system even without functioning bootloader on the hard disk Debian Reference 78 265 For GRUB Legacy the menu configuration file is located at boot grub menu 1st For example it has entries as the following 1eal ie LS Debian GNU Linux root hd0 2 kernel vmlinuz root dev hda3 ro oil esa ba Sel ame For GRUB 2 the menu configuration file is located at boot grub grub cfg Itis automatically generated by usr s bin update grub using templates from etc grub d x and settings from etc default grub For example 1t has entries as the following menuentry Debian GNU Linux set root hd0 3 linux vmlinuz root dev hda3 ame miere ao For these examples these GRUB parameters mean the following GRUB
268. ine 1 gdb run args run program with args gdb next next line gdb step step forward gdb p parm print parm gdb p parm 12 set value to 12 gdb quit Tip Many gdb 1 commands can be abbreviated Tab expansion works as in the shell 12 4 2 Debugging the Debian package Since all installed binaries should be stripped on the Debian system by default most debugging symbols are removed in the normal package In order to debug Debian packages with gdb 1 corresponding dbg packages need to be installed e g libc6 dbg in the case of 1ibc6 If a package to be debugged does not provide its x dbg package you need to install it after rebuilding it by the following mkdir path new cd path new sudo aptitude update sudo aptitude dist upgrad sudo aptitude install fakeroot devscripts build essential sudo apt get build dep source_package_name apt get source package_name cd package_namex UE UN UE UE UY UY UY Fix bugs if needed Bump package version to one which does not collide with official Debian versions e g one appended with debug1 when recompiling existing package version or one appended with pre1 when compiling unreleased package version by the fol lowing dch i Compile and install packages with debug symbols by the following export DEB_BUILD_OPTIONS nostrip noopt debuild S sel sudo debi package_namex changes You need to check build scripts of the package and ensure to use C
269. interface_name_glob gt matches eth0 this execution produces the execution of the following command to configure et hO automatically sudo ifup eth0 echo i lt voueayoic slijoieis gt Na lt eyoueslione mobs Wal san Sci name gt Sr lt Here script input lines with map are optional and can be repeated Note The glob for mapping stanza works like shell filename glob see Section 1 5 6 Debian Reference 109 265 5 4 6 The manually switchable network configuration Here is how to switch manually among several network configurations without rewriting the etc network interfaces file as in Section 5 3 13 For all the network configuration you need to access you create a single etc network interfaces file as the following auto lo iface lo inet loopback iface configl inet dhcp hostname mymachine iface config2 inet static acllress 192 168 LI 100 mermas kao ZOO agerlsasie 192 16 11 295 gateway 192 168 11 1 dns domain lan dns nameservers 192 168 11 1 iface pppoe inet manual pre up sbin ifconfig eth0 up up ifup ppp0 ds1 down ifdown ppp0 dsl post down sbin ifconfig eth0 down The following is used internally only iface dsl inet ppp provider dsl provider iface pots inet ppp provider provider Please note the network configuration name which is the token after iface does not use the token for the network interface name Also there are no auto stanza nor allow hotpl
270. into X trash and exit i X Advertisement IIN Subject BUSINESS PROPOSAL Subject URGENT ASISSTANCE Subject I NEED YOUR ASSISTANCE to SHOME Maildir X trash Delivering mailinglist messages using automatically generated mailbox a Precedence list Precedence bulk ia Mises Als 150 MATLBOX SMATCH1 else if X Loop MATLBOX SMATCH1 SMATCH2 else LE Return Path debian org MATLBOX automatic debian org else MATLBOX unknown list test d MAILROOT SMAILBOX if SRETURNCODE 1 Debian Reference 128 265 maildirmake MAILROOT MAILBOX to SMAILROOT SMAILBOX to SHOME Maildir Inbox exit I Warning Unlike procmail maildrop does not create missing maildir directories automatically You must create them man ually using maildirmake 1 in advance as in the example SHOME mailfilter 6 6 2 procmail configuration Here is an equivalent configuration with HOME procmailrc for procmai1 1 MAILDIR HOME Maildir DEFAULT MAILDIR Inbox LOGFILE MAILDIR Maillog clearly bad looking mails drop them into X trash and exit 0 x 1 0 X Advertisement OSUDE CE BUS INES SABROBO SAT 1 0 Subject URGENT ASISSTANCE 1 0 Subject I NEED YOUR ASSISTANCE X trash 20 x 1 0
271. ion e 120 6 3 1 The configuration ofexim4 R R E R RR RR RRR RRR R RRR ee 120 6 3 2 The configuration of postfix with SASL 2 0 000 0 0000000000000 000 122 6 3 3 The mail address Configuration 123 6 3 4 Basic MTA Operations as cg SR asa RG GR ERS ERA a eo 124 6 4 Mail user agent MUA aaa ee 124 6 4 1 BasicMUA Mutt s e o ca eao aeee k hei 2 200000 R RR N RER ee 124 6 5 The remote mail retrieval and forward utility 2 2 ee 125 6 5 1 getmail configuration 2 ee 125 6 5 2 fetchmail configuration 126 6 6 Mail delivery agent MDA with filter ee 127 6 6 1 maildrop configuration 2 ee 127 6 6 2 procmail configuration 2 ee 128 6 6 3 Redelivermbox contents ooa 129 67 PPOPS IMAPA Server 32d da be a EE a 129 6 8 The print server and utility 0 2 000 002 0000 000000000000 0000004 129 6 9 The remote access server and utility SSH e 130 6 9 1 Basics OF SSH 2 2 4 6 ek Beads Sg eR Be a Se e a bs e 130 6 9 2 Port forwarding for SMTP POP3 tunneling 2 2 e 132 6 9 3 Connecting without remote passwords 2 2 ee 132 6 9 4 Dealing with alien SSH clients 0 2 0 0 0 00000022 133 69 5 Setting up ssh apent 2 4 04 4 4 ee arte e dh SG wae Sa wd Ee Se che ta ee k 133 6 9 6 How to shutdown the remote system on SSH 20000022 eee eee 133 6 9 7 TroubleshootingSSH cannae 134 6 10 Other network ap
272. ion of tools Archive and compression tools Copy and synchronization tools Network filesystems Removable storage media The secure shell The authentication system Version control system tools Hash and cryptographic encryption tools Debian Reference 191 265 10 1 1 Archive and compression tools Here is a summary of archive and compression tools available on the Debian system package popcon size command extension comment tar al psizel tar 1 tar the standard cpio Piani psizel cpio l cpio Unix System binutils ie psizel arl Jali archiver for t fastjar oe psizel fastjar l Jar archiver for pax ign psizel pax 1 pax new POSIX afio ea psizel afio l afio extended cp gzip a psizel gzip l zcat l gz GNU LZ77 bzip2 da psizel bzip2 1 bzcat l bz2 ral lzma anana psizel 1zma 1 1 sma Gn xz utils deci psizel xz 1 xzdec 1 XZ ooo p7zip E psize1 7zr 1 p7zip 1 Tz 7 Zip file arc p7zip full ee psize1 7z 1 7za 1 Tz 7 Zip file arc lzop ie aes psizel 1zop 1 lzo basi zip cc Q OpsizelO O zip 1 zip InfoZIP DO unzip iania psizel unzip 1 zip InfoZIP DO Table 10 1 List of archive and compression tools Warning Do not set the STAP E variable unless you know what to expect It changes t ar 1 behavior
273. ionally new core packages first e g aptitude install perl 12 Run the aptitude full upgrade s command to assess impact 13 Run the aptitude full upgrade command at last Caution Itis not wise to skip major Debian release when upgrading between stable releases l Caution In previous Release Notes GCC Linux Kernel initrd tools Glibc Perl APT tool chain etc have required some special attention for system wide upgrade For daily upgrade in unstable see Section 2 4 3 2 4 Advanced package management operations 2 4 1 Advanced package management operations with commandline Here are list of other package management operations for which apt itude is too high level or lacks required functionalities I Caution Lower level package tools such as dpkg i and debi should be carefully used by the system admin istrator It does not automatically take care required package dependencies Dpkg s commandline options for ce al1 and similar see dpkg 1 are intended to be used by experts only Using them without fully understanding their effects may break your whole system Please note the following e All system configuration and installation commands require to be run from root e Unlike aptitude which uses regex see Section 1 6 2 other package management commands use pattern like shell glob see Section 1 5 6 e apt file l pro
274. irectory 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 8 daemon running one can use a mouse on Linux character consoles too Make sure to press the shift key to obtain the normal behavior of cut and paste in MC key key binding F1 help menu F3 internal file viewer F4 internal editor F9 activate pull down menu F10 exit Midnight Commander Tab move between two windows Insert or Ctrl T mark file for a multiple file operation such as copy Del delete file be careful set MC to safe delete mode Cursor keys self explanatory Table 1 11 The key bindings of MC 1 3 4 Command line tricks in MC e cd command changes the directory shown on the selected screen e Ctrl Enter or Alt Enter copies a filename to the command line Use this with cp 1 and mv 1 commands together with command line editing Debian Reference 18 265 e Alt Tab shows shell filename expansion choices e One can specify the starting directory for both windows as arguments to MC for example mc etc root e Esc n key gt Fn 1 e Esc 1 gt F1 etc Esc 0 F10 e Pressing Esc before the key has the same effect as pressing the Alt and the key together i e type Esc c for Alt C Esc is called meta key and sometimes noted as M 1 3 5 Th
275. ist of tools to generate password Modern Unix like systems such as the Debian system provide PAM Pluggable Authentication Modules and NSS Name Service Switch mechanism to the local system administrator to configure his system The role of these can be summarizes as the following e PAM offers a flexible authentication mechanism used by the application software thus involves password data exchange e NSS offers a flexible name service mechanism which is frequently used by the C standard library to obtain the user and group name for programs such as 1s 1 and id 1 These PAM and NSS systems need to be configured consistently The notable packages of PAM and NSS systems are the following package popcon size description libpam modules popcon psize1 Pluggable Authentication Modules basic service libpam 1dap popcon psize1 Pluggable Authentication Module allowing LDAP interfac libpam cracklib popcon psize1 Pluggable Authentication Module to enable cracklib suppi popcon libpam doc o psize1 Pluggable Authentication Modules documentation in htm libc 6 a aga psize1 GNU C Library Shared libraries which also provides Na glibc doc CAP aiiai psizel1 GNU C Library Manpages glibc doc referenc popcon psize1 GNU C Library Reference manual in info pdf and html f l
276. ists package dependencies Table 2 1 List of Debian package management tools Debian Reference 38 265 2 1 2 Basic precautions Warning Do not install packages from random mixture of suites It probably breaks the package consistency which requires deep system management knowledge such as compiler ABI library version interpreter features etc The newbie Debian system administrator should stay with the stable release of Debian while applying only security updates I mean that some of the following valid actions are better avoided as a precaution until you understand the Debian system very well Here are some reminders e Do not include testing or unstable in etc apt sources list e Do not mix standard Debian with other non Debian archives such as Ubuntu in etc apt sources list e Do not create etc apt preferences e Do not change default behavior of package management tools through configuration files without knowing their full impacts e Do not install random packages by dpkg i lt random_package gt s Do not ever install random packages by dpkg force all i lt random_package gt s Do not erase or alter files in var lib dpkg s Do not overwrite system files by installing software programs directly compiled from source Install them into usr local or opt if needed The non compatible effects caused by above actions to the Debian package management system may leave your
277. ites all prerequisites Sx matched stem in the target pattern Table 12 10 List of make automatic variables variable expansion description fool bar one time expansion foo2 bar recursive expansion foo3 bar append Table 12 11 List of make variable expansions Run make p f dev null to see automatic internal rules 123 C You can set up proper environment to compile programs written in the C programming language by the following aptitude install glibc doc manpages dev libc 6 dev gcc build essential Debian Reference 256 265 The 1ibc6 dev package i e GNU C Library provides C standard library which is collection of header files and library routines used by the C programming language See references for C as the following e info libc C library function reference e gcc l and info gcc e each C library _function_name 3 e Kernighan amp amp Ritchie The C Programming Language 2nd edition Prentice Hall 12 3 1 Simple C program gcc A simple example example c can compiled with a library 1 ibm into an executable run_example by the following S cat gt eramalea c lt lt HOF include lt stdio h gt include lt math h gt include lt string h gt imei malm antra rge ehari kra ro ehar Sao double x Ciasne AN TE EEOC l o SN strncpy y argv 0 10 prevent buffer overflow x LO NOE gt GE tO make Surs T ence mila NO a primet VoL SE
278. ject 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 9 5 3 The ps command The ps 1 command on the Debian support both BSD and SystemV features and helps to identify the process activity statically For the zombie defunct children process you can kill them by the parent process ID identified in the PP ID field The pst ree 1 command display a tree of processes Debian Reference 171 265 package popcon size description coreutils Ea E psizel nice 1 run a program with modified scheduling priority bsdutils A e psizel renice 1 modify the scheduling priority of a running process procps a a psizel proc filesystem utilities ps 1 top 1 kil 1 1 watch 1 psmisc oe psizel proc filesystem utilities ki11a11 1 fuser 1 peekfda 1 ps time oer GR psizel time 1 run a program to report system resource usages with respect t sysstat aoe psizel sar 1 iostat 1 mpstat 1 system performance tools for Li isag aoe Garat psizel Interactive System Activity Grapher for sysstat lsof eae psizel 1sof 8 list open files by a running process using p option strace a GR psizel strace 1 trace system calls and signals ltrace S psizel 1ltrace 1 trace library calls xtrace C OIE Es psizel xtrace
279. k image file The empty disk image disk img which can grow up to 5MiB can be made using dd 1 as follows dd bs 1 count 0 if dev zero of disk img seek 5G You can create an ext3 filesystem on this disk image disk img using the loop device as follows losetup f v disk img Loop device is dev loopl mkfs ext3 dev loopl oo o DEEE 4 5 0 MECA y o DEAT losetup d dev loopl Debian Reference 205 265 du apparent siz h disk img S0C ds ima du h disk img 83M disk img For disk img its file size is 5 0 GiB and its actual disk usage is mere 83MiB This discrepancy is possible since ext2fs can hold sparse file Tip The actual disk usage of sparse file grows with data which are written to it Using similar operation on devices created by the loop device or the device mapper devices as Section 10 2 3 you can partition this disk image disk img using parted 8 or fdisk 8 and can create filesystem on it using mk fs ext 3 8 mkswa p 8 etc 10 2 6 Making the ISO9660 image file The 1509660 image file cd i so from the source directory tree at source_directory can be made using genisoi mage 1 provided by cdrkit by the following genisoimage r J T V volume_id o cd iso source_directory Similarly the bootable ISO9660 image file cdboot iso can be made from debian installer like directory tree at source_directory by the following genisoimage r o cdboot iso V vo
280. kernel when it is started other filesystems are mounted in the runlevel S by the following init scripts e etc init d mountkernfs sh for kernel filesystems in proc sys etc e etc init d mountdevsubfs sh for virtual filesystems in dev e etc init d mountall sh for normal filesystems using etc fstab e etc init d mountnfs sh for network filesystems using etc fstab Debian Reference 82 265 The mount options of the filesystem are set in etc fstab See Section 9 3 5 Note The actual mounting of network filesystems waits for the start of the network interface Warning I After mounting all the filesystems temporary files in tmp var lock and var run are cleaned for each boot up 3 5 7 Network interface initialization Network interfaces are initialized in runlevel S by the init script symlinked to etc init d ifupdown clean and etc init d ifupdown See Chapter 5 for how to configure them 3 5 8 Network service initialization Many network services see Chapter 6 are started under multi user mode directly as daemon processes at boot time by the init script e g etc rc2 da S20exim4 for RUNLEVEL 2 which is a symlink to etc init d exim4 Some network services can be started on demand using the super server inetd or its equivalents The inetd is started at boot time by etc rc2 d S20inetd for RUNLEVEL 2 which is a symlink to etc init d inetd Esse
281. l combination of the symbolic links results in loops in the filesystem Note It is generally preferable to use symbolic links rather than hardlinks unless you have a good reason for using a hardlink 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 subdirectories If you are just moving to Linux from Windows it soon becomes clear how well designed the filename linking of Unix is compared with the nearest Windows equivalent of shortcuts Because it is implemented in the filesystem applications can t see any difference between a linked file and the original In the case of hardlinks there really is no difference 1 2 8 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 is nothing to read before terminating The size of the pipe is always zero it does not store data it just links two processes like the shell Ho
282. l converter from troff to DocBook XML Table 11 10 List of XML data extraction tools For non XML HTML files you can convert them to XHTML which is an instance of well formed XML XHTML can be processed by XML tools package popcon size keyword description libxm12 utils ne psize1 xml html lt gt xhtml command line XML tool with xm11i tidy a portones psize1 xmlhtml lt gt xhtml HTML syntax checker and reformatte Table 11 11 List of XML pretty print tools Once proper XML is generated you can use XSLT technology to extract data based on the mark up context etc 11 3 Printable data Printable data is expressed in the PostScript format on the Debian system Common Unix Printing System CUPS uses Ghostscript as its rasterizer backend program for non PostScript printers 11 3 1 Ghostscript The core of printable data manipulation is the Ghostscript PostScript PS interpreter which generates raster image The latest upstream Ghostscript from Artifex was re licensed from AFPL to GPL and merged all the latest ESP version changes such as CUPS related ones at 8 60 release as unified release Debian Reference 239 265 package popcon size description ghostscript popcon psizel The GPL Ghostscript PostScript PDF interpreter ghostscript x popcon psizel GPL Ghostscript PostScript PDF interpreter X display supp
283. l these additional scripts you should customize these scripts to avoid interferences 5 4 8 Mapping with guessnet Instead of manually choosing configuration as described in Section 5 4 6 you can use the mapping mechanism described in Section 5 4 5 to select network configuration automatically with custom scripts The guessnet ifupdown 8 command provided by the guessnet package is designed to be used as a mapping script and provides powerful framework to enhance the i fupdown system e You list test condition as the value for guessnet options for each network configuration under iface stanza e Mapping choses the iface with first non ERROR result as the network configuration This dual usage of the etc network interfaces file by the mapping script guessnet ifupdown and the original network configuration infrastructure ifupdown does not cause negative impacts since guessnet options only export extra environment variables to scripts run by the i fupdown system See details in guessnet ifupdown 8 Note When multiple guessnet option lines are required in etc network interfaces use option lines started with g uessnetl guessnet2 and so on since the ifupdown package does not allow starting strings of option lines to be repeated 5 5 The network configuration for desktop 5 5 1 GUI network configuration tools The capability of default GUI network configuration tools for each desktop environments such as GNOME tends to
284. lder 32 bit OS the maximum file size was even smaller 2731 1 bytes 42GiB 1 by te Debian does not suffer the latter problem Debian Reference 201 265 Note Microsoft itself does not recommend to use FAT for drives or partitions of over 200 MB Microsoft highlights its short comings such as inefficient disk space usage in their Overview of FAT HPFS and NTFS File Systems Of course we should normally use the ext3 filesystem for Linux Tip For more on filesystems and accessing filesystems please read Filesystems HOWTO 10 1 11 Sharing data via network When sharing data with other system via network you should use common service Here are some hints network service SMB CIFS network mounted filesystem with Samba NFS network mounted filesystem with the Linux kernel HTTP service HTTPS service FTP service Table 10 6 List of the network service to chose with the typical usage scenario Although these filesystems mounted over network and file transfer methods over network are quite convenient for sharing data these may be insecure Their network connection must be secured by the following e Encrypt it with SSL TLS s Tunnel it via SSH e Tunnel it via VPN s Limit it behind the secure firewall See also Section 6 10 and Section 6 11 10 1 12 Archive media When choosing computer data storage media for important data archive you should be careful about their limi
285. lesystem and everything is included This is a huge advantage compared to Windows 1 2 1 Unix file basics Here are some Unix file basics s Filenames are case sensitive That is MYFILE and MyFile are different files s The root directory means root of the filesystem referred as simply Don t confuse this with the home directory for the root user root s Every directory has a name which can contain any letters or symbols except 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 s All fully qualified filenames begin with the directory and there s a between each directory or file in the filename The first is the top level directory and the other s separate successive subdirectories until we reach the last entry which is the name of the actual file The words used here can be confusing Take the following fully qualified filename as an example usr share keytables us map gz However people also refers to its basename us map gz alone as a filename e The root directory has a number of branches such as etc and usr These subdirectories in turn branch into still more subdirectories such as etc init d and usr l
286. limit the download bandwidth for APT to e g 800Kib sec 100kiB sec you should configure APT with its configuration parameter as the following Debian Reference 70 265 APT SAC quiro k Nete DIE ramie 00i 2 7 7 Emergency downgrading Caution Downgrading is not officially supported by the Debian by design It should be done only as a part of emergency recovery process Despite of this situation it is known to work well in many incidents For critical systems You should backup all important data on the system after the recovery operation and re install the new system from the scratch You may be lucky to downgrade from newer archive to older archive to recover from broken system upgrade by manipulating candidate version see Section 2 7 3 This is lazy alternative to tedious actions of many dpkg i lt broken package gt _ lt old version gt deb commands see Section 2 6 4 Search lines in the etc apt sources list file tracking unstable as the following deb http ftp us debian org debian codename unstable main contrib non free Replace it with the following to track testing deb http ftp us debian org debian codename testing main contrib non free Set the etc apt preferences file as the following Package Pin release a testing Pan T e Og Run apt get dist upgrade to force downgrading of packages across the system Remove this special etc apt preferences file after
287. lity to verify installed package files against MDS checksums chkrootkit dl psizel rootkit detector clamav guinidio psizel anti virus utility for Unix command line interface tiger aa ences psizel report system security vulnerabilities tripwire oe qe psizel file and directory integrity checker john E SHOES psizel active password cracking tool aide 3 SHOES psizel Advanced Intrusion Detection Environment static binary bastille ia psizel security hardening tool integrit a a psizel file integrity verification program crack a aaia psizel password guessing program Table 9 21 List of tools for system security and integrity check Here is a simple script to check for typical world writable incorrect file permissions IO YY a l typ s a Ml type 1 a type d a perm 1777 Debian Reference 182 265 audit tool against malicious attacks Caution I Since the debsums package uses MD5 checksums stored locally it can not be fully trusted as the system security 9 7 The kernel Debian distributes modularized Linux kernel as packages for supported architectures 9 7 1 Linux kernel 2 6 There are few notable features on Linux kernel 2 6 compared to 2 4 e Devices are created by the udev system see Section 3 5 11 s Read write accesses to IDE CD DVD devices do not use the ide scsi module e Net
