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)