apt-get

This post was most recently updated on December 11th, 2018

Apt-Get

The apt-get command is a powerful command-line tool used to work with Ubuntu’s Advanced Packaging Tool (APT) performing such functions as installation of new software packages, upgrade of existing software packages, updating of the package list index, and even upgrading the entire Ubuntu system.

Being a simple command-line tool, apt-get has numerous advantages over other package management tools available in Ubuntu for server administrators. Some of these advantages include ease of use over simple terminal connections (SSH) and the ability to be used in system administration scripts, which can in turn be automated by the cron scheduling utility.

Some examples of popular uses for the apt-get utility:

  • Install a Package: Installation of packages using the apt-get tool is quite simple. For example, to install the network scanner nmap, type the following:

    sudo apt-get install nmap

     

  • Remove a Package: Removal of a package or packages is also a straightforward and simple process. To remove the nmap package installed in the previous example, type the following:

    sudo apt-get remove nmap

     

     

    Tip: Multiple Packages: You may specify multiple packages to be installed or removed, separated by spaces.

     

  • Update the Package Index: The APT package index is essentially a database of available packages from the repositories defined in the /etc/apt/sources.list file. To update the local package index with the latest changes made in repositories, type the following:

    sudo apt-get update

     

  • Upgrade Packages: Over time, updated versions of packages currently installed on your computer may become available from the package repositories (for example security updated). To upgrade your system, first update your package index as outlined above, and then type:

    sudo apt-get upgrade

     

    If a package needs to install or remove new dependencies when being upgraded, it will not be upgraded by the upgrade command. For such an upgrade, it is necessary to use the dist-upgrade command.

    Also, you may upgrade your entire Ubuntu system from one revision to another with dist-upgrade. For example, to upgrade from Ubuntu version 5.10 to version 6.06 LTS, you would first ensure the version 6.06 LTS repositories replace the existing 5.10 repositories in your computer’s /etc/apt/sources.list, then simply issue the apt-get update command as detailed above, and finally, perform the actual upgrade by typing:

    sudo apt-get dist-upgrade

     

    After a fairly considerable amount of time, your computer will be upgraded to the new revision. Typically, some post-upgrade steps would be required as detailed in the upgrade notes for the revision you are upgrading to.

    Actions of the apt-get command, such as installation and removal of packages, are logged in the /var/log/dpkg.log log file.

 

 

For further information about the use of APT, read the comprehensive Debian APT User Manual or type:

apt-get help

apt-get command cheat sheet for Debian Linux

apt-get is the command-line tool for handling packages for Debian Linux which is use to:

  • Install/manage individual packages
  • Upgrade packages
  • Apply security patch(s)
  • Keep Debian system up to date
  • Download source .deb files
  • Front-end to many GUI and other utilities

Here is quick cheat sheet you will find handy while using apt-get at shell prompt:

Syntax Description Example(s)
apt-get install {package} Install the new package. If package is installed then try to upgrade to latest version apt-get install zip
apt-get install lsof samba mysql-client
apt-get remove {package} Remove/Delete an installed package except configuration files apt-get remove zip
apt-get –purge remove {package} Remove/Delete everything including configuration files apt-get –purge remove mysql-server
apt-get update
apt-get upgrade
Resynchronize the package index files and Upgrade the Debian Linux system including security update (Internet access required) apt-get update
apt-get upgrade
apt-get update
apt-get dist-upgrade
Usually use to upgrade to Debian distribution. For example Woody to Sarge upgrade. ‘dist-upgrade’ in addition to performing the function of upgrade, also intelligently handles changing dependencies with new versions of packages; apt-get has a “smart” conflict resolution system, and it will attempt to upgrade the most important packages at the expense of less important ones if necessary. apt-get update
apt-get dist-upgrade

{package} – Replace with actual package name

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