288. llowing sudo lsof p 1 PID 1 is usually init program 9 5 6 Tracing program activities You can trace program activity with strace 1 ltrace 1 or xtrace 1 for system calls and signals library calls or communication between X11 client and server You can trace system calls of the 1s command as the following sudo strace ls 9 5 7 Identification of processes using files or sockets You can also identify processes using files by fuser 1 e g for var log mail log by the following sudo fuser v var log mail log USER PID ACCESS COMMAND var log mail log root 2946 F syslogd You see that file var log mail 1log is open for writing by the syslogd 8 command You can also identify processes using sockets by fuser 1 e g for smtp tcp by the following sudo fuser v smtp tcp USER PID ACCESS COMMAND smtp tcp Debian exim SUS Wagan Simi Now you know your system runs exim4 8 to handle TCP connections to SMTP port 25 9 5 8 Repeating a command with a constant interval watch 1 executes a program repeatedly with a constant interval while showing its output in fullscreen watch w This displays who is logged on to the system updated every 2 seconds Debian Reference 173 265 9 5 9 Repeating a command looping over files There are several ways to repeat a command looping over files matching some condition e g matching glob pattern x ext Shell for loop method see Section 1
289. llowing sudo pon lt isp_name gt S sudo poff lt isp_name gt See usr share doc ppp README Debian gz 5 2 4 The alternative PPP connection with wvdialconf A different approach to using pppd 8 is to run it from wvdial 1 which comes in the wvdial package Instead of pppd running chat 8 to dial in and negotiate the connection wvdial does the dialing and initial negotiating and then starts pppd to do the rest The configuration script wvdialconf configures the PPP connection interactively just by selecting the following s The telephone number s The ISP user name e The ISP password wvdial succeeds in making the connection in most cases and maintains authentication data list automatically file function etc ppp peers wvdial The wvdialconf generated configuration file for pppd specific to wvdial etc wvdial conf The wvdialconf generated configuration file etc ppp options The general execution parameter for pppd etc ppp pap secret Authentication data for the PAP security risk etc ppp chap secret Authentication data for the CHAP more secure Table 5 7 List of configuration files for the PPP connection with wvdialconf You can test configuration using low level network configuration tools as the following sudo wvdial sudo killall wvdial See wvdial 1 and wvdial conf 5 5 2 5 The PPPoE connection with pppoeconf When your ISP serves you with PPPoE connection a
290. lly use unstable or testing archives For this transition period both unsta ble and testing archives are not good for most people Your system is difficult to keep in good working condition with the unstable archive since it suffers surges of major upgrades for core packages The testing archive is not useful either since it contains mostly the same content as the st able archive without its security support Debian testing security announce 2008 12 After a month or so the unstable archive may be usable if you are careful Tip When tracking the testing archive problem caused by a removed package is usually worked around by installing corre sponding package from the unstable archive which is uploaded for bug fix See Debian Policy Manual for archive definitions s Sections e Priorities e Base system e Essential packages 2 1 5 Package dependencies The Debian system offers a consistent set of binary packages through its versioned binary dependency declaration mechanism in the control file fields Here is a bit over simplified definition for them e Depends This declares an absolute dependency and all of the packages listed in this field must be installed at the same time or in advance Debian Reference 43 265 Pre Depends This is like Depends except that it requires completed installation of the listed packages in advance Recommends This declares a strong but not absolute dep
291. lume_id b isolinux isolinux bin c isolinux boot cat no emul boot boot load size 4 boot info table source_directory Here Isolinux boot loader see Section 3 3 is used for booting You can calculate the md5sum value and make the ISO9660 image directly from the CD ROM device as follows isoinfo d i dev cdrom CDEROME SES OS CORO ema Logical block size is 2048 Volume sizes 2350592 dd if dev cdrom bs 2048 count 23150592 conv notrunc noerror md5sum dd if dev cdrom bs 2048 count 23150592 conv notrunc noerror gt cd iso s Warning You must carefully avoid ISO9660 filesystem read ahead bug of Linux as above to get the right result 10 2 7 Writing directly to the CD DVD R RW Tip DVD is only a large CD to wodim 1 provided by cdrkit Debian Reference 206 265 You can find a usable device by the following wodim devices Then the blank CD R is inserted to the CD drive and the ISO09660 image file cd iso is written to this device e g dev hda using wodim 1 by the following wodim v ject dev dev hda cd iso If CD RW is used instead of CD R do this instead by the following wodim v eject blank fast dev dev hda cd iso Tip If your desktop system mounts CD automatically unmount it by sudo unmount dev hda before using wodim 1 10 2 8 Mounting the ISO9660 image file If cd iso contains an ISO9660 image then the following manually mounts it
292. m rf old modulel bugfixes Tip You can replace URLs such as file by any other URL formats such as http and svn ssh Tip You can checkout only a sub directory of nodule1 by providing its name as svn co file srv svn project modulel trunk subdir modulel subdir etc Debian Reference 227 265 option meaning dry run dry run no effect v display detail messages of svn activity Table 10 19 Notable options for Subversion commands use as first argument s to svn 1 10 9 Git Git can do everything for both local and remote source code management This means that you can record the source code changes without needing network connectivity to the remote repository 10 9 1 Configuration of Git client You may wish to set several global configuration in gitconfig such as your name and email address used by Git by the following git config global user name Name Surname git config global user email yourname example com If you are too used to CVS or Subversion commands you may wish to set several command aliases by the following S girt Comrie alobal elias el emu a git config global alias co checkout You can check your global configuration by the following 6 oirt contie llosa ligg 10 9 2 Git references See the following manpage git 1 usr share doc git doc git html e Git User s Manual usr share doc git doc user manual h
293. m often Having backup data is more important than how technically good your backup method is There are 3 key factors which determine actual backup and recovery policy 1 Knowing what to backup and recover e Data files directly created by you data in e Data files created by applications used by you data in var except var cache var run and v ar tmp e System configuration files data in etc e Local softwares data in usr local or opt e System installation information a memo in plain text on key steps partition e Proven set of data confirmed by experimental recovery operations in advance 2 Knowing how to backup and recover e Secure storage of data protection from overwrite and system failure e Frequent backup scheduled backup e Redundant backup data mirroring e Fool proof process easy single command backup 3 Assessing risks and costs involved e Value of data when lost e Required resources for backup human hardware software e Failure mode and their possibility As for secure storage of data data should be at least on different disk partitions preferably on different disks and machines to withstand the filesystem corruption Important data are best stored on a write once media such as CD DVD R to prevent overwrite accidents See Section 10 3 for how to write to the storage media from the shell commandline GNOME desktop GUI environment gives you easy access via menu
294. m pipe separated by tab col bx remove backspace and expand tabs to spaces expand expand tabs sort unig sort and remove duplicates tr A Z a z convert uppercase to lowercase tr d An concatenate lines into one line tr d Ar remove CR sed s add to the start of each line sed s ext g T remove ext sed n e 2p print the second line head n 2 print the first 2 lines taik r 2 print the last 2 lines Table 1 26 List of script snippets for piping commands One line shell script can loop over many files using find 1 and xargs 1 to perform quite complicated tasks See Sec tion 10 1 5 and Section 9 5 9 When using the shell interactive mode becomes too complicated please consider to write a shell script see Section 12 1 Debian Reference 36 265 Chapter 2 Debian package management Note This chapter is written assuming the latest stable release is codename codename stable Debian is a volunteer organization which builds consistent distributions of pre compiled binary packages of free software and distributes them from its archive The Debian archive is offered by many remote mirror sites for access through HTTP and FTP methods It is also available as CD ROM DVD The Debian package management system when used properly offers the user to install consistent sets of binar
295. ment 1sscsi 8 pnputils o psize1 Plug and Play BIOS utilities 1 spnp 8 procinfo ie psizel system information obtained from proc 1sdev 8 lshw dd paani psizel information about hardware configuration 1shw 1 discover oe psizel hardware identification system discover 8 Table 9 16 List of hardware identification tools package popcon size description hal GR an S psizel Hardware Abstraction Layer 1sha1 1 console tools oes E psizel Linux console font and keytable utilities x11 xserver utils a psize1 X server utilities xset 1 xmodmap 1 acpid E aia psizel daemon to manage events delivered by the Advanced Config acpi 7 oer psizel1 utility to display information on ACPI devices apmd a G psizel daemon to manage events delivered by the Advanced Power noflushd Re er psizel daemon to allow idle hard disks to spin down sleepd Pins S psizel daemon to put a laptop to sleep during inactivity hdparm ee oF psizel hard disk access optimization see Section 9 3 7 smartmontools ri a psizel control and monitor storage systems using S M A R T setserial ie oe S psizel collection of tools for serial port management memtest86 PPOP g psizel collection of tools for memory hardware management scsitools dn S psizel collection of tools for SCSI hardware management tpconfig eee S psizel utility to configure touchp
296. mmand to the standard input of command2 concurrent exec commandl 2 gt amp 1 command2 pipe both standard output and standard error of command_1 to the standard input of command commandl command2 execute command1 and command2 sequentially commandl amp amp command2 execute command if successful execute command2 sequentially return success if both c command1 command2 execute command_1 if not successful execute command2 sequentially return success if co command gt foo redirect standard output of command to a file foo overwrite command 2 gt foo redirect standard error of command to a file foo overwrite command gt gt foo redirect standard output of command to a file foo append command 2 gt gt foo redirect standard error of command to a file foo append command gt foo 2 gt 41 redirect both standard output and standard error of command to a file foo command lt foo redirect standard input of command to a file foo command lt lt delimiter redirect standard input of command to the following lines until delimiter is met here d L redirect standard input of command to the following lines until delimiter is met here d command lt lt delimiter input lines Table 1 22 Shell command idioms echo Hello gt foo exec 3 lt foo 4 gt bar open files Call lt ES Se redirect stdin to 3 close files stdout to 4 xec 3 lt amp 4 gt amp cat bar Hello He
297. mming See Shell Mistakes http www greenend org uk rjk 2001 04 shell html to learn from mistakes Unlike shell interactive mode see Section 1 5 and Section 1 6 shell scripts frequently use parameters conditionals and loops Debian Reference 248 265 package popcon size documentation autoconf E psizel info autoconf provided by autoconf doc automake ii S psizel info automake provided by automake1 10 doc bash a aa psizel info bash provided by bash doc bison ees psizel info bison provided by bison doc cpp m ES psizel info cpp provided by cpp doc ddd oe psizel info ddd provided by ddd doc exuberant ctags a psizel exuberant ctags 1 flex ee psizel info flex provided by flex doc gawk are en psizel info gawk provided by gawk doc gcc i ad psizel info gcc provided by gec doc gdb mas psizel info gdb provided by gdb doc gettext o psizel info gettext provided by gettext doc gfortran oe psizel info gfortran provided by gfortran doc glade ae SS psizel help provided via menu glade gnome nan S psizel help provided via menu libc 6 ii psizel info libc provided by glibc doc and glibc doc r make e ene psizel info make provided by make doc mawk oe psize1 mawk 1 perl eel psizel
298. mplicated input method support such as SCIM discussed next Debian Reference 151 265 8 1 1 The input method support with SCIM Setup of multilingual input for the Debian system is simplified by using the Smart Common Input Method SCIM family of packages with the im switch package The list of SCIM packages are the following package popcon size supported locale scim anthy a adn psizel Japanese scim canna di ES psizel scim skk oo ar psizel scim prime popconi psizel scim tables ja popcon1 psizel not very useful scim tables zh popcon1 psizel Chinese for zh_ popcon1 scim pinyin psizel for zh_CN scim chewing popcon1 psizel for zh_TW scim hangul e blandit psizel Korean scim tables ko ERa G psizel scim thai E popcoml _ psize1 Thai scim m17n SEO psizel Multilingual Indic Arabic and others scim tables additional alee Es psizel scim uim oe a psizel Table 8 2 List of input method supports with SCIM The kinput2 method and other locale dependent Asian classic input methods still exist but are not recommended for the modern UTF 8 X environment The uim tool chain is an alternative approach for the international input method for the modern UTF 8 X environment which is al
299. mponent binary architecture combination C Sources top of each distribution component source combination C Table 2 14 The content of the Debian archive meta data In the recent archive these meta data are stored as the compressed and differential files to reduce network traffic 2 5 2 Top level Release file and authenticity Tip The top level Release file is used for signing the archive under the secure APT system Each suite of the Debian archive has a top level Release file e g http ftp us debian org debian dists unstable Release as follows Origin Debian Label Debian Suite unstable Codename sid Date Gat 26 Jan 2008 2031358 UTC Architectures alpha amd64 arm hppa hurd i386 i386 ia64 m68k mips mipsel powerpc s390 sparc Components main contrib non free Description Debian x y Unstabl Not Released MD5Sum e9f1l1lbc50b12af7927d6583de0a3bd06 22788722 main binary alpha Packages 43524d07 7fa21b10 472c426db66168 6561398 main binary alpha Packages gz Note Here you can find my rationale to use the suite codeneme and components in Section 2 1 4 The distribution is used when referring to both suite and codeneme The integrity of the top level Release file is verified by cryptographic infrastructure called the secure apt Debian Reference 57 265 e The cryptographic signature file Release gpg is created from the authentic top level Release file and the secret De
300. ms ee 133 List of other network application servers o oo a a 134 List of network application clients ooa ee 135 Listot popular RFCS irme E AE ees T N 136 List of key meta packages for X Window aoaaa ee 138 List of server client terminology sooo a 139 List of connection methods to the X server 2 aaa 140 Table of packages to support X Window font systems 2 2000002 eee eee eee 144 Table of corresponding PostScript Type 1 fonts aaa aa 0 20000 0000000000004 144 Table of corresponding TrueType fonts oaoa ee 145 Table of key words used in CJK font names to indicate font types o ooa o o 145 Debian Reference 7 8 7 9 8 1 8 2 9 1 9 2 9 3 9 4 9 5 9 6 9 7 9 8 9 9 9 10 9 11 9 12 9 13 9 14 9 15 9 16 9 17 9 18 9 19 9 20 9 21 9 22 9 23 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 8 10 9 xxi List of basic X office applications ee ee 147 List of basic X utility applications a 148 List of keyboard reconfiguration methods 2 2 2 0 000000 eee eee 150 List of input method supports with SCIM 2 2 000000 2 ee 131 List of programs to support interrupted network connections o o 156 List of key bindings for screen a 157 Listof system log analyzers s sre ER R RRR R o a a e RRR i a 158 Display examples of time and date for the ls 1 command for lenny sassa ooo 160 List of graphic
301. n Roi match packages to which no other installed packages depend on LAR match packages to which some other installed packages depend or recommend on R i Rrecomm match lt term gt package with filtered version S filter lt te match all packages true T match no packages false E Table 2 11 List of the aptitude regex formula Debian Reference 50 265 Tip When lt regex_pattern gt is a null string place T immediately after the command Here are some short cuts s P lt term gt Dprovides lt term gt e C lt term gt Dconflicts lt term gt s TW term term Users familiar with mut t pick up quickly as mutt was the inspiration for the expression syntax See SEARCHING LIMITING AND EXPRESSIONS in the User s Manual usr share doc aptitude README Note With the Lenny version of apt itude 8 the new long form syntax such as broken may be used for regex matching in place for its old short form equivalent b Now space character is considered as one of the regex terminating character in addition to tilde character See User s Manual for the new long form syntax 2 2 7 Dependency resolution of aptitude The selection of a package in apt it ude not only pulls in packages which are defined in its Depends list but also defined in the Recommends list if the menu F10 Options Dependency handling is set
302. n a remote host linked by a fast network connection may be the only realistic option 10 2 The disk image Here we discuss manipulations of the disk image See Section 9 3 too 10 2 1 Making the disk image file The disk image file disk img of an unmounted device e g the second SCSI drive dev sdb can be made using cp 1 or dd 1 by the following cp dev sdb disk img dd if dev sdb of disk img The disk image of the traditional PC s master boot record MBR see Section 9 3 1 which reside on the first sector on the primary IDE disk can be made by using dd 1 by the following dd if dev hda of mbr img bs 512 count 1 dd if dev hda of mbr nopart img bs 446 count 1 dd if dev hda of mbr part img skip 446 bs 1 count 66 e mbr img The MBR with the partition table e mbr nopart img The MBR without the partition table e part img The partition table of the MBR only If you have a SCSI device including the new serial ATA drive as the boot disk substitute dev hda with dev sda If you are making an image of a disk partition of the original disk substitute dev hda with dev hdal etc Debian Reference 203 265 10 2 2 Writing directly to the disk The disk image file disk img can be written to an unmounted device e g the second SCSI drive dev sdb with matching size by the following dd if disk img of dev sdb Similarly the disk partition image file partition img c
303. n allow and etc cron deny for crontab 1 s Network firewall of netfilter infrastructure See Section 3 5 3 Section 3 5 4 Section 4 5 1 Section 3 5 8 and Section 5 8 Tip Sun RPC services need to be active for NFS and other RPC based programs Tip If you have problems with remote access in a recent Debian system comment out offending configuration such as ALL PARANOID in etc hosts deny if it exists But you must be careful on security risks involved with this kind of action 4 7 Security of authentication The information here may not be sufficient for your security needs but it should be a good start 4 7 1 Secure password over the Internet Many popular transportation layer services communicate messages including password authentication in the plain text It is very bad idea to transmit password in the plain text over the wild Internet where it can be intercepted You can run these services over Transport Layer Security TLS or its predecessor Secure Sockets Layer SSL to secure entire communication including password by the encryption The encryption costs CPU time As a CPU friendly alternative you can keep communication in plain text while securing just password with the secure authentication protocol such as Authenticated Post Office Protocol APOP for POP and Challenge Response Authentication Mechanism MDS CRAM MDS for SMTP and IMAP For sending mail messages over the Internet to your mail ser
304. n marks are not available in ASCII double quoted text single quoted text When ASCII plain text data is converted to UTF 8 one it has exactly the same content and size as the original ASCII one So you loose nothing by deploying UTF 8 locale Some programs consume more memory after supporting I18N This is because they are coded to use UTF 32 UCS4 internally to support Unicode for speed optimization and consume 4 bytes per each ASCII character data independent of locale selected Again you loose nothing by deploying UTF 8 locale The vendor specific old non UTF 8 encoding systems tend to have minor but annoying differences on some characters such as graphic ones for many countries The deployment of the UTF 8 system by the modern OSs practically solved these conflicting encoding issues 8 3 3 The reconfiguration of the locale In order for the system to access a particular locale the locale data must be compiled from the locale database The Debian system does not come with all available locales pre compiled unless you installed the l0ocales al1 package The full list of supported locales available for compiling are listed in usr share il8n SUPPORTED This lists all the proper locale names The following lists all the available UTF 8 locales already compiled to the binary form locale a grep utf8 The following command execution reconfigures the locales package dpkg reconfigure locales This process involves
305. n of complete system quickly from backup CD DVD etc without going through normal system installation processes e sbackup and keep packages provide easy GUI frontend for desktop users to make regular backups of user data An equiva lent function can be realized by a simple script Section 10 1 8 and cron 8 e Bacula Amanda and BackupPC are full featured backup suite utilities which are focused on regular backups over network Basic tools described in Section 10 1 1 and Section 10 1 2 can be used to facilitate system backup via custom scripts Such script can be enhanced by the following Debian Reference 197 265 e The rdiff backup package enables incremental remote backups e The dump package helps to archive and restore the whole filesystem incrementally and efficiently Tip See files in usr share doc dump and Is dump really deprecated to lean about the dump package 10 1 8 Anexample script for the system backup For a personal Debian desktop system running unstable suite I only need to protect personal and critical data I reinstall system once a year anyway Thus I see no reason to backup the whole system or to install a full featured backup utility I use a simple script to make a backup archive and burn it into CD DVD using GUI Here is an example script for this bin sh e Copyright C 2007 2008 Osamu Aoki lt osamu debian org gt Public Domain BUUID 1000 USER osamu UID and name of a user who
306. n standard for the disk partitioning tool part ed 8 is replacing it package popcon size GPT description util linux i ES psizel Not supported miscellaneous system utilities including fdisk parted E peones psizel Supported GNU Parted disk partition resizing program popcon1 rh gparted psizel Supported GNOME partition editor based on libparted qtparted a E popon O psizel Supported KDE partition editor based on libparted popcon1 2 E gptsync psizel Supported synchronize classic MBR partition table with the kpartx G ene psizel Supported program to create device mappings for partitions Table 9 7 List of disk partition management packages Caution T Although parted 8 claims to create and to resize filesystem too it is safer to do such things using best maintained specialized tools such as mk f s 8 mk fs msdos 8 mkfs ext2 8 mkfs ext3 8 and resize2fs 8 Debian Reference 163 265 Note In order to switch between GPT and MBR you need to erase first few blocks of disk contents directly see Section 10 3 6 and use parted dev sdx mklabel gpt or parted dev sdx mklabel msdos to setit Please note msdos is use here for MBR 9 3 2 Accessing partition using UUID Although reconfiguration of your partition or activation order of removable storage media may yield different names for par titi
