batch read commands from standard input or a specified file which are to be executed at a later time, using /bin/sh
Reads the job from file rather than standard input.
Send mail to the user when the job has completed even if there was no output.
uses the specified queue. A queue designation consists of a single letter; valid queue designations range from a to z. and A to Z. The a queue is the default for at and the b queue for batch. Queues with higher letters run with increased niceness. The special queue "=" is reserved for jobs which are currently running.
Prints the version number to standard error.
Shows the time the job will be executed.
The files at.allow and at.deny reside in /etc rather than /usr/lib/cron.