Updating Debian Based Linux Installs

The Package Management System

Applications and the operating system itself is broken down in to piece of software called packages. Packages can be installed, uninstalled, and updated independently of each other.  Packages are held in depositories.  Depository's must be configured by URL, although a there will be a default depository per-configured for your Distro's Make and Model. Th default depository maintained by Ubuntu developers with stock packages that they maintain, regardless of the organization or team that wrote the software. This ensures everything you install has been compiled and tested for your specific version of Linux.  Third party developers can and do maintain their own independent depositories, which can added or removed bu the user/administrator, Although that will be covered in a future post.

APT

For Ubuntu and most other Debian based distributions to install software updates the command you need to know is  "apt".  apt is a a command that streamlines the use of two other commands "apt-get" and "apt-cache" into a single and more user friendly command. This command uses a the Debian Package Management System. "apt" is a front end command for both  "apt-get" and "apt-cache" commands into a single more user friendly command.

General Usage Structure:

"sudo apt  [options] <commands/argument>" - as usual you can get more information via "apt --help" and "man apt"

Update Package lists.

"sudo apt update"  - This updates the package lists.  It downloads fresh package lists and compares it to the system's own list of installed packages. It does NOT download or install any actual updates!

"sudo apt upgrade" - downloads and installs new versions of installed packages. It does not install any new dependencies.

"sudo apt full-upgrada"  will upgrades to the new version of the packages and install new dependencies.

"sudo apt autoremove"  - Removes unused packages, freeing up storage space.

Getting information with apt. 

 "apt list" - lists all packages, probably will fill buffer.

"apt list --installed" - lists installed packages.

"apt show <package name>"  - shows information about specific package(s).  Can use * symbol to list multiple matching.