$ Linux Command

System

at

Schedule a command to run once at a later time.

schedulejobtimeautomation

Additional Notes

at schedules one-time jobs to run in the future. It is useful for delayed commands, reminders, maintenance tasks, or simple automation that should run once rather than repeatedly.

For recurring jobs, use cron or systemd timers. For one-time jobs, at is simpler.

Syntax

at TIME
at [options] TIME

Parameters

  • TIME: Time expression such as now + 5 minutes, 10:30 PM, or tomorrow.
  • command: Command lines typed into the interactive prompt or read from a file.
  • options: Queue, file, listing, and removal controls.

Common Options

  • -f FILE: Read commands from FILE.
  • -q QUEUE: Use a specific queue letter.
  • -l: List pending jobs. Same idea as atq.
  • -r JOB: Remove a pending job. Same idea as atrm.
  • -m: Send mail when the job completes, if mail is configured.

Examples

at now + 5 minutes

Open an interactive prompt for a job five minutes from now. Press Ctrl+D when finished entering commands.

echo "touch /tmp/at-test" | at now + 1 minute

Schedule a command from standard input.

at -f backup.sh 02:00

Run commands from a script at 02:00.

atq
atrm 3

List jobs and remove job 3.

Practical Notes

  • The atd service must be running for jobs to execute.
  • Output may be mailed to the user if local mail is configured.
  • The job runs with a snapshot of much of the current environment, but scripts should still use absolute paths for reliability.