Detect the presence of a graphic server on OSX?

Question

I need to know if my program running on OSX is in a graphic capable environment ?

are we running via ssh through a console only pipe ?

on most unix I would test for DISPLAY in the environment variables, but how do you test this on OSX ?

Answer 1

It is my understanding that the loginwindow process isn't running if OS X is not launched in GUI mode (like when you boot in single user mode or if this is a server you're connecting to via SSH).

So I suppose that if a grep on loginwindow returns empty, you know the machine is not in GUI mode, for example:

ps auxww | grep "/System/Library/CoreServices/loginwindow.app/Contents/MacOS/loginwindow" | grep the_logged_in_username | grep -v "grep" | awk '{print $2}'

would return the PID of loginwindow if the process is launched or return nothing if the process is not launched.

Note that I have not tested, it's just an idea, I don't know for sure if it works...