You can set up a file to control access to the at command, permitting only specified users to create, remove, or display queue information about their at jobs. The file that controls access to the at command, /etc/cron.d/at.deny, consists of a list of user names, one user name per line. The users who are listed in this file cannot access at commands.
The at.deny file, which is created during SunOS software installation, contains the following user names:
daemon bin smtp nuucp listen nobody noaccess