Skip site navigation (1)Skip section navigation (2)

FreeBSD Man Pages

Man Page or Keyword Search:
Man Architecture
Apropos Keyword Search (all sections) Output format
home | help
AT(1)                      Linux Programmer's Manual                     AT(1)

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

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

DESCRIPTION
       at and batch read commands from standard input or a specified file
       which are to be executed at a later time, using the shell set by the
       user's environment variable SHELL, the user's login shell, or
       ultimately /bin/sh.

       at      executes commands at a specified time.

       atq     lists the user's pending jobs, unless the user is the
               superuser; in that case, everybody's jobs are listed.  The
               format of the output lines (one for each job) is: Job number,
               date, hour, job class.

       atrm    deletes jobs, identified by their job number.

       batch   executes commands when system load levels permit; in other
               words, when the load average drops below 0.8, or the value
               specified in the invocation of atrun.

       At allows fairly complex time specifications, extending the POSIX.2
       standard.  It accepts times of the form 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 specify midnight, noon, or teatime (4pm) and
       you can have a time-of-day suffixed 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 MMDDYY or MM/DD/YY or DD.MM.YY.  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
       tomorrow 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 and to run a job at 1am tomorrow, you would do at 1am tomorrow.

       /usr/share/doc/at-3.1.8/timespec contains the exact definition of the
       time specification.

       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, DISPLAY and _) and the
       umask are retained from the time of invocation.  An at - or batch -
       command invoked from a su(1) shell will retain the current userid.  The
       user will be mailed standard error and standard output from his
       commands, if any.  Mail will be sent using the command
       /usr/sbin/sendmail.  If at is executed from a su(1) shell, the owner of
       the login shell will receive the mail.

       The superuser may use these commands in any case.  For other users,
       permission to use at is determined by the files /etc/at.allow and
       /etc/at.deny.

       If the file /etc/at.allow exists, only usernames mentioned in it are
       allowed to use at.

       If /etc/at.allow does not exist, /etc/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 /etc/at.deny means that every user is allowed use these
       commands, this is the default configuration.

OPTIONS
       -V      prints the version number to standard error.

       -q queue
               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.

       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      Is an alias for atq.

       -d      Is an alias for atrm.

       -v      Shows the time the job will be executed.

       Times displayed will be in the format "1997-02-20 14:50" unless the
       environment variable POSIXLY_CORRECT is set; then, it will be "Thu Feb
       20 14:50:00 1996".

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

FILES
       /var/spool/at
       /var/spool/at/spool
       /proc/loadavg
       /var/run/utmp
       /etc/at.allow
       /etc/at.deny

SEE ALSO
       cron(1), nice(1), sh(1), umask(2), atd(8).

BUGS
       The correct operation of batch for Linux depends on the presence of a
       proc- type directory mounted on /proc.

       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
       userid found in the environment variable LOGNAME.  If that is undefined
       or empty, the current userid 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.

AUTHOR
       At was mostly written by Thomas Koenig, ig25@rz.uni-karlsruhe.de.

local                              Nov 1996                              AT(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | FILES | SEE ALSO | BUGS | AUTHOR

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=at&sektion=1&manpath=Red+Hat+Linux%2fi386+9>

home | help