Usage: ON [#|+|-|^|&|@]EXEC_EXIT [-|^]<parameters> [action]
  This is activated when any EXEC'd process exits.  The parameters
  are:
	$0	Process number or logical name (if assigned)
	$1	Signal that killed the process (or 0 if it exited normally)
	$2	Exit code for process (non-zero only if $1 is 0)
