The portage package suit tools provide a query tool that allows you to grab some information from your installed packages. Let’s see some usages of the equery utility.
For example to see all the files owned by a given package type:
equery files snort
Another example: show me the package that owns the top command.
equery belongs `which top`
Now tell me the USE flags for MySQL.
equery uses mysql
Show me the dependency tree for php.
equery depgraph php
For more information simply type…
equery -h