307. nald E Knuth Addison Wesley 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 provided by the 1yx package and GNU TeXmacs provided by the texmacs package offer 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 s The TEX Live Guide TEX Live 2007 usr share doc texlive doc base english texliv n liv html texlive doc base package e A Simple Guide to Latex Lyx e Word Processing Using LaTeX e Local User Guide to teTeX LaTeX 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 texm 8 to fix this Note The TeX source of The TeXbook is available at http tug ctan org tex archive systems knuth dist tex texbook tex This file contains most of the required macros I heard that you can process this document with t ex 1 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
308. name gt Table 5 12 List of terminology for network devices Basic network configuration commands in Section 5 3 1 require the network configuration name token of the iface stanza to match the network interface name in the etc network interfaces Advanced network configuration commands enables separation of the network configuration name and the network interface name in the etc network interfaces as the following command action ifup eth0 configl bring up a network interface eth0 with the configuration configl ifdown eth0 configl bring down a network interface et h 0 with the configuration configl ifup eth0 bring up a network interface et hO with the configuration selected by mapping stanza ifdown eth0 bring down a network interface et h 0 with the configuration selected by mapping stanza Table 5 13 List of advanced network configuration commands with ifupdown 5 4 5 The mapping stanza We skipped explaining the mapping stanza in the etc network interfaces in Section 5 3 2 to avoid complication This stanza has the following syntax mapping lt interface_name_glob gt script lt script_name gt mapi scrip Anput map lt script_input2 gt map This provides advanced feature to the etc network interfaces file by automating the choice of the configuration with the mapping script specified by lt script_name gt Let s follow the execution of the following sudo ifup eth0 When the lt
309. name stable main contrib non free deb src http ftp XX debian org debian codename stable main contrib non free deb http security debian org codename stable updates main contrib deb src http security debian org codename stable updates main contrib Please note ftp XX debian org must be replaced with appropriate mirror site URL for your location for USA ftp u s debian org which can be found in the list of Debian worldwide mirror sites The status of these servers can be checked at Debian Mirror Checker site Here I tend to use codename codename stable instead of suite name stable to avoid surprises when the next stable is released The meaning of etc apt sources 1list is described in sources 1ist 5 and key points are followings e The deb line defines for the binary packages e The deb src line defines for the source packages e The Ist argument is the root URL of the Debian archive s The 2nd argument is the distribution name either the suite name or the codename The 3rd and following arguments are the list of valid archive component names of the Debian archive The deb src lines can safely be omitted or commented out by placing at the start of the line if it is just for aptitude which does not access source related meta data It speeds up the updates of the archive meta data The URL can be http Pepe MN Eiles S ymas Tip If sid is used in the ab
310. nced features such as anti aliasing Xft 2 0 connects modern X applications such as ones from GNOME KDE and OpenOffice org with FreeType 2 0 library FreeType 2 0 provides font rasterization library Fontconfig provides resolution of the font specification for Xft 2 0 See fonts con 5 for its configuration All modern X applications using Xft 2 0 can talk to modern X server using the X Rendering Extension The X Rendering Extension moves font access and glyph image generation from the X server to the X client You can check font configuration information by the following e xset q for core X11 font path e fc match for fontconfig font default e fc list for available fontconfig fonts Tip The Penguin and Unicode is a good overview of modern X Window System Other documentations at http unifont org should provide good information on Unicode fonts Unicode enabled software internationalization and Unicode usability issues on free libre open source FLOSS operating systems Tip You should rely on fontconfig infrastructure to configure fonts on the Debian system Debian Font Manager defoma 1 is only useful for font installation and X logical font description XLFD data registration for lenny Debian Reference 144 265 package popcon size description xfonts utils popcon psizel X Window System font utility programs popcon l
311. nd SLANG is set to the system default locale value en_US UTF 8 s For the second command SLANG is set to the French UTF 8 locale value fr_FR UTF 8 Most command executions usually do not have preceding environment variable definition For the above example you can alternatively execute as the following LANG fr_FR UTF 8 date damanche Ss quan 20077 2027233 ULE 09010 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 subprocesses e g when calling shell script you need to export it instead by the following export LANG Tip When filing a bug report running and checking the command under LANG en_US UTF 8 is good idea if you use non English environment See locale 5 and locale 7 for SLANG and related environment variables Note recommend you to configure the system environment just by the SLANG variable and to stay away from LC_x variables unless it is absolutely needed 1 5 3 PATH variable When you type a command into the shell the shell searches the command in the list of directories contained in the SPATH environment variable The value of the SPATH 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 and us r sbin For example the ifconfig c
312. nd amp has no special meaning For example try the following echo zzzlabc2efg3hij4 A sed e s 1 a z TO SEN X 5 8 zzz labc2efg3hij4 echo zzzlabc2efg3hij4 sed e s 1 a z 0 9 2 1 zzzefg3hi34 labc echo zzzlabc2efg3hij4 perl pe s 1 a z x 0 9 2 1 zzzefg3hi34 labc echo zzzlabc2efg3hij4 perl pe s 1 a z 0 9 amp ZZZ 6 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 cursor movements and text replacement actions in some editors too The back slash at the end of line in the shell commandline escapes newline as a white space character and continues shell command line input to the next line Please read all the related manual pages to learn these commands 1 6 4 Global substitution with regular expressions The ed 1 command can replace all instances of FROM_REGEX with TO_TEXT in file S cel rile lt Jo0l S FROM_REGEX TO_TEXT g W q EOF The sea 1 command can replace all instances of F ROM_REGEX with TO_TEXT in file Debian Reference 33 265 S sed file s FROM_REGEX TO_TEXT g sponge file Tip The sponge 8 command is a non standard Unix tool offere
313. nd keep your system simple see Section 5 3 5 We describe these traditional cases in detail here We also touch on some alternative high level tools such as network manager and wicd which ease configuration of wireless networks see Section 5 5 2 5 1 The basic network infrastructure Let s review the basic network infrastructure on the modern Debian system 5 1 1 The domain name The naming for the domain name is a tricky one for the normal PC workstation users The PC workstation may be mobile one hopping around the network or located behind the NAT firewall inaccessible from the Internet For such case you may not want the domain name to be a valid domain name to avoid name collision According to rfc2606 invalid seems to be a choice for the top level domain TLD to construct domain names that are sure to be invalid from the Internet The mDNS network discovery protocol Apple Bonjour Apple Rendezvous Avahi on Debian uses local as the pseudo top level domain Microsoft also seems to promote local for the TLD of local area network l Warning If the DNS service on your LAN uses local as TLD for your LAN it may interfare with mDNS won Other popular choices for the invalid TLD seem to be localdomain lan localnet or home according to my incoming mail analysis Debian Reference 95 265 5 1 2 The hostname resolution The hostname resolution is currently supported by the N
314. nd server system There is usually a common sound engine for each popular desktop environment Each sound engine used by the application can choose to connect to different sound servers 9 6 8 Disabling the screen saver For disabling the screen saver use following commands 9 6 9 Disabling beep sounds One can always unplug the PC speaker to disable beep sounds Removing pcspkr kernel module does this for you The following prevents the read1ine 3 program used by bash 1 to beep when encountering Ya ASCII 7 S echo set bell style none gt gt inputre 9 6 10 Memory usage The kernel boot message in the var log dmesg contains the total exact size of available memory free 1 and top 1 display information on memory resources on the running system S grep Memory var log dmesg 0 004000 Memory 990528k 1016784k available 1975k kernel code 25868k reserved 931k data 296k init So CS total used free shared buffers cached Mem 997184 976928 20256 0 129592 i ALS sy buffers cache 675404 321780 Swap 4545576 4 4545572 Tip Do not worry about the large size of used and the small size of free in the Mem line but read the one under them 675404 and 321780 in the example below and relax For my MacBook with 1GB 1048576k DRAM video system steals some of this I see the following Debian Reference 180 265 package popcon size description linux sound base
315. nd you decide to connect your PC directly to the WAN the network of your PC must be configured with the PPPoE The PPPoE stand for PPP over Ethernet The configuration script pppoeconf configures the PPPoE connection interactively The configuration files are the following You can test configuration using low level network configuration tools as the following sudo sbin ifconfig eth0 up sudo pon dsl provider sudo poff dsl provider sudo sbin ifconfig eth0 down See usr share doc pppoeconf README Debian Debian Reference 101 265 file function etc ppp peers dsl provider The pppoeconf generated configuration file for pppd specific to pppoe etc ppp options The general execution parameter for pppd etc ppp pap secret Authentication data for the PAP security risk etc ppp chap secret Authentication data for the CHAP more secure Table 5 8 List of configuration files for the PPPoE connection with pppoeconf 5 3 The basic network configuration with ifupdown The i fupdown package provides the standardized framework for the high level network configuration in the Debian system In this section we learn the basic network configuration with ifupdown with simplified introduction and many typical examples 5 3 1 The command syntax simplified The i fupdown package contains 2 commands i fup 8 and ifdown 8 They offer high level network configuration dictated by the configura
316. nf package is not installed If installed it is a symbolic link Either way it contains information that initialize the resolver routines If the DNS is found at IP 192 168 11 1 it contains the following nameserver 192 168 11 1 The resolvconf package makes this etc resolv conf into a symbolic link and manages its contents by the hook scripts automatically The hostname resolution via Multicast DNS using Zeroconf aka Apple Bonjour Apple Rendezvous which effectively allows name resolution by common Unix Linux programs in the ad hoc mDNS domain local can be provided by installing the 1 ibnss mdns package The etc nsswitch conf file should have stanza like hosts files mdns4_minimal NOTFOUND return dns mdns4 to enable this functionality 5 1 3 The network interface name The network interface name e g et hO is assigned to each hardware in the Linux kernel through the user space configuration mechanism udev see Section 3 5 11 as it is found The network interface name is referred as physical interface in i fup 8 and interfaces 5 In order to ensure each network interface to be named persistently for each reboot using MAC address etc there is a record file etc udev rules d 70 persistent net rules This file is automatically generated by the 1ib udev wr ite_net_rules program probably run by the persistent net generator rules rules file You can modify it to change naming rule Debian Reference
317. ng and unstable suite of Debian system and a few of them were not so trivial to resolve It may be quite painful for you Sometimes you may have a broken package or missing functionality for a few weeks Here are some ideas to ensure quick and easy recovery from bugs in Debian packages Debian Reference 39 265 e Make the system dual bootable by installing the st able suite of Debian system to another partition e Make the installation CD handy for the rescue boot e Consider installing apt 1istbugs to check the Debian Bug Tracking System BTS information before the upgrade e Learn the package system infrastructure enough to work around the problem e Create a chroot or similar environment and run the latest system in it in advance see Section 9 8 If you can not do any one of these precautionary actions you are probably not ready for the testing and unstable suites Enlightenment with the following saves a person from the eternal karmic struggle of upgrade hell and let him reach Debian nirvana 2 1 4 Debian archive basics Let s look into the Debian archive from a system user s perspective Tip Official policy of the Debian archive is defined at Debian Policy Manual Chapter 2 The Debian Archive For the typical HTTP access the archive is specified in the etc apt sources list file as the following e g for the current stable codename stable system deb http ftp XX debian org debian code
318. ng shell builtin and external commands e Avoid using command option e and E e Avoid using any command options except n e Avoid using escape sequences in the string since their handling varies Note Although n option is not really POSIX syntax it is generally accepted Tip Use the printf command instead of the echo command if you need to embed escape sequences in the output string 12 1 2 Shell parameters Special shell parameters are frequently used in the shell script Basic parameter expansions to remember are followings wom Here the colon in all of these operators is actually optional e with operator test for exist and not null wom e without operator test for exist only Debian Reference 250 265 shell parameter value 0 name of the shell or shell script 1 first 1 shell argument 9 ninth 9 shell argument S number of positional parameters TSEN 1 2 3 4 T se E AE ES ESE exit status of the most recent command PID of this shell script 5 PID of most recently started background job Table 12 3 List of shell parameters parameter expression form value if var is set value if var is not set S var string Svar string S var string string null S var string Svar string and run var string S var string Svar echo string to stderr and exit with e
319. ng steps of cvs activity Table 10 18 Notable options for CVS commands use as first argument s to cvs 1 10 7 8 Latest files from CVS To get the latest files from CVS use tomorrow by the following cvs ex D tomorrow module_name Debian Reference 222 265 10 7 9 Administration of CVS Add module alias mx to a CVS project local server by the following export CVSROOT srv cvs project cvs co CVSROOT modules cd CVSROOT echo mx a modulel gt gt modules cvs ci m Now mx is an alias for modulel cvs release d UP Uy UU UES Uy Now you can check out module1 alias mx from CVS to new directory by the following cvs co d new mx cd new Note In order to perform above procedure you should have appropriate file permissions 10 7 10 Execution bit for CVS checkout When you checkout files from CVS their execution permission bit is retained Whenever you see execution permission problems in a checked out file e g filename change its permission in the corre sponding CVS repository by the following to fix it chmod ugo x filename 10 8 Subversion Subversion is a recent generation version control system replacing older CVS It has most of CVS s features except tags and branches You need to install subversion libapache2 svn and subversion tools packages to set up a Subversion server 10 8 1 Configuration of Subversion repository Currently the subversion package does
320. niques see Section 9 8 to run programs from different archives Debian Reference 65 265 2 7 3 Tweaking candidate version Warning In lenny apt itude 8 has a bug for handling etc apt preferences file Bug 514930 Without the etc apt preferences file APT system choses the latest available version as the candidate version using the version string This is the normal state and most recommended usage of APT system All officially supported combinations of archives do not require the etc apt preferences file since some archives which should not be used as the automatic source of upgrades are marked as NotAutomatic and dealt properly Tip The version string comparison rule can be verified with e g dpkg compare versions verl 1 gt verl 1 1 echo 7 see dpkg 1 When you install packages from mixed source of archives see Section 2 7 2 regularly you can automate these complicated operations by creating the etc apt preferences file with proper entries and tweaking the package selection rule for candidate version as described in apt_preferences 5 This is called apt pinning Warning Use of apt pinning by a novice user is sure call for major troubles You must avoid using apt pinning except when you absolutely need it Caution When using apt pinning you must ensure compatibility of packages by yourself since the Debian does not guarantee
321. nment using the source package is desirable This avoids massive package upgrades due to their dependencies Add the following entries to the etc apt sources list of a stable system deb sre http http us debian org debian unstable main contrib non free Install required packages for the compilation and download the source package as the following apt get update apt get dist upgrad apt get install fakeroot devscripts build essential apt get build dep foo apt get source foo T R 4 Uy de Se Se Adjust installed packages if needed Execute the following dch i Bump package version e g one appended with bp1 in debian changelog Build packages and install them to the system as the following debuild S el se debi foox changes 2 7 11 Proxy server for APT Since mirroring whole subsection of Debian archive wastes disk space and network bandwidth deployment of a local proxy server for APT is desirable consideration when you administer many systems on LAN APT can be configure to use generic web http proxy servers such as squid see Section 6 10 as described in apt conf 5 and in usr share doc apt exa mples configure index gz The http_proxy environment variable can be used to override proxy server setting in the etc apt apt conf file There are proxy tools specially for Debian archive You should check BTS before using them package popcon size description approx S ope psizel1
322. ntially inetd allows one running daemon to invoke several others reducing load on the system Whenever a request for service arrives at super server inetd its protocol and service are identified by looking them up in the databases in etc protocols and etc services inetd then looks up a normal Internet service in the etc inetd conf database or a Open Network Computing Remote Procedure Call ONC RPC Sun RPC based service in etc rpc conf Sometimes inetd does not start the intended server directly but starts the TCP wrapper program t cpd 8 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 For system security disable as much network service programs as possible See Section 4 6 3 See ineta 8 inetd conf 5 protocols 5 services 5 tcpd 8 hosts_access 5 hosts_options 5 r pcinfo 8 portmap 8 and usr share doc portmap portmapper txt gz 3 5 9 The system message The system message can be customized by etc default syslogd and etc syslog conf for both the log file and on screen display See syslogd 8 and syslog conf 5 See also Section 9 2 2 3 5 10 The kernel message The kernel message can be customized by etc default kloga for both the log file and on screen display Set KLOG c 3 in this file and run etc
323. nto the runlevel to lt n gt 1t execute following scripts 1 The script names starting with a K in etc rc lt n gt d are executed in alphabetical order with the single argument stop killing services 2 The script names starting with an S in etc rc lt n gt d are executed in alphabetical order with the single argument start starting services For example if you had the links S10sysklogd and S20exim4 in a runlevel directory S10sysklogd which is symlinked to init d sysklogd would run before S20exim4 which is symlinked to init d exim4 s Warning It is not advisable to make any changes to symlinks in etc rcS d unless you know better than the maintainer Debian Reference 81 265 3 5 3 The runlevel management example For example let s set up runlevel system somewhat like Red Hat Linux as the following e init starts the system in runlevel 3 as the default e init does not start gdm 1 in runlevel 0 1 2 6 e init starts gdm 1 in runlevel 3 4 5 This can be done by using editor on the etc inittab file to change starting runlevel and using user friendly runlevel management tools such as sysv rc conf or bum to edit the runlevel If you are to use command line only instead here is how you do it after the default installation of the gdm package and selecting it to be the choice of display manager cde Cec re2 p mw Sales iadmn cd etc perl i p ES IS alo
324. o deb http www example com foo debian unstable main gt gt etc apt sources list apt key add foo public key Debian Reference 74 265 Tip If the archive is located on the local filesystem you can use deb file home foo debian instead 2 7 13 Recording and copying system configuration You can make a local copy of the package and debconf selection states by the following dpkg get selections x gt selection dpkg debconf get selections gt selection debconf wom Here x makes selection dpkg to include package entries for purge too You can transfer these 2 files to another computer and install there with the following dselect update debconf set selections lt myselection debconf dpkg set selections lt myselection dpkg apt get u dselect upgrade or dselect install If you are thinking about managing many servers in a cluster with practically the same configuration you should consider to use specialized package such as fai to manage the whole system 2 7 14 Converting or installing an alien binary package alien 1 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 another Linux distribution than the one you have installed on your system you can use alien to convert it from your preferred package format and install it alien
325. o esmt p msmtp di psize1 light msmtp mta CAC aie psizel1 light sendmail compatibility extension to msmt p Table 6 4 List of choices for mail transport agent MTA packages in Debian archive Debian Reference 122 265 Start exim4 by the following sudo etc init d exim4 start The host name in etc exim4 passwd client should not be the alias You check the real host name with the following S host smtp hostname dom smtp hostname dom is an alias for smtp99 hostname dom smtp99 hostname dom has address 123 234 123 89 I use regex in etc exim4 passwd client to work around the alias issue SMTP AUTH probably works even if the ISP moves host pointed by the alias Caution Y You must execute update exim4 conf 8 after manually updating exim4 configuration files in etc exim4 I Caution l Starting exim4 takes long time if No default value was chosen for the debconf query of Keep number of DNS queries minimal Dial on Demand and the system is not connected to the Internet while booting Note Please read the official guide at usr share doc exim4 base README Debian gz and update exim4 c on 8 Tip Local customization file etc exim4 exim4 conf localmacros may be created to set MACROs For example Yahoo s mail service is said to require MAIN_TLS_ENABLE true and AUTH_CLIENT_ALLOW_NOTLS_PASSWO RDS yes
326. o the remote host using scp 1 or rsync 1 or burn them to CD DVD for extra data security I use GNOME desktop GUI for burning CD DVD See Section 12 1 8 for extra redundancy Keep it simple Tip You can recover debconf configuration data with debconf set selections debconf selections and dpkg se lection data with dpkg set selection lt dpkg selections list Debian Reference 198 265 10 1 9 A copy script for the data backup For the set of data under a directory tree the copy with cp a provides the normal backup For the set of large non overwritten static data under a directory tree such as the one under the var cache apt packa ges directory hardlinks with cp al provide an alternative to the normal backup with efficient use of the disk space Here is a copy script which I named as bkup for the data backup This script copies all non VCS files under the current directory to the dated directory on the parent directory or on a remote host bin sh e Copyright C 2007 2008 Osamu Aoki lt osamu debian org gt Public Domain aio Coor Eine o Me e Saco UB o Simca VOWS AJ pro O dica Op Ha Ta TT aan y a OS E HT asco alichtie 9 WEST damoel 700 TE T I H a FIND fdot OPT a MODE CPIOP HOST localhost EXTP S hostname f BKUP basename pwd bkup TIME date Y m d HSM S BU SBKUP STIME while getopts gcCsStrlLaAxe h T f do case f in T
