dpkg 是系統層面處理 Debian 套件的基礎指令。若您有 .deb 套件，可以用 dpkg 安裝及分析其內容。但此指令祗能看到 Debian 世界的部份內容：它知道系統安裝那些套件、指令列給了那些參數，但不知道還有那些可用的套件。因此，沒有相依性就完了。apt 之類的工具，則可產生相依性清單，儘量自動安裝套件。
dpkg 是安裝 Debian 已經可用套件的工具 (因為不需下載任何東西)。我們使用它的 -i 或 --install 選項。
範例 5.2. 以 dpkg 安裝套件
#dpkg -i man-db_2.7.6.1-2_amd64.deb(Reading database ... 110431 files and directories currently installed.) Preparing to unpack man-db_2.7.6.1-2_amd64.deb ... Unpacking man-db (2.7.6.1-2) over (2.7.6.1-1) ... Setting up man-db (2.7.6.1-2) ... Updating database of manual pages ... Processing triggers for mime-support (3.60) ...
dpkg 執行的不同階段；因此，我們知道可能發生錯誤的時刻。安裝可能分為兩個階段；解壓縮、組態。apt-get 用到此等階段，限制被 dpkg 調用的內容 (因為調用的過程極為費力，必須載入記憶體的資料庫，尤其是已經被安裝清單內的)。
範例 5.3. 分開解壓與組態
#dpkg --unpack man-db_2.7.6.1-2_amd64.deb(Reading database ... 110431 files and directories currently installed.) Preparing to unpack man-db_2.7.6.1-2_amd64.deb ... Unpacking man-db (2.7.6.1-2) over (2.7.6.1-2) ... Processing triggers for mime-support (3.60) ... #dpkg --configure man-dbSetting up man-db (2.7.6.1-2) ... Updating database of manual pages ...
dpkg 安裝套件時偶而失敗並送回錯誤的訊息；若使用者要求忽略該等訊息，就能送出警示；這就是 --force-* 選項的用途。dpkg --force-help 命令，或此命令的文件，將提供完整的選項。最常發生的錯誤，遲早每個人都會碰到，就是檔案衝突。已被其他套件安裝使用的檔案，另個套件同時需要用到它時，dpkg 會於安裝時再次使手它。此時出現以下的訊息：
Unpacking libgdm (from .../libgdm_3.8.3-2_amd64.deb) ...
dpkg: 處理 /var/cache/apt/archives/libgdm_3.8.3-2_amd64.deb (--unpack) 時發生錯誤:
試圖覆寫 '/usr/bin/gdmflexiserver'，也同時在套件 gdm3 3.4.1-9 內--force-overwrite，告訴 dpkg 忽略此錯誤並覆寫該檔案。
--force-* 有很多選項，祗有 --force-overwrite 是固定使用的。這些選項祗存在於極為特殊的情況，最好是儘量不要碰它以尊重套件本身的機制。別忘了，這些機制確保系統的一致性與穩定性。
dpkg 加上 -r 或 --remove 選項，再加上套件名稱，就可移除該套件。然而，這種方式的移除並不完整：仍保留所有的組態檔、維護腳本、記錄檔案 (系統記錄檔) 及該套件的其他使用者資料。這種方式是停用程式，仍可以相同的組態快速地再安裝回來。完全移除該套件的所有相關檔案，應使用 -P 或 --purge 選項，再加上套件名稱。
dpkg 選項。先給長版的選項再給對應的短版選項 (其參數是一樣的) 以 --listfiles 套件 (或 -L) 為例，列出該套件安裝的檔案清單；--search 檔案 (或 -S)，尋找包括該檔案的套性；--status 套件 (或 -s)，顯示該套件的標頭；--list (或 -l)，顯示該系統內套件清單與安裝狀態；--contents file.deb (或 -c)，列出 Debian 指定套件清單；--info file.deb (或 -I)，列出該套件的標頭。
範例 5.5. dpkg 的各種查詢
$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: 15103 Maintainer: Michael Stone <mstone@debian.org> Architecture: amd64 Multi-Arch: foreign Version: 8.26-3 Replaces: mktemp, realpath, timeout Pre-Depends: libacl1 (>= 2.2.51-8), libattr1 (>= 1:2.4.46-8), libc6 (>= 2.17), libselinux1 (>= 2.1.13) Conflicts: timeout 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) un baekmuk-ttf <none> <none> (no description available) un base <none> <none> (no description available) un base-config <none> <none> (no description available) ii base-files 9.9+deb9u1 amd64 Debian base system miscellaneous files ii base-passwd 3.5.43 amd64 Debian base system master password and group ii bash 4.4-5 amd64 GNU Bourne Again SHell [...] $dpkg -c /var/cache/apt/archives/gnupg_2.1.18-8~deb9u1_amd64.debdrwxr-xr-x root/root 0 2017-09-18 20:41 ./ drwxr-xr-x root/root 0 2017-09-18 20:41 ./usr/ drwxr-xr-x root/root 0 2017-09-18 20:41 ./usr/bin/ -rwxr-xr-x root/root 996648 2017-09-18 20:41 ./usr/bin/gpg -rwxr-xr-x root/root 3444 2017-09-18 20:41 ./usr/bin/gpg-zip -rwxr-xr-x root/root 161192 2017-09-18 20:41 ./usr/bin/gpgconf -rwxr-xr-x root/root 26696 2017-09-18 20:41 ./usr/bin/gpgparsemail -rwxr-xr-x root/root 76112 2017-09-18 20:41 ./usr/bin/gpgsplit -rwxr-xr-x root/root 158344 2017-09-18 20:41 ./usr/bin/kbxutil -rwxr-xr-x root/root 1081 2014-06-25 16:17 ./usr/bin/lspgpot -rwxr-xr-x root/root 2194 2017-09-18 20:41 ./usr/bin/migrate-pubring-from-classic-gpg -rwxr-xr-x root/root 14328 2017-09-18 20:41 ./usr/bin/watchgnupg drwxr-xr-x root/root 0 2017-09-18 20:41 ./usr/sbin/ -rwxr-xr-x root/root 3078 2017-09-18 20:41 ./usr/sbin/addgnupghome -rwxr-xr-x root/root 2219 2017-09-18 20:41 ./usr/sbin/applygnupgdefaults drwxr-xr-x root/root 0 2017-09-18 20:41 ./usr/share/ drwxr-xr-x root/root 0 2017-09-18 20:41 ./usr/share/doc/ drwxr-xr-x root/root 0 2017-09-18 20:41 ./usr/share/doc/gnupg/ -rw-r--r-- root/root 18964 2017-01-23 18:39 ./usr/share/doc/gnupg/DETAILS.gz [...] $dpkg -I /var/cache/apt/archives/gnupg_2.1.18-8~deb9u1_amd64.debnew debian package, version 2.0. size 1124042 bytes: control archive=2221 bytes. 1388 bytes, 24 lines control 2764 bytes, 43 lines md5sums Package: gnupg Source: gnupg2 Version: 2.1.18-8~deb9u1 Architecture: amd64 Maintainer: Debian GnuPG Maintainers <pkg-gnupg-maint@lists.alioth.debian.org> Installed-Size: 2088 Depends: gnupg-agent (= 2.1.18-8~deb9u1), libassuan0 (>= 2.0.1), libbz2-1.0, libc6 (>= 2.15), libgcrypt20 (>= 1.7.0), libgpg-error0 (>= 1.14), libksba8 (>= 1.3.4), libreadline7 (>= 6.0), libsqlite3-0 (>= 3.7.15), zlib1g (>= 1:1.1.4) Recommends: dirmngr (= 2.1.18-8~deb9u1), gnupg-l10n (= 2.1.18-8~deb9u1) Suggests: parcimonie, xloadimage Breaks: debsig-verify (<< 0.15), dirmngr (<< 2.1.18-8~deb9u1), gnupg2 (<< 2.1.11-7+exp1), libgnupg-interface-perl (<< 0.52-3), libgnupg-perl (<= 0.19-1), libmail-gnupg-perl (<= 0.22-1), monkeysphere (<< 0.38~), php-crypt-gpg (<= 1.4.1-1), python-apt (<= 1.1.0~beta4), python-gnupg (<< 0.3.8-3), python3-apt (<= 1.1.0~beta4) Replaces: gnupg2 (<< 2.1.11-7+exp1) Provides: gpg Section: utils Priority: optional Multi-Arch: foreign Homepage: https://www.gnupg.org/ Description: GNU privacy guard - a free PGP replacement GnuPG is GNU's tool for secure communication and data storage. It can be used to encrypt data and to create digital signatures. It includes an advanced key management facility and is compliant with the proposed OpenPGP Internet standard as described in RFC4880. [...]
