[133] in Zephyr Mailing List
Re: zwgc question...
daemon@ATHENA.MIT.EDU (Roland J. Schemers III)
Mon Jun 20 19:47:59 1994
From: "Roland J. Schemers III" <schemers@Slapshot.Stanford.EDU>
Date: Mon, 20 Jun 1994 16:44:44 -0700
In-Reply-To: Marc Horowitz <marc@cam.ov.com>
"Re: zwgc question..." (Jun 20, 6:52pm)
To: Marc Horowitz <marc@cam.ov.com>
Cc: zephyr@MIT.EDU
On Jun 20, 6:52pm, Marc Horowitz wrote:
>
> Don't background it. zwgc forks by itself, and tries very hard to
> make sure it dies when you log out. Nothing you background with &
> dies automatically when you log out.
>
That didn't work either. It looks like (on a SunOS system):
elaine10:~ 15# ps -jxww
PPID PID PGID SID TT TPGID STAT UID TIME COMMAND
23396 23398 23398 23392 p3 23398 IWE 4337 0:00 -scsh (tcsh)
1 23409 23398 23392 p3 23398 IW 4337 0:00 /usr/leland/etc/zwgc
-ttymode
23314 23315 23315 23313 p9 23491 SE 4337 0:01 -scsh (tcsh)
23315 23491 23491 23313 p9 23491 RE 4337 0:00 ps -jxww
After logging out on tty p3:
elaine10:~ 16# ps -jxww
PPID PID PGID SID TT TPGID STAT UID TIME COMMAND
1 23409 23398 23392 ? -1 IWO 4337 0:00 /usr/leland/etc/zwgc
-ttymode
23314 23315 23315 23313 p9 23501 SE 4337 0:01 -scsh (tcsh)
23315 23501 23501 23313 p9 23501 RE 4337 0:00 ps -jxww
It looks like the process group and the session are the same as tcsh, but
after logging out the process doesn't die. Sending it a "kill -HUP" will
kill it.
I've tried it under SunOS 4.1.2, Solaris 2.3, OSF 1.3, IRIX 5.2, AIX 3.2.3,
and Ultrix 4.4. Only Ultrix 4.4 seemed to work.
I can see what the code is supposed to be doing in detach() (zwgc/main.c).
I'll have to poke around some more I guess.
thanks about the no "-nofork" tip. I had forgotten about "&"'s behavior.
Roland
ps. Speaking of detach.c, I'm looking at three different sources, and I see
three different things being done:
CMU.022:
(void) setpgrp(0, getpgrp(getppid())); /* to try to get SIGHUP on user
logout */
..fork...
DECathena:
#ifdef POSIX
(void) setpgid(getpid(), getppid()); /* to try to get SIGHUP on user
logout */
#else
(void) setpgrp(0, getpgrp(pid)); /* to try to get SIGHUP on user
logout */
#endif
...fork....
#ifdef POSIX
setpgid(0,pid);
#endif
And MIT.940217:
#ifdef POSIX
(void) setpgid(0, tcgetpgrp(1));
#else
(void) setpgrp(0, getpgrp(getppid()));
#endif
...fork....
Any idea which one is right?
thanks, Roland
--
Roland J. Schemers III | Networking Systems
Authentication Services Programmer | 414 Sweet Hall +1 (415) 723-6740
Distributed Computing Operations | Stanford, CA 94305-3090
Stanford University | schemers@Slapshot.Stanford.EDU