327. oc text files AsciiDoc is used as convenience only since it is less typing than straight XML and supports table in the very intuitive format You should think XML and PO files as real source files Via build script it is converted to DocBook XML format and automatically generated data are inserted to form a final Docbook XML source This final Docbook XML source can be converted to HTML plain text PostScript and PDF Currently only HTML and plain text conversions are enabled
328. ocal The whole thing viewed collectively is called the directory tree You can think of an absolute filename as a route from the base of the tree to the end of some branch a file You also hear people talk about the directory tree as if it were a family tree thus subdirectories 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 This terminology also applies to other directory like structures such as hierarchical data structures Debian Reference 8 265 There s no special directory path name component that corresponds to a physical device such as your hard disk This differs from RT 11 CP M OpenVMS MS DOS AmigaOS and Microsoft Windows where the path contains a device name such as C However directory entries do exist that refer to physical devices as a part of the normal filesystem See Section 1 2 2 Note While you can use almost any letters or symbols in a file name in practice it is a bad idea to do so It is better to avoid any characters that often have special meanings on the command line including spaces tabs newlines and other special characters 1 gt lt amp If you want to separate words in a name good choices are the period hyphen and underscore You could also capitalize each word LikeThis
329. ommand needs to be issued with full path as sbin ifconfig Similar ip command is located in bin You can change the PATH environment variable of Bash shell by bash_profile or bashrc files 1 5 4 SHOME variable Many commands stores user specific configuration in the home directory and changes their behavior by their contents The home directory is identified by the environment variable HOME Tip Shell expands to current user s home directory i e SHOME Shell expands foo to foo s home directory i e home foo Debian Reference 27 265 value of HOME program execution situation program run by the init process daemon root program run from the normal root shell home lt normal_user gt program run from the normal user shell home lt normal_user gt program run from the normal user GUI desktop menu home lt normal_user gt program run as root with sudo program root program run as root with sudo H program Table 1 19 List of SHOME values 1 5 5 Command line options Some commands take arguments Arguments starting with or are called options and control the behavior of the command date MONROE ZO ZOO ACE DO OS date R MOZO SE 2003 23702340 O00 Here the command line argument R changes date 1 behavior to output RFC2822 compliant date string 1 5 6 Shell glob Often you want a command to work
330. ommands 0 0 0 0 2 ee 34 Debian Reference vi 2 Debian package management 36 2 1 Debian package management prerequisites o oo o a e 36 2 1 1 Package configuration ee ee eG ee ee 36 2 1 2 Basic precautiopsS 2 4 00 44 004A eee EE Dee ea PAA ee eae ade 38 2 1 3 Life with eternal upgrades 2 ee 38 214 Deblativarchive basics oo msg C 5 bee Ped Sa eee e 39 2 1 5 Packagedependencies ceses dago e R R RR ee R R E 42 2 1 6 The event flow of the package management 20000022 eee eee 43 2 1 7 First response to package management troubles 2 2 2 ee 44 2 2 Basic package management operations 2 1 ee 45 2 2 1 Basic package management operations with commandline oo saoao 45 2 2 2 Interactive se of aptitid s s da sink R ie ee ee ee a e a 46 2 2 3 Key bindings of aptitude sec s pe 24 6 RE Bh ee hed a E e L 46 2 2 4 Package views under aptitude ee 46 2 2 5 Search method options with aptitude 2 ee 48 2 2 6 The aptitude regex formula ooa ee 48 2 2 7 Dependency resolution of aptitude 2 2 ee 50 2 28 Packase activity logs 26 4 5 eo Ge die BR eee EES GBs SRS he das eS 50 2 2 9 Aptitudeadvantages cis c sega Raa ke REG RRB a eae EER GRE RS e Sea wo 50 2 3 Examples of aptitude operations 2 e 51 2 3 1 Listing packages with regex matching on package names o 51 2 3 2 Browsing With the regex matching ee 51 2 3 3 P
331. on getmail 1 configuration is described in getmail documentation Here is my set up to access multiple POP3 accounts as user Create usr local bin getmails as the following Debian Reference 126 265 bin sh set a rcfiles usr bin getmail for file in HOME getmail config x do rcfiles Srcfiles calle Sarai done exec rcfiles Configure it as the following sudo chmod 755 usr local bin getmails mkdir m 0700 SHOME getmail mkdir m 0700 SHOME getmail config mkdir m 0700 SHOME getmail log Create configuration files SHOME getmail config pop3_name for each POP3 accounts as the following retriever type SimplePOP3SSLRetriever server pop example com username pop3_name example com password secret destination type MDA_external path usr bin maildrop unixfrom True options verbose 0 delete True delivered_to Fals message_log getmail log pop3_name log Configure it as the following chmod 0600 SHOME getmail config x Schedule usr local bin getmails to run every 15 minutes with cron 8 by executing sudo crontab e u lt user_name gt and adding following to user s cron entry 5 20 35 50 x x usr local bin getmails quiet Tip Problems of POP3 access may not come from getmail Some popular free POP3 services may be violating the POP3 protocol and their SPAM filter may not be perfect For example the
332. on by sudo etc init d smartmontools restart Tip The smart d 8 daemon can be customized with the etc smartd conf file including how to be notified of warnings 9 3 9 Expansion of usable storage space via LVM For partitions created on Logical Volume Manager LVM Linux feature at install time they can be resized easily by concate nating extents onto them or truncating extents from them over multiple storage devices without major system reconfiguration Caution l Deployment of the current LVM system may degrade guarantee against filesystem corruption offered by journaled filesystems such as ext3fs unless their system performance is sacrificed by disabling write cache of hard disk 9 3 10 Expansion of usable storage space by mounting another partition If you have an empty partition e g dev sdx you can format it with mk fs ext 3 1 and mount 8 it to a directory where you need more space You need to copy original data contents sudo sudo sudo sudo sudo UL Ur Ur UY UY mv work dir old dir mkfs ext3 dev sdx mount t ext3 dev sdx work dir cp a old dir work dir ia ETEL aG LE Tip You may alternatively mount an empty disk image file see Section 10 2 5 as a loop device see Section 10 2 3 The actual disk usage grows with the actual data stored Debian Reference 167 265 9 3 11 Expansion of usable storage space using symlink If you have an empty directory
333. on entry in the etc network inte rfaces file as the following allow hotplug eth0 iface ethO inet static address 192 168 11 100 netas ZOO arcas 192 SM 20 gateway 192 168 11 1 dns domain lan dns nameservers 192 168 11 1 When the Linux kernel detects the physical interface et h0 the allow hotplug stanza causes i fup to bring up the interface and the iface stanza causes ifup to use the static IP to configure the interface Here I assumed the following e IP address range of the LAN network 192 168 11 0 192 168 11 255 Debian Reference 103 265 e IP address of the gateway 192 168 11 1 e IP address of the PC 192 168 11 100 e The resolvconf package installed e The domain name lan s IP address of the DNS server 192 168 11 1 When the resolvconf package is not installed DNS related configuration needs to be done manually by editing the etc resolv conf as the following nameserver 192 168 11 1 domain lan Caution The IP addresses used in the above example are not meant to be copied literally You have to adjust IP numbers to your actual network configuration 5 3 6 The basics of wireless LAN interface The wireless LAN WLAN for short provides the fast wireless connectivity through the spread spectrum communication of unlicensed radio bands based on the set of standards called IEEE 802 11 The WLAN interfaces are almost like normal Ethernet interfaces but require some network
334. on 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 ssh known_hosts on the local host 6 10 Other network application servers Here are other network application servers package popcon size protocol telnetd lA psize1 TELNET telnetd ssl oe psizel1 nfs kernel server ie ae psizel NFS samba ia aaa psizel1 SMB netatalk oe psize1 ATP proftpd basic i aia psizel1 FTP wu ftpd peer psize1 apache2 mpm prefork A psizel1 HTTP apache2 mpm worker A psizel1 squid aa psizel1 squid3 pa psizel1 slpd ae psize1 SLP bind9 ee psize1 DNS dhcp3 server Ce anii psizel1 DHCP Table 6 18 List of other network application servers Common Internet File System Protocol CIFS is the same protocol as Server Message Block SMB and is used widely by Microsoft Windows Tip Use of proxy server such as squid is much more effi
335. on technology to do it Although GNU privacy guard see Section 10 4 can encrypt files it takes some user efforts dm crypt and eCryptfs facilitates automatic data encryption natively via Linux kernel modules with minimal user efforts Dm crypt is a cryptographic filesystem using device mapper Device mapper maps one block device to another eCryptfs is another cryptographic filesystem using stacked filesystem Stacked filesystem stacks itself on top of an existing directory of a mounted filesystem Debian Reference 168 265 package popcon size description cryptsetup as er psize1 utilities for encrypted block device dm crypt LUKS Opopconl ics l cryptmount psize1 utilities for encrypted block device dm crypt LUKS with focu ecryptfs utils popcon1 psize1 utilities for encrypted stacked filesystem eCryptfs Table 9 9 List of data encryption utilities Caution Data encryption costs CPU time etc Please weigh its benefits and costs Note Entire Debian system can be installed on a encrypted disk by the debian installer lenny or newer using dm crypt LUKS and initram s Tip See Section 10 4 for user space encryption utility GNU Privacy Guard 9 4 1 Removable disk encryption with dm crypt LUKS You can encrypt contents of removable mass devices e g USB memory stick on dev sdx using dm crypt LUKS
336. on tools 12 11 Making Debian package If you want to make a Debian package read followings e Chapter 2 to understand the basic package system e Section 2 7 10 to understand basic porting process Debian Reference e Section 9 8 4 to understand basic chroot techniques e debuild 1 pbuilder 1 and pdebuild 1 e Section 12 4 2 for recompiling for debugging e Debian New Maintainers Guide as tutorial the maint guide package e Debian Developer s Reference the developers reference package e Debian Policy Manual the debian policy package There are packages such as dh make dh make perl etc which help packaging 263 265 Debian Reference 264 265 Appendix A Appendix Here are backgrounds of this document A 1 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 LPR printer with non PostScript printer was a good example of stumble points There are no issues anymore since newer installations use new CUPS system 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 to 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 I hope t
337. ones from GNU and BSD display brief help information if you invoke them in one of the following ways or without any arguments in some cases lt commandname gt help lt commandname gt h 1 5 The simple shell command 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 Here I have simplified reality for the newbie See bash 1 for the exact explanation A simple command is a sequence of components 1 Variable assignments optional 2 Command name 3 Arguments optional 4 Redirections optional gt gt gt lt lt lt etc 5 Control operator optional amp amp lt newline gt amp Debian Reference 25 265 1 5 1 Command execution and environment variable Values of some environment variables change the behavior of some Unix commands Default values of environment variables are initially set by the PAM system and then some of them may be reset by some application programs e The display manager such as gdm resets environment variables e The shell in its start up codes resets environment variables in bash_profile and bashrc 1 5 2 SLANG variable The full locale value given to LANG variable consists of 3 parts xx_YY ZZZZ locale value meaning XX ISO 639 language codes lower case such as en YY ISO 3166 country codes upper case such as US YALL codeset
338. onnection with pppconfig 2 2 ee 99 5 2 4 The alternative PPP connection with wvdialconf 0 0 00 00000000004 100 5 2 5 The PPPoE connection with pppoeconf 2 2 0 0 020 ee 100 The basic network configuration with ifupdown 2 ee 101 5 3 1 The command syntax simplified 0 0 0 0 0 0 0000000000000 000 101 5 3 2 The basic syntax of etc network interfaces 2 ee 101 5 3 3 The loopback network interface ee 102 5 3 4 The network interface served by the DHCP o e 102 5 3 5 The network interface with the static IP o o e ee 102 5 3 6 The basics of wireless LAN interface ee 103 5 3 7 The wireless LAN interface with WPA WPA2 o o 103 5 3 8 The wireless LAN interface with WEP 00 00 0000 e 104 2 3 9 The PPP connection lt e e lt e sed t 6 ee Bae ee A A A ee ae ee 104 5 3 10 The alternative PPP connection s se e se 2 0 00 cei atmana ee 104 5 3 11 The PPPoE connection 2 2 E R E R E ee 104 5 3 12 The network configuration stateofifupdown 2 0 0000 2p ee 105 5 3 13 The basic network reconfiguration 2 ee 105 5 3 14 The ifupdown extra package ee 105 The advanced network configuration with ifupdown 2 2 ee 106 24 1 The Hplted package 2 p be bea he oe eR Ee ee a ESE Le RE a 106 942 The Hm tric package cido 24 546 40 4b4 255 44454 howd ees eR ESE A 107 54 3 The virtualinterfac e
339. ons you can access them consistently This is also helpful if you have multiple disks and your BIOS doesn t give them consistent device names e mount 8 with U option can mount a block device using UUID instead of using its file name such as dev sda3 e etc fstab see fstab 5 can use UUID e Boot loaders Section 3 3 may use UUID too Tip You can probe UUID of a block special device with vol_id 8 Tip Device nodes of devices such as removable storage media can be made static by using udev rules if needed See Sec tion 3 5 11 9 3 3 Filesystem configuration For ext3 filesystem the e2 f sprogs package provides the following e mkfs ext 3 8 to create new ext3 filesystem e fsck ext3 8 to check and to repair existing ext3 filesystem e tune2fs 8 to configure superblock of ext3 filesystem The mk f s 8 and sck 8 commands are provided by the e2 f sprogs package as front ends to various filesystem dependent programs mkfs fstype and fsck fstype For ext3 filesystem they are mkfs ext3 8 and fsck ext 3 8 they are hardlinked to mke2 s 8 and e2fsck 8 Similar commands are available for each filesystem supported by Linux Tip Ext3 filesystem is the default filesystem for the Linux system and strongly recommended to use it unless you have some specific reasons not to After Linux kernel 2 6 30 Debian squeeze ext4 filesystem is available and expected to be the default filesystem for the
340. ore it via init script with iptables restore 8 upon system reboot Configuration helper scripts such as shorewall ease this process See documentations at http www netfilter org documentation orin usr share doc iptables html e Linux Networking concepts HOWTO e Linux 2 4 Packet Filtering HOWTO e Linux 2 4 NAT HOWTO Tip Although these were written for Linux 2 4 both iptables 8 command and netfilter kernel function apply for current Linux 2 6 Debian Reference Chapter 6 Network applications 117 265 After establishing network connectivity see Chapter 5 you can run various network applications 6 1 Web browsers There are many web browser packages to access remote contents with Hypertext Transfer Protocol HTTP package popcon size type description of web browser iceweasel E qe psizel X unbranded Mozilla Firefox iceape browser A SS psizel unbrandedMozilla removed due to security co epiphany browser a aks psizel GNOME HIG compliant Epiphany galeon oe eE psizel GNOME Galeon superseded by Epiphany konqueror ad psizel KDE Konqueror w3m di psizel text w3m lynx pa dal psizel Lynx elinks a psizel1 ELinks links ica psizel Links text only links2 a SEO psizel graphics Links console graphics without X Table 6 1 List of web browsers 6 1 1 Browser configuration
341. ormat use CP 932 as the encoding name instead of shi ft JIS to get the expected results 0x5C X and 0x7E gt Otherwise these are converted to wrong characters Tip recode 1 may be used too and offers more than the combined functionality of iconv 1 fromdos 1 todos 1 from mac 1 and tomac 1 For more see info recode Debian Reference 232 265 11 1 2 Checking file to be UTF 8 with iconv You can check if a text file is encoded in UTF 8 with iconv 1 by the following S Leon Sie Weis E Wero dae tee S clewe mmilil echo Vmnon urr 6 ota Tip Use verbose option in the above example to find the first non UTF 8 character 11 1 3 Converting file names with iconv Here is an example script to convert encoding of file names from ones created under older OS to modern UTF 8 ones in a single directory bin sh ENCDN iso 8859 1 EON Se aa sy do mv Sx S echo Sx iconv f SENCDN t utf 8 done The SENCDN variable should be set by the encoding value in Table 11 2 For more complicated case please mount a filesystem e g a partition on a disk drive containing such file names with proper encoding as the mount 8 option see Section 8 3 6 and copy its entire contents to another filesystem mounted as UTF 8 with cp a command 11 1 4 EOL conversion The text file format specifically the end of line EOL code is dependent on the platform
342. ote synchronization and backup unison E Gpopeouh psize1 2 way remote synchronization and backup pdumpfs a banda psizel1 daily local backup using hardlinks similar to Plan9 Table 10 2 List of copy and synchronization tools Copying files with rsync 8 offers richer features than others delta transfer algorithm that sends only the differences between the source files and the existing files in the destination quick check algorithm by default that looks for files that have changed in size or in last modified time U xclude and xclude from options similar to tar 1 a trailing slash on the source directory syntax that avoids creating an additional directory level at the destination Tip Execution of the bkup script mentioned in Section 10 1 9 with the g1 option under cron 8 should provide very similar functionality as pdumpfs for the static data archive Tip Version control system VCS tools in Table 10 16 can function as the multi way copy and synchronization tools Debian Reference 193 265 10 1 3 Idioms for the archive Here are several ways to archive and unarchive the entire content of the directory source using different tools GNU tar 1 SAS ZO O CIA oC s OMICS S Wale OYE HRL ES ej cpio l S Eine Sois ley rrac colo Sony null gt archiva alos I REE EE colo zeat ciclo co cala i afio l S find source xdev print0 afio
343. ou must always use the lowest privilege level possible like a regular user account Easy ways to run a particular X client e g foo as root is to use sudo 8 etc as the following C sudo Too amp S nbel foo amp gksu foo amp S ssh X root localhost foo amp l Caution Use of ssh 1 just for this purpose as above is waste of resource In order for the X client to connect to the X server please note the following e Values of the old user s SXAUTHORITY and SDISPLAY environment variables must be copied to the new user s ones e The file pointed by value of the XAUTHORITY environment variable must be readable by the new user The gksu package popcon pop gksu is a specialized GTK GUI package for gaining the root privileges It can be configured to use su 1 or sudo 8 as its backend depending on the apps gksu sudo mode gconf key You can edit gconf key using gconf editor 1 menu Applications System Tools Configuration Editor Debian Reference 150 265 Chapter 8 Multilingualization M17N or Native Language Support for an application software is done in 2 steps e Internationalization 118N To make a software potentially handle multiple locales e Localization LION To make a software handle an specific locale Tip There are 17 18 or 10 letters between m and n i and n or I and n in multilingualization internationalization and
344. ovZ0 archive afio afio ivZ archive afio 10 1 4 Idioms for the copy Here are several ways to copy the entire content of the directory source using different tools e Local copy source directory dest directory e Remote copy source directory at local host dest directory at user host dom host rsync 8 CAE SOULCC reyne PEE Ce Sits cd source rsync av user host dom dest You can alternatively use a trailing slash on the source directory syntax rsync av source dest rsync av source user host dom dest GNU cp 1 and openSSH scp 1 FC Clary AS OULC Cl anG A o CE Si cd source scp pr user host dom dest GNU tar 1 7 esl of SOUS Ge tar Ci s eel Joest ce tar Saito cd source amp amp tar cf ssh user host dom cd dest amp amp tar xvfp cpio l i Cel soba Eine orcalioic joo Aena null sparse dest afio l E Col y Soun cal Dictar ario 90 cese You can substitude with foo for all examples containing to copy files from source foo directory to des t 00 directory You can substitude with the absolute path path to source foo for all examples containing to drop cd source These will copy files to different locations depending on tools used as follows Debian Reference 194 265 dest foo rsync 8 GNU cp 1 and scp 1 dest path to source foo GNU tar 1 cpio 1 and afio 1 Ti
345. ove example instead of codename stable Q the deb http security d ebian org line for security updates in the etc apt sources list is not required Security updates are only available for stable and testing i e codename stable and codename testing Debian Reference 40 265 archive URL suite nan http ftp XX debian org debian stable http ftp XX debian org debian testinc http ftp XX debian org debian unstab http ftp XX debian org debian experin http ftp XX debian org debian stable http security debian org stable http security debian org testinc http volatile debian org debian volatile volatil http volatile debian org debian volatile volatil http backports org debian code Table 2 2 List of Debian archive sites Debian Reference 41 265 Here is the list of URL of the Debian archive sites and suite name or codename used in the configuration file Caution Only pure stable release with security updates provides the best stability Running mostly stable release mixed with some packages from testing or unstable release is riskier than running pure unstable release If you really need the latest version of some programs under stable release please use packages from the debian volatile project and backports org see Section 2 7 4 services These services must be used with extra care
346. owing find path to mount point xdev inum 2738404 10 3 12 Invisible disk space consumption All deleted but open files consumes disk space although they are not visible from normal du 1 They can be listed with their size by the following lsof s X grep deleted 10 4 Data security infrastructure The data security infrastructure is provided by the combination of data encryption tool message digest tool and signature tool See Section 9 4 on dm crypto and ecryptfs which implement automatic data encryption infrastructure via Linux kernel modules 10 4 1 Key management for GnuPG Here are GNU Privacy Guard commands for the basic key management Here is the meaning of the trust code The following uploads my key A8061F32 to the popular keyserver hkp subkeys pgp net S gpg keyserver hkp subkeys pgp net send keys A8061F32 A good default keyserver set up in gnupg gpg conf or old location gnupg options contains the following keyserver hkp subkeys pgp net Debian Reference 212 265 command package popcon size description gpg 1 gnupg ans psize2 GNU Privacy Guard OpenPGP N A gnupg doc a peones psize2 GNU Privacy Guard documentati gpgv 1 gpgv ME psize2 GNU Privacy Guard signature v paperkey 1 paperkey A aaia psize2 extract just the secret information cryptsetup 8 cryptsetup re cal psize2 utilities for dm cry
347. p rsync 8 and GNU cp 1 have option u to skip files that are newer on the receiver 10 1 5 Idioms for the selection of files find 1 is used to select files for archive and copy commands see Section 10 1 3 and Section 10 1 4 or for xargs 1 see Section 9 5 9 This can be enhanced by using its command arguments Basic syntax of find 1 can be summarized as the following Its conditional arguments are evaluated from left to right This evaluation stops once its outcome is determined Logical OR specified by o between conditionals has lower precedence than logical AND specified by a or nothing between conditionals Logical NOT specified by before a conditional has higher precedence than logical AND prune always returns logical TRUE and if it is a directory searching of file is stopped beyond this point name matches the base of the filename with shell glob see Section 1 5 6 but it also matches its initial with metachar acters such as x and 7 New POSIX feature regex matches the full path with emacs style BRE see Section 1 6 2 as default size matches the file based on the file size value precedented with for larger precedented with for smaller e newer matches the file newer than the one specified in its argument e print0 always returns logical TRUE and print the full filename null terminated on the standard output find 1 is often used with
