Advanced Packaging Tool is a user interface that lets the user install and remove packages/softwares on Debian/GNU Linux Distributions.
Searching for Packages
To search for a software/package in the repositories run the following command in the terminal
apt-cache search <search-term>|less
less is used for a better navigation through the output list
Adding Repositories
To add the repository run the following command
sudo add-apt-repository <repository name>
Manually the repositories can be added or changed by editing APTs source file
sudo vi /etc/apt/sources.list
Updating Sources
After adding repositories, the Package List has to be updated
sudo apt-get update
This will update the package list from all repositories in one go.
Remember to do this after every added repository
Installation
Now that you have added the software repository and updated your package list, and found the package name you need, you can install it by running the following command
sudo apt-get install <Package Names>
This will download and install all of the packages mentioned.If there are dependencies-other prerequisite packages-they will also be installed
Removing Packages
To get rid of a program run the following command
sudo apt-get remove <Package Name>
To get rid of the configuration files and associated directories as well
sudo apt-get --purge remove <Package Name>
Checking What is Installed
A list of all the installed packages can be seen by
sudo dpkg --list
To search through the list use the grep command
sudo dpkg --list|grep <search term>
If you want to know whether the particular package has been installed or not
dpkg -s <Package Name>