Use flags

From XPUB & Lens-Based wiki

Use flags are options in Gentoo Linux's Portage system.

Setting Use Flags

Per package

Typically, you would add a use flags on a per-package basis by making changes to the file:

  • /etc/portage/package.use

Use a text editor as "superuser" to edit this file.

For instance to add jpeg, png, and TrueType support to ImageMagick, you need to add the following line somewhere (it doesn't matter where) to the package.use file:

media-gfx/imagemagick jpeg png truetype

To explicitly disable a particular feature, put a dash (-) before the flag name, as in:

media-gfx/imagemagick jpeg png truetype -tiff

Globally

Sometimes a particular use flag is used by many packages. To set such a flag for all software packages you install with portage, you can add them to the file /etc/make.conf. In that case, you would add the flag to the line that looks like USE="...", as in:

USE="-ipv6 gtk2 unicode"

For more in information on Portage, check out Cal's post in the forum.