Need help writing StartupItem(or launchd?) for dansguardian

Question

Hey there,
i have successfully set up squid and dansguardian (what a pain that was, haha!!!!!) and got squid to launch as a daemon at startup. i am quite new to this stuff, but thinking positive! i manage squid and dansguardian through webmin. i can easily start dansguardian through webmin and i can also start it by doing.
sudo /usr/local/sbin/dansguardian
in terminal. it's a unix-executable
without sudo it says
Viersteins-Power-Mac-G5:~ vierstein$ /opt/local/sbin/dansguardian; exit
Unable to setgid()
logout
i did not figure out yet how the dansguardian webmin module starts/stops dansguardian and which files it uses to do that..
now to finish all this i need to write a startup script for dansguardian, because doing it manually is a bit laborious. i am a bit desperate here, have been trying so many things during the last two days and i'm really stuck. hopefully somebody here knows a way to do this.
the following code I put in a file called DansGuardian in /Library/StartupItems/Dansguardian - the file is a unix-executable
#! /bin/sh
# DansGuardian Filter
. /etc/rc.common
StartService ()
if [ "${DGSQUID:=-NO-}" = "-YES-" ]; then
CheckForNetwork
if [ "${NETWORKUP}" = "-NO-" ]; then exit; fi
ConsoleMessage "Starting DansGuardian Content Filter"
/usr/local/sbin/dansguardian -s
fi
StopService ()
/usr/local/sbin/dansguardian -q
RestartService ()
/usr/local/sbin/dansguardian -r
RunService "$1"
my StartupParameters.plist file in the same folder says
Description = "DansGuardian Content Filter";
Provides = ("Content Filter");
Requires = ("Web Proxy");
OrderPreference = "None";
after rebooting i get this in console
SystemStarter[55]: The following StartupItems were not attempted due to failure of a required service:
SystemStarter[55]: /Library/StartupItems/DansGuardian
it would be great if somebody here knew how to do this:)

Answer 1

(copy&paste from http://discussions.apple.com/thread.jspa?threadID=2094011&messageID=9887461#9887 461 )
in case somebody else is looking for an answer on this, here is the working launchd script. i did not write it myself though..
put the following code in
/Library/LaunchDaemons/org.dansguardian.dansguardian.plist
change the "Program" string to point to your binary, and the "WatchPaths" as well. The way this one works is that it waits until Squid is launched before it starts. That's what the WatchPath does - it looks for Squid's PID file to be created, and then launches DansGuardian.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>org.dansguardian.dansguardian</string>
<key>Disabled</key>
<false/>
<key>UserName</key>
<string>root</string>
<key>GroupName</key>
<string>nogroup</string>
<key>Program</key>
<string>/opt/dansguardian/sbin/dansguardian</string>
<key>ProgramArguments</key>
<array>
<string>dansguardian</string>
<string>-N</string>
</array>
<key>RunAtLoad</key>
<false/>
<key>OnDemand</key>
<false/>
<key>WatchPaths</key>
<array>
<string>/opt/squid/var/logs/squid.pid</string>
</array>
<key>Umask</key>
<integer>027</integer>
<key>ServiceDescription</key>
<string>The DansGuardian Content Filter Daemon</string>
</dict>
</plist>