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Systems & Data Center · Foundational

crontab

A per-user schedule table for cron jobs, and the command used to edit, list or remove it.

Definition

crontab -e edits, crontab -l lists and crontab -r removes the current user's table; root can manage others with -u. Each line has five time fields followed by the command. Special strings such as @reboot and @daily are supported.

Example

*/15 * * * * /opt/scripts/check.sh runs a check every 15 minutes.

Exam tip

*/15 in the minute field means every 15 minutes, not at minute 15.

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