[ALL OS]Linux,Mac,Windows & handles how find?

[minimy]

With @willbert help i can move windows by handler in OSX and MSWindows, im trying translate this to linux.
Exist some thing in Linux (gdk or other way) similar to MSAPI:

FindWindow_(0, win_name.s)
SetParent_(hWnd,WindowID(windowPB))
SendMessage_(hWnd,#WM_CLOSE,0,0)
MoveWindow_(hWnd,x,y,w,h,#True)

This can be very interesting to acces to other windows by API.

Somebody can help with this?
Thanks a lot!