Platforms
Cron in Linux
Linux cron runs commands on a recurring schedule. It is commonly edited with crontab and is available on most Unix-like systems.
Crontab basics
crontab -e # edit your user crontab
crontab -l # list installed cron entries
crontab -r # remove the current user crontabEnvironment and logs
Cron jobs often run with a smaller environment than your interactive shell. Set PATH, use absolute paths, and redirect output to logs.
PATH=/usr/local/bin:/usr/bin:/bin
0 9 * * 1-5 /usr/local/bin/report.sh >> /var/log/report.log 2>&1Production cautions
- Check file permissions for scripts and log files.
- Avoid commands that require interactive input.
- Use locks for long-running jobs.
Common mistakes
- Assuming shell aliases work in cron.
- Forgetting executable permissions on scripts.
- Not redirecting stderr, so failures disappear.
FAQ
How do I edit a Linux cron job?
Run crontab -e for the current user, then add or update a 5-field cron entry.
Where are cron logs stored?
It depends on the distribution. Check system logs such as /var/log/syslog, /var/log/cron, or journalctl.