You can schedule commands to run at a later time by using the ‘at’ command. Why use ‘at’ when you can use ‘cron’? Because ‘at’ is good for tasks that only need to run once.
To set a task (to email a log file at a later time) to run in one hour from now:
at now + 1 hour (Enter) mail email@example.com < /var/log/messages (Enter) (Control+D)
To see your queued tasks:
You will get output like this:
333 2015-03-12 14:27 a root
In the above you can see there is one task labeled '333'. You can see the command set by issuing the command:
at -c 333
The above command will output plenty of details. The part you want is the second to last line.
You can remove a tasks by issuing the following: