cron running scripts

Rynnkel · May 2009

Hi. I've been reading about cron and I think it's a pretty useful utility. However, I've had a bit of trouble with it running scripts.

I'm running Ubuntu 9.04 with Gnome, by the way.

For example, if I put the following line into my crontab

* * * * * ~/script

(I've tried variations of this using the full path to the script and the $HOME variable.)

And I wait a minute or so, nothing happens. In the System Log Viewer an entry in syslog is added every minute saying that the script was being run, but nothing actually happens. I tried redirecting the output to a file, but the file is blank after the script is run. No errors are shown. I tried "sudo chmod a+rwx" on the script (just in case the script wasn't being run due to permissions issues) but it still isn't working...

Crontab works for other things though. I use it as an alarm clock with

30 5 * * * export DISPLAY=:0 && firefox pandora.com

...and it works as expected.

I'm confused as to why I can't seem to get the program to run the script, or failing that give any sort of error message.

My script, by the way, isn't that complicated, and it works properly when running it regularly...

#!/bin/bash

git add .

git commit -m "Commit on `date`"

Has anyone dealt with this issue before? Any help would be appreciated.

~Dennis

mfillpot · May 2009

have you tried telling cron to run it as a shell script?

* * * * * sh ~/script

bastib · May 2009

or you have to cd to the right directory first (in the script)?

Rynnkel · May 2009

@bastib I tried a couple of different scripts using full path names; none of them run.

I tried doing
#!/bin/bash
touch /home/dennis/testing

And it doesn't run.

@mfillpot I just tried it with the sh in front. It still doesn't work.

mfillpot · May 2009

what output do you get when you try to run the contents of script or the script itself within a terminal?

Rynnkel · May 2009

@mfillpot

When I run it from the terminal it works fine.

Created commit 0c2664e: Commit on Sun May 24 10:58:40 EDT 2009
1 files changed, 1 insertions(+), 0 deletions(-)
create mode 100644 .gitignore

mfillpot · May 2009

I ma unfamiliar with git so bear with me, could this be an issue were you user account that is used to run the job as insufficient rights to git?

bastib · May 2009

Just to be shure...

Did you try the touch-script with absolute path in crontab?
Perhaps ~/script.sh expands to /root/script.sh as cron is run as root (?)

If you tried an absolute path with the git-script and
just redirected stdout the file is blank because it just tells you that there is no repository on stderr and exits.

Basti

Rynnkel · May 2009

@mfillpot

I don't think it's an issue with git. I tried other test scripts as well and none of them worked.

@bastlib

I used absolute paths with all the test scripts (and in crontab) and none of them worked. I also tried giving everyone permission to read, write, and execute the script to see if that helped (sudo chmod a+rwx script). It didn't.

...and just redirected stdout the file is blank because it just tells you that there is no repository on stderr and exits.

I'm not sure what you mean by this... Could you explain? I'm a noob. >_<;

bastib · May 2009

Hi,

I thought your script produces an error and you won't see that in the output file if you had an entry like

* * * * * script.sh > output.txt

because that redirects only stdout.

The last thing I can imagine is that you have to use the full path of touch like:

#!/bin/bash
/usr/bin/touch /home/dennis/delme.txt

and see if that works...

To see where it is installed type

which touch

Basti

Rynnkel · May 2009

@bastlib

Wow, that actually worked. I was using full paths in the crontab and in the script itself for the file to touch, but I wasn't using the commands' full paths.

Thanks everyone for your help.

cron running scripts

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