cron, what am I doing wrong?

By jvincher on 27 Mar 2005 at 03:20 UTC

I am attempting to create a crontab in order to automatically update over 200 external RSS feeds on my drupal based site.

I thought I was doing it right (well, guess not since it's not working) but I need someone with a good level of expertise to see what I am doing wrong.

First off, I made sure I could create a crontab with my host. Following their instructions:

1. I used telnet to get into my shell
2.typed crontab -e
3. in VI, typed i and used as crontab instructions: 50 * * * * /home/www/scripts/cron-lynx.sh, closed off with escape and wq. I verified with crontab -l that the cron had been created. My intent is to run the cron-lynx.sh 50 minutes past every hour.
4. I made sure cron-lynx.sh contained the actual path to the drupal cron file on my host.

and I waited, and waited...and waited. No error message in drupal, nothing. Nothing happened.

What am I doing wrong? Am I missing something?

Comments

What's in cron-lynx.sh?

Torenware commented 27 March 2005 at 08:08

Assuming that you're using vixie cron, it looks like your crontab entry is just fine. So that leaves two classes of problems you need to check for:

Is cron-lynx.sh really doing what you think it's doing? Have you tried executing the file manually, and making sure that the watchdog thinks that cron.php was accessed?
Is cron-lynx.sh really at exactly that path, and is it executable?

I'm also assuming that /home/www/scripts is readable to your user. If that isn't true, then that's another problem you could be having.

Rob Thorne
Torenware Networks

Ambiguous Redirect

jvincher commented 27 March 2005 at 15:40

I manually executed the cron-lynx.sh script and I'm getting the following:

: ambiguous redirect

The cron.lynx.sh script reads:

#!/bin/sh
/usr/bin/lynx -source http://www.myowndomain.com/cron.php > /dev/null 2>&1

My gut feels tells me it's related to the /dev/null 2>&1 portion of the code but I have no clue as to what I should adjust to make the script (and cron) run properly.

Any ideas?

Anyone?

jvincher commented 28 March 2005 at 16:53

Anyone?

have you tried it otherwise

cel4145 commented 28 March 2005 at 17:04

I Have you confirmed that lynx works from the command line. For example,

/usr/bin/lynx http://drupal.org/

should bring you to the Drupal website in lynx. You an can also test it the same way with your cron address

/usr/bin/lynx http://example.com/cron.php

And your cron should update. If it doesn't, then perhaps the path is wrong for executing lynx. However, if that works, then perhaps it is the /dev/null 2>&1 portion of the script code.

Interesting...

jvincher commented 28 March 2005 at 19:17

Okay, well this is interesting indeed.

First the good news:

/usr/bin/lynx http://example.com/cron.php executes problem free and the drupal logs show indeed that cron was updated.

Now the persistant bad news:

Seems to me that the issue is with cron-lynx.sh but what it is...? I've been googling /dev/null 2>&1 for solutions but with no avail.

could be your cron script

cel4145 commented 28 March 2005 at 20:34

Before figuring out whether /dev/null 2>&1 is the problem, I would check to see whether the cron-lynx.sh script is being run via your server logs.

looks okay

bertboerland commented 28 March 2005 at 17:06

i use wget which has a "quiet" option, like
/usr/bin/wget -O - -q http://www.example.com/cron.php

my best quess is that you are using the csh for your crontab instead of hash bang slash bin slash sh

btw: allways tail logging when troubleshooting and use google with the errormessages.
--
groets
bertb

--
groets
bert boerland

Solved

jvincher commented 28 March 2005 at 23:49

Okay, I got it running. I ended up applying Bert's suggestion of using wget and adjusted the cron with the exact code (welll, replacing www.example.com with my site) and it works like a champ.

Thanks to everyone who contributed.

Redirection

yelvington commented 29 March 2005 at 01:27

/usr/bin/lynx -source http://www.myowndomain.com/cron.php > /dev/null 2>&1 says ...

"run lynx with the -source option;
redirect standard output to /dev/null,
and redirect errors to the standard output file handle (therefore also to /dev/null)."

It works fine with bash. What sort of system are you running this on? What is the output of "/bin/sh --version"?

/dev/null bit

robertDouglass commented 12 August 2005 at 16:07

That is to send the output into the deep dark void and probably isn' t causing the problem. More likely cron isn't authorized to execute the script.

- Robert Douglass

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I had the same problem, but

cluckk commented 22 December 2005 at 17:41

I had the same problem, but I have my host stup to mail me logs when things go wrong. Mine told me that the script permissions were denied. To correct this I simply:

chmod 755 scriptname