Cron is a time-based job scheduling daemon found in Unix-like operating systems (Linux, macOS, BSD). The name originates from the Greek word chronos, meaning time.
How Cron Operates
The cron daemon (crond) runs silently in the background. Every minute, it wakes up, inspects configuration files called crontabs (cron tables), and executes any shell commands or scripts that match the current system date and time.
Common Use Cases
- Database Backups: Running database dumps at 2:00 AM every night.
- Log Rotation: Compressing or archiving server access logs weekly.
- Email Reports: Sending daily digest emails to subscribers at 8:00 AM.
- Cache Warming & Garbage Collection: Purging expired sessions every 15 minutes.