The Yellowdog Updater Modified (YUM) is an rpm package management opensource tool which is available for Redhat Linux and other Linux flavors.In earlier days, its very difficult to install packages in Linux systems since it will ask for many dependencies.After yum introduction,its become very simple and yum has algorithm to select all the dependencies automatically once you configured the yum repository.
This article explains the basic yum commands and its usages. For a complete list see the yum man page.
yum list List all packages in all the repositories and all the packages installed on your system. yum list available Lists all the packages available to be installed in any enabled repository on your system. yum list installed Lists all the packages installed on the system. yum list extras Lists any installed package which no longer appears in any of your enabled repositories. yum list obsoletes Lists any obsoleting relationships between any available package and any installed package. yum list updates Lists any package in an enabled repository which is an update for any installed package. yum list recent Lists any package added to any enabled repository in the last seven(7) days. yum list pkgspec This command allows you to refine your listing for particular packages. yum check-update This is like yum list updates but returns an exit code of 100 if there are updates available. yum install This allows to install package. yum info This displays more information about any package installed or available. yum search This allows you to search for information from the various metadata available about packages. yum provides/yum whatprovides This command searches for which packages provide the requested dependency of file. This also takes wildcards for files. yum makecache Is used to download and make usable all the metadata for the currently enabled yum repos. yum clean The yum clean command allows you to clean up these files.