Re: [gentoo-user] Can a script tell if it's running under X?

[Marko Vallius]

On Sat, Dec 04, 2004 at 02:54:47PM -0800, Peter Gordon wrote:
> Kevin O'Gorman wrote:
> | Is there a way for a script (bash, for instance) to know
> | if it's running under X, such as in an xterm or konsole?
>
> One way to do it (though I don't know how to do this in Bash) is to
> check X's Process ID (PID). If `pidof X` returns an integer, than
> that's the PID of the currently running X server. If X is not running
> it will return an empty string.

That doesn't really work. `pidof X` does often return the PID of the
currently running X server, yes, but it does not tell you if you are
running under it (it can be some other user's X, for example). On the
other hand, the X server's process name probably is X only if you're
running XFree or X.org. What if you're running Xvnc? :)

You can also log in remotely and run X applications. Running `pidof X`
will then make absolutely no sense, as *your* X server is running on
the machine you logged in from...

Checking if $DISPLAY is set is the way to go. If it's not set, you
cannot start any X apps anyway. (Well, sometimes you can if you know
what your display is, but if we knew that we wouldn't be having this
conversation.)

-- 
Marko Vallius   	#  PGP public key A4B84F58

--
gentoo-user@g.o mailing list