*nix Documentation Project
·  Home
 +   man pages
·  Linux HOWTOs
·  FreeBSD Tips
·  *niX Forums

  man pages->FreeBSD man pages -> at (1)              
Title
Content
Arch
Section
 

AT(1)

Contents


NAME    [Toc]    [Back]

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

SYNOPSIS    [Toc]    [Back]

     at [-q queue] [-f file] [-mldbv] time
     at [-q queue] [-f file] [-mldbv] -t [[CC]YY]MMDDhhmm[.SS]
     at -c job [job ...]
     at -l [job ...]
     at -l -q queue
     at -r job [job ...]

     atq [-q queue] [-v]

     atrm job [job ...]

     batch [-q queue] [-f file] [-mv] [time]

DESCRIPTION    [Toc]    [Back]

     The at and batch utilities read commands from standard input or a specified
 file which are to be executed at a later time, using sh(1).

     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;

     atrm    deletes jobs;

     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 atrun.

     The at utility allows some moderately complex time specifications.  It
     accepts times of the form HHMM or HH:MM to run a job at a specific time
     of day.  (If that time is already past, the next day is assumed.)	As an
     alternative, the following keywords may be specified: midnight, noon, or
     teatime (4pm) and time-of-day may be suffixed with AM or PM for running
     in the morning or the evening.  The day on which the job is to be run may
     also be specified by giving a date in the form month-name day with an
     optional year, or giving a date of the forms DD.MM.YYYY, DD.MM.YY,
     MM/DD/YYYY, MM/DD/YY, MMDDYYYY, or MMDDYY.  The specification of a date
     must follow the specification of the time of day.	Time can also be specified
 as: [now] + count time-units, where the time-units can be minutes,
     hours, days, weeks, months or years and at may be told 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, use at 4pm + 3
     days, to run a job at 10:00am on July 31, use at 10am Jul 31 and to run a
     job at 1am tomorrow, use at 1am tomorrow.

     The at utility also supports the POSIX time format (see -t option).

     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, TERMCAP, 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 commands, if
     any.  Mail will be sent using the command sendmail(8).  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 /var/at/at.allow and
     /var/at/at.deny.

     If the file /var/at/at.allow exists, only usernames mentioned in it are
     allowed to use at.  In these two files, a user is considered to be listed
     only if the user name has no blank or other characters before it on its
     line and a newline character immediately after the name, even at the end
     of the file.  Other lines are ignored and may be used for comments.

     If /var/at/at.allow does not exist, /var/at/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.  This is the
     default configuration.

IMPLEMENTATION NOTES    [Toc]    [Back]

     Note that at is implemented through the cron(8) daemon by calling
     atrun(8) every five minutes.  This implies that the granularity of at
     might not be optimal for every deployment.  If a finer granularity is
     needed, the system crontab at /etc/crontab needs to be changed.

OPTIONS    [Toc]    [Back]

     -q queue
	     Use the specified queue.  A queue designation consists of a single
 letter; valid queue designations range from a to z and A to
	     Z.  The c queue is the default for at and the E queue for batch.
	     Queues with higher letters run with increased niceness.  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
	     Read the job from file rather than standard input.

     -l      With no arguments, list all jobs for the invoking user.  If one
	     or more job numbers are given, list only those jobs.

     -d      Is an alias for atrm (this option is deprecated; use -r instead).

     -b      Is an alias for batch.

     -v      For atq, shows completed but not yet deleted jobs in the queue;
	     otherwise shows the time the job will be executed.

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

     -r      Remove the specified jobs.

     -t      Specify the job time using the POSIX time format.	The argument
	     should be in the form [[CC]YY]MMDDhhmm[.SS] where each pair of
	     letters represents the following:

		   CC	   The first two digits of the year (the century).
		   YY	   The second two digits of the year.
		   MM	   The month of the year, from 1 to 12.
		   DD	   the day of the month, from 1 to 31.
		   hh	   The hour of the day, from 0 to 23.
		   mm	   The minute of the hour, from 0 to 59.
		   SS	   The second of the minute, from 0 to 61.

	     If the CC and YY letter pairs are not specified, the values
	     default to the current year.  If the SS letter pair is not specified,
 the value defaults to 0.

FILES    [Toc]    [Back]

     /var/at/jobs	     directory containing job files
     /var/at/spool	     directory containing output spool files
     /var/run/utmp	     login records
     /var/at/at.allow	     allow permission control
     /var/at/at.deny	     deny permission control
     /var/at/jobs/.lockfile  job-creation lock file

SEE ALSO    [Toc]    [Back]

      
      
     nice(1), sh(1), umask(2), atrun(8), cron(8), sendmail(8)

BUGS    [Toc]    [Back]

     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.

     The at and batch utilities as presently implemented are not suitable when
     users are competing for resources.  If this is the case, another batch
     system such as nqs may be more suitable.

     Specifying a date past 2038 may not work on some systems.

AUTHORS    [Toc]    [Back]

     At was mostly written by Thomas Koenig <ig25@rz.uni-karlsruhe.de>.  The
     time parsing routines are by
     David Parsons <orc@pell.chi.il.us>, with minor enhancements by
     Joe Halpin <joe.halpin@attbi.com>.


FreeBSD 5.2.1		       January 13, 2002 		 FreeBSD 5.2.1
[ Back ]
 Similar pages
Name OS Title
miser_qinfo IRIX query information on miser queues, queue resource status, and list of jobs scheduled against a queue
atrun FreeBSD run jobs queued for later execution
atrun Linux run jobs queued for later execution
atd Linux run jobs queued for later execution
atq Tru64 Prints the queue of jobs waiting to be run
lprm OpenBSD remove jobs from the line printer spooling queue
lprm FreeBSD remove jobs from the line printer spooling queue
scsi_max_qdepth HP-UX maximum number of I/Os that target will queue up for execution
fg IRIX run jobs in the foreground
bg IRIX run jobs in the background
Copyright © 2004-2005 