Managing Packages in Linux using CLI

Packages can be updates using graphical user interface (GUI) and command line interface (CLI) in Linux. This post discusses about various commands which can be used for managing the software installed on the device running Linux.

Installing Packages

apt-get is the command-line tool for handling packages.

• Install package
  sudo apt-get install <package name>
  install is followed by one or more packages desired for installation or upgrading. All packages required by the package(s) specified for installation will also be retrieved and installed. A specific version of a package can be selected for installation by following the package name with an equals and the version of the package to select.
  
  For example, below command is used for installing git
  sudo apt-get install git
• Install existing package
  sudo apt-get reinstall <package name>
  It is an alias for install –reinstall.
• Fix broken package by re-installing
  sudo apt install -f --reinstall <package name>

-f (--fix-broken) option attempt to correct a system with broken dependencies in place. --reinstall option re-install packages that are already installed and at the newest version. Following example resolve the broken dependencies by reinstalling minimal python3.
  sudo apt install -f --reinstall python3-minimal

Updating Packages

apt is a command-line utility for installing, updating and removing packages on Debian.

• Fetches the list of available updates
  sudo apt update
  It is used to download package information from all configured sources.
• Installs updates; does not remove packages
  sudo apt upgrade
  It is used to install available upgrades of all packages currently installed on the system from the sources configured. New packages will be installed if required to satisfy dependencies, but existing packages will never be removed.
• Installs updates; may also remove some packages, if needed
  sudo apt full-upgrade

Removing Packages

• Removes any old packages that are no longer needed
  sudo apt autoremove
  It is used to remove packages that were automatically installed to satisfy dependencies for other packages and are now no longer needed as dependencies changed or the package(s) needing them were removed in the meantime.
• Remove installed package
  sudo apt-get remove <package name>
  remove is identical to install except that packages are removed instead of installed. Removing a package leaves its configuration files on the system.
• Remove installed package along with configuration
  sudo apt-get purge <package name>
  purge is identical to remove except that packages are removed and purged (any configuration files are deleted too).