348. packages to adapt to many kinds of Unix like systems using the entire GNU build system won autoconf 1 produces the configuration script configure configure automatically creates a customized Makef ile using the Makefile in template Debian Reference 261 265 12 7 1 Compile and install a program Warning Do not overwrite system files with your compiled programs when installing them Debian does not touch files in usr local or opt Soif you compile a program from source install it into usr local so it does not interfere with Debian cel size S configure prefix usr local make make install this puts the files in the system 12 7 2 Uninstall program If you have the original source and if it uses autoconf 1 automake 1 and if you can remember how you configured it execute as follows to uninstall the program configure all of the options you gave 1t make uninstall 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 the following find usr local type f printO xargs 0 rm f If you are not sure where files are installed you should consider using checkinstal1 8 from the checkinstall package which provides a clean path for the uninstall It now supports to create a Debian package with D option 12 8 Perl short script ma
349. password guessing attack etc from the Internet Use of the firewall policy see Section 5 8 together with the following secure tools may improve the security situation package popcon size description knockd i aes psizel1 small port knock daemon knocka 1 and client konck 1 denyhosts a portones psize1 utility to help sysadmins thwart ssh hackers fail2ban OA E psize1 ban IPs that cause multiple authentication errors libpam shield popcon psize1 lock out remote attackers trying password guessing Table 4 8 List of tools to provide extra security measures 4 7 4 Securing the root password To prevent people to access your machine with root privilege you need to make following actions e Prevent physical access to the hard disk e Lock BIOS and prevent booting from the removable media e Set password for GRUB interactive session e Lock GRUB menu from editing With physical access to hard disk resetting the password is relatively easy with following steps Debian Reference 93 265 1 Move the hard disk to a PC with CD bootable BIOS 2 Boot system with a rescue media Debian boot disk Knopix CD GRUB CD 3 Mount root partition with read write access 4 Edit etc passwad in the root partition and make the second entry for the root account empty If you have the edit access to the GRUB menu entry see Section 3 3 for grub rescue pc at the
350. pe 1 font package popcon size sans serif font PostScript N A N A Helvetica gsfonts Perea he psizel Nimbus Sans L gsfonts x11 popcon1 psizel Nimbus Sans L tl cyrillic popcon1 psizel Free Helvetian Imodern popcon1 psizel LMSans Table 7 5 Table of corresponding PostScript Type 1 fonts Tip DejaVu fonts are based on and superset of Bitstream Vera fonts Debian Reference 145 265 font package popcon size sans serif font ttf mscorefonts installer GR Grait psizel Arial ttf liberation ERa apreni psizel1 Liberation Sans ttf freefont pea TOS psizel FreeSans ttf dejavu a eae psizel DejaVu Sans ttf dejavu core A e psizel DejaVu Sans ttf dejavu extra oe psizel N A ttf unifont a psizel N A Table 7 6 Table of corresponding TrueType fonts 7 6 2 Additional fonts apt itude 8 helps you find additional fonts easily e The short package list under Tasks Localization e The filtered flat package list of font data with regex on debtag Gmade of data font e The filtered flat package list of the BDF bitmap font packages with regex on package name nxfonts e The filtered flat package list of the TrueType outline font packages with regex on package name ntt f Since Fre
351. plication servers ee 134 6 11 Other network application clients 135 6 12 The diagnosis of the system daemons 2 2 0 ee 135 Debian Reference 7 1 7 2 7 3 7 4 7 5 7 6 7 1 7 8 8 I18N and LION 8 1 8 2 8 3 7 The X Window System Key packages mais ee ae Bute OSs ee SPER aoe A SRE BRU Cee See ae Ee bee Setting up desktop environment 2 2 a 1 2 1 MSDN menti crm a See ROR we E a e EA h RS a ek Be we 722 Freedesktop org menu 1 ee 7 2 3 Debian menu under GNOME desktop environment The server client relationship THE X Server won oo oa a ee Rew ae a Eo ae eee ea Dee ea de ew a ee ee be 7 4 1 The re configuration of the X server ee 7 4 2 The connection methods tothe X server ee Starting the X Window System 2 9 R RRR R RR R RRR RR R RRR RR RR RR e a 7 5 1 Starting X session With gdm s p s sace R R E p Ae R R NR R RR RR L 7 5 2 Customizing the X session classic method o ee 7 5 3 Customizing the X session new method pe ee ee 7 5 4 Connecting a remote X client via SSH ee 7 5 5 Secure X terminal via the Internet ee ee Fonts in the X Window 2 ee POA Basictonts lt a A OE Bw E Ee es ew E Be eae ds P Additional fonts Lares A ee a Bs aOR eS RAG DA Re ee Re A ee A 7 6 3 e r fonts so ee Re ER Ee Ree ERE ee RE ii a X Applications panpa e Boek R Site eee ek Se e Eh ae ee ele doa ee Be Seek Ae N iA of
352. ponents to configure character console and ncurses 3 system features s The etc terminfo x x file terminfo 5 s The STERM environment variable t erm 7 e setterm 1 stty 1 tic 1 and toe 1 If the terminfo entry for xterm doesn t work with a non Debian xterm change your terminal type TERM from xte rm to one of the feature limited versions such as xt erm r6 when you log in to a Debian system remotely See usr s hare doc libncurses5 FAQ for more dumb is the lowest common denominator for TERM Debian Reference 179 265 9 6 7 The sound infrastructure Device drivers for sound cards for current Linux 2 6 are provided by Advanced Linux Sound Architecture ALSA ALSA provides emulation mode for previous Open Sound System OSS for compatibility Run dpkg reconfigure linux sound base to select the sound system to use ALSA via blacklisting of kernel mod ules Unless you have very new sound hardware udev infrastructure should configure your sound system Tip Use cat dev urandom gt dev audio or speaker test 1 to test speaker C to stop Tip If you can not get sound your speaker may be connected to a muted output Modern sound system has many outputs alsamixer 1 in the alsa utils package is useful to configure volume and mute settings Application softwares may be configured not only to access sound devices directly but also to access them via some standardized sou
353. pp DHCP described in etc dhcp3 dhclient conf dhcp3 client static IP IPv4 described in etc network interfaces net tools static IP IPv6 described in etc network interfaces iproute Table 5 4 List of network connection configurations The network connection acronyms mean the following acronym meaning POTS plain old telephone service BB broadband BB service e g the digital subscriber line BB modem e g the DSL modem the cabl LAN local area network WAN wide area network DHCP dynamic host configuration pr PPP point to point protocol PPPoE point to point protocol over El ISP Internet service provider Table 5 5 List of network connection acronyms Debian Reference 99 265 Note The WAN connection services via cable TV are generally served by DHCP or PPPoE The ones by ADSL and FTTP are generally served by PPPoE You have to consult your ISP for exact configuration requirements of the WAN connection Note When BB router is used to create home LAN environment PCs on LAN are connected to the WAN via BB router with network address translation NAT For such case PC s network interfaces on the LAN are served by static IP or DHCP from the BB router BB router must be configured to connect the WAN following the instruction by your ISP 5 2 1 The DHCP connection with the Ethernet The typical modern home and small business network i e LAN are connected to the WAN Internet using some consumer grade broa
354. pposed to be solution for formatting The fop package is in the Debian contrib not main archive still So the LaTeX code is usually generated from XML using XSLT and the LaTeX system is used to create printable file such as DVI PostScript and PDF Since XML is subset of Standard Generalized Markup Language SGML it can be processed by the extensive tools available for SGML such as Document Style Semantics and Specification Language DSSSL Tip GNOMEyelp is sometimes handy to read DocBook XML files directly since it renders decently on X Debian Reference 237 265 package popcon size keyword description docbook xml ii eE psizel xml XML document type definition DTD for DocBoo xsltproc eee S psizel xslt XSLT command line processor XML XML HT docbook xs1l ae SS psizel xml xslt XSL stylesheets for processing DocBook XML to xmlto S SE psizel xml xslt XML to any converter with XSLT dblatex a SEE psizel xml xslt convert Docbook files to DVI PostScript PDF doc fop er GS psizel xml xsl fo convert Docbook XML files to PDF Table 11 8 List of XML tools package popcon size keyword description openjade S O psize1 dsss ISO IEC 10179 1996 standard DSSSL processor openjadel 3 or psizel dsssl ISO IEC 10179 1996 standard DSSSL processor jade eee psize1 dsssl James Clark s original DSSSL processo
355. processes using files or sockets 2 ee 172 9 5 8 Repeating a command with a constant interval eee 172 9 5 9 Repeating a command looping over files o aaa o 173 9 5 10 Starting a program from GU 20 2 000000 2 ee ee 173 9 5 11 Customizing program to be started ee 174 9512 Killing process 8 aoe hh PRS See eee eee ee hee SS Ae eee sf 174 9 5 13 Scheduling tasks once c e e e ee 174 9 5 14 Scheduling tasks regularly e e R ee 175 9515 AlESYsRq key rr Rd Sak A A 48 175 9 6 System Malntenance tips lt cc E A AR A e da 176 9 6 1 Wholsonthesystem ss eo 0 00 52 Re eG a A ee eee 176 9 6 2 Warningeveryone R e RR R R RRR RRR RR RRR e RRR RR 176 9 6 3 Hardware identification eos e pe o ER N RRR R RRR R RR 0 176 9 64 Hardware configuration ose sy sea ide ee GE BS BS ARE 178 9 6 5 System and hardware time 2 2 2 ee 178 9 6 6 The terminal configuration ooa ee 178 9 6 7 The sound infrastructure se soes eue a ee E a ee 179 9 6 8 Disabling the screensaver e e ee 179 9 6 9 Disabling beep sounds 2 2 2 2 0 0 2 ee 179 9 6 10 Memory usage ces OG Ge a a e a Bee ae a ea 179 9 6 11 System security and integrity check aoaaa ee 181 Ov Thekemel s siasio i 20546668 44058 4590465564248 4 oh ES G4 182 971 Linux kemel 2 6 es cee enh dw ee Pee ke ee ee ee ee a bea ee eas oe 182 9 7 2 Kernel parameters sos ec Ra R 2 ba ee AA RS RR RR RG EEE Ra RG eke a 182 9 7 3 Kernel headers eco K
356. pto block devi ecryptfs 7 ecryptfs utils an psize2 utilities for ecryptfs stacked files md5sum 1 coreutils ieee psize2 compute and check MD5 messag shalsum 1 coreutils da psize2 compute and checks SHAI mess openss1 1ssl openssl Get a aiai psize2 compute message digest with ox Table 10 11 List of data security infrastructure tools command description gpg gen key generate a new key gpg gen revoke my_user_ID generate revoke key for my_user_ID gpg dit key user_ID edit key interactively help for help 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 refresh keys update local keyring Table 10 12 List of GNU Privacy Guard commands for the key management description of trust no owner trust assigned not yet calculated trust calculation failed not enough information for calculation never trust this key marginally trusted fully trusted ultimately trusted Table 10 13 List of the meaning of the trust code Debian Re
357. put to a file the default is gdb txt Table 12 12 List of advanced gdb commands 12 4 5 Debugging X Errors If a GNOME program preview1 has received an X error you should see a message as follows The program previewl received an X Window System error If this is the case you can try running the program with sync and break on the gdk_x_error function in order to obtain a backtrace 12 4 6 Check dependency on libraries Use 1dd 1 to find out a program s dependency on libraries by the followings S ele forms AS O AA Es o OEA O OSO libc so 6 gt lib libc so 6 0x40030000 libpthread so 0 gt lib libpthread so 0 0x40153000 lib ld linux so 2 gt lib 1d linux so 2 0x40000000 For 1s 1 to work in a chroot ed environment the above libraries must be available in your chroot ed environment See Section 9 5 6 Debian Reference 259 265 package popcon size description libc dev 4 Gropeenh psize1 mtrace 1 malloc debugging functionality in glibc valgrind ee S psize1 memory debugger and profiler kmt race a aie psize1 KDE memory leak tracer using glibe s mt race 1 alleyoop a ania Opsizel0 GNOME front end to the Valgrind memory checker lectric fenc popcon1 psize1 malloc 3 debugger leaktracer popcon1 psize1 memory leak tracer for C programs libdmalloc5
358. quired pam_ecryptfs so unwrap Insert the following line just at the last line in etc pam d common session session optional pam_ecryptfs so unwrap Insert the following line at first active line in etc pam d common password Debian Reference 170 265 password required pam_ecryptfs so This is quite convenient s Warning Configuration errors of PAM may lock you out of your own system See Chapter 4 Caution If you use your login password for wrapping encryption keys your encrypted data are as secure as your user login password see Section 4 3 Unless you are careful to set up a strong password your data is at risk when someone runs password cracking software after stealing your laptop see Section 4 7 4 9 5 Monitoring controlling and starting program activities Program activities can be monitored and controlled using specialized tools Tip The procps packages provide very basics of monitoring controlling and starting program activities You should learn all of them 9 5 1 Timing a process Display time used by the process invoked by the command time some_command gt dev null real 0m0 035s time on wall clock elapsed real time user 0m0 000s time in user mode sys 0m0 020s time in kernel mode 9 5 2 The scheduling priority A nice value is used to control the scheduling priority for the process nice 19 top very nice nice 20 wodim v e
359. r 1 2 x s popcon lt docbook dsssl o psize1 xml dsssl DSSSL stylesheets for processing DocBook XM ear ae popcon1 utilities for DocBook files including conversion 1 docbook utils psizel1 xml dsssl commands with DSSSL sgml2x lia psizel SGML dsssI converter from SGML and XML using DSSSL s Table 11 9 List of DSSL tools Debian Reference 11 2 3 The XML data extraction You can extract HTML or XML data from other formats using followings 238 265 package popcon size keyword description wv a oreo psizel MSWord any document converter from Microsoft Word texi2html G SE psizel texi html converter from Texinfo to HTML man2html Pa SE psizel manpage html converter from manpage to HTML CGI s tex4ht anada psizel tex gt html converter between La TeX and HTML x1html ay epeonhee psizel MSExcel html converter from MSExcel xls to HTML ppthtml E popconl psizel MSPowerPoint gt html converter from MSPowerPoint to HTML unrtf o Opeon O psizel rtf html document converter from RTF to HTML e info2www ae psize1 info html converter from GNU info to HTML CGI s ooo2dbk ae anda psizel sxw xml converter from OpenOffice org SXW docu wp2x S epconnee psizel WordPerfect any WordPerfect 5 0 and 5 1 files to TeX LaTe doclifter a aai psizel troff xm
360. r and BTS of wicd for current issues and limitations The configuration of NM is described in usr share doc network manager README Debian Essentially this is as follows 1 Make desktop user e g foo belong to group net dev by the following sudo adduser foo netdev 2 Keep configuration of etc network interfaces as simple as the the following auto lo iface lo inet loopback auto eth0 iface eth0 inet dhcp 3 Restart NM by the following sudo etc init d network manager restart Note Only interfaces which are not listed in etc network interfaces or which have been configured with auto or allow hotplug and iface inet dhcp with no other options are managed by NM to avoid conflict with i fupdown The configuration of Wicd is described in usr share doc wicd README Debian Essentially this is as follows 1 Make configuration in etc network interfaces only as the following Debian Reference 113 265 auto lo iface lo inet loopback 2 Restart Wicd as the following sudo etc init d wicd restart 5 6 The low level network configuration 5 6 1 Iproute2 commands Iproute2 commands offer complete low level network configuration capabilities Here is a translation table from obsolete net tools commands to new iproute2 etc commands obsolete net tools new iproute2 etc manipulation ifconfig 8 ip addr p
361. re n lt amp and n gt amp mean to close the file descriptor n The file descriptor 0 2 are predefined device description file descriptor stdin standard input 0 stdout standard output 1 stderr standard error 2 Table 1 23 Predefined file descriptors 1 5 9 Command alias You can set an alias for the frequently used command For example try the following alias la ls la Now la works as a short hand for 1s 1a which lists all files in the long listing format You can list any existing aliases by alias see bash 1 under SHELL BUILTIN COMMANDS S aias alias la 1s la You can identity exact path or identity of the command by t ype see bash 1 under SHELL BUILTIN COMMANDS For example try the following Debian Reference 30 265 type ls ls e bashed Moim Ls type la la is aliased to ls la type echo echo is a shell builtin type file silo is fusion calles 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 Tip See Section 9 2 7 1 6 Unix like text processing In Unix like work environment text processing is done by piping text through chains of standard text processing tools This was another crucial Unix innovation 1 6 1 Unix text tools There are few standard text processing tools which are used very often on the Unix like sy
362. read manpage of hdparam 8 before playing with hard disk configuration because this may be quite dangerous for the data integrity You can test disk access speed of a hard disk e g dev hda by hdparm tT dev hda For some hard disk con nected with E IDE you can speed it up with hdparm q c3 d1 ul m16 dev hda by enabling the E IDE 32 bit I O support enabling the using dma flag setting interrupt unmask flag and setting the multiple 16 sector I O dangerous You can test write cache feature of a hard disk e g dev sda by hdparm W dev sda You can disable its write cache feature with hdparm W 0 dev sda You may be able to read badly pressed CDROMs on modern high speed CD ROM drive by slowing it down with setcd x 2 Debian Reference 166 265 9 3 8 Using SMART to predict hard disk failure You can monitor and log your hard disk which is compliant to SMART with the smart d 8 daemon 1 Enable SMART feature in BIOS 2 Install the smartmontools package 3 Identify your hard disk drives by listing them with df 1 s Let s assume a hard disk drive to be monitored as dev hda 4 Check the output of smartctl a dev hda to see if SMART feature is actually enabled e If not enable it by smartctl s on a dev hda 5 Enable smart d 8 daemon to run by the following e uncomment start_smartd yes in the etc default smartmontools file e restart the smart d 8 daem
363. rite X window session managers 7 5 3 Customizing the X session new method Here are new methods to customize the X session without completely overriding the system code as above e The display manager gdm can select a specific session and set it as the argument of etc X11 Xsession e The xsessionrc file is executed as a part of start up process desktop independent e The gnomerc file is executed as a part of start up process GNOME desktop only e The GUI program based session management software may use the gnome2 session file etc Debian Reference 142 265 7 5 4 Connecting a remote X client via SSH The use of ssh X enables a secure connection from a local X server to a remote application server Set X11Forwarding entries to yes in etc ssh sshd_config of the remote host if you want to avoid X command line option Start the X server on the local host Open an xterm in the local host Run ssh 1 to establish a connection with the remote site as the following localname localhost ssh q X loginname remotehost domain Password Run an X application command e g gimp on the remote site as the following loginname remotehost gimp amp This method can display the output from a remote X client as if it were locally connected through a local UNIX domain socket 7 5 5 Secure X terminal via the Internet Secure X terminal via the Internet which displays remotely run entire X
364. rity check The mk s 8 command creates the filesystem on a Linux system The sck 8 command provides the filesystem integrity check and repair on a Linux system Caution It is generally not safe to run fsck on mounted filesystems Tip Check files in var log fsck for the result of the sck 8 command run from the boot script Tip Use shutdown F r now to force to run the sck 8 command safely on all filesystems including root filesystem on reboot See the shut down 8 manpage for more 9 3 5 Optimization of filesystem by mount options Performance and characteristics of a filesystem can be optimized by mount options used on it see fst ab 5 and mount 8 Notable ones are the following e defaults option implies default options rw suid dev exec auto nouser async general e noatime or relatime option is very effective for speeding up the read access general e user option allows an ordinary user to mount the filesystem This option implies noexec nosuid nodev option combination general used for CD and floppy Debian Reference 165 265 e noexec nodev nosuid option combination is used to enhance security general e noauto option limits mounting by explicit operation only general e data journal option for ext3fs can enhance data integrity against power failure with some loss of write speed Tip You need to provide kernel boot p
365. rotocol IP or IPv6 address on a device route 8 ip route routing table entry arp 8 ip neigh ARP or NDISC cache entry ipmaddr ip maddr multicast address iptunnel ip tunnel tunnel over IP nameif 8 ifrename 8 name network interfaces based on MAC addresses mii tool 8 ethtool 8 Ethernet device settings Table 5 15 Translation table from obsolete net t cols commands to new iproute2 commands See ip 8 and IPROUTE2 Utility Suite Howto 5 6 2 Safe low level network operations You may use low level network commands as follows safely since they do not change network configuration Tip Some of these low level network configuration tools reside in sbin You may need to issue full command path such as sbin ifconfig oradd sbin to the PATH list in your bashrc 5 7 Network optimization Generic network optimization is beyond the scope of this documentation I touch only subjects pertinent to the consumer grade connection 5 7 1 Finding optimal MTU The Maximum Transmission Unit MTU value can be determined experimentally with ping 8 with M do option which sends ICMP packets with data size starting from 1500 with offset of 28 bytes for the IP ICMP header and finding the largest size without IP fragmentation For example try the following Debian Reference 114 265 command description ifconfig display the link and address status of active interfaces ip addr show display the link and addr
366. rror Table 12 4 List of shell parameter expansions parameter substitution form result S var suffix remove smallest suffix pattern S vars suffix remove largest suffix pattern S var prefix remove smallest prefix pattern S tvar t prefix remove largest prefix pattern Table 12 5 List of key shell parameter substitutions Debian Reference 251 265 12 1 3 Shell conditionals Each command returns an exit status which can be used for conditional expressions e Success 0 True e Error non 0 False Note 0 in the shell conditional context means True while O in the C conditional context means False Note is the equivalent of the test command which evaluates its arguments up to as a conditional expression Basic conditional idioms to remember are followings e lt command gt amp amp lt if_success_run_this_command_too gt true e lt command gt lt if_not_success_run_this_command_too gt true e A multi line script snippet as the following if lt conditional_expression gt then lt if_success_run_this_command gt else lt if_not_success_run_this_command gt inal Here trailing true was needed to ensure this shell script does not exit at this line accidentally when shell is invoked with Lo flag equation condition to return logical true e lt file gt lt file gt exists d lt file gt lt file gt exists and is a directory f
