at Command: Tutorial & Examples
Execute a command at a specified time
at command is a Linux utility that allows you to schedule a command or script to run at a specific time in the future. It is useful for scheduling tasks that need to be
performed on a one-time or recurring basis, such as backups, system maintenance, or email notifications.
at, you must first specify a time and date for the task to run. You can do this by providing a numerical value for the time, such as 14:30 for 2:30 PM, or by using
keywords such as midnight, noon, or teatime (4 PM). You can also specify a relative time, such as now
+ 1 hour or next Monday.
Once you have specified the time, you can enter the command or script that you want to run. You can enter the command directly on the command line, or you can specify a script file
by using the
-f option. For example:
at 14:30 at> /path/to/script.sh
at -f /path/to/script.sh 14:30
When you are finished entering the command or script, press
CTRL+D to submit it to the
at daemon. The
at daemon will execute the command or script at the specified time.
You can view a list of tasks scheduled to run with at by running the
atq command. You can cancel a scheduled task by running
atrm followed by the task's ID, which can be found
Note that the
at command is not enabled by default on all Linux distributions. You may need to install the
at package and configure the
atd daemon to start automatically at
boot before you can use it.