Perl Script Not Working With Crontab

monkfan has asked for the wisdom of the Perl Monks concerning the following question:

Hi experts,
I was trying to run this simple script (cron.pl) with CRON

#!/usr/local/bin/perl -w
use strict;
system("echo test > testcron.txt");
#system("nohup perl later_other_code.pl&");
[download]

but it fail to be executed with my cron entries that look like this:

MAILTO=monkfan@gmail.com
* * * * * /usr/local/bin/perl /home/monkfan/MyPerl/cron.pl
[download]

Meaning that 'testcron.txt' wasn't created at all at this directory: /home/monkfan/MyPerl/. Why is that?

Update:

Also, I have no root access in this Linux box.
Five (*) indicates cron to run the command at every minute of every hour of every day of every month.

Regards,
Edward

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Re: Perl Script Not Working With Crontab by moritz (Cardinal) on Aug 23, 2007 at 15:02 UTC
There are two things that usually causes cron failures: It runs from a different directory than expected Different environment variables, usually `PATH` is rather minimal in cronjobs. Check those two issues, and change your program to produce useful error messages on failure, so that cron will send you a mail with the error message. Update: and be sure always to edit your crontab with `crontab -e`, it will warn you when the syntax is wrong. Perl 6 in German -- Difficult Sudoku	[reply] [d/l] [select]
Re: Perl Script Not Working With Crontab by clinton (Priest) on Aug 23, 2007 at 14:54 UTC
The two things I can think of both have to do with your environment: You don't have permission to write to that folder (ie your script isn't running as the user you think it is) The current working directory is different from what you think it is, so `testcron.txt` is being created (or not if you don't have permissions), but not in the place where you expect Try running a simple cron command like: `env && pwd > /home/monkfan/test.txt` Clint	[reply] [d/l] [select]
Re: Perl Script Not Working With Crontab by misc (Friar) on Aug 23, 2007 at 14:37 UTC
What do you mean with "it fails" exactly ? If you get an error message mailed, this would be helpful. A guess: You could try replacing testcron.txt with /absolutepath/testcron.txt (update) so system("echo test > testcron.txt"); gets system("echo test > /absolutepath/testcron.txt") michael	[reply]
Re: Perl Script Not Working With Crontab by pinetree (Scribe) on Aug 24, 2007 at 22:05 UTC
Edward, As a couple of comments have already pointed out, you do not necessarily have your expected environment set when your cron job runs. The solution is to fully path your commands and files. So, make sure you know where your commands are: `MBPro:~ oren$ which echo /bin/echo MBPro:~ oren$ which nohup /usr/bin/nohup` [download] and update your script (change your locations as needed) `#!/usr/local/bin/perl -w use strict; system("/bin/echo test > /home/monkfan/testcron.txt"); #system("/usr/bin/nohup perl /home/monkfan/later_other_code.pl&");` [download]	[reply] [d/l] [select]
Re: Perl Script Not Working With Crontab by cengineer (Pilgrim) on Aug 24, 2007 at 13:59 UTC
Change your crontab to look something like: `* * * * * /usr/local/bin/perl /home/monkfan/MyPerl/cron.pl >> /home/mo +nkfan/mycron.log 2>&1` [download] Then you can check mycron.log to see whats happening	[reply] [d/l]
Re: Perl Script Not Working With Crontab by FunkyMonk (Chancellor) on Aug 23, 2007 at 14:31 UTC
Shouldn't one of the ``'s be a number so cron knows when to run it? For example: `10 * * * /usr/local/bin/perl /home/monkfan/MyPerl/cron.pl` [download] ~~To run it at 10 past each hour~~ I was wrong, sorry. Have you looked in your home directory? That's where my cron places the file with code equivalent to yours. update: crontab entry was wrong	[reply] [d/l] [select]
Re^2: Perl Script Not Working With Crontab by clinton (Priest) on Aug 23, 2007 at 14:56 UTC
No. `* * * * *` is legal - it means run the program every minute of every hour of every day. Clint	[reply] [d/l]