This command is a command to add PPA source to the Source list when installing software through PPA source. The software installation process is as follows:

 1. Search the PPA software source, such as the software name keyword + PPA on Google, or you can directly search on launchpad.net2.sudo apt-add-repository ppa_source_name //Add PPA source to the source list (/etc/apt/sources.list)3. sudo apt update //Visit each URL in the source list, read the software list, and save it on the local computer, that is, get the latest update information of the software4.udo apt-get install [package name corresponding to the ppa source] //Download and install

Details are as follows:

add-apt-repository

Perhaps you have already noticed that when we introduce the software, we generally provide the PPA source installation method in the installation section, which is a fast and convenient software installation method, but for some novices, PPA is not very important.Very familiar, we will introduce it in detail below.

Let's take a look at the definition of PPA:

PPA is called Personal Package Archives (Personal Package Archives), it is Ubuntu Launchpad is a service that is not limited to Launchpad, of course.It allows individual users to upload software source code, compile it via Launchpad and publish it as a binary package, as an apt/Synaptic source for other users to download and update.Each user and team on the Launchpad website can have one or more PPAs.

Usually the software in the PPA source is not in the official source, or is the latest version of the software.The advantage of using PPA is that once the software is updated, you can directly upgrade to the new version through sudo apt-get upgrade command.

How to install software from a PPA source:

1. Usually we can search the PPA source of some commonly used software through Google, the usual search method is software name keyword + PPA, or directly on launchpad.netGo to Search
2. After searching, we can directly use the sudo apt-add-repository command to add the PPA source to the Source list.
   For example FireFox PPA source: https://launchpad.net/~ubuntu-mozilla-daily/+archive/ppa, we can find the words ppa:ubuntu-mozilla-daily/ppa here,Then we add this source to the source list with the following command.
   

sudo apt-add-repository ppa:ubuntu-mozilla-daily/ppa

1. Then we find the package name of FireFox 4.0 for the current Ubuntu version from the Packages list below, update the source and install:

 sudo apt-get updatesudo apt-get install firefox-4.0

In fact, in addition to the command line mode, Ubuntu also provides a third-party source management tool with a GUI interface, which will not be described in detail.In addition, Ubuntu-Tweak also contains a large number of third-party sources, which can be installed with one clickThird-party software is strongly recommended for novice installation.