Adding repositories

Ubuntu ships pre-configured to connect to the standard repositories.

A lot of extra packages are available from the "universe" and "multiverse" repositories.

You can add these by editing the file /etc/apt/sources.list (backup the original file first!)

gksu cp /etc/apt/sources.list /etc/apt/sources.list.bak
gksu gedit /etc/apt/sources.list

The sources.list file can look a bit daunting to the novice. Essentially there are four "sections" in each repository, they are;

hardy
hardy-updates
hardy-backports
hardy-security

Note: If you are using another release, replace "hardy" with the name of your release.

There are also four primary repositories;

main
restricted
universe
multiverse

The default sources.list file uses a seperate line for each repository and section. Most of the extra lines you require are already included but are commented out. You can uncomment them by removing the # from the beginning of each line that starts with "deb"

It is also possible to neaten things up by just adding all the repositories to a single set of four lines and simply removing everything else from the file (assuming you did the backup above!)

A simple sources.list using the repository at the main ubuntu site (http://archive.ubuntu.com) would be;

deb http://archive.ubuntu.com/ubuntu/ hardy main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ hardy-updates main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ hardy-backports main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ hardy-security main restricted universe multiverse

After you have made the changes and saved the file you need to tell the system to update the repository information;

sudo apt-get update

Now you have access to a whole lotta extra software goodness!

Packages

Traditionally on Linux systems, if you wanted to install a software package, you were required to obtain the source code and compile it using the compiler that was included in your system. This is still possible today, and hardcore geeks will still tell you it is the best way to maintain your system.

This may be true, but it is also more difficult for novice users and less convenient, especially when you need to update a package.

Fortunately, most modern linux distributions include software systems known as "package managers" which allows you to install pre-compiled binaries and avoid all that mucking about.

Ubuntu, being based on the debian distribution uses "deb" packages for installing binary packages.

While it is possible to download a deb file from the internet and install it (like installing an exe under that other OS), it is much better wherever possible to use your distributions online repositories to avoid being plunged into "dependency hell

In ubuntu, the easiest way to install software packages is by using "Add/Remove" on the "Applications" menu.

A lightly more advanced way is by using "Synaptic Package Manager" which can be found under "System>Administration"

On the command line you can use the apt-cache command to search for a package or apt-get to install and remove packages.

To search for a package using a text string;

apt-cache search | grep search_text

To install a package named "package"

sudo apt-get install package


Next we will look at adding extra software repositories.

Introduction

A place for all the tips and tricks I've learned or gleaned while using Ubuntu Linux

I'm currently using 8.04 (Hardy Heron) but most of the tips should work on older releases as well as any debian based distro's.

Although I might occasionally mention graphic tools, I tend to prefer the command line so most of my tips are command line based using text editors.

Generally speaking, if I use italics in a sample command, the italics indicate a generic term that needs to be changed to suit your particular purpose. For example;

To view the manual page for a command in the linux shell;

man command