Ubuntu / Linux news and application reviews.

You probably know that starting with Ubuntu Karmic, you can add a Launchpad PPA using a simple command:
sudo add-apt-repository ppa:THE_PPA

Where "THE_PPA" is the Personal Package Archive you want to add, for instance ubuntu-mozilla-daily, etc.

To remove a PPA via the command line, you can use the same "add-apt-repository" command with the "-r" parameter, which will remove the PPA:
sudo add-apt-repository -r ppa:<repository-name>/<subdirectpory>

For instance, to remove the ubuntu-mozilla-daily PPA, use:
sudo add-apt-repository -r ppa:ubuntu-mozilla-daily/ppa

This only removes the PPA, which means you'll no longer receive updates from that PPA, but it doesn't affect the packages installed from that PPA.

If you want to remove the PPA but also downgrade all the packages installed from that PPA, you can use PPA Purge. 

PPA Purge is available in the official Ubuntu repositories to so install it, use the following command:
sudo apt-get install ppa-purge

To use PPA Purge to purge a PPA, use:
sudo ppa-purge ppa:<repository-name>/<subdirectory>

For instance, to purge the ubuntu-mozilla-daily PPA:
sudo ppa-purge ppa:ubuntu-mozilla-daily/ppa
(this is just an example)