OpenBSD manual page server

Manual Page Search Parameters

AT(1)                      OpenBSD Reference Manual                      AT(1)

     at, atq, atrm, batch - queue, examine or delete jobs for later execution

     at [-V] [-q queue] [-f file] [-mldbv] time
     at [-V] -c job [job ...]
     atq [-V] [-q queue] [-v]
     atrm [-V] job [job ...]
     batch [-V] [-q queue] [-f file] [-mv] [time]

     at and batch read commands from standard input or a specified file which
     are to be executed at a later time, using sh(1).

     The related programs are as follows:

     at      Executes commands at a specified time.

     atq     Lists the user's pending jobs, unless the user is the superuser.
             In that case, all users' jobs are listed.

     atrm    Deletes jobs.

     batch   Executes commands when system load levels permit.  In other
             words, when the load average drops below 1.5, or the value speci-
             fied in the invocation of atrun.

     The options are as follows:

     -V      Prints the version number to standard error.

     -q queue
             Uses the specified queue.  A queue designation consists of a sin-
             gle letter.  Valid queue designations range from a to z and A to
             Z. The c queue is the default for at and the E queue for batch.
             Queues with higher letters run with increased niceness.  If a job
             is submitted to a queue designated with an uppercase letter, it
             is treated as if it had been submitted to batch at that time.  If
             atq is given a specific queue, it will only show jobs pending in
             that queue.

     -m      Send mail to the user when the job has completed, even if there
             was no output.

     -f file
             Reads the job from file rather than standard input.

     -l      An alias for atq.

     -d      An alias for atrm.

     -b      An alias for batch.

     -v      For atq, shows completed but not yet deleted jobs in the queue.
             Otherwise shows the time the job will be executed.

     -c      Prints the jobs listed on the command line to standard output.

     at allows some moderately complex time specifications.  It accepts times
     of the form HHMM or HH:MM to run a job at a specific time of day.  (If
     that time is already past, the next day is assumed.)  You may also speci-
     fy midnight, noon, or teatime (4pm) and you can have a time-of-day suf-
     fixed with ``AM'' or ``PM'' for running in the morning or the evening.
     You can also say what day the job will be run, by giving a date in the
     form month-name day with an optional year, or giving a date of the form

     The year may be given as two or four digits.  If the year is given as two
     digits, it is taken to occur as soon as possible in the future, which may
     be in the next century -- unless it's last year, in which case it's con-
     sidered to be a typo.

     The specification of a date must follow the specification of the time of
     day.  You can also give times like [`now'] + count time-units, where the
     time-units can be minutes, hours, days, or weeks and you can tell at to
     run the job today by suffixing the time with today and to run the job to-
     morrow by suffixing the time with tomorrow.

     For example, to run a job at 4pm three days from now, you would do at 4pm
     + 3 days. To run a job at 10:00am on July 31, you would do at 10am Jul
     31. To run a job at 1am tomorrow, you would do at 1am tomorrow.

     For both at and batch, commands are read from standard input or the file
     specified with the -f option and executed.  The working directory, the
     environment (except for the variables TERM, TERMCAP, DISPLAY, and _), and
     the umask are retained from the time of invocation.  An at or batch com-
     mand invoked from a su(1) shell will retain the current user ID.  The us-
     er will be mailed standard error and standard output from his commands,
     if any.  Mail will be sent using the command sendmail(8). If at is exe-
     cuted from a su(1) shell, the owner of the login shell will receive the

     The superuser may use these commands in any case.  For other users, per-
     mission to use at is determined by the files /var/at/at.allow and

     If the file /var/at/at.allow exists, only usernames mentioned in it are
     allowed to use at. If /var/at/at.allow does not exist, /var/at/at.deny is
     checked.  Every username not mentioned in it is then allowed to use at.
     If neither exists, only the superuser is allowed use of at.

     An empty /var/at/at.deny means that every user is allowed use these com-
     mands.  This is the default configuration.

     /var/at/jobs       directory containing job files
     /var/at/spool      directory containing output spool files
     /var/run/utmp      login records
     /var/at/at.allow   allow permission control
     /var/at/at.deny    deny permission control
     /var/at/.lockfile  job-creation lock file

     nice(1), sh(1), umask(2), atrun(8), cron(8), sendmail(8)

     at was mostly written by Thomas Koenig <>.  The
     time parsing routines are by David Parsons <>.

     If the file /var/run/utmp is not available or corrupted, or if the user
     is not logged on at the time at is invoked, the mail is sent to the user
     ID found in the environment variable LOGNAME. If that is undefined or
     empty, the current user ID is assumed.

     at and batch as presently implemented are not suitable when users are
     competing for resources.  If this is the case for your site, you might
     want to consider another batch system, such as nqs.

     atq always prints the year as two digits.  Since at only permits submis-
     sion of jobs in the future, it is somewhat clear which century the job
     will run in.

OpenBSD 3.0                     April 12, 1995                               3