USE Variables

mitchm0521 · n00b Joined: 17 Dec 2005 Posts: 12

I asked this in another post, but perhaps its best to not change the subject in the Gnome 2.12 and start a new thread. What I am wondering is what exactly are the USE flags good for. I've read the documentation for it from the Gentoo Handbook, but is it honestly a matter of if I don't put X as a use flag, I can never use X windows? I am wondering what I need as my use flags I want to run Gnome and KDE as well. should I use alsa? here is what I have so far

USE="x86 X kde gnome gtk gtk2 qt samba -arts alsa"

What else do I need? If I don't add things like truetype, can I never use my Microsoft fonts on my Linux partition?

I'm just a little confused as to how exactly they work. And what I need.

Thanks,
Mitch

tom56 · Posted: Tue Jan 24, 2006 7:43 pm Post subject:

Firstly, x86 isn't a use flag.

The easiest way to choose use flags is to always run emerges as -pv first (man emerge if you don't know what I mean) then lookup each flag you don't recognise. Then, if you are unhappy with any of the defaults (as in whether they are + or -), change them in your make.conf or your package.use. Eventually, through that method you'll build up quite a hefty list, for example here is my make.conf...

desultory · Bodhisattva Joined: 04 Nov 2005 Posts: 9410

You do not need to set USE flag 'foo' to emerge package 'foo', in fact most (all?) packages which have a corresponding USE flag set that flag automatically when you emerge the package, for example emerging xorg-x11 sets 'X'.

When you have a USE flag set it indicates to software which you subsequently install (or reinstall) what features to enable and which to disable. Thus if there is optional support fo a feature with a corresponding USE flag the package will either enable that support or not depending upon how you have that USE flag set.

For a quick summary of what each USE flag governs have a look at: /usr/portage/profiles/use.desc.
You already know about the section of the Handbook:
You can set USE flags for specific packages using /etc/portage/package.use, this is covered in the portage man page.

tost · Guru Joined: 10 Dec 2005 Posts: 506

Always take a look on the output of emerge -pv and then choose the use-flags

http://gentoo-portage.com has a few explanations of some flags ..

If the use-flags are often used, then i wrote them into make.conf .
If not i add an entry in package.use

All in all my make.conf contains this entries: