+ exec subprocesses; we handle that by polling the pid later.
+
+ Note that one must use _exit() instead of exit() in procs forked
+ off of Gtk programs -- Gtk installs an atexit handler that has a
+ copy of the X connection (which we've already closed, for safety.)
+ If one uses exit() instead of _exit(), then one sometimes gets a
+ spurious "Gdk-ERROR: Fatal IO error on X server" error message.
+ */
+ _exit (1); /* exits child fork */