USE flag

USE flags are a core feature of Gentoo, and a good understanding of how to deal with them is needed for administering your Gentoo system.

Tools
Some tools are available for analyzing and managing USE flags:
 * euse
 * equery hasuse (USE flag)
 * equery uses (package name)
 * ufed
 * eix eix --use (USE flag), eix --installed-with-use (USE flag), eix --installed-without-use (USE flag)
 * eix eix --use (USE flag), eix --installed-with-use (USE flag), eix --installed-without-use (USE flag)