367. s BAR wh ed AA ae eee Be Se Be dle amp 4 z 1 2 1 Umme basics s oog gcs eee er a ee ee ee ee a pa 7 1 2 2 Filesystem internals 2 seare e ORR ee a e e e ee ea eee 8 1 2 3 Filesystem permissions lt se e ee 5 1 2 4 Control of permissions for newly created files umask o o 11 1 2 5 Permissions for groups of users group 2 ee 11 1 2 6 S T lt eaga 4 re ook ea RE ee ee a Lee E a 12 LAT Links 42434228 dad sd a i PEERS SE a dee ES Lg 1 2 8 Named pipes FIFOs o sa cepere RRR RRR RRR RRR R RRR RR R a 14 12 9 Sockets ice A A dl a a ee 14 1 2 10 Devices s e e ir a a a de 15 1 2 11 Special device Heg sp a sonk ZE KRK RE A A OE T T a 15 1212 procts and SYS S sam i ds A e A 16 1 3 Midnight Commander MO a pe e R TE R RE R RR R RR K ee 16 1 3 1 Customizaton AMC ce sead ewe eek ua Ed R R RE NR NT RRR R R R R NR R 17 Debian Reference 1 4 1 5 1 6 v 1 3 2 Starting MC ec os rr e RET RN E ds eS 17 1 33 Fil ma ager nME ss sooi a bk QR BARES DERE ATR RR RRR da A as ae 17 1 3 4 Command line tricks in MC 2 ee IK 1 3 5 The internal editoriiME Wes scsi RN RR Dee ee a VR eee RRR 18 1 3 6 Theanternal viewer in MC RRR RR ee a a N 18 1 3 7 Auto startfeaturesofMC 2 ee 18 1 3 8 FTP virtual filesystemofMC c ereere estas 00000022 Eee e ee 19 The basic Unix like work environment oaoa ee 19 141 Thelogin shelll e exo A AA 2 ee e EAE eA 19 1 42 Customizing bashes es
368. s 5 Thus apt pinning works sl only with code name for volatile Debian archives This is different from other Debian archives For example you can do Pin release a codename stable but can not do Pin release a stable in the etc apt preferences file for volatile Debian archives Here is an example of apt pinning technique to include specific newer upstream version packages found in codename stablel f backports while tracking codename stable and volatile You list all required archives in the etc apt sources list file as the following deb http ftp us debian org debian codename stable main contrib non free deb http security debian org codename stable updates main contrib deb http volatile debian org debian volatile codename stable volatile main contrib gt non free deb http volatile debian org debian volatile codename stable volatile sloppy main contrib non free deb http backports org debian codename stable backports main contrib non free The default Pin Priority value for backports org and volatile sloppy archives are always 1 lt lt 100 since they are NotAu tomatic archive see Section 2 5 3 There is no need to set Pin Priority value explicitly in the etc apt preferences file just to use for backports org and volatile sloppy archive unless you wish to track packages automatically for next upgrading So whenever you wi
369. s owner or root account to change file and directory access permissions Basic syntax to manipulate a foo file is the following Debian Reference 10 265 chown lt newowner gt foo chgrp lt newgroup gt foo chmod ugoa rwxXst foo For example you can make a directory tree to be owned by a user foo and shared by a group bar by the following cd some location chown R foo bar chmod R ug rwX o rX There are three more special permission bits The set user ID bit s or S instead of user s x s The set group ID bit s or S instead of group s x e The 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 prevents a file in the directory from being removed by a user who is not the owner of the file In order to secure contents of a file in world
370. s their action and ends up with partially installed packages When a package contains bugs in its removal scripts the package may become impossible to remove and quite nasty For the package script problem of lt package_name gt you should look into following package scripts Debian Reference 62 265 e var lib dpkg info lt package_name gt preinst e var lib dpkg info lt package_name gt postinst e var lib dpkg info lt package_name gt prerm e var lib dpkg info lt package_name gt postrm Edit the offending package script from the root using following techniques e disable the offending line by preceding 1 e force to return success by appending the offending line with true Configure all partially installed packages with the following command dpkg configure a 2 6 4 Rescue with the dpkg command Since dpkg is very low level package tool it can function under the very bad situation such as unbootable system without network connection Let s assume foo package was broken and needs to be replaced You may still find cached copies of older bug free version of foo package in the package cache directory var cache a pt archives If not you can download it from archive of http snapshot debian net or copy it from package cache of a functioning machine If you can boot the system you may install it by the following command dpkg i path to foo_ lt old_version gt _ lt arch gt d
371. s very powerful type setting tool and is the de facto standard LaTeX originally written by Leslie Lamport enables a high level access to the power of TeX package popcon size keyword description texlive S SEO psize1 La TeX TeX system for typesetting previewing and printing groff ES S psizel1 troff GNU troff text formatting system Table 11 14 List of type setting tools 11 4 1 roff typesetting Traditionally roff is the main Unix text processing system See roff 7 groff 7 grof 1 grotty 1 troff 1 gro ff _mdoc 7 groff_man 7 groff_ms 7 groff_me 7 groff_mm 7 and info groff You can read or print a good tutorial and reference on me macro in usr share doc groff by installing the groff package Tip groff Tascii me produces plain text output with ANSI escape code If you wish to get manpage like output with many H and _ use GROFF_NO_SGR 1 groff Tascii me instead Tip To remove H and _ from a text file generated by groff filter it by col b x 11 4 2 TeX LaTeX The TeX Live software distribution offers a complete TeX system The texlive metapackage provides a decent selection of the TeX Live packages which should suffice for the most common tasks There are many references available for TeX and LaTeX Debian Reference 242 265 s The teTeX HOWTO The Linux teTeX Local Guide e tex 1 e latex l e The TeXbook by Do
372. sconnected again Let s move your PC to a location without LAN or BB modem but with POTS and modem You bring up the network interface pppo by assigning the network configuration name pots to it by the following S sudo ifup ppp0 pots The interface ppp0 is up and connected to the Internet with PPP sudo ifdown ppp0 pots The interface pppO is down and disconnected from the Internet You should check the etc network run ifstate file for the current network configuration state of the ifupdown system e Warning You may need to adjust numbers at the end of ethx ppp etc if you have multiple network interfaces 5 4 7 Scripting with the ifupdown system The ifupdown system automatically runs scripts installed in etc network x while exporting environment variables to scripts Here each environment variable SIF_ lt OPTION gt is created from the name for the corresponding option such as lt option1 gt and lt option2 gt by prepending IF_ converting the case to the upper case replacing hyphens to underscores and discarding non alphanumeric characters Tip See Section 5 3 2 for lt address_family gt lt method_name gt lt option1 gt and lt option2 gt The ifupdown ext ra package see Section 5 3 14 uses these environment variables to extend the functionality of the i f updown package The i fmet ric package see Section 5 4 2 installs the etc network if up d ifmetric script which
373. screen E EPOPEA E psize1 terminal multiplexer with VT100 ANSI terminal emulation Table 9 1 List of programs to support interrupted network connections 9 1 1 The use scenario for screen 1 screen 1 not only allows one terminal window to work with multiple processes but also allows remote shell process to survive interrupted connections Here is a typical use scenario of screen 1 1 You login to a remote machine 2 You start screen on a single console 3 You execute multiple programs in screen windows created with A c Control A followed by c NH mn A e Brutally unplug your network connection You switch among the multiple screen windows by A n Control A followed by n Suddenly you need to leave your terminal but you don t want to lose your active work by keeping the connection You may detach the screen session by any methods e Type A d Control A followed by d and manually logging out from the remote connection e Type A DD Control A followed by DD to have screen detach and log you out 7 You log in again to the same remote machine even from a different terminal 8 You start screen as screen r Debian Reference 9 screen magically reattaches all previous screen windows with all actively running programs Tip You can save connection fees with screen for metered network connections such as dial up and packet ones because you can leave a process activ
374. sh to install a package named lt package name gt with its dependency from fcodename stabl e backports archive you use following command while switching target release with t option sudo apt get install t codename stable backports lt package name gt If you wish to upgrade particular packages you must create the etc apt preferences file and explicitly lists all pack ages in it as the following Debian Reference 69 265 Package lt package 1 gt Pin release o Backports org archive Paros ADO Package lt package 2 gt Pin release o volatile debian org E BII E Alternatively with the etc apt preferences file as the following Package Pin release a stable o Debian Piar orales S00 Package x Pin release a codename stable o volatile debian org Pacos 00 Package x Pin release a codename stable backports o Backports org archive Daia e HEE 2010 Package x Pin release a codename stable sloppy o volatile debian org ESOS yz 010 Execution of apt get upgrade and apt get dist upgrade or aptitude safe upgrade and aptit ude full upgrade for squeeze upgrades packages which were installed from stable archive using current stable archive and packages which were installed from other archives using current corresponding archive for all archives in the e tc apt sources list file 2 7 5 Automatic download and upgrade of packages T
375. sion site URL file srv svn project e Subversion directory modulel1 trunk Subversion tag module1l tags Release initial cd path to modulel svn import file srv svn project modulel trunk m Start modulel svn cp file srv svn project modulel trunk file srv svn project modulel tags Release gt TEI Alternatively by the following svn import path to modulel file srv svn project modulel trunk m Start modulel svn cp file srv svn project modulel trunk file srv svn project modulel tags Release gt ne ek Tip You can replace URLs such as file by any other URL formats such as http and svn ssh 10 8 7 Work flow of Subversion Here is an example of typical work flow using Subversion Check all available modules from Subversion project pointed by URL file srv svn project by the following svn list file srv svn project modulel module2 Debian Reference 225 265 Checkout modulel trunk to a directory nodule1 by the following S cd path to svn co file srv svn project modulel trunk modulel cd modulel Make changes to the content as needed Check changes by making diff u repository local equivalent by the following SNS You find that you broke some file file_to_undo severely but other files are fine Overwrite file_to_undo file with the clean copy from Subversion by the following svn revert file _to_undo Save
376. sizel ms tnef unpacking MIME attachments of type applicatio uudeview al SETS psizel mail encoder and decoder for the following formats ut readpst i eas ue psizel PST convert Microsoft Outlook PST files to mbox forr Table 11 16 List of packages to help mail data conversion 11 5 1 Mail data basics Mail SMTP data should be limited to 7 bit So binary data and 8 bit text data are encoded into 7 bit format with the Multipurpose Internet Mail Extensions MIME and the selection of the charset see Section 8 3 1 The standard mail storage format is mbox formatted according to RFC2822 updated RFC822 See mbox 5 provided by the mutt package For European languages Content Transfer Encoding quoted printable with the ISO 8859 1 charset is usually used for mail since there are not much 8 bit characters If European text is encoded in UTF 8 Content Tran sfer Encoding quoted printable is likely to be used since it is mostly 7 bit data For Japanese traditionally Content Type text plain charset 1S0 2022 JP is usually used for mail to keep text in 7 bits But older Microsoft systems may send mail data in Shift JIS without proper declaration If Japanese text is encoded in UTF 8 Base64 is likely to be used since it contains many 8 bit data The situation of other Asian languages is similar Note If your non Unix mail data is accessible by a non Debian client software which can talk to the
377. sizel ps pdf text extract text from PostScript and PDF files unhtml Pe Gaan psizel html text remove the markup tags from an HTML file odt2txt G Sporn psizel odt text converter from OpenDocument Text to text wpd2sxw SHO E psizel WordPerfect sxw WordPerfect to OpenOffice org StarOffice wr Table 11 5 List of tools to extract plain text data 11 1 8 Highlighting and formatting plain text data You can highlight and format plain text data by the following 11 2 XML data The Extensible Markup Language XML is a markup language for documents containing structured information See introductory information at XML COM e What is XML e What Is XSLT e What Is XSL FO e What Is XLink 11 2 1 Basic hints for XML XML text looks somewhat like HTML It enables us to manage multiple formats of output for a document One easy XML system is the docbook xs1 package which is used here Each XML file starts with standard XML declaration as the following lt xml version 1 0 ncoding UTF 8 gt The basic syntax for one XML element is marked up as the following Debian Reference 235 265 package popcon size keyword description vim runt ime a CPOPO psizel highlight Vim MACRO to convert source code to H1 cxref S openi psizel c html converter for the C program to latex and H src2tex
378. so capable for non X environment 8 1 2 An example for Japanese I find the Japanese input method started under English environment en_US UTF 8 very useful Here is how I did this with SCIM 1 Install the Japanese input tool package scim anthy with its recommended packages such as im switch Execute im switch c from user s shell and select scim Relogin to user s account Verify setting by im switch 1 Setup input method and mode by right clicking GUI toolbar You can reduce menu choice of input method NH Ui A N Start SCIM input method by CTRL SPACE Debian Reference 152 265 Note In order to start SCIM under the non CJK and non en_US locale you need to add list of those locales in UTF 8 to the s cim global or etc scim global file as the following SupportedUnicodeLocales en_US UTF 8 en_GB UTF_8 fr_FR UTF 8 Please note the following e im switch 8 behaves differently if command is executed from root or not e Input method started by im switch depends on the locale e Use of new immodule mechanism by setting SGTK_IM_MODULE or SQT_IM_MODULE may cause instability during the library transition in unstable E For the detail of setup see usr share doc im switch README Debian gz usr share doc scim RI ADME Debian gz or usr share doc uim README Debian gz Here key points are described 8 1 3 Disabling the inpu
379. soe ee RRR a a EE Ee E a T a 20 1 43 Special key Strokes eR eR a Rae ERG GR ERS A R O ea 20 1 4 4 Unix style mouse operations 2 e 21 LAS The pagers see Se a A e A a aE A a E Be 21 146 Thetexteditot sor sisri A aa EEG a RRS Aa 21 1 4 7 Setting a default text editor 2 a Z 1 4 8 Customizing VIM E Z X R RRR RRR R RR R E RR RN RRR R RT R eee R 22 1 4 9 Recording the shell activities e 22 1 4 10 Basic Unix commands c e seee esere seese ea ee 22 The simple shell command oaoa ee 24 1 5 1 Command execution and environment variable oaoa a 23 1 5 2 SLANG Variable 2 546 526 64 225240844455 644454 Sh bd rs eRe SEH E 23 15 3 SPATH variable 4 25 4 a paoi See ea Se ee Ea AE o A ae ea O 26 15 4 SHOME variable yaaa se pe ee ba Ge ee oe ba ee ee a we eee ee Bek eS 26 1 5 5 Command line options 27 15 6 Sh ll dl b s sose aa RRR ae eae eee y ea R a R 27 1 5 7 Return value of the command 28 1 5 8 Typical command sequences and shell redirection o oo a 28 125 9 Command alias gws gusce go o dos amp RE eh e o rd a x 29 Unix like text processing sp ccona pe ead aaa ER RE ES EERO REE a RR N 30 1 6 1 Unixtexttools soc o tirar a a a a 30 1 6 2 Regular expressions e etarras e eo a RE 31 1 6 3 Replacement expressions 32 1 6 4 Global substitution with regular expressions a 32 1 6 5 Extracting data from text file table aoaaa e 33 1 6 6 Script snippets for piping c
380. ss platform sharing of static data on CD UDF incremental data writing on CD R and DV MINIX filesystem space efficient unix file data storage on the ext2 filesystem sharing of data on the hard disk like device ext3 filesystem sharing of data on the hard disk like device Table 10 5 List of filesystem choices for removable storage devices with typical usage scenarios e Partitioning them with fdisk 8 cfdisk 8 or parted 8 see Section 9 3 1 into a single primary partition and to mark it as the following Type 6 for FAT16 for media smaller than 2GB Type c for FAT32 LBA for larger media e Formatting the primary partition with mk fs v at 8 with the following Just its device name e g dev sdal for FAT16 The explicit option and its device name e g F 32 dev sdal for FAT32 When using the FAT or ISO9660 filesystems for sharing data the following should be the safe considerations e Archiving files into an archive file first using tar 1 cpio 1 or afio 1 to retain the long filename the symbolic link the original Unix file permission and the owner information e Splitting the archive file into less than 2 GiB chunks with the sp1it 1 command to protect it from the file size limitation e Encrypting the archive file to secure its contents from the unauthorized access Note For FAT filesystems by its design the maximum file size is 2732 1 bytes 4GiB 1 byte For some applications on the o
381. stem e No regular expression is used cat 1 concatenates files and outputs the whole content tac 1 concatenates files and outputs in reverse cut 1 selects parts of lines and outputs head 1 outputs the first part of files tail 1 outputs the last part of files sort l sorts lines of text files uniq 1 removes duplicate lines from a sorted file tr 1 translates or deletes characters diff 1 compares files line by line e Basic regular expression BRE is used grep 1 matches text with patterns ed 1 is a primitive line editor sed 1 is a stream editor vim 1 is a screen editor emacs 1 is a screen editor somewhat extended BRE s Extended regular expression ERE is used egrep 1 matches text with patterns awk 1 does simple text processing tcl 3tel can do every conceivable text processing re_syntax 3 Often used with t k 3tk Debian Reference 31 265 per1 1 can do every conceivable text processing perlre 1 pcregrep 1 from the pcregrep package matches text with Perl Compatible Regular Expressions PCRE pattern python 1 with the re module can do every conceivable text processing See usr share doc python html index html If you are not sure what exactly these commands do please use man command to figure it out by yourself Note Sort order and range expression are locale dependent If you wish to ob
382. t devices X client a program run on a remote host that processes data and talks to the X server application server a program run on a remote host that processes data and talks to the clients application client a program run on a local host connected to the user s display and input devices Table 7 2 List of server client terminology 7 4 The X server See xorg 1 for X server information 7 4 1 The re configuration of the X server Note X server post 1enny is rewritten to use more information from standardized OS services such as HAL and D bus for its configuration than that from etc X11 xorg conf So contents in etc X11 xorg conf are getting less You may need to work around transitional problems of X server The following re configures an X server by generating a new etc Xx11 xorg conf file using dexconf 1 dpkg reconfigure priority low x11 common dpkg reconfigure priority low xserver xorg If you have manually edited this etc X11 xorg conf file but would like it to be automatically updated again run the following command sudo dpkg reconfigure phigh xserver xorg Please check your X configuration with respect to the specification of your monitor carefully For the large high resolution CRT monitor it is a good idea to set the refresh rate as high as your monitor can handle 85 Hz is great 75 Hz is OK to reduce flicker For the LCD monitor slower standard refresh rate 60Hz is usually
383. t 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 1 4 1 The login shell You can select your login shell with chsh 1 package popcon size POSIX shell description bash oe Es psizel Yes Bash the GNU Bourne Again SHell de facto standard tesh lid e psizel No TENEX C Shell an enhanced version of Berkeley csh dash Ea oes S psizel Yes Debian Almquist Shell good for shell script zsh la epeoele psizel Yes Z shell the standard shell with many enhancements pdksh ae psizel Yes public domain version of the Korn shell csh oo eS psizel No OpenBSD C Shell a version of Berkeley csh sash at Ganda psizel Yes Stand alone shell with builtin commands Not meant for s ksh S opconl psizel Yes the real AT amp T version of the Korn shell rc o opgong psizel No implementation of the AT amp T Plan 9 rc shell posh a papeon ee psizel Yes Policy compliant Ordinary SHell pdk sh derivative Table 1 13 List of shell programs In this tutorial chapter the interactive shell always means bash Debian Reference 1 4 2 Customizing bash You can customize bash 1 behavior by bashrc For example try the following CD upon exiting MC usr share mc bin mc sh set CDPATH to good one 20
384. t login to the account and offers the multiuser environment This multiuser environment is a great Unix feature and very addictive If you are under the X Window System you gain access to the character console 1 by pressing Ctrl Alt F1 key i e the left Ctrl key the left Alt key and the F1 key are pressed together You can get back to the X Window System normally running on the virtual console 7 by pressing A1lt F7 You can alternatively change to another virtual console e g to the console 1 from the commandline chvt 1 Debian Reference 4 265 1 1 7 How to leave the command prompt You type Ctrl D i e the left Ctrl key and the d key pressed together at the command prompt to close the shell activity If you are at the character console you return to the login prompt with this Even though these control characters are referred as control D with the upper case you do not need to press the Shift key The short hand expression D is also used for Ctrl D Alternately you can type exit If you are at x terminal emulator 1 you can close x terminal emulator window with this 1 1 8 How to shutdown the system Just like any other modern OS where the file operation involves caching data in memory for improved performance the Debian system needs the proper shutdown procedure before power can safely be turned off This is to maintain the integrity of files by forcing all changes in memory to be written to disk If the sof
385. t method If you wish to input without going through XIM set XMODIFIERS value to none while starting a program This may be the case if you use Japanese input infrastructure egg on emacs 1 From shell execute as the following XMODIFIERS none emacs In order to adjust the command executed by the Debian menu place customized configuration in etc menu following method described in usr share doc menu html 8 2 The display output Linux console can only display limited characters You need to use special terminal program such as jfbterm 1 to display non European languages on the non X console X Window can display any characters in the UTF 8 as long as required font data exists The encoding of the original font data 1s taken care by the X Window System and transparent to the user 8 3 The locale The following focuses on the locale for applications run under X Window environment started from gdm 1 8 3 1 Basics of encoding The environment variable LANG xx_YY ZZZZ sets the locale to language code xx country code yy and encoding 7222 see Section 1 5 2 Current Debian system normally sets the locale as LANG xx_YY UTF 8 This uses the UTF 8 encoding with the Unicode character set This UTF 8 encoding system is a multibyte code system and uses code points smartly The ASCII data which consist only with 7 bit range codes are always valid UTF 8 data consisting only with 1 byte per character Previous De
386. t r1 S can be disabled using stt y 1 Debian Reference 21 265 action response Left click and drag mouse select and copy to the clipboard Left click select the start of selection Right click select the end of selection and copy to the clipboard Middle click paste clipboard at the cursor Table 1 15 List of Unix style mouse operations 1 4 4 Unix style mouse operations Unix style mouse operations are based on the 3 button mouse system The center wheel on the modern wheel mouse is considered middle mouse button and can be used for middle click Clicking left and right mouse buttons together serves as the middle click under the 2 button mouse system situation In order to use a mouse in Linux character consoles you need to have gpm 8 running as daemon 1 4 5 The pager less 1 is the enhanced pager file content browser Hit h for help It can do much more than more 1 and can be super charged by executing eval lesspipe or eval 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 1 4 6 The text editor You should become proficient in one of variants of Vim or Emacs programs which are popular in the Unix like system I think getting used to Vim commands is the right thing to do since Vi editor is always there in the Linux Unix world Actually ori
