Network access fails in script after Terminal logout/disconnect

Question

I have a script which is running in the background (script invoked using amp[&]) and occasionally it attempts to access a URL (using wget, lynx etc). This works fine when I start the script, but as soon as I logout of the Terminal from which the script was initiated it fails. Enclosed is a small demonstration reproducing the problem using a csh script. To reproduce the problem on OS X 10.5.8 run the script from command line in background:
script.csh &
It will then create duplicate files with different filenames on disk. Exit the command line window and login again... it is no longer producing the files, but the process is still running.
Regards,
Andreas
#!/bin/tcsh
any_label:
wget http://gcn.gsfc.nasa.gov/gcn3/10146.gcn3
goto any_label

Answer 1

In theory it should not matter what shell launchd starts up with, as you have #!/bin/tcsh at the beginning of your script.
If you suspect that you do not have the correct environment variables, then add the following to your script:
printenv >/tmp/myscript.enviroment.txt
Then go look at the file after your script has run. Add any other debugging information to the .txt file that might be helpful in diagnosing your problem.
Another thing you might look at is your PATH when your script runs. launchd generally has a very reduced PATH setup. It might be that wget is not even being found. For example, on my Leopard system, the only version of wget I have is from <http://fink.sf.net> and stored in /sw/bin/wget, which is not normally in a default PATH. Mac OS X Leopard did not provide a copy of wget.
I do not personally use launchd, I'm still a cron kind of guy, and I have any number of cron based scripts that run just fine, including one that uses "curl" (a similar utility to wget).