How to test things in crontab

Question

This keeps happening to me all the time: 1) I write a script(ruby, shell, etc). 2) run it, it works. 3) put it in crontab so it runs in a few minutes so I know it runs from there. 4) It doesnt, no error trace, back to step 2 or 3 a 1000 times.

When I ruby script fails in crontab, I can't really know why it fails cause when I pipe output like this:

ruby script.rb >& /path/to/output

I sorta get the output of the script, but I don't get any of the errors from it and I don't get the errors coming from bash (like if ruby is not found or file isn't there)

I have no idea what environmental variables are set and whether or not it's a problem. Turns out that to run a ruby script from crontab you have to export a ton of environment variables.

Is there a way for me to just have crontab run a script as if I ran it myself from my terminal?

When debugging, I have to reset the timer and go back to waiting. Very time consuming.

How to test things in crontab better or avoid these problems?

Answer 1

"Is there a way for me to just have crontab run a script as if I ran it myself from my terminal?"

Yes:

bash -li -c /path/to/script

From the man page:

[vindaloo:pgl]:~/p/test $ man bash | grep -A2 -m1 -- -i
   -i        If the -i option is present, the shell is interactive.
   -l        Make bash act as if it had been invoked as a login shell (see
             INVOCATION below).