dpkg 把所有的交易記錄存在名為 /var/log/dpkg.log 的日誌檔。這個日誌檔的內容頗為詳盡且囉唆，記錄套件被 dpkg 處理的每個程序。追蹤 dpkg 的每個作為之外，日誌檔還保留系統發展的記錄：可以覆查每個套件的安裝與移除步驟，對於瞭解最近的變動極有幫助。此外，還記錄所有的版本，可以交互檢查 changelog.Debian.gz 的內容，查看有問題的套件或線上的錯誤報告。
Architecture 欄位。其內容為 “all” (表示該套件不受架構限制) 或指出其適用的架構 (如 “amd64”、“armhf”、…)。以後例而言，主機的架構符合後，dpkg 才開始安裝該套件，並送回 dpkg --print-architecture。
dpkg 的多架構支授允許使用者限制 “怪異的架構” 安裝在現行的系統上。以下例的 dpkg --add-architecture 就能做到。有個對應的 dpkg --remove-architecture 指令可以除去怪異的架構，不過祗發生於無套件可用時。
#dpkg --print-architectureamd64 #dpkg --print-foreign-architectures#dpkg -i gcc-6-base_6.3.0-18_armhf.debdpkg: error processing archive gcc-6-base_6.3.0-18_armhf.deb (--install): package architecture (armhf) does not match system (amd64) Errors were encountered while processing: gcc-6-base_6.3.0-18_armhf.deb #dpkg --add-architecture armhf#dpkg --add-architecture armel#dpkg --print-foreign-architecturesarmhf armel #dpkg -i gcc-6-base_6.3.0-18_armhf.debSelecting previously unselected package gcc-6-base:armhf. (Reading database ... 112000 files and directories currently installed.) Preparing to unpack gcc-6-base_6.3.0-18_armhf.deb ... Unpacking gcc-6-base:armhf (6.3.0-18) ... Setting up gcc-6-base:armhf (6.3.0-18) ... #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” header field to tell the packaging system that the various architectures of the package can be safely co-installed (and that those packages can only satisfy dependencies of packages of the same architecture). The most important libraries have been converted since the introduction of multi-arch in Debian Wheezy, but there are many libraries that will likely never be converted unless someone specifically requests it (through a bug report for example).
$dpkg -s gcc-6-basedpkg-query: error: --status needs a valid package name but 'gcc-6-base' is not: ambiguous package name 'gcc-6-base' with more than one installed instance Use --help for help about querying packages. $dpkg -s gcc-6-base:amd64 gcc-6-base:armhf | grep ^MultiMulti-Arch: same Multi-Arch: same $dpkg -L libgcc1:amd64 |grep .so/lib/x86_64-linux-gnu/libgcc_s.so.1 $dpkg -S /usr/share/doc/gcc-6-base/copyrightgcc-6-base:amd64, gcc-6-base:armhf: /usr/share/doc/gcc-6-base/copyright
Multi-Arch: same 套件的名稱必須符合其架構才能被明確的指認出來。也可能以相同的套件在其他情況下共享檔案；共享時，dpkg 確認所有套件的每個位元都相同。最後但不是最不重要，套件的所有實例必須使用相同的版本。也必須一起更新。
Multi-Arch: foreign” 或宣告其匹配架構的相依性 (在這種相依性解決過程中，假設架構獨立的套件與主機不同)。相依性可能被弱化以允許納入其他架構，以 套件:any 語法，但怪異套件祗需滿足一個相依性，如果標示為 “Multi-Arch: allowed”。