387. table archive to the testing archive the archive maintenance script not only checks the maturity about 10 days old and the status of the RC bug reports for the packages but also tries to ensure them to be compatible with the latest set of packages in the testing archive This process makes the testing archive very current and usable Through the gradual archive freeze process led by the release team the testing archive is matured to make it completely consistent and bug free with some manual interventions Then the new stable release is created by assigning the codename for the old testing archive to the new stable archive and creating the new codename for the new testing archive The initial contents of the new test ing archive is exactly the same as that of the newly released stable archive Both the unstable and the testing archives may suffer temporary glitches due to several factors e Broken package upload to the archive mostly for unstable e Delay of accepting the new packages to the archive mostly for unstable e Archive synchronization timing issue both for testing and unstable e Manual intervention to the archive such as package removal more for test ing etc So if you ever decide to use these archives you should be able to fix or work around these kinds of glitches Caution For about few months after a new stable release most desktop users should use the stable archive with its e security updates even if they usua
388. tain traditional behavior for a command use C locale instead of UTF 8 ones by prepnding command with LANG C see Section 1 5 2 and Section 8 3 Note Perl regular expressions per 1re 1 Perl Compatible Regular Expressions PCRE and Python regular expressions offered by the re module have many common extensions to the normal ERE 1 6 2 Regular expressions Regular expressions are used in many text processing tools They are analogous to the shell globs but they are more complicated and 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 above BRE ERE description of the regular expression Vo 7 Vo S common metacharacters AF VC NE AER NI BRE only escaped metacharacters FI ERE only non escaped metacharacters c G match non metacharacter c c c match a literal character c even if c is metacharacter by itse match any character including newline position at the beginning of a string position at the end of a string lt lt position at the beginning of a word gt gt position at the end of a word abe abe sa match any characters in abc X abc M abc match any characters except in abc
389. tation The first document to read is the Debian specific usr share doc lt package_name gt README Debian Other documentation in usr share doc lt package_name gt should be consulted too If you set shell as Section 1 4 2 type the following cd lt package_name gt pager README Debian S mE You may need to install the corresponding documentation package named with doc suffix for detailed information If you are experiencing problems with a specific package make sure to check out the Debian bug tracking system BTS sites first n n Site wiki debian org site lists debi Search Google with search words including site debian org an org etc When you file a bug report please use reportbug 1 command Debian Reference 45 265 web site command Home page of the Debian bug tracking system BTS sensible browser h The bug report of a known package name eee eee an The bug report of known bug number eo mre een Table 2 5 List of key web site to resolving problems with a specific package 2 2 Basic package management operations Aptitude is the current preferred package management tool for the Debian system It can be used as the commandline alternative to apt get apt cache and also as the full screen interactive package management tool For the package management operation which involves package installation or updates package metadata
390. tation text and common files exim4 doc html P ES psizel Exim4 documentation html exim4 doc info ser ES psizel Exim4 documentation info postfix E popan a psize1 Postfix mail transport agent MTA alternative postfix doc En oo psizel Postfix documentation html text popcon1 sasl2 bin psize1 Cyrus SASL API implementation supplement postfix for S cyrus sasl2 doc ee psizel Cyrus SASL documentation Table 6 3 List of basic mail transport agent related packages for workstation Although the popcon vote count of exim4 looks several times popular than that of post fix this does not mean post fix is not popular with Debian developers The Debian server system uses both exim4 and post fix The mail header analysis of mailing list postings from prominent Debian developers also indicate both of these MTAs are as popular The exim4 x packages are known to have very small memory consumption and very flexible for its configuration The post fix package is known to be compact fast simple and secure Both come with ample documentation and are as good in quality and license There are many choices for mail transport agent MTA packages with different capability and focus in Debian archive 6 3 1 The configuration of exim4 For the Internet mail via smarthost you re configure exim4 x packages as the following sudo etc init d exim4 stop sudo dpkg reconfigure
391. tations For small personal data backup I use CD R and DVD R by the brand name company and store in a cool shaded dry clean environment Tape archive media seem to be popular for professional use Note A fire resistant safe are meant for paper documents Most of the computer data storage media have less temperature tolerance than paper usually rely on multiple secure encrypted copies stored in multiple secure locations Optimistic storage life of archive media seen on the net mostly from vendor info e 100 years Acid free paper with ink e 100 years Optical storage CD DVD CD DVD R e 30 years Magnetic storage tape floppy Debian Reference 202 265 e 20 years Phase change optical storage CD RW These do not count on the mechanical failures due to handling etc Optimistic write cycle of archive media seen on the net mostly from vendor info e 250 000 cycles Harddisk drive e 10 000 cycles Flash memory e 1 000 cycles CD DVD RW e 1 cycles CD DVD R paper I Caution I Figures of storage life and write cycle here should not be used for decisions on any critical data storage Please consult the specific product information provided by the manufacture Tip Since CD DVD R and paper have only 1 write cycle they inherently prevent accidental data loss by overwriting This is advan tage Tip If you need fast and frequent backup of large amount of data a hard disk o
392. ted information in initramfs too1ls 8 update initra mfs 8 mkinitramfs 8 and initramfs conf 5 Warning Do not put symlinks to the directories in the source tree e g usr src linuxx from usr include 1 inux and usr include asm when compiling the Linux kernel source Some outdated documents suggest this Note When compiling the latest Linux kernel on the Debian stable system the use of backported latest tools from the Debian unstable may be needed Note The dynamic kernel module support DKMS is a new distribution independent framework designed to allow individual kernel modules to be upgraded without changing the whole kernel This will be endorsed for the maintenance of out of tree modules for squeeze This also makes it very easy to rebuild modules as you upgrade kernels 9 7 5 Compiling the kernel source Debian standard method The Debian standard method for compiling kernel source to create a custom kernel package uses make kpkg 1 The official documentation is in the bottom of usr share doc kernel package README gz See kernel pkg conf 5 and kernel img conf 5 for customization Debian Reference 184 265 Here is an example for amd64 system aptitude install linux tree lt version gt cdl Vuar ere tar xjvf linux source lt version gt tar bz2 cd linux source lt version gt cp boot config lt oldversion gt config make menuconfig UN Ur L
393. tem via removable storage device you should format it with common filesystem supported by both systems Here is a list of filesystem choices Tip See Section 9 4 1 for cross platform sharing of data using device level encryption The FAT filesystem is supported by almost all modern operating systems and is quite useful for the data exchange purpose via removable hard disk like media When formatting removable hard disk like devices for cross platform sharing of data with the FAT filesystem the following should be safe choices Debian Reference 200 265 package popcon size description gnome mount aoe aon psizel wrapper for un mounting and ejecting storage devices used by GN pmount ae eae psizel mount removable devices as normal user used by KDE cryptmount ae ane psizel Management and user mode mounting of encrypted filesystems usbmount ar paia psizel automatically mount and unmount USB storage devices Table 10 4 List of packages which permit normal users to mount removable devices without a matching etc fstab entry filesystem description of typical usage scenario FAT12 cross platform sharing of data on the flopp FAT16 cross platform sharing of data on the small cross platform sharing of data on the large FAT32 MS Windows95 OSR2 NTFS cross platform sharing of data on the large Windows NT and later version and suppo1 1509660 cro
394. the memory It is a shell script program which initializes the kernel in user space and hands control over to the next stage This mini Debian system offers flexibility to the boot process such as adding kernel modules before the main boot process or mounting the root filesystem as an encrypted one You can interrupt this part of the boot process to gain root shell by providing break init etc to the kernel boot parameter See the init script for more break conditions This shell environment is sophisticated enough to make a good inspection of your machine s hardware Commands available in this mini Debian system are stripped down ones and mainly provided by a GNU tool called busybox 1 e Caution You need to use n option for mount command when you are on the readonly root filesystem 3 5 Stage 4 the normal Debian system Note This section describes classical System V style boot system on lenny Debian is moving to the event driven boot system See The future of the boot system in Debian and Dependency based boot sequence The normal Debian system is the 4th stage of the boot process which is started by the mini Debian system The system kernel for the mini Debian system continues to run in this environment The root filesystem is switched from the one on the memory to the one on the real hard disk filesystem The sbin init program is executed as the first program and performs the main boot process The Debian
395. time the file status change time 1s 1c atime the last file access time 1s 1u Table 1 9 List of types of timestamps Note ctime is not file creation time e Overwriting a file changes all of the mtime ctime and atime attributes of the file e Changing ownership or permission of a file changes the ctime and atime attributes of the file e Reading a file changes the atime of the file Note Even simply reading a file on the Debian system normally causes a file write operation to update atime information in the inode Mounting a filesystem with noat ime or relatime option makes the system skip this operation and results in faster file access for the read This is often recommended for laptops because it reduces hard drive activity and saves power See mount 8 Debian Reference Use touch 1 command to change timestamps of existing files 13 265 For timestamps the 1s command outputs different strings under the modern English locale en_US UTF 8 from under the old one C S LANG en_US UTF 8 1s 1 foo LANG C 1s 1 foo EW 18 e 1 penguin penguin 3 2008 03 05 00 47 foo ieee 1 penguin penguin 3 Mar 5 00 47 foo Tip See Section 9 2 5 to customize 1s 1 output 1 2 7 Links There are two methods of associating a file foo with a different filename bar s Hard link Duplicate name for an existing file ln foo bar e Symbolic link or symlink
396. ting xsane ad S psizel GTK scanner frontend kooka CE POP Onr E psizel KDE scanner frontend Table 7 9 List of basic X utility applications Debian Reference 149 265 7 8 2 Classic X clients Most traditional X client programs such as xterm 1 can be started with a set of standard command line options to specify geometry font and display They also use the X resource database to configure their appearance The system wide defaults of X resources are stored in etc X11 Xresources x and application defaults of them are stored in etc X11 app defaults x Use these settings as the starting points The Xresources file is used to store user resource specifications This file is automatically merged into the default X resources upon login To make changes to these settings and make them effective immediately merge them into the database using the following command xrdb merge Xresources See x 7 and xrdb 1 7 8 3 The X terminal emulator xterm Learn everything about xt erm 1 at http dickey his com xterm xterm faq html 7 8 4 Running X clients as root Warning Never start the X display session manager under the root account by typing in root to the prompt of the display s manager such as gdm because it is considered unsafe insecure even when you plan to perform administrative activities The entire X architecture is considered insecure if run as root Y
397. tion file etc network interfaces command action ifup eth U bring up a network interface et hO with the configuration eth0 if iface eth O stanza exists ifdown ethO0 bring down a network interface et hO with the configuration eth0 if iface eth0 stanza exists Table 5 9 List of basic network configuration commands with ifupdown state Warning I Do not use low level configuration tools such as ifconfig 8 and ip 8 commands to configure an interface in up Note There is no command ifupdown 5 3 2 The basic syntax of etc network interfaces The key syntax of etc network interfaces as explained in interfaces 5 can be summarized as the following stanza meaning start interface lt interface_name gt upon start of the system auto lt interface_name gt allow auto lt interface_name gt 2 U allow hotplug lt interface_name gt start interface lt interface_name gt when the kernel detects Lines started with i face lt config_name gt U define the network configuration lt config_name gt Lines started with mapping lt interface_name_glob gt U define mapping value of lt config_name gt for the matching A line starting with a hash ignore as comments end of line comments are not suppc A line ending with a backslash extend the configuration to the next line Table 5 10 List of stanzas in etc ne
398. tml e A tutorial introduction to git usr share doc git doc gittutorial html e A tutorial introduction to git part two usr share doc git doc gittutorial 2 html e Everyday GIT With 20 Commands Or So usr share doc git doc everyday html e git for CVS users usr share doc git doc gitcvs migration html This also describes how to set up server like CVS and extract old data from CVS into Git e Other git resources available on the web Git SVN Crash Course Git Magic usr share doc gitmagic html index html git gui l and gitk 1 commands make using Git very easy Warning l Do not use the tag string with spaces in it even if some tools such as gitk 1 allow you to use it It may choke some other git commands Debian Reference 10 9 3 Git commands 228 265 Even if your upstream uses different VCS it may be good idea to use git 1 for local activity since you can manage your local copy of source tree without the network connection to the upstream Here are some packages and commands used with git 1 command package popcon size description N A git doc S SE psize2 official documentation fo N A gitmagic A psize2 Git Magic easier to un git 7 git core Dinni psize2 Git the fast scalable dis gitk 1 gitk Danang psize2 GUI Git repository brows git gui l git gui a psize2 GUI for Git No history git svnimport l git svn A
399. to the system A UPG has the same name as the user for which it was created and that user is the only member of the UPG UPG scheme makes it is safe to set umask to 0002 since every user has their own private group In some Unix variants it is quite common to setup all normal users belonging to a single users group and is good idea to set umask to 0022 for security in such cases 1 2 5 Permissions for groups of users group In order to make group permissions to be applied to a particular user that user needs to be made a member of the group using sudo vigr Note Alternatively you may dynamically add users to groups during the authentication process by adding auth optional pa m_group so line to etc pam d common auth and setting etc security group conf See Chapter 4 The hardware devices are just another kind of file on the Debian system If you have problems accessing devices such as CD ROM and USB memory stick from a user account you should make that user a member of the relevant group Some notable system provided groups allow their members to access particular files and devices without root privilege Tip You need to belong to the dialout group to reconfigure modem dial anywhere etc But if root creates pre defined configuration files for trusted peers in etc ppp peers you only need to belong to the dip group to create Dialup IP connection to those trusted peers using pppd 8 pon 1 and pof 1 commands
400. tool makepatch 1 makepatch eae psize2 generate extended patch files applypatch 1 makepatch G psize2 apply extended patch files wdiff 1 wdiff ie OE psize2 display word differences between text files Table 10 15 List of source code merge tools Debian Reference 216 265 package popcon size tool cssc m psize1 CSSC res ce psizel1 RCS cvs nee psizel CVS subversion ee aa psizel Subversion git core ad psizel Git mercurial gia aa psizel Mercurial bzr ai psizel Bazaar darcs A psizel Darcs tla e psize1 GNU arch monotone ici psizel Monotone tkevs P aa psizel CVS gitk i ae psizel Git Table 10 16 List of version control system tools VCS is sometimes known as revision control system RCS or software configuration management SCM Distributed VCS such as Git is the tool of choice these days CVS and Subversion may still be useful to join some existing open source program activities Debian provides free VCS services via Debian Alioth service It supports practically all VCSs Its documentation can be found at http wiki debian org Alioth l Caution The git package is GNU Interactive Tools which is not the DVCS There are few basics for creating a shared access VCS archive e Use umask 002 see Section 1 2 4 e
401. try of this file means the following e Login name e Encrypted password The initial 1 indicates use of the MDS encryption The indicates no login e Days since Jan 1 1970 that password was last changed e Days before password may be changed e Days after which password must be changed e Days before password is to expire that user is warned etc group contains the following groupl x 20 userl user2 As explained in group 5 each separated entry of this file means the following e Group name e Encrypted password not really used e Numerical group ID n e separated list of user names Note etc gshadow provides the similar function as etc shadow for etc group but is not really used Note The actual group membership of a user may be dynamically added if auth optional pam_group so line is added to Jetc pam d common auth and setitin etc security group conf See pam_group 8 Debian Reference 87 265 Note The base passwd package contains an authoritative list of the user and the group usr share doc base passw d users and groups html 4 2 Managing account and password information Here are few notable commands to manage account information command function getent passwd lt user_name gt browse account information of lt user_name gt getent shadow lt user_name gt browse shadowed account information of lt user_name gt getent group
402. tware power control is available the shutdown procedure automatically turns off power of the system Otherwise you may have to press power button for few seconds after the shutdown procedure You can shutdown the system under the normal multiuser mode from the commandline shutdown h now You can shutdown the system under the single user mode from the commandline poweroff i f Alternatively you may type Ctr1 Alt Delete The left Ctrl key the left Al1t Key and the Delete are pressed together to shutdown if etc inittab contains ca 12345 ctrlaltdel sbin shutdown t1 a h now in it See inittab 5 for details See Section 6 9 6 1 1 9 Recovering a sane console When the screen goes berserk after doing some funny things such as cat lt some binary file gt type reset at the command prompt You may not be able to see the command echoed as you type You may also issue clear to clean up the screen 1 1 10 Additional package suggestions for the newbie Although even the minimal installation of the Debian system without any desktop environment tasks provides the basic Unix functionality it is a good idea to install few additional commandline and curses based character terminal packages such as mc and vim with apt itude 8 for beginners to get started by the following aptitude update aptitude install mc vim sudo If you already had these packages installed no new packages are installed It may be a good i
403. twork interfaces Lines started with iface stanza has the following syntax Debian Reference 102 265 iface lt config_name gt lt address_family gt lt method_name gt lt optionl gt lt valuel gt lt option2 gt lt value2 gt For the basic configuration the mapping stanza is not used and you use the network interface name as the network configuration name See Section 5 4 5 s Warning Do not define duplicates of the i face stanza for a network interface in etc network interfaces 5 3 3 The loopback network interface The following configuration entry in the etc network interfaces file brings up the loopback network interface 1o upon booting the system via auto stanza auto lo iface lo inet loopback This one always exists in the etc network interfaces file 5 3 4 The network interface served by the DHCP After prepairing the system by Section 5 2 1 the network interface served by the DHCP is configured by creating the configura tion entry in the etc network interfaces file as the following allow hotplug eth0 iface eth0 inet dhcp hostname mymachine When the Linux kernel detects the physical interface et h0 the allow hotplug stanza causes ifup to bring up the interface and the iface stanza causes i fup to use DHCP to configure the interface 5 3 5 The network interface with the static IP The network interface served by the static IP is configured by creating the configurati
404. u must learn to take advantage of the power of these features and similarities between Unix and GNU Linux Don t shy away from Unix oriented texts and don t rely solely on GNU Linux texts as this robs you of much useful information Rute User s Tutorial and Exposition in the Debian non free archive as the rut ebook package popcon pop rutebook provides a good online resource to the generic system administration Note If you have been using any Unix like system for a while with command line tools you probably know everything explain here Please use this as a reality check and refresher 1 1 Console basics 1 1 1 The shell prompt Upon starting the system you are presented with the character based login screen if you did not install X Window System with the display manager such as gdm Suppose your hostname is foo the login prompt looks as follows LOO loginy If you did install a GUI environment such as GNOME or KDE then you can get to a login prompt by Ctrl Alt F1 and you can return to the GUI environment via Alt F7 see Section 1 1 6 below for more At the login prompt you type your username e g penguin and press the Enter key then type your password and press the Enter key again Note Following the Unix tradition the username and password of the Debian system are case sensitive The username is usually chosen only from the lowercase The first user account is usually created during the installation
405. ual installed 7 Exit aptitude 8 Start apt get s autoremove less as root to check what are not used 9 Restart aptitude in interactive mode and mark needed packages as m 10 Restart apt get s autoremove less as root to recheck REMOVED contain only expected packages 11 Start apt get autoremove less as root to autoremove unused packages The m action over Tasks is an optional one to prevent mass package removal situation in future 2 3 5 System wide upgrade with aptitude Note When moving to a new release etc you should consider to perform a clean installation of new system even though Debian is upgradable as described below This provides you a chance to remove garbages collected and exposes you to the best combination of latest packages Of course you should make a full backup of system to a safe place see Section 10 1 6 before doing this recommend to make a dual boot configuration using different partition to have the smoothest transition You can perform system wide upgrade to a newer release by changing contents of the etc apt sources list file pointing to a new release and running the aptitude update aptitude full upgrade command To upgrade from stable to testing or unstable you replace codename stable in the etc apt so urces list example of Section 2 1 4 with codename testing or sid In reality you may face some complications due to some package transition issu
