How to Deny Access to the at Command

1. Become superuser.

2. Edit the /etc/cron.d/at.deny file and add the names of users, one per line, that will be prevented from using at commands.

   daemon bin smtp nuucp listen nobody noaccess username1 username2 username3 . . .

Example—Denying at Access

The following example shows an at.deny file that has been edited so that the users smith and jones cannot access the at command.

$ cat at.deny
daemon
bin
smtp
nuucp
listen
nobody
noaccess
jones
smith