Equery

equery is a tool to make several common portage operations simpler. Among other operations, it can display package dependencies, metadata, and installed files.

Installation
Equery is available as part of the package:

Capabilities
To see a list of all equery's capabilities, simply run it without arguments:

Module (b)elongs
List what package equery belongs to?

Module (d)epends
List all packages diqrectly depending on udev

Module (f)iles
List all files installed by ncmpcpp

Descriptions of other modules and additional command line flags can be found in the equery man page.

Aliases
If you found yourself using equery all the time to check USE flags, package files... you could write down a few handy aliases with `eq' as a prefix and the letter used by a function. I use `~/.aliasrc' for bash which could be used for any shell and `~/.oh-my-zsh/lib/aliases.zsh' for zsh because I use oh-my-zsh.

External Resources

 * [Community Gentoo Wiki article]