NAME

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

SYNOPSIS

       at [-V] [-q queue] [-f file] [-mMlv] timespec...
       at [-V] [-q queue] [-f file] [-mMkv] [-t time]
       at -c job [job...]
       atq [-V] [-q queue]
       at [-rd] job [job...]
       atrm [-V] job [job...]
       batch
       at -b

DESCRIPTION

       at  and  batch  read commands from standard input or a specified file which are to be executed at a later
       time, using /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, queue,
               and username.

       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 1.5, or the value specified in the invocation of atd.

       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
       MMDD[CC]YY, MM/DD/[CC]YY, DD.MM.[CC]YY or [CC]YY-MM-DD.  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.

       The definition of the time specification can be found in /usr/share/doc/at/timespec.

       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 BASH_VERSINFO, DISPLAY, EUID,
       GROUPS, SHELLOPTS, TERM, UID, and _) and the umask are retained from the time of invocation.

       As at is currently implemented as a setuid program, other environment variables (e.g.  LD_LIBRARY_PATH or
       LD_PRELOAD) are also not exported.  This may change in the future.  As a workaround, set these  variables
       explicitly in your job.

       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.  See at.allow(5) for details.

OPTIONS

       -V      prints the version number to standard error and exit successfully.

       -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, the job is treated as  if  it  were
       submitted  to  batch  at  the time of the job.  Once the time is reached, the batch processing rules with
       respect to load average apply.  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.

       -M      Never send mail to the user.

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

       -t time run the job at time, given in the format [[CC]YY]MMDDhhmm[.ss]

       -l      Is an alias for atq.

       -r      Is an alias for atrm.

       -d      Is an alias for atrm.

       -b      is an alias for batch.

       -v      Shows the time the job will be executed before reading the job.

       Times displayed will be in the format "Thu Feb 20 14:50:00 1997".

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

FILES

       /var/spool/cron/atjobs
       /var/spool/cron/atspool
       /proc/loadavg
       /var/run/utmp
       /etc/at.allow
       /etc/at.deny

SEE ALSO

       at.allow(5), at.deny(5), atd(8), cron(1), nice(1), sh(1), umask(2).

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.

                                                   2009-11-14                                              AT(1)