A crontab file contains instructions to the cron(8) daemon of the general form: “run this command at this time on this date”. Each user has their own crontab, and commands in any given crontab will be executed as the user who owns the crontab.
Example File
# use /bin/sh to run commands, overriding the default set by cron
SHELL=/bin/sh
# mail any output to `paul’, no matter whose crontab this is
MAILTO=paul
# run botchk every hour & after system is back from rebooting
@hourly /home/paul/eggdrop/botchk
@reboot /home/paul/eggdrop/botchk
Installing the crontab file
To install a new crontab file, run the command below:
$ crontab yourcron.file
To edit an existing crontab file, run the command below:
$ crontab -e
To view an existing crontab file, run the command below:
$ crontab -l