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AT(1)			    General Commands Manual			 AT(1)

NAME
       at, batch - execute a command or	script at a specified time

SYNOPSIS
       at [ -csm ] [ -qqueue ] time [ date ] [ + increment ]
	    [ script ]
       at -r jobs...
       at -l [ jobs...	]

       batch [ -csm ] [	script ]

DESCRIPTION
       at  and	batch  read  commands  from standard input to be executed at a
       later time.  at allows you to specify when the commands should be  exe-
       cuted,  while jobs queued with batch will execute as soon as the	system
       load level permits.  script is the name of a file to be used as command
       input for the Bourne shell, sh(1), the C	shell, csh(1), or an arbitrary
       shell specified by the SHELL environment	variable.  If script is	 omit-
       ted, command input is accepted from the standard	input.

       Standard	output and standard error output are mailed to the user	unless
       they are	redirected elsewhere.  The shell environment  variables,  cur-
       rent  directory,	 and umask(2V) are retained when the commands are exe-
       cuted.  Open file descriptors, traps, and priority are lost.

       Users are permitted to use  at  if  their  name	appears	 in  the  file
       /var/spool/cron/at.allow.   If  that  file  does	 not  exist,  the file
       /var/spool/cron/at.deny is checked to determine if the user  should  be
       denied  access  to  at.	If neither file	exists,	only the super-user is
       allowed to submit a job.	 If at.deny is empty, global usage is  permit-
       ted.  The allow/deny files consist of one user name per line.

       The time	may be specified as 1, 2, or 4 digits.	One and	two digit num-
       bers are	taken to be hours, four	digits to be hours and	minutes.   The
       time  may alternately be	specified as two numbers separated by a	colon,
       meaning hour:minute.  A suffix am or pm may be  appended;  otherwise  a
       24-hour clock time is understood.  The suffix zulu may be used to indi-
       cate GMT.  The special names noon, midnight, now,  and  next  are  also
       recognized.

       An  optional date may be	specified as either a month name followed by a
       day number (and possibly	year number preceded by	an optional comma)  or
       a  day  of the week (fully spelled or abbreviated to three characters).
       Two special ``days'', today and tomorrow	are recognized.	 If no date is
       given,  today  is assumed if the	given hour is greater than the current
       hour and	tomorrow is assumed if it is less.  If the given month is less
       than the	current	month (and no year is given), next year	is assumed.

       The  optional  increment	is simply a number suffixed by one of the fol-
       lowing: minutes,	hours, days, weeks, months, or years.	(The  singular
       form is also accepted.)

       Thus legitimate commands	include:

	      at 0815am	Jan 24
	      at 8:15am	Jan 24
	      at now + 1 day
	      at 5 pm Friday

       at and batch write the job number and schedule time to standard error.

       batch  submits  batch jobs to queue b; this ``batch'' queue is for jobs
       to be run as soon as possible.  A job submitted to b  is	 scheduled  to
       run  immediately	 and  its  arguments  will not be interpreted as time,
       date, or	+ increment.

       batch is	similar	to `at now', but does not, for example,	 go  into  the
       same queue or respond with the error message `too late'.

OPTIONS
       -c	 C shell.  csh is used to execute script.

       -s	 Standard  (Bourne) shell.  sh is used to execute the job.  By
		 default, the  SHELL  environment  variable  determines	 which
		 shell to use.

       -m	 Mail.	 Send mail after the job has been run, even if the job
		 completes successfully.

       -qqueue	 Submit	the job	in queue queue rather than the	default	 queue
		 a.   The valid	queues are a through z.	 batch submits jobs in
		 queue b.  Queue c is reserved for cron(8) and jobs cannot  be
		 submitted to that queue.

       -r jobs ...
		 Remove	 the  specified	 jobs  previously  scheduled  by at or
		 batch.	 The job numbers are the numbers of the	jobs given  to
		 you previously	by the at or batch commands.  You can only re-
		 move your own jobs unless you are the super-user.

       -l [jobs	...]
		 If jobs is specified, print the queue entry for  those	 jobs;
		 if  jobs  is  not  specified, print the queue entries for all
		 jobs for the user.

ENVIRONMENT
       If neither at.allow nor at.deny exists, only the	super-user is  allowed
       to  submit  a  job.   If	at.deny	is present, but	empty, global usage is
       permitted.  The allow/deny files	consist	of one user name per line.

EXAMPLES
       Unless a	script is specified, the at and	batch commands read from stan-
       dard  input  the	 commands  to be executed at a later time.  sh and csh
       provide different ways of specifying standard input.  Within your  com-
       mands, it may be	useful to redirect standard output.

       This sequence can be used at a terminal:

	      batch
	      nroff filename > outfile
	      CTRL-D (hold down	`control' and depress `D')

       This sequence, which demonstrates redirecting standard error to a pipe,
       is useful in a shell procedure  (the  sequence  of  output  redirection
       specifications is significant):

	      batch <<!
	      nroff filename 2>&1 > outfile  |	mail loginid
	      !

       To have a job reschedule	itself,	invoke at from within the shell	proce-
       dure, by	including code similar to the following	within the shell file:

	      at 1900 thursday next week shellfile

FILES
       /var/spool/cron		main cron directory
       /var/spool/cron/at.allow	list of	allowed	users
       /var/spool/cron/at.deny	list of	denied users
       /var/spool/cron/atjobs	spool area

SEE ALSO
       atq(1), atrm(1),	 csh(1),  kill(1),  mail(1),  nice(1),	ps(1),	sh(1),
       umask(2V), cron(8)

DIAGNOSTICS
       Complaints about	various	syntax errors and times	out of range.

BUGS
       If  the	system crashes,	mail stating that the job was not completed is
       not sent	to the user.

       Shell interpreter specifiers (such as, !/bin/csh) in the	 beginning  of
       script are ignored.

				31 October 1988				 AT(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | ENVIRONMENT | EXAMPLES | FILES | SEE ALSO | DIAGNOSTICS | BUGS

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