How to add ppa repositories?

Question

Possible Duplicate:
What are PPAs and how do I use them?

I always like to have my programs up to date but in ubuntu software center the software aren't always up to date. I know about repositorys and i'd like to add some so how can i find the repository of certain programs in launchpad. I'm using Ubuntu 12.04.1.

Solution

You can add a PPA location with the command

sudo add-apt-repository ppa:<ppa_name>

For example sudo add-apt-repository ppa:gnome-desktop

You can find some help on Ubuntu Documentation

Comments

[E. Arslan]

Although there is no real 'root' user on Ubuntu, you have to have superuser permissions to add a PPA. On a regular system you have to do it with sudo: sudo add-apt-repository ...

[NorTicUs]

I edited my answer to reflect that. Thanks for the informations

[Veazer]

And if you're sure the PPA name is typed correctly, you can add ' -y' to the end to auto-allow the new PPA. (sudo add-apt-repository ppa:gnome-desktop -y). This makes it easier to use post-installation scripts that add multiple PPAs without user intervention.

[puk]

Just curious what would happen if you accidentally added the same ppa twice?

[Cbhihe]

@puk : I know this post is old but I tried it. It did not coplained and added a duplicate line in my list of software sources. I tried it with: sudo add-apt-repository ppa:freefilesync/ffs ..... It reported zero error, correct keyring (priv and pub) creation,etc... Exited normally. At the end I was left with a repeated line: ppa.launchedpad.net/freefilesync/ffs/ubuntu trusty main (Source Code)

[NoOne]

To use this command, I am asked to install software-properties-common. After I try to install it, I see that is 10.5MB in total! That's some serious size of binaries to simply add a URL to a list of URLs! :O