Showing posts with label cron. Show all posts
Showing posts with label cron. Show all posts
Working with Crontab
Crontab is the scheduler program used ina unix servers.
Each user can have their own crontab, and though these are files in /var/spool/cron , they are not intended to be edited directly.
If the cron.allow file exists, then you must be listed therein in order to be allowed to use this command.
If the cron.allow file does not exist but the cron.deny file does exist, then you must not be listed in the cron.deny file in order to use this command.
If neither of these files exists, only the super user will be allowed to use this command.
cronatb -l --- To view the crontab
crontab -e --- To edit the crontab
crontab -e --- To edit the crontab
MIN HOUR DOM MON DOW CMD /script/location/full/path
minute 0 through
59
hour 0 through
23
day_of_month 1
through 31
month 1 through
12
weekday 0
through 6 for Sunday through Saturday
Example :
Example :
30 08 10 06 * /home/xyz/full-backup
- 30 – 30th Minute
- 08 – 08 AM
- 10 – 10th Day
- 06 – 6th Month (June)
- * – Every day of the week
Editing crontab
#crontab –l
# crontab -l
> crontab.current ------backup
crontab
#vi
crontab.current---------Modify changes to backup file
# crontab
crontab.current---------To re-enable crontab with modified changes
