dpkg 是系统上处理 Debian 软件包的基础指令。如果有 .deb 软件包，那么可以用 dpkg 来安装或分析其内容。但此指令只能看到 Debian 世界的部分内容：它知道系统安装了那些软件包，以及命令行给出了什么，但不知道其它还有哪些可用的软件包。这样，如果没有相依性就会失败。如 apt 和 aptitude 这样的工具，相反会可产生相依性清单，来尽量自动地安装软件包。
dpkg 是安装 Debian 已经可用软件包的工具 (因为不需下载任何东西)。我们使用它的 -i 或 --install 选项。
例 5.2. 通过dpkg来安装一个软件包
#dpkg -i man-db_2.9.4-2_amd64.deb(Reading database ... 227466 files and directories currently installed.) Preparing to unpack man-db_2.9.4-2_amd64.deb ... Unpacking man-db (2.9.4-2) over (2.8.5-2) ... Setting up man-db (2.9.4-2) ... Updating database of manual pages ... man-db.service is a disabled or a static unit not running, not starting it. Processing triggers for mailcap (3.69) ...
dpkg 执行的不同步骤；这样，我们知道在哪一点会发生错误。安装也可以分为两个阶段来生效：首先拆包，然后配置。apt 会利用这个优点，来限制调用 dpkg 的次数（因为每次调用都有成本，要把数据加载到内存中，特别是已经安装的文件的列表）。
例 5.3. 分开解压和配置
#dpkg --unpack man-db_2.9.4-2_amd64.deb(Reading database ... 227466 files and directories currently installed.) Preparing to unpack man-db_2.9.4-2_amd64.deb ... Unpacking man-db (2.9.4-2) over (2.9.4-2) ... Processing triggers for mailcap (3.69) ... #dpkg --configure man-dbSetting up man-db (2.9.4-2) ... Updating database of manual pages ... man-db.service is a disabled or a static unit not running, not starting it.
dpkg 在安装软件包的时候会失败并且返回一个错误信息；如果用户命令 dpkg 忽略掉这个错误，那么它仅仅会发出一个警告；就是这个原因使我们有不同的 --force--* 选项。dpkg --force-help 命令，或者这个命令的文档，将给出这些选项的完整列表。早晚会遇到的最常见的错误，是文件冲突。当软件包包含一个由其它软件包已经安装的文件时，dpkg 会拒绝安装。然后出现后面的消息：
Unpacking libgdm (from .../libgdm_3.8.3-2_amd64.deb) ...
dpkg: 处理 /var/cache/apt/archives/libgdm_3.8.3-2_amd64.deb (--unpack) 时发生错误:
试图覆写 '/usr/bin/gdmflexiserver'，也同时在软件包 gdm3 3.4.1-9 内--force-overwrite选项来告诉dpkg去忽略这个错误并且覆盖该文件。
--force-* options, only --force-overwrite is likely to be used regularly. These options only exist for exceptional situations, rarely encountered in Debian Stable. It is better to leave them alone as much as possible in order to respect the rules imposed by the packaging mechanism. Do not forget, these rules ensure the consistency and stability of your system.
dpkg 加上 -r 或 --remove 选项，再加上软件包名称，就可移除该软件包。然而，这种方式的移除并不完整：仍保留了所有的配置文件、维护脚本、日志文件（系统日志）及由软件包而处理的其他用户数据。停用程序的方式是卸载它，并且仍可以用相同的配置快速地重新安装回来。要完全移除与软件包相关的所有内容，应使用 -P 或 --purge 选项，再加上软件包的名称。
dpkg options that query the internal database in order to obtain information. Giving first the long options and then corresponding short options (that will evidently take the same possible arguments) we cite
--listfiles package (or -L), which lists the files installed by this package;
--search file (or -S), which finds the package(s) containing the file;
--status package (or -s), which displays the headers of an installed package;
--list (or -l), which displays the list of packages known to the system and their installation status;
--contents file.deb (or -c), which lists the files in the Debian package specified;
--info file.deb (or -I), which displays the headers of this Debian package.