406. ug stanza to start the network interface eth0 automatically upon events Now you are ready to switch the network configuration Let s move your PC to a LAN served by the DHCP You bring up the network interface the physical interface eth0 by assigning the network configuration name the logical interface name conf ig 1 to it by the following sudo ifup eth0 configl Password The interface et h0 is up configured by DHCP and connected to LAN sudo ifdown eth0 configl The interface et h0 is down and disconnected from LAN Let s move your PC to a LAN served by the static IP You bring up the network interface lt t hO by assigning the network configuration name config2 to it by the following sudo ifup eth0 config2 The interface et hO is up configured with static IP and connected to LAN The additional parameters given as dns configures etc resolv conf contents This etc resolv conf is better manged if the resolvconf package is installed Debian Reference 110 265 sudo ifdown eth0 config2 The interface et hO is down and disconnected from LAN again Let s move your PC to a port on BB modem connected to the PPPoE served service You bring up the network interface et h0 by assigning the network configuration name pppoe to it by the following sudo ifup eth0 pppoe The interface et h0 is up configured with PPPoE connection directly to the ISP sudo ifdown eth0 pppoe The interface et h0 is down and di
407. ult installation configured with proper file permissions which prevent non privileged users from damaging the system Of course there may still be some holes which can be exploited but those who worry about these issues should not be reading this section but should be reading Securing Debian Manual We learn the Debian system as a Unix like system with the following e Section 1 2 basic concept e Section 1 3 survival method e Section 1 4 basic method e Section 1 5 shell mechanism e Section 1 6 text processing method 1 2 Unix like filesystem In GNU Linux and other Unix like operating systems files are organized into directories All files and directories are arranged in one big tree rooted at It s called a tree because if you draw the filesystem it looks like a tree but it is upside down These files and directories can be spread out over several devices mount 8 serves to attach the filesystem found on some device to the big file tree Conversely umount 8 detaches it again On recent Linux kernels mount 8 with some options can bind part of a file tree somewhere else or can mount filesystem as shared private slave or unbindable Supported mount options for each filesystem are available in share doc linux doc 2 6 Documentation filesystems Directories on Unix systems are called folders on some other systems Please also note that there is no concept for drive such as A on any Unix system There is one fi
408. up as a single file you can backup its content after splitting it into e g 2000MiB chunks and merge those chunks back into the original file later split b 2000m large_file S cat xx gt large_file e Caution Please make sure you do not have any files starting with x to avoid name crashes 10 3 6 Clearing file contents In order to clear the contents of a file such as a log file do not use rm 1 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 S gt fille to be clleared 10 3 7 Dummy files The following commands create dummy or empty files dd if dev zero of 5kb file bs 1k count 5 dd if dev urandom of 7mb file bs 1M count 7 touch zero file S gt alwayszero file You should find following files e 5kb file is 5KB of zeros e 7mb file is 7MB of random data e zero file may be a 0 byte file If it existed its mt ime is updated while its content and its length are kept e alwayszero file is always a 0 byte file If it existed its mt ime is updated and its content is reset 10 3 8 Erasing an entire hard disk There are several ways to completely erase data from an entire hard disk like device e g USB memory stick at dev sda Caution a Check your USB memory stick location with mount 8 first before executing comman
409. urging removed packages for good 2 2 2 ee 51 2 3 4 Tidying auto manual install status ee 52 2 3 5 System wide upgrade With aptitude ee 52 2 4 Advanced package management operations osoa e ee 53 2 4 1 Advanced package management operations with commandline o sooo 33 2 4 2 Verification of installed package files ooo o 55 2 43 Safeguarding for package problems 000 0002 eee ee 53 2 4 4 Searching on the package meta data ooa ee 33 2 5 Debian package management internals ee 56 2 0 1 Archivemeta data socorro e a 56 2 5 2 Top level Release file and authenticity e 56 2 5 3 Archive level Release files o 0 0 o e a7 2 5 4 Fetching of the meta data for the package 2 2 2 ee 58 2 5 5 The package state for APT 58 2 5 6 The package state for aptitude o oo ee 58 2 5 7 Local copies of the fetched packages o o 58 2 5 8 Debian package filenames ooa ee 58 Debian Reference vii 2 2 9 The dpkscommMatds sce se oe weed Ped A 39 2 5 10 The update alternative command ooo 000 2p ee 59 2 5 11 The dpkg statoverride command ooo 000 ee ee 60 2 5 12 The dpkg divert command osoa 0 ee 61 2 6 Recovery from a broken system e e e cso RRR RRR RRR RRR RRR RRR 61 2 6 1 Incompatibility with old user configuration 2 ee 61 2 6 2 Di
410. ution gt _Release e var lib apt lists ftp us debian org_debian_dists_ lt distribution gt _Release gpg e var lib apt lists ftp us debian org_debian_dists _ lt distribution gt _ lt component gt _binary lt architecture gt _Packages e var lib apt lists ftp us debian org_debian_dists _ lt distribution gt _ lt component gt _source _Sources e var cache apt apt file ftp us debian org_debian_dists_ lt distribution gt _Contents lt arc hitecture gt gz for apt file First 4 types of files are shared by all the pertinent APT commands and updated from command line by apt get update and aptitude update The Packages meta data are updated if there is the deb line in etc apt sources list The Sources meta data are updated if there is the deb src line in etc apt sources list The Packages and Sources meta data contain Filename stanza pointing to the file location of the binary and source packages Currently these packages are located under the pool directory tree for the improved transition over the releases Local copies of Packages meta data can be interactively searched with the help of aptitude The specialized search command grep dctr1 1 can search local copies of Packages and Sources meta data Local copy of Contents lt architecture gt meta data can be updated by apt file update and its location is different from other 4 ones See apt fi1le 1 The auto apt uses different
411. ven at the bottom of Help screen shown by pressing The candidate version is chosen according to the current local preferences see apt_preferences 5 and Section 2 7 3 Several types of package views are available under the menu Views view status description of view Package View Good see Table 2 10 default Audit Recommendations Good list packages which are recommended by some installed packages but not ye Flat Package List Good list packages without categorization for use with regex Debtags Browser Very usable list packages categorized according to their debtags entries Categorical Browser Deprecated list packages categorized according to their category use Debtags Brow Table 2 9 List of views for aptitude Note Please help us improving tagging packages with debtags Debian Reference 48 265 category description of view Upgradable Packages list packages organized as section component package New Packages gt gt Installed Packages T Not Installed Packages 53 Obsolete and Locally Created Packages E Virtual Packages list packages with the same function Tasks list packages with different functions generally needed for a task Table 2 10 The categorization of standard package views The standard Package View categorizes packages somewhat like dselect with few extra features Tip Tasks view can be used to cherry pick packages for your
412. ver from your mail client it is recently popular to use new message submission port 587 instead of traditional SMTP port 25 to avoid port 25 blocking by the network provider while authenticating yourself with CRAM MDS Debian Reference 92 265 insecure service name port secure service name port www http 80 https 443 smtp mail 25 ssmtp smtps 465 ftp data 20 ftps data 989 ftp 21 ftps 990 telnet 23 telnets 992 imap2 143 imaps 993 pop3 110 pop3s 995 Idap 389 Idaps 636 Table 4 7 List of insecure and secure services and ports 4 7 2 Secure Shell The Secure Shell SSH program provides secure encrypted communications between two untrusted hosts over an insecure network with the secure authentication It consists of the OpenSSH client ssh 1 and the OpenSSH daemon sshd 8 This SSH can be used to tunnel the insecure protocol communication such as POP and X securely over the Internet with the port forwarding feature The client tries to authenticate itself using host based authentication public key authentication challenge response authentica tion or password authentication The use of public key authentication enables the remote password less login See Section 6 9 4 7 3 Extra security measures for the Internet Even when you run secure services such as Secure Shell SSH and Point to point tunneling protocol PPTP servers there are still chances for the break ins using brute force
413. vesdropping attack Tip You can dare to enable remote TCP IP connection by setting DisallowTCP false in etc gdm gdm conf to override usr share gdm defaults conf and by removing nolisten from lines found by find etc X11 type f print0 xargs 0 grep nolisten if you are in the fully secured environment Tip LTSP stands for Linux Terminal Server Project 7 5 Starting the X Window System The X Window System is usually started as an X session which is the combination of an X server and connecting X clients For the normal desktop system both of them are executed on a workstation The X session is started by the following Debian Reference 141 265 e startx command started from the command line e One of the X display manager daemon programs dm started from the end of the start up script in etc rc d corresponding to the runlevel directory Tip The start up script for the display manager daemons checks the content of the etc X11 default display mana ger file before actually executing themselves This ensures to have only one X display manager daemon program activated Tip See Section 8 3 5 for initial environment variables of the X display manager Essentially all these programs execute the etc X11 Xsession script Then the etc X11 Xsession script per forms run parts 8 like action to execute scripts in the etc X11 Xsession d directory This is essentially an
414. vided by the apt file package must run apt file update in advance De bian Reference 54 265 command action CO LUMNS 120 dpkg 1 lt package_name_pattern gt list status of an installed package for the bug dpkg L lt package_name gt list contents of an installed package dpkg L lt package_name gt egrep usr share man man x list manpages for an installed package dpkg S lt file_name_pattern gt list installed packages which have matching 1 apt file search lt file_name_pattern gt list packages in archive which have matching apt file list lt package_name_pattern gt list contents of matching packages in archive dpkg reconfigure lt package_name gt reconfigure the exact package dpkg reconfigure p low lt package_name gt reconfigure the exact package with the most configure debian reconfigure packages from the full screen me dpkg audit audit system for partially installed packages dpkg configure a configure all partially installed packages apt cache policy lt binary_package_name gt show available version priority and archive 1 apt cache madison lt package_name gt show available version archive information c apt cache showsrc lt binary_package_name gt show source package information of a binary apt get build dep lt package_name gt install required packages to build package apt get source lt p
415. vn project chown R root src srv svn project chmod R ug rwX srv svn project Your new Subversion repository is group accessible at URL file localhost srv svn project or file srv svn project from svn 1 for local users belonging to project group You must run commands such as svn svnserve svnlook and svnadmin under umask 002 to ensure group access 10 8 4 Remote access to Subversion via SSH A group accessible Subversion repository is at URL example com srv svn project for SSH you can access it from svn 1 at URL svn ssh example com srv svn project 10 8 5 Subversion directory structure Many projects uses directory tree similar to the following for Subversion to compensate its lack of branches and tags modulel branches cage release 1 0 release 2 0 Nes ere julie Debian Reference 224 265 filel file2 file3 module2 Tip You must use svn copy command to mark branches and tags This ensures Subversion to record modification history of files properly and saves storage spaces 10 8 6 Importing a new source to Subversion Create a new local source tree location at path to module1 by the following mkdir p path to modulel cd path to modulel Populate a new local source tree under path to module1 with files Import it to Subversion with the following parameters Module name modulel Subver
416. wever 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 Pipes were a very influential innovation of Unix For example try the following cd mkfifo mypipe echo hello gt mypipe amp put into background A e022 ls 1 mypipe piw e BA EN gin pen guia OM 200M 042 9 SOs 2a my pap e cat mypipe hello 1 Done echo hello gt mypipe S ls mypipe mypipe rm mypipe 1 2 9 Sockets Sockets are used extensively by all the Internet communication databases and the operating system itself It is similar to the named pipe FIFO and allows processes to exchange information even between different computers For the socket those processes do not need to be running at the same time nor to be running as the children of the same ancestor process This is the endpoint for the inter process communication IPC The exchange of information may occur over the network between different hosts The two most common ones are the Internet socket and the Unix domain socket Tip netstat an provides a very useful overview of sockets that are open on a given system Debian Reference 15 265 1 2 10 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 2 types of device files s Character d
417. wing S serio Script started file is typescript Do whatever shell commands under script Press Ctrl D to exit script vim typescript See Section 9 2 3 1 4 10 Basic Unix commands Let s learn basic Unix commands Here I use Unix in its generic sense Any Unix clone OSs usually offer equivalent commands The Debian system is no exception Do not worry if some commands do not work as you wish now If alias is used in the shell its corresponding command outputs are different These examples are not meant to be executed in this order Try all following commands from the non privileged user account Debian Reference 23 265 command description pwd display name of current working directory whoami display current user name id display current user identity name uid gid and associated groups file lt foo gt display a type of file for the file lt foo gt type p lt commandname gt display a file location of command lt commandname gt which lt commandname gt y type lt commandname gt i i i commandname display information on command lt d gt apropos lt key word gt find commands related to lt key word gt man k lt key word gt gt whatis lt commandname gt display one line explanation on command lt commandname gt man a lt commandname gt display explanation on command lt commandname gt Unix style info
418. wing short form lt name attribute value gt The attribute value in the above examples are optional The comment section in XML is marked up as the following lt comment gt Other than adding markups XML requires minor conversion to the content using predefined entities for following characters predefined entity character to be converted from amp quot quote Sapos apostrophe amp lt lt less than amp gt gt greater than amp amp amp ampersand Table 11 7 List of predefined entities for XML Caution lt or KT can not be used in attributes or elements Note When SGML style user defined entities e g amp some tag are used the first definition wins over others The entity definition is expressed in lt ENTITY some tag entity value gt Note As long as the XML markup are done consistently with certain set of the tag name either some data as content or attribute value conversion to another XML is trivial task using Extensible Stylesheet Language Transformations XSLT 11 2 2 XML processing There are many tools available to process XML files such as the Extensible Stylesheet Language XSL Basically once you create well formed XML file you can convert it to any format using Extensible Stylesheet Language Trans formations XSLT The Extensible Stylesheet Language for Formatting Object XSL FO is su
419. with this manual approach But this is very cumbersome Caution When using mixed source of archives you must ensure compatibility of packages by yourself since the Debian does not guarantee it If package incompatibility exists you may break system You must be able to judge these technical requirements The use of mixed source of random archives is completely optional operation and its use is not something encourage you to use General rules for installing packages from different archives are followings e Non binary packages Architecture all are safer to install documentation packages no special requirements interpreter program packages compatible interpreter must be available e Binary packages non Architecture all usually face many road blocks and unsafe to install library version compatibility including 1ibc related utility program version compatibility Kernel ABI compatibility C ABI compatibility Note In order to make a package to be safer to install some commercial non free binary program packages may be provided with completely statically linked libraries You should still check ABI compatibility issues etc for them Note Except to avoid broken package for a short term installing binary packages from officially unsupported archives is generally bad idea This is true even if you use apt pinning see Section 2 7 3 You should consider chroot or similar tech
420. work packet filtering functions use ipt able kernel modules 9 7 2 Kernel parameters Many Linux features are configurable via kernel parameters as follows e Kernel parameters initialized by the bootloader see Section 3 3 e Kernel parameters changed by syscr1 8 at runtime for ones accessible via sysfs see Section 1 2 12 e Module parameters set by arguments of modprobe 8 when a module is activated see Section 10 2 3 See kernel parameters txt gz and other related documents in the Linux kernel documentation usr share doc linux doc 2 6 Documentation filesystems provided by the linux doc 2 6 x package 9 7 3 Kernel headers Most normal programs don t need kernel headers and in fact may break if you use them directly for compiling They should be compiled against the headers in usr include linux and usr include asm provided by the 1ibc 6 dev package created from the glibc source package on the Debian system Note For compiling some kernel specific programs such as the kernel modules from the external source and the automounter daemon amd you must include path to the corresponding kernel headers e g 1 usr src linux particular versi on include to your command line module assistant 8 or its short form m a helps users to build and install module package s easily for one or more custom kernels Debian Reference 183 265 package popcon size description build
421. xample com gpg gen key gpg K sec 1024D 3A3CB5A6 2008 08 14 uid Foo ARCHIVE KEY lt foo www example com gt ssb 20489 6856F4A7 2008 08 14 gpg export a 3A3CB5A6 gt foo public key Publish the archive key file foo public key with the key ID 3A3CB5A6 for Foo Create an archive tree called Origin Foo as the following umask 022 mkdir p public_html debian pool main mkdir p public_html debian dists unstable main binary amd64 mkdir p public_html debian dists unstable main source cd public_html debian cat gt dists unstable main binary amd64 Release lt lt EOF Archive unstable Version 4 0 Component main CHAGAS 100 Label Foo Architecture amd64 EOF S cat gt dists unstable main source Release lt lt EOF Archive unstable Version 4 0 MMM WM mM Ur Component main Origin Foo Label Foo Architecture source EOF cat gt aptftp conf lt lt EOF APT FTPArchive Release Debian Reference Origine BOOM Label Foo Suite unstable Codename sid Architectures amd64 Components main Deceit ion WE Ubi ware IVC o BOOY he EOF cat gt aptgenerate conf lt lt EOF Diners e ATG AIVE DARE Y Wo Direne ETES aa TreeDefault Directory pool TreeDefault SrcDirectory pool Default Packages Extensions deb Default Packages Compress gzip bzip2 Default Sources Compress gzip bzip2 Default
422. y may delete messages just after receiving RETR command before receiving DELE command and may quarantined messages into Spam mailbox You should minimize damages by configuring them to archive accessed messages and not to delete them See also Some mail was not downloaded 6 5 2 fetchmail configuration fetchmai1 1 configuration is set by etc default fetchmail etc fetchmailrc and SHOME fetch mailrc See its example in usr share doc fetchmail examples fetchmailrc example Debian Reference 127 265 6 6 Mail delivery agent MDA with filter Most MTA programs such as post fix and exim4 function as MDA mail delivery agent There are specialized MDA with filtering capabilities Although procmail 1 has been de facto standard for MDA with filter on GNU Linux author likes maildrop 1 now Whichever filtering utilities are used it is good idea to configure system to deliver filtered mails to a qmail style Maildir package popcon size description procmail ea a al psize1 MDA with filter old mailagent ee psize1 MDA with Perl filter maildrop Prans k psize1 MDA with structured filtering language Table 6 10 List of MDA with filter 6 6 1 maildrop configuration maildrop 1 configuration is described in maildropfilter documentation Here is a configuration example for SHOME ma ilfilter logfile HOME maildroplog clearly bad looking mails drop them
423. y packages to the system from the archive Currently there are all packages packages available for the arch architecture The Debian package management system has a rich history and many choices for the front end user program and back end archive access method to be used Currently we recommend aptitude 8 as the main front end program for the Debian package management activity Note The annoying bug 411123 for the mixed use of apt itude 8 and apt get 8 commands has been resolved If this kept you from using aptitude please reconsider 2 1 Debian package management prerequisites 2 1 1 Package configuration Here are some key points for package configuration on the Debian system The manual configuration by the system administrator is respected In other words the package configuration system makes no intrusive configuration for the sake of convenience Each package comes with its own configuration script with standardized user interface called debconf 7 to help initial installation process of the package Debian Developers try their best to make your upgrade experience flawless with package configuration scripts Full functionalities of packaged software are available to the system administrator But ones with security risks are disabled in the default installation If you manually activate a service with some security risks you are responsible for the risk containment Esoteric configuration may be manually
424. ys such as Esc to disable this These keys are highly dependent on the hardware The hardware location and the priority of the code started by the BIOS can be selected from the BIOS setup screen Typically the first few sectors of the first found selected device hard disk floppy disk CD ROM are loaded to the memory and this initial code is executed This initial code can be any one of the following e The boot loader code e The kernel code of the stepping stone OS such as FreeDOS e The kernel code of the target OS if it fits in this small space Typically the system is booted from the specified partition of the primary hard disk partition First 2 sectors of the hard disk on legacy PC contain the master boot record MBR The disk partition information including the boot selection is recorded at the end of this MBR The first boot loader code executed from the BIOS occupies the rest of this MBR 3 3 Stage 2 the boot loader The boot loader is the 2nd stage of the boot process which is started by the BIOS It loads the system kernel image and the initrd image to the memory and hands control over to them This initrd image is the root filesystem image and its support depends on the bootloader used The Debian system normally uses the Linux kernel as the default system kernel The initrd image for the current 2 6 Linux kernel is technically the initramfs initial RAM filesystem image The initramfs image is a gzipped cpio archive of files

Debian reference guide (23 Feb 2010)

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