Practice
The given example displays the use of at command.
[root@icg3 /etc]# at 11:45 pm at> rm /home/krishen/*core* at> <EOT>
warning: commands will be executed by using /bin/sh
job 1 at 2001-05-26 23:45 [root@icg3 /etc]#
In the given example at job removes core files from the user account belonging to krishen near midnight.