Why does my command-line not run from cron?

Question

I have a perl script (part of the XMLTV family of "grabbers", specifically `tv_grab_oztivo`). I can successfully run it like this: ``` /sw/bin/perl /path/to/tv_grab_oztivo --output /path/to/tv.xml ``` I use the full paths to everything to eliminate issues with the Working Directory. Permissions shouldn't be a problem. So, if I run it from the Terminal (Mac OSX) it works just fine. But when I set it to run via a cron job, nothing appears to happen at all. No output is created etc. There isn't anything wrong with the crontab as far as I can see, because if I substitute a helloworld.pl for the actual script, it runs just fine at the right time. So, what can I do to debug? I can see from looking at `%ENV` in the two cases that the environment is very different, but what other approaches can I take to debugging? How can I see the output of the cron job, which might be some kind of perl "die" message or "not found" message from the shell or whatever? Or should I be trying to somehow give th…

Accepted Answer

It's often because you don't get the full environment when running under cron. Best bet is to capture the ouput by using the command:

```
( /sw/bin/perl /path/to/tv_grab_oztivo ... ) >/tmp/qq 2>&1
```

and then have a look at `/tmp/qq`.

If it does turn out to be a missing environment, then you may need to put:

```
. ~/.profile
```

or something similar, into the execution chain of your cron job, such as:

```
( . ~/.profile ; /sw/bin/perl /path/to/tv_grab_oztivo ... ) >/tmp/qq 2>&1
```

Why does my command-line not run from cron?

Solution

Problem