Operating Systems

Cron Examples

Practical cron job examples and patterns.

Backup Examples

Daily backup at 2am
0 2 * * * /scripts/backup.sh

Weekly backup on Sunday
0 3 * * 0 /scripts/weekly-backup.sh

Database backup every 6 hours
0 */6 * * * /scripts/db-backup.sh

Log Management

Clear logs daily
0 0 * * * find /var/log -name *.log -mtime +7 -delete

Rotate logs weekly
0 0 * * 0 /usr/sbin/logrotate /etc/logrotate.conf

Output Redirection

Save output to file
* * * * * command >> /var/log/cron.log 2>&1

Discard output
* * * * * command > /dev/null 2>&1

Email output
[email protected]
0 2 * * * /scripts/backup.sh

Environment Variables

Set PATH
PATH=/usr/local/bin:/usr/bin:/bin

Set SHELL
SHELL=/bin/bash

Set HOME
HOME=/home/user

Custom variable
MY_VAR=value