From owner-freebsd-current  Thu Nov 18 21: 8:30 1999
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Date: Fri, 19 Nov 1999 00:08:25 -0500 (EST)
From: Garrett Wollman <wollman@khavrinen.lcs.mit.edu>
Message-Id: <199911190508.AAA43114@khavrinen.lcs.mit.edu>
To: Luoqi Chen <luoqi@watermarkgroup.com>
Cc: current@FreeBSD.ORG
Subject: Re: init runs with console as control terminal?
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<<On Thu, 18 Nov 1999 22:59:28 -0500 (EST), Luoqi Chen <luoqi@watermarkgroup.com> said:

> Hmm, good point. So I still need to find a way to start up rc5des, it seems
> that rc5des installs a SIGHUP handler and therefore nohup is
> useless.

Bug the authors to fix it?  daemon(3) is provided for a reason!

Here's my version of a simple daemonizing program....  Neither
TIOCNOTTY nor setpgid() is sufficient to detach from a terminal
session in a POSIX environment; setsid() is required.  daemon(3) does
a nice job of encapsulating this along with the other more obvious
prerequisites.

------------------------------------
#include <sys/types.h>

#include <err.h>
#include <stdlib.h>

int
main(int argv, char *argv)
{
	static char *shargs[4] = { "sh", "-c" };

	if (argv[1] == 0 || argv[2] != 0)
		errx(1, "must specify exactly one argument");

	if (daemon(1, 0) < 0)
		err(1, "daemon");

	shargs[2] = argv[1];
	execv("/bin/sh", shargs);
	/*
	 * Not much point in printing an error message since the tty
	 * is already gone.  It doesn't really matter what we return
	 * here, either, since the only one waiting is init.
	 */
	return 1;
}
------------------------------------

-GAWollman

--
Garrett A. Wollman   | O Siem / We are all family / O Siem / We're all the same
wollman@lcs.mit.edu  | O Siem / The fires of freedom 
Opinions not those of| Dance in the burning flame
MIT, LCS, CRS, or NSA|                     - Susan Aglukark and Chad Irschick


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