equery

View information about Portage packages. More information: https://wiki.gentoo.org/wiki/Equery.

• List all installed packages:
  equery list '*'
• Search for installed packages in the Portage tree and in overlays:
  equery list -po {{package1 package2 ...}}
• List all packages that depend on a given package:
  equery depends {{package}}
• List all packages that a given package depends on:
  equery depgraph {{package}}
• List all files installed by a package:
  equery files --tree {{package}}