When setting up a crontab job in Linux machine, these essential steps are required for a successful system operation
- Update the cron file by adding the new script on schedule
- Check the frequency of the schedule. Such as for running at 7 minutes interval, use
*/7 * * * * python /path/to/script.py
Or for running every hour at 7th minute, use
7 * * * * python /path/to/script.py
- Check the file permission for the script. If it is not executable, then make it executable
ls -l /path/to/script.py
Then if the file is not executable by the user add the permission by
chmod 755 /path/to/script.py
(you may need to have sudo access if you are not the owner of the file. For changing ownership of a file or folder, use chown command on Linux variants)
- Check the file permission for the output site if the script produces some files. If the continuing folder or the output file does not have a write-access, ensure it is writable. Follow the similar process as in step#3.
- You may channel any print statements to a file such as
7 * * * * python /path/to/script.py /path/to/output/file.txt 2&1
- Or better yet, use Python logging library to create useful log files and show if the program ran correctly.