UNIX for Dummies Questions & Answers

Hi,

I'm executing a python script via cron job. The way it is set up is, I'm editing a file called local[ inside /etc/cron.d/.The local file content is as follows:

Code:

00 22 * * * root su - -c "/opt/setup_dir/bin/run_bkp -p"

When this job executes, the command-specific logfile and the syslog (where the logs are supposed to go) show half of the logs(no errors) and the command (and also the child cron) gets terminated in the midway(checked it with ps -ef | grep su and same way for the child cron) without deleting the lock files(which it is normally supposed to do even on an abnormal termination).

I browsed for this issue and found the suspect might be the way stdout(print in python) is handled in cron! To confirm, i just executed another python script that logs to logfile and also prints to console. It gave me the same failure.

But if I change the content of the local file to

Code:

00 22 * * * root su - -c "/opt/setup_dir/bin/run_bkp -p > /root/cronlog"

it works just fine. The process completes gracefully with all the cleanup actions done and logs updated.

But i still do not understand so clearly what was exactly the issue, can someone explain if it is known to you? And also the MAILTO field in /etc/crontab file is empty ("").I'm hoping this is the default path where we get the cron logs as mails . Will it help to solve this if i change this filed? (pls let me know what to populate this with)

Kindly suggest the best solution for this.

if the process is schedules on root then ucan simplewrite

00 22 * * * /opt/setup_dir/bin/run_bkp -p > /root/cronlog

you can read /var/mail/root file to identify error

Sadly that didn't work. The user field seems to be compulsory.

But I found something here. In my python script, the python module used for writing into syslog and console is the "logger" module. I noticed that most of the scripts that uses this are showing the behaviour mentioned above. But the scripts that use python "syslog" modules for the same works all fine. I'm trying to make out the exact difference between these but meanwhile, Just wanted to know if I'm in the right direction to investigate the issue. So if anyone is aware if this might cause such issues, pls comment.