Using apt-get Commands in Ubuntu

A summary for Ubuntu beginners

References: It's FOSS, ttend.tistory.com

What is apt-get ?

• Ubuntu is an operating system derived from Debian Linux

  • Ubuntu's core utilities come from Debian!

• Debian uses the dpkg packaging system

  • What is a packaging system?

    • One of the methods for installing and maintaining software on a system

    • Using a packaging system means you don't need to receive the source code and build the program yourself!

    • Linux has the Debian family which uses deb packages and the RedHat family (.rpm) which uses rpm packages

      • Debian family

        : Debian, Ubuntu, Linspire, Xandros

      • RedHat family

        : Fedora, CentOS, RHEL, openSUSE, Mandirva

APT (Advanced Package Tool)

• A command line tool for interacting with the packaging system

  • You can also use the dpkg command, but apt is more user-friendly for handling packages!

• You can install, upgrade, and clean packages with apt

• It is a high level tool

High Level & Low Level Tool

Low level package tool

• Manages the tasks of installing and removing package files

  • ex) dpkg for Debian family, rpm for RedHat family

High level package tool

• Manages metadata search and dependency resolution tasks

Main Tools of APT

: The main tools of apt are apt-get and apt-cache

apt-get

• Used to install, upgrade, and clean packages

apt-cache

• Used to find new packages

Using apt-get commands

Updating packages with apt-get

Command

sudo apt-get update

Result

• Hit

  • Means there is no change in the package version

• Ign

  • Means the package was ignored

    • There can be various reasons

      • ex)

        • When it is so up-to-date that there is no need to check for a newer version

        • When an error occurred while searching for the package but it was a minor error so it was ignored

          • In conclusion, it is not an error so no need to worry!

• Get

  • When there is a new version of the package, apt-get downloads that information

    • The new version information, not the package itself!

Upgrading packages with apt-get

• Once you have an updated package database through $ sudo apt-get update, you can now upgrade the packages

Command

Upgrade all packages

sudo apt-get upgrade

• Adding -y at the end means you don't need to separately type y when asked whether to upgrade

Upgrade a specific package

sudo apt-get upgrade [package name]

Result

Using apt-cache commands

Searching for packages with apt-cache

• Useful for finding specific libraries

Command

When you know the exact package name

apt-cache search [package name]

When searching for packages starting with a specific name

apt-cache pkgnames [package name]

Result