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From: Jan-Benedict Glaw <jbglaw@lug-owl.de>
To: linux-c-programming@vger.kernel.org
Subject: Re: daemonization
Date: Fri, 28 Jun 2002 23:03:48 +0200	[thread overview]
Message-ID: <20020628210348.GT17216@lug-owl.de> (raw)
In-Reply-To: <20020628154913.A377@nietzsche>

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On Fri, 2002-06-28 15:49:13 -0500, xlp <xlp@emtel.net.co>
wrote in message <20020628154913.A377@nietzsche>:
> Hi, I want to understand How can a executale object in Unix can become a "daemon" ? How can it deal with stdout, and ttys it's connected to? What are the C library function I should read man?.

- chdir() to "/"

Most important are these:

- become session leader: setsid()
- fork() and let parent exit(0)
- close() stdin, stdout and stderr and re-open() them with /dev/null
- maybe do a chroot()
- maybe open any IP ports to listen on them
- Drop root privileges: setuid(), setgid()
- Ready (TM)
- Afterwards: At any file you open, don't forget O_NOCTTY!

MfG, JBG
PS: And ___always___ check the return values of those library calls!!!

-- 
Jan-Benedict Glaw   .   jbglaw@lug-owl.de   .   +49-172-7608481
	 -- New APT-Proxy written in shell script --
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  reply	other threads:[~2002-06-28 21:03 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-06-28 20:49 daemonization xlp
2002-06-28 21:03 ` Jan-Benedict Glaw [this message]
2002-06-28 22:13   ` daemonization Glynn Clements

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