Man Linux: Main Page and Category List


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


       at [-V] [-q queue] [-f file] [-mldv] timespec...
       at [-V] [-q queue] [-f file] [-mkdv] [-t time]
       at -c job [job...]
       atq [-V] [-q queue]
       atrm [-V] job [job...]
       at -b


       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

       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 exact  definition  of  the  time  specification  can  be  found  in

       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

       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.


       -V      prints   the   version   number  to  standard  error  and  exit

       -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

       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.

       -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.

       -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.




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


       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.


       At was mostly written by Thomas Koenig,

                                  2009-11-14                             AT(1)