We can find lots of Ubuntu programs available that can meet the requirements of Ubuntu users. Many of such programs are nothing but archives which are most commonly known as repositories. With the help of repositories we can easily install the new software on our Ubuntu system with the help of Internet connection. Each of these programs also provides higher security because each of them is thoroughly tests and built for different version of Ubuntu. These Ubuntu repositories are generally divided in for separate components based of the support level offered by Ubuntu. These components are:
1. Main – These are generally officially supported software.
2. Restricted – this software are not licensed under GPL but still they are supported.
3. Universe – These are community maintained software but not officially supported.
4. Multiverse – These are software which is not free.
With the install CDs of Ubuntu we can get “Main” and “Restricted” components. Once you configure your system for Internet, you can specify locations about different repositories and get more software programs. You can easily make use of package management tool of Ubuntu and search for different programs from the Internet.
There are also some additional repositories available for Ubuntu. They can also be called as Third party repositories. Many software developers have their own repositories from where we can download and install packages to our computer. Many of such third party repositories are never reviewed by Debian community so it can have a security risk to the computer. While using such repositories you should have confidence in that website before you enable them and install it in your computer. Another category is Personal Package Archive. It is a special repository that is generally used for experimental purpose and they are under development. They neither are nor generally approved by Debian or Ubuntu developer community. This software should be used on our own risk.
How to Add Repositories with Synaptic Package Manager?
This is one of the preferred methods in Ubuntu.
Goto, Menu -> System -> Administration -> Synaptic Package Manager -> Settings -> Repositories. Here, you need to enable the repositories for Ubuntu based software and third party software.
For third party software you should select Add -> enter address of repository. For example it is going to be in following format:
Deb http://packages.medibuntu.org/ precise free non-free
Manually adding repositories
Adding the Repository
Adding repository manually can also be performed through command line. For example, Launchpad ppa repository can be added like this:
# sudo apt-add-repository ppa:user/repository
Here, ppa:user/repository is taken as an example, you can mention the repository that we want to add.
Removing the Repository
If you want to remove repository manually:
# sudo apt-add-repository –r ppa:user/repository
Refreshing the package list
This command with refresh and get all the latest packages from the given repository.
# sudo apt-get update
Note: In case, if apt-add-repository command is not there in your system then you can install the same with following command:
# sudo apt-get install python-software-properties