How to get an X11 Window from a Process ID?

Question

Under Linux, my C++ application is using fork() and execv() to launch multiple instances of OpenOffice so as to view some powerpoint slide shows. This part works.

Ne

Answer 1

The only way I know to do this is to traverse the tree of windows until you find what you're looking for. Traversing isn't hard (just see what xwininfo -root -tree does by looking at xwininfo.c if you need an example).

But how do you identify the window you are looking for? Some applications set a window property called _NET_WM_PID.

I believe that OpenOffice is one of the applications that sets that property (as do most Gnome apps), so you're in luck.