例 5.5. dpkg的各种查询
$dpkg -L base-passwd/. /usr /usr/sbin /usr/sbin/update-passwd /usr/share /usr/share/base-passwd /usr/share/base-passwd/group.master /usr/share/base-passwd/passwd.master /usr/share/doc /usr/share/doc/base-passwd /usr/share/doc/base-passwd/README /usr/share/doc/base-passwd/changelog.gz /usr/share/doc/base-passwd/copyright /usr/share/doc/base-passwd/users-and-groups.html /usr/share/doc/base-passwd/users-and-groups.txt.gz /usr/share/doc-base /usr/share/doc-base/users-and-groups /usr/share/lintian /usr/share/lintian/overrides /usr/share/lintian/overrides/base-passwd /usr/share/man /usr/share/man/de /usr/share/man/de/man8 /usr/share/man/de/man8/update-passwd.8.gz /usr/share/man/es /usr/share/man/es/man8 /usr/share/man/es/man8/update-passwd.8.gz /usr/share/man/fr /usr/share/man/fr/man8 /usr/share/man/fr/man8/update-passwd.8.gz /usr/share/man/ja /usr/share/man/ja/man8 /usr/share/man/ja/man8/update-passwd.8.gz /usr/share/man/man8 /usr/share/man/man8/update-passwd.8.gz /usr/share/man/pl /usr/share/man/pl/man8 /usr/share/man/pl/man8/update-passwd.8.gz /usr/share/man/ru /usr/share/man/ru/man8 /usr/share/man/ru/man8/update-passwd.8.gz $dpkg -S /bin/datecoreutils: /bin/date $dpkg -s coreutilsPackage: coreutils Essential: yes Status: install ok installed Priority: required Section: utils Installed-Size: 17478 Maintainer: Michael Stone <[email protected]> Architecture: amd64 Multi-Arch: foreign Source: coreutils (8.32-4) Version: 8.32-4+b1 Pre-Depends: libacl1 (>= 2.2.23), libattr1 (>= 1:2.4.44), libc6 (>= 2.28), libgmp10, libselinux1 (>= 3.1~) Description: GNU core utilities This package contains the basic file, shell and text manipulation utilities which are expected to exist on every operating system. . Specifically, this package includes: arch base64 basename cat chcon chgrp chmod chown chroot cksum comm cp csplit cut date dd df dir dircolors dirname du echo env expand expr factor false flock fmt fold groups head hostid id install join link ln logname ls md5sum mkdir mkfifo mknod mktemp mv nice nl nohup nproc numfmt od paste pathchk pinky pr printenv printf ptx pwd readlink realpath rm rmdir runcon sha*sum seq shred sleep sort split stat stty sum sync tac tail tee test timeout touch tr true truncate tsort tty uname unexpand uniq unlink users vdir wc who whoami yes Homepage: http://gnu.org/software/coreutils $dpkg -l 'b*'Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name Version Architecture Description +++-==========================-==============-============-================================== un backupninja <none> <none> (no description available) un backuppc <none> <none> (no description available) ii baloo-kf5 5.78.0-3 amd64 framework for searching and manag> un balsa <none> <none> (no description available) ii baobab 3.38.0-1 amd64 GNOME disk usage analyzer un base <none> <none> (no description available) un base-config <none> <none> (no description available) ii base-files 11.1 amd64 Debian base system miscellaneous > ii base-passwd 3.5.51 amd64 Debian base system master passwor> ii bash 5.1-2+b1 amd64 GNU Bourne Again SHell [..] $dpkg -c /var/cache/apt/archives/bash_5.1-3+b1_amd64.debdrwxr-xr-x root/root 0 2021-07-25 20:43 ./ drwxr-xr-x root/root 0 2021-07-25 20:43 ./bin/ -rwxr-xr-x root/root 1234376 2021-07-25 20:43 ./bin/bash drwxr-xr-x root/root 0 2021-07-25 20:43 ./etc/ -rw-r--r-- root/root 1994 2021-07-25 20:43 ./etc/bash.bashrc drwxr-xr-x root/root 0 2021-07-25 20:43 ./etc/skel/ -rw-r--r-- root/root 220 2021-07-25 20:43 ./etc/skel/.bash_logout -rw-r--r-- root/root 3526 2021-07-25 20:43 ./etc/skel/.bashrc -rw-r--r-- root/root 807 2021-07-25 20:43 ./etc/skel/.profile drwxr-xr-x root/root 0 2021-07-25 20:43 ./usr/ drwxr-xr-x root/root 0 2021-07-25 20:43 ./usr/bin/ -rwxr-xr-x root/root 6759 2021-07-25 20:43 ./usr/bin/bashbug -rwxr-xr-x root/root 14648 2021-07-25 20:43 ./usr/bin/clear_console drwxr-xr-x root/root 0 2021-07-25 20:43 ./usr/share/ drwxr-xr-x root/root 0 2021-07-25 20:43 ./usr/share/doc/ [..] $dpkg -I /var/cache/apt/archives/bash_5.1-3+b1_amd64.debnew Debian package, version 2.0. size 1416600 bytes: control archive=7256 bytes. 77 bytes, 4 lines conffiles 1030 bytes, 27 lines control 4511 bytes, 64 lines md5sums 603 bytes, 31 lines * postinst #!/bin/bash 500 bytes, 25 lines * postrm #!/bin/sh 14536 bytes, 33 lines * preinst 289 bytes, 22 lines * prerm #!/bin/bash Package: bash Source: bash (5.1-3) Version: 5.1-3+b1 Architecture: amd64 Essential: yes Maintainer: Matthias Klose <[email protected]> Installed-Size: 6470 Pre-Depends: libc6 (>= 2.25), libtinfo6 (>= 6) Depends: base-files (>= 2.1.12), debianutils (>= 2.15) Recommends: bash-completion (>= 20060301-0) Suggests: bash-doc Conflicts: bash-completion (<< 20060301-0) Replaces: bash-completion (<< 20060301-0), bash-doc (<= 2.05-1) Section: shells Priority: required Multi-Arch: foreign Homepage: http://tiswww.case.edu/php/chet/bash/bashtop.html Description: GNU Bourne Again SHell Bash is an sh-compatible command language interpreter that executes commands read from the standard input or from a file. Bash also incorporates useful features from the Korn and C shells (ksh and csh). . Bash is ultimately intended to be a conformant implementation of the IEEE POSIX Shell and Tools specification (IEEE Working Group 1003.2). . The Programmable Completion Code, by Ian Macdonald, is now found in the bash-completion package.
dpkg 把所有的交易记录存在名为 /var/log/dpkg.log 的日志档。这个日志档的内容颇为详尽且啰唆，记录软件包被 dpkg 处理的每个进程。追踪 dpkg 的每个作为之外，日志档还保留系统发展的记录：可以覆查每个软件包的安装与移除步骤，对于了解最近的变动极有帮助。此外，还记录所有的版本，可以交互检查 changelog.Debian.gz 的内容，查看有问题的软件包或在线的错误报告。
架构 字段。该字段可包含：“全部“（对与架构无关的包），或者它的目标架构名称（如“amd64”， “armhf”，…）。对于后者，默认情况下，dpkg将只能接受安装与主机架构匹配的软件包，主机架构可通过dpkg --print-architecture来获得。
dpkg的多架构支持允许用户定义可安装于当前系统的“异质架构” 。这可以方便的通过 dpkg --add-architecture完成，如下例。有一相应的 dpkg --remove-architecture 以放弃对异质架构的支持，但仅可用于未余留该架构软件包的情况。
#dpkg --print-architectureamd64 #dpkg --print-foreign-architectures#dpkg -i gcc-9-base_9.3.0-22_armhf.debdpkg: error processing archive gcc-9-base_9.3.0-22_armhf.deb (--install): package architecture (armhf) does not match system (amd64) Errors were encountered while processing: gcc-9-base_9.3.0-22_armhf.deb #dpkg --add-architecture armhf#dpkg --add-architecture armel#dpkg --print-foreign-architecturesarmhf armel #dpkg -i gcc-9-base_9.3.0-22_armhf.deb(Reading database ... 456367 files and directories currently installed.) Preparing to unpack gcc-9-base_9.3.0-22_armhf.deb ... Unpacking gcc-9-base:armhf (9.3.0-22) ... Setting up gcc-9-base:armhf (9.3.0-22) ... #dpkg --remove-architecture armhfdpkg: error: cannot remove architecture 'armhf' currently in use by the database #dpkg --remove-architecture armel#dpkg --print-foreign-architecturesarmhf
Multi-Arch: same”标头字段，以告诉打包系统此软件包的不同架构可以安全地并存安装（而且这些软件包仅能满足相同架构的软件包的依赖）。自从 Debian 7 Wheezy 引入多重架构后，最重要的库已经转换了。但也有很多库恐怕永远不会被转换，除非有人特别请求（例如通过缺陷报告）。
$dpkg -s gcc-9-basedpkg-query: error: --status needs a valid package name but 'gcc-9-base' is not: ambiguous package name 'gcc-9-base' with more than one installed instance Use --help for help about querying packages. $dpkg -s gcc-9-base:amd64 gcc-9-base:armhf | grep ^MultiMulti-Arch: same Multi-Arch: same $dpkg -L libgcc-s1:amd64 |grep .so/lib/x86_64-linux-gnu/libgcc_s.so.1 $dpkg -S /usr/share/doc/gcc-9-base/copyrightgcc-9-base:amd64, gcc-9-base:armhf: /usr/share/doc/gcc-9-base/copyright
Multi-Arch: same软件包需具备能够明晰识别架构的名称。它们也能够与相同包的其他实例共享文件；dpkg确保所有的包在共享时具有逐位对应识别的文件。最后但并非最不重要的，一个包的所有实例必须为相同版本。它们必须同时升级。
Multi-Arch: foreign标识的软件包，或者架构上能匹配已声明依赖的软件包（在该依赖方案处理中，架构无关包假定为同样架构，而非主机架构）。通过 软件包 :any语法，依赖可以被弱化，以便允许任意架构能够满足依赖，但异质软件包仅能满足如下依赖：有“ Multi-Arch: allowed ”标识的依赖。