How to start a daemon (specifically svnserve) as a specific user in /etc/rc.local

[Tabor Kelly]

Hello,

I just installed subversion, and I want to start the standalone 
subversion server (svnserve) on every reboot. The command I need to 
execute is:

svnserve -d -r /usr/local/repositories

I created a user called subversiond, with the shell in /etc/passwd set 
to /nonexistent. If I am logged into the system, I can use the following 
commands to start the subversion server as subversiond:

su -m subversiond
svnserve -d -r /usr/local/repositories
exit

However, I have not had any luck automating this. What I tried was placing:

/usr/local/repositories/subversiond.sh

in /etc/rc.local, and creating the following executable file 
/usr/local/repositories/subversiond.sh:

#!/bin/sh
umask 022 #just to make sure
su -m subversiond
svnserve -d -r /usr/local/repositories
exit #note: I added these exit's when the script
exit #   didn't work without them, but it still doesn't work

However, if I reboot and do a 'ps -axu | grep "subversiond"' the only 
process that I see is "_su -m (csh)".

I would appreciate any help/pointers you could give me.

Thank You,

Tabor Kelly