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From Stefan Fritsch ...@sfritsch.de>
Subject Re: apr_proc_detach and chdir
Date Thu, 24 Jan 2013 23:04:09 GMT
On Friday 18 January 2013, Javier Castillo II wrote:
> Looking into the code for apr_proc_detach(int daemonize), it
> appears that chdir("/") is being run unconditionally.
> 
> Was there a specific reason that "/" is chosen?
> 
> I guess it's not much of a big deal, because you can chdir into the
> directory it should be in after you detach, however, why is this
> forced into the function to begin with?

I guess that this is to avoid troubles when unmounting file systems. 
If the daemon would not change its working directory explicitly, the 
file system where it was started could not be unmounted until the 
daemon is killed. The assumption is probably that "/" will not need to 
be unmounted. And it is guaranteed to exist.

> At the moment, I am fine with using getcwd and chdir to get back to
> where I started, however it does seem counter-intuitive.
> 
> So, I am guessing that this is the expected practice when calling
> this function, correct? Any insight would be great and any other
> methods to use with this function to get around it would be
> appreciated.

Many daemons don't need a specific working directory, so it would seem 
quite likely that many daemon authors would not consider the 
unmounting problem and forget doing a chdir(). Therefore it makes 
sense to do it automatically.

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