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Ubuntu Package Management


  • dpkg
  • apt-get
  • apt-cache

dpkg or apt-get

dpkg should be seen as a system tool (backend), and apt-get as a tool closer to the user, which overcomes the limitations of the former. These tools work together, each one with its particularities, suited to specific tasks.

List installed packages

grep /var/lib/dpkg/status

aracity@aracity-desktop:~$ grep Package: /var/lib/dpkg/status | sort | head -10
Package: acl
Package: acpi-support
Package: acpid
Package: adduser
Package: alacarte
Package: alsa-base
Package: alsa-utils
Package: anacron
Package: app-install-data
Package: app-install-data-partner


aracity@aracity-desktop:~$ dpkg-query -Wf '${Installed-Size}\t${Package}\n' | sort -n - | tail -10
40772   evolution-common
42052   gnome-games-data
59784   ubuntu-docs
65072   linux-headers-2.6.28-19
74940   libroot5.18
109552  linux-image-2.6.28-11-generic
109956  linux-image-2.6.28-18-generic
109972  linux-image-2.6.28-19-generic

Search for packages

Info for a package

understanding unmet dependencies

The following packages have unmet dependencies:
  libc6-dev: Depends: libc6 (= 2.9-4ubuntu6.3) but 2.12.1-0ubuntu10.2 is to be installed
  libgcc1: Depends: gcc-4.5-base (= 4.5.1-7ubuntu2) but it is not installable

dpkg –status OR dpkg -s

aracity@aracity-desktop:~$ dpkg --status libc6
Package: libc6
Status: install ok unpacked
Priority: required
Section: libs
Installed-Size: 10232
Maintainer: Ubuntu Core developers <>
Architecture: amd64
Source: eglibc
Version: 2.12.1-0ubuntu10.2
Config-Version: 2.9-4ubuntu6.3
Replaces: belocs-locales-bin
Provides: glibc-2.11-1
Depends: libc-bin (= 2.12.1-0ubuntu10.2), libgcc1, tzdata, findutils (>= 4.4.0-2ubuntu2)
Suggests: glibc-doc, debconf | debconf-2.0, locales
Breaks: nscd (<< 2.12)
Conflicts: belocs-locales-bin, tzdata (<< 2007k-1), tzdata-etch
 /etc/ 593ad12389ab2b6f952e7ede67b8fbbf
 /etc/bindresvport.blacklist db84c47f31f8d5a334a4053d8368e902 obsolete
 /etc/gai.conf ab538b366edabe44a9a4020fdd3d93a4 obsolete
 /etc/ d4d833fd095fb7b90e1bb4a547f16de6 obsolete
Description: Embedded GNU C Library: Shared libraries
 Contains the standard libraries that are used by nearly all programs on
 the system. This package includes shared versions of the standard C library
 and the standard math library, as well as many others.
Original-Maintainer: GNU Libc Maintainers <>
aracity@aracity-desktop:~$ dpkg --status libc6-dev
Package: libc6-dev
Status: install ok installed
Priority: optional
Section: libdevel
Installed-Size: 11456
Maintainer: Ubuntu Core developers <>
Architecture: amd64
Source: glibc
Version: 2.9-4ubuntu6.3
Replaces: man-db (<= 2.3.10-41), gettext (<= 0.10.26-1), ppp (<= 2.2.0f-24), libgdbmg1-dev (<= 1.7.3-24)
Provides: libc-dev
Depends: libc6 (= 2.9-4ubuntu6.3), linux-libc-dev
Recommends: gcc | c-compiler
Suggests: glibc-doc, manpages-dev
Conflicts: libstdc++2.10-dev (<< 1:2.95.2-15), gcc-2.95 (<< 1:2.95.3-8), binutils (<< 2.17cvs20070426-1), libc-dev
Description: GNU C Library: Development Libraries and Header Files
 Contains the symlinks, headers, and object files needed to compile
 and link programs which use the standard C library.
Original-Maintainer: GNU Libc Maintainers <>

apt-cache showpkg

aracity@aracity-desktop:~$ apt-cache showpkg subversion
Package: subversion
1.5.4dfsg1-1ubuntu2.1 (/var/lib/apt/lists/tw.archive.ubuntu.com_ubuntu_dists_jaunty-updates_main_binary-amd64_Packages) (/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_jaunty-security_main_binary-amd64_Packages)
 Description Language:
                 File: /var/lib/apt/lists/tw.archive.ubuntu.com_ubuntu_dists_jaunty-updates_main_binary-amd64_Packages
                  MD5: 15da1bb51fb2e9ea5e25b3a489b864d9

1.5.4dfsg1-1ubuntu2 (/var/lib/apt/lists/tw.archive.ubuntu.com_ubuntu_dists_jaunty_main_binary-amd64_Packages)
 Description Language:
                 File: /var/lib/apt/lists/tw.archive.ubuntu.com_ubuntu_dists_jaunty_main_binary-amd64_Packages
                  MD5: 15da1bb51fb2e9ea5e25b3a489b864d9


List Files in a package

dpkg -L

aracity@aracity-desktop:~$ dpkg -L libc6 | head -10

Install packages