centOS5 install git

Installing git on CentOS 5 using yum
Since you're using CentOS 5, the default package manager is  yum , not  apt-get . To install a program using it, you'd normally use the following command:

$ sudo yum install <packagename>

However, when trying to install git this way, you'll encounter the following error on CentOS 5:

$ sudo yum install git
Setting up Install Process
Parsing package install arguments
No package git available.
Nothing to do

This tells you that the package repositories that  yum  knows about don't contain the required rpms (RPM Package Manager files) to install  git . This is presumably because CentOS 5 is based on RHEL 5, which was released in 2007, before  git  was considered a mature version control system. To get around this problem, we need to add additional repositories to the list that  yum  uses (We're going to add the RPMforge repository, as per these instructions ).
This assumes you want the i386 packages. Test by running  uname -i . If you want the x86_64 packages, replace all occurrences of i386 with x86_64 in the following commands
First, download the  rpmforge-release  package:

$ wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el5.rf.i386.rpm

Next, verify and install the package:

$ rpm --import http://apt.sw.be/RPM-GPG-KEY.dag.txt
$ rpm -K rpmforge-release-0.5.2-2.el5.rf.i386.rpm
$ rpm -i rpmforge-release-0.5.2-2.el5.rf.i386.rpm

And now we should be able to install  git :

$ sudo yum install git-gui

yum  will work out the dependancies, and ask you at relevant points if you want to proceed. Press y for Yes, andn or return for No.