discuss: Thread: Linux Daemon HOWTO

	Everyone - 

	I've written a somewhat short but informative introduction into writing
daemons in Linux. I noticed that this isn't really out there right now,
and I thought I'd at least try my hand at writing this.

	The SGML (LinuxDoc) file can be found at:

	http://www.linuxprofilm.com/articles/linux-daemon-howto.sgml

	I've also got HTML and PDF versions there:

	http://www.linuxprofilm.com/articles/linux-daemon-howto.html
	http://www.linuxprofilm.com/articles/linux-daemon-howto.pdf

	I'd like any suggestions and feedback on this.

	-Devin Watson

On Tue, May 18, 2004 at 06:55:57PM -0400, Devin Watson wrote:
> 	Everyone - 
> 
> 	I've written a somewhat short but informative introduction into writing
> daemons in Linux. I noticed that this isn't really out there right now,
> and I thought I'd at least try my hand at writing this.
> 
> 	The SGML (LinuxDoc) file can be found at:
> 
> 	http://www.linuxprofilm.com/articles/linux-daemon-howto.sgml
> 
> 	I've also got HTML and PDF versions there:
> 
> 	http://www.linuxprofilm.com/articles/linux-daemon-howto.html
> 	http://www.linuxprofilm.com/articles/linux-daemon-howto.pdf
> 
> 	I'd like any suggestions and feedback on this.

Don't forget to add a copyright statement and license, both for the
LDP's protection and for your own.

It's been a while since I engaged in daemonology :-), but shouldn't
this:

        /* Open any logs here */
        
        /* Change the current working directory */
        if ((chdir("/")) < 0) {
                exit(EXIT_FAILURE);
        }

be:

        /* Open any logs here */
        
        /* Change the current working directory */
        if ((chdir("/")) < 0) {
   		/* Log failure, then close logs */


		exit(EXIT_FAILURE);
        }

You should probably log the failure so that the user knows she doesn't
have a necessary directory. In that case, if you are handling your
log files yourself, you have to close them gracefully before you exit
so that the last few entries are preserved.

Also, I doubt you want a daemon to run in /.

I'm not sure how you open log files in daemons in Linux, but shouldn't
you set umask before you open a log file?

These are nit picks. The code you have shows how to do it. As this is
an instructional article, the code should not get loaded down with
error checking to the point that it obscures your main point. You
might suggest ways to tighten up the code at the end.

I like it. It's short, sweet and to the point. The user can go from
there. Well done.

-- 

Charles Curley                  /"\    ASCII Ribbon Campaign
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