$releasever // The release version number of the current system Version : 6
View the command: rpm -qi centos-release
$basearch // The platform architecture of the current system is x86_64
View command: arch
Reinstall to change the software version, set the resource file --> clear cache --> install
Clear the yum cache and rebuild the yum cache with the following commands:
yum clean all && yum clean metadata && yum clean dbcache && yum makecache && yum update
yum install <packages>
Introduction to yum command
yum check-update Check all packages that can be updated yum update
Download and update all packages installed in the system <packages> installs new packages yum update <packages> updates specified packages yum remove <packages> uninstalls specified packages yum groupinstall <groupnames> installs packages in specified software groups yum groupupdate <groupnames> updates specified software groups yum groupremove <groupnames> Uninstall packages in the specified software group yum grouplist View installed and available software groups in the system yum list List all rpm packages that can be installed or updated and installed in the repository yum list < regex> List the rpm packages that can be installed or updated and installed that match the regular expression in the repository yum list available List all the rpm packages that can be installed in the repository yum list available <regex> List the rpm packages in the repository that match the regular expression All rpm packages that can be installed that match the expression yum list updates List all rpm packages that can be updated in the repository yum list updates <regex> List all rpm packages that can be updated that match the regular expression in the repository
yum list installed Lists all installed rpm packages in the repository
yum list installed <regex> Lists all installed rpm packages in the repository that match the regular expression
yum list extras Lists installed but not included in the resource rpm packages in the repository
yum list extras <regex> List installed rpm packages that match the regular expression but not included in the repository
yum list recent List packages recently added to the repository
yum search < regex> Detects the names, descriptions, overviews, and listed maintainers of all available
software , looking for values that match a regular expression Expression matching value
yum clean headers Clear the rpm header files in the cache
yum clean packages Clear the rpm package files
in the cache yum clean all Clear the rpm header files and package files in the cache
yum deplist <packages> Display package dependency information
yum info List package information
When using yum for the first time or the yum repository is updated, yum will automatically download all the required headers and place them in the /var/cache/yum directory, which may take a long time.
The yum command can use the -y parameter to answer questions asked when the command is run with yes