SIGSTOP and SIGCONT rules

[Spencer W. Thomas]

Actually, the rules are not nearly as complicated as you imply.  If
you are not root, you can send signals to any process with the same
uid.  If you are root, you can send signals to any process.  You can
send SIGCONT to any process which is a direct descendent of your
process (in addition to the above rule).

If an orphan (a process whose parent is init (process 1)) receives a
SIGTSTP, it will be killed instead.  However, you can send SIGSTOP to
an orphan and restart it later with SIGCONT [[Oops -- not true on the
Iris.  It is true on Suns and 4BSD systems.]]

Process groups have nothing to do with it (unless you use the killpg
function).

--
=Spencer W. Thomas 		EECS Dept, U of Michigan, Ann Arbor, MI 48109
spencer at eecs.umich.edu		313-936-2616 (8-6 E[SD]T M-F)