Linux for Everyone

To clean the cache from system which apt caches when we update/install the packages apt-get clean    To downloads  packages list from repository and update them,to get data on latest available packages apt-get update   To install specific version of  package apt-get install package-name  To check OS version    Ex : lsb_release -a To provides the package's description, its dependencies, the name of its maintainer. apt search, apt show, aptitude search, aptitude show work in the similar manner Ex : apt-cache search php5-fpm The checkrestart program tries to determine if there are  processes  in the  system  that  need to be restarted after a system upgrade .Consequently, checkrestart is sometimes used as an audit tool  to  find outdated  versions  of  libraries  in  use, particularly after security upgrades Ex : checkrestart -h  List all installed packages, along with package version and short details. Ex : dpkg -l php5-fpm