Shell Programming and Scripting

Any error messages? I guess it starts but doesn't find the two scripts called. cron only provides a minimalistic environment, so you need to either define your own or use absolute pathnames for scripts.

Hello Zooma,

If you want your script to run each 5th minute then could you please try following into your crontab by doing crontab -eand let us know if this helps you.

Code:

0,5,10,15,20,25,30,35,40,45,50,55 * * * * /path/to/script.sh

Thanks,
R. Singh

cron uses a very minimal path. I suggest setting your own PATH, or sourcing /etc/profile, in your scripts or it may not find all the commands they need.

Code:

0-59/5 * * * * . /etc/profile ; /usr/Measurements/getStats.sh

Just using /etc/profile to set the environment for a user's cron job probably isn't going to help much. There is a good chance you'll also need the user $HOME/.profile, $HOME/.bashrc, or some other user specific initialization script that the script being executed (and any commands it invokes) depend upon. The problem is that you are running a shell script that uses relative pathnames to find scripts to run:

Code:

./startMeasuring.sh
./collectStats.sh

and there is nothing in your script to move into the directory that would make those relative pathnames valid. And, we don't know whether or not those scripts depend on being invoked from a certain directory so they can find other files.

The directory in which cron runs a job is implementation specific, but the likelihood that it will be the current working directory at the time that the user invoked crontab to add that job to the list of jobs cron will execute is extremely small.

Any script being executed by cron needs to be capable of setting up whatever environment variables and it needs to run and needs to be capable of making its current working directory appropriate for it to access any files it needs to access and to put any files it may create in a place where the user will be able to find them when the script completes.

Thanks for all replies. I tried calling for a more simple file (echo "hello") and it works fine, so it seems that the problem is related to that I try to run scripts that are calling for other scripts (as some of you suggested).

I have close to 20 bash/awk scripts that are located in the /usr/Measurement/ folder. The file that I call every 5th minute with Crontab is supposed to coordinate and run these scripts and then populate a database with the output.

Questions:

1. Is this doable with Crontab or are there too many pitfalls?
2. Is there some other better way of scheduling these tasks? The measurements need to happen exactly every fifth minute, and as the time to run through the ~20 scripts may vary I can't use sleep() or anything else that is relative to the excecution time. Has to be a timer.

Cheers and thanks for all answers!
Z

That's what cron is made for, given its "features" are dealt with, e.g. sourcing various .profile scripts in the beginning of your scripts, as proposed above.
How exact does the start of the various script need to be? Although cron closely interacts with the system clock, there are situations (e.g. heavy system load) wherein starts can be delayed.

Thanks Rudi. I will try to fix it and post the "solution" here once done. It doesn't have to be exact, it can be a bit late but not drift.

Cheers,
Z