[tlug] Completely baffled as to why Cron job is not working

[Dave M G <martin@example.com>]

TLUG,

I have a machine that is a dedicated media centre, running MythTV.

I have a cron job that runs a script every day at 1 PM. The entry in 
crontab looks like this:
0 13 * * * /home/mythtv/myscript.sh

In that shell script are three commands. Two are to MythTV related 
commands that first retrieve TV show information, and then fill the 
MythTV database with the information.

The third command in that script is an sendEmail command that alerts me 
to say the script has been run.

Every day, I've been getting an email at 1 PM that tells me the command 
has been run. So it seems cron is executing my script.

But, I've discovered that the database is not being filled with the 
right data.

Okay, so obviously the first assumption is that the script is probably 
not running the command correctly. So I try running the script from the 
command line, and it works perfectly.

So I'm baffled. Why would a script that runs perfectly from the command 
line not complete its task when executed from cron?

--
Dave M G
http://www.tlug.jp/wiki/User:Dave_M_G