3. Software Management Tools in CentOS

The yum utility is a complete software management system. CentOS also includes several other applications that can supplement yum.

On your desktop is an Alert Icon that keeps you informed about package updates. Until your system is updated the icon appears as a red circle with a flashing exclamation mark. The Alert Icon is part of the up2date application, which enables you to easily install system updates.

CentOS also includes system-config-packages. To run this application from the graphical interface, select Desktop->System Settings->Add/Remove Applications. Unlike up2date and yum, system-config-packages installs software packages from your CentOS installation discs only, and does not use repositories. This application is used on systems that do not have a network connection.

[Caution]system-config-packages

The system-config-packages utility can ONLY be used if you do not update any packages and install only from the CD/DVD. This utility will fail if updates have been done.

The rpm command-line utility has many functions for working with individual RPM packages. You may use it to manually install and remove packages from your system. If you install software with the rpm utility, you must manually check and install any dependencies. For this reason, yum is the recommended method for installing software.

[Caution]Current Package Versions

The up2date and yum utilities ensure that you have the most recent version of software packages. Other methods do not guarantee that the packages are current.