Package administration commands

Basic Configuration

 As part of its operation, APT uses a file that lists the 'sources' from which packages can be obtained. This file is /etc/apt/sources.list. The entries in this file normally follow this format:


     deb http://host/debian distribution section1 section2 section3
     deb-src http://host/debian distribution section1 section2 section3

Of course, the above entries are fictitious and should not be used. The first word on each line, deb or deb-src, indicates the type of archive: whether it contains binary packages (deb), that is, the pre-compiled packages that we normally use, or source packages (deb-src), which are the original program sources plus the Debian control file (.dsc) and the diff.gz containing the changes needed for `debianizing' the program.


We usually find the following in the default Debian sources.list:

     # See sources.list(5) for more information, especially
     # Remember that you can only use http, ftp or file URIs
     # CDROMs are managed through the apt-cdrom tool.
     deb stable main contrib non-free
     deb stable/non-US main contrib non-free
     deb stable/updates main contrib non-free
     # Uncomment if you want the apt-get source function to work
     #deb-src stable main contrib non-free
     #deb-src stable/non-US main contrib non-free


These are the lines needed by a basic Debian install. The first deb line points to the official archive, the second to the non-US archive and the third to the archive of Debian security updates.


The two last lines are commented out (with a `#' in front), so apt-get will ignore them. These are deb-src lines, that is, they point to Debian source packages. If you often download program sources for testing or recompiling, uncomment them.


The /etc/apt/sources.list file can contain several types of lines. APT knows how to deal with archives of types http, ftp, file (local files, e.g., a directory containing a mounted ISO9660 filesystem) and ssh, that I know of.


Do not forget to run apt-get update after modifying the /etc/apt/sources.list file. You must do this to let APT obtain the package lists from the sources you specified.

When you install a package APT retrieves the needed files from the hosts listed in /etc/apt/sources.list, stores them in a local repository (/var/cache/apt/archives/), and then proceeds with installation

Main package management tools

     dpkg       – Debian package file installer
     apt-get   – Command line front end for APT
     aptitude  – Advanced text and command line front end for APT
     synaptic  – Gtk GUI front end for APT
     dselect    – Menu-driven package manager
     tasksel    – Task installer

To install software using apt

#apt-get install software

     -h  This help text.
     -d  Download only - do NOT install or unpack archives
     -f  Attempt to continue if the integrity check fails
     -s  No-act. Perform ordering simulation
     -y  Assume Yes to all queries and do not prompt
     -u  Show a list of upgraded packages as well

If you somehow damage an installed package, or simply want the files of a package to be reinstalled with the newest version that is available, you can use the --reinstall option like so:

# apt-get --reinstall install packagename

Updating the list of packages in your sources.list

#apt-get update

Update software using apt

#apt-get -u upgrade

To change the list of apt mirrors


Search for package

#apt-cache search package

Uninstall software using apt

#apt-get remove software

Shortcuts / Cheatcodes

update the package lists

# apt-get update

update the available package lists

# dselect update

upgrade all installed packages

# apt-get upgrade

installs package

# apt-get install pkg

uninstall package

# apt-get remove pkg

show all installed and removed packages

#dpkg -l

show install status of package

#dpkg -l pkg

show all packages that match pattern

#dpkg -S pattern

list packages that contain string


 list files in package

#dpkg -L pkg

show status of package

#dpkg -s pkg

show details of package

#dpkg -p pkg

list relevant packages

#apt-cache search string

install package from a deb file

# dpkg -i file.deb

purge package

# dpkg -P pkg

re-run the configure for a package

# dpkg-reconfigure pkg

get the source

# apt-get source pkg

config build-deps for source and install as needed

# apt-get build-dep

install package from specific release

# apt-get -t release install pkg

prevent name from running at bootup

# update-rc.d -f name remove

upgrade the distribution

# apt-get –u dist-upgrade

How to know what packages may be upgraded

apt-show-versions is a program that shows what packages in the system may be updated and several useful information.

The -u option displays a list of upgradeable packages:

 # apt-show-versions -u

aptitude is now the preferred text front end for APT, the Advanced Package Tool. It remembers which packages you deliberately installed and which packages were pulled in through dependencies; the latter packages are automatically de-installed by aptitude when they are no longer needed by any deliberately installed packages. It has advanced package-filtering features but these can be difficult to configure.

aptitude update: Update the local cache of available packages (formerly apt-get update.

aptitude upgrade: Upgrade available packages (formerly apt-get upgrade).

aptitude dist-upgrade: Upgrade available packages even if it means removing stuff (formerly apt-get dist-upgrade).

aptitude install pkgname: Install package (formerly apt-get install).

aptitude remove pkgname: Uninstall package (formerly apt-get remove).

aptitude purge pkgname: Uninstall package and config files (formerly apt-get –purge remove).

aptitude search string: Search for a package with “string” in the name or description (formerly apt-cache search string).

aptitude show pkgname: Show detailed of a package (formerly apt-cache show pkgname).

aptitude clean: Delete downloaded package files (formerly apt-get clean).

aptitude autoclean: Delete only out-of-date package files but keep current ones (formerly apt-get autoclean).

aptitude hold pkgname: Fix a package at its current version and don’t upgrade it automatically (formerly an obscure echo-to-file command). unhold to remove the hold.

Optimized sources.list

In short, fancy efforts to create an optimized sources.list did not produce a significant improvement for me from a location in the USA. I manually chose a nearby site using apt-setup.


apt-spy creates sources.list automatically, based on latency and bandwidth. netselect-apt creates a more complete sources.list, but uses an inferior method of choosing the best mirror (ping time comparison).


     # aptitude install apt-spy
     # cd /etc/apt ; mv sources.list
     # apt-spy -d testing -l sources.apt

The dpkg-divert command


File diversions are a way of forcing dpkg not to install a file into its default location, but to a diverted location. Diversions can be used through the Debian package scripts to move a file away when it causes a conflict. System administrators can also use a diversion to override a package's configuration file, or whenever some files (which aren't marked as conffiles) need to be preserved by dpkg, when installing a newer version of a package which contains those files.


     # dpkg-divert [--add]  filename # add "diversion"
     # dpkg-divert --remove filename # remove "diversion"

 if the dpkg command is broken follow this


A broken dpkg may make it impossible to install any .deb files. A procedure like the following will help you recover from this situation. (In the first line, you can replace "links" with your favorite browser command.)


     $ links
       ... download the good dpkg_version_arch.deb
     $ su
     password: *****
     # ar x dpkg_version_arch.deb
     # mv data.tar.gz /data.tar.gz
     # cd /
     # tar xzfv data.tar.gz

For i386, may also be used as the URL.


 Local package archive

In order to create a local package archive which is compatible with APT and the dselect system, Packages needs to be created and package files need to be populated in a particular directory tree.


A local deb repository similar to an official Debian archive can be made in this way:


     # aptitude install dpkg-dev
     # cd /usr/local
     # install -d pool # physical packages are located here
     # install -d dists/unstable/main/binary-i386
     # ls -1 pool | sed 's/_.*$/ priority section/' | uniq > override
     # editor override # adjust priority and section
     # dpkg-scanpackages pool override /usr/local/ \
        > dists/unstable/main/binary-i386/Packages
     # cat > dists/unstable/main/Release << EOF
     Archive: unstable
     Version: 3.0
     Component: main
     Origin: Local
     Label: Local
     Architecture: i386
     # echo "deb file:/usr/local unstable main" \ >> /etc/apt/sources.list

Alternatively, a quick-and-dirty local deb repository can be made:

     # aptitude install dpkg-dev
     # mkdir /usr/local/debian
     # mv /some/where/package.deb /usr/local/debian
     # dpkg-scanpackages /usr/local/debian /dev/null | \
       gzip - > /usr/local/debian/Packages.gz
     #  echo "deb file:/usr/local/debian ./" >> /etc/apt/sources.list

These archives can be remotely accessed by providing access to these directories through either HTTP or FTP methods and changing entries in /etc/apt/sources.list accordingly.

auto-apt command

auto-apt is an on-demand package installation tool.


     $ sudo auto-apt update
      ... update database
     $ auto-apt -x -y run
     Entering auto-apt mode: /bin/bash
     Exit the command to leave auto-apt mode.
     $ less /usr/share/doc/med-bio/copyright # access non-existing file
      ...  Install the package which provide this file.
      ... Also install dependencies

Package Management Common errors

Errors will always happen, many of them caused by users not paying attention. The following is a list of some of the most frequently reported errors and how to deal with them.

If you receive a message that looks like the one below when trying to run apt-get install package

Reading Package Lists... Done
Building Dependency Tree... Done
W: Couldn't stat source package list ' unstable/ Packages' (/var/state/apt/lists/people.debian.org_%7ekov_debian_unstable_Packages) - stat (2 No such file or directory)
W: You may want to run apt-get update to correct these missing files
E: Couldn't find package penguineyes

you forgot to run apt-get update after your last change to the /etc/apt/sources.list file.

If the error looked like:

E: Could not open lock file /var/lib/dpkg/lock - open (13 Permission denied)
E: Unable to lock the administration directory (/var/lib/dpkg/), are you root?

when trying any apt-get method other than source, you don't have root permission, that is, you're running as a normal user.

There's an error similar to the above which happens when you run two copies of apt-get at the same time, or even if you try to run apt-get while a dpkg process is active. The only method that can be used simultaneously with others is the source method.

If an installation breaks in the middle of the process and you find that it's no longer possible to install or remove packages, try running these two commands:

# apt-get -f install
# dpkg --configure -a

And then try again. It may be necessary to run the second of the above commands more than once. This is an important lesson for those adventurers who use `unstable'.

If you receive the error "E: Dynamic MMap ran out of room" when running apt-get update,

add the following line to /etc/apt/apt.conf:

APT::Cache-Limit 10000000;