Update RHEL5

See here (within intranet, may require authentication) for how to register RHEL4 for up2date and RHEL5 for yum.

After that, then can use yum update for a complete update.

To install a certain package: yum install package_name

To see what a package does: yum provides package_name

To find packages containing some keyword: yum list | grep keyword

To check already installed packages that contains some keyword: rpm -qa | grep keyword