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AT(1)			   Linux Programmer's Manual			 AT(1)

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

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	 ulti-
       mately /bin/sh.

       at      executes	commands at a specified	time.

       atq     lists  the  user's  pending  jobs, unless the user is the supe-
	       ruser; 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 spe-
       cific time of day.  (If that time is already past, the next day is  as-
       sumed.)	 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	 morn-
       ing  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 giv-
       ing  a date of the form MMDDYY or MM/DD/YY or DD.MM.YY.	The specifica-
       tion 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  com-
       mands, 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	 user-
       name 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 com-
       mands, 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 en-
       vironment 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

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