apt-cache

Usage:

apt-cache [options] commandapt-cache [options] show pkg1 [pkg2 …]

apt-cache queries and displays available information about installed and installable packages. It works exclusively on the data acquired into the local cache via the ‘update’ command of e.g. apt-get. The displayed information may therefore be outdated if the last update was too long ago, but in exchange apt-cache works independently of the availability of the configured sources (e.g. offline).

Most used commands:

showsrc - Show source recordssearch - Search the package list for a regex patterndepends - Show raw dependency information for a packagerdepends - Show reverse dependency information for a packagepkgnames - List the names of all packages in the systempolicy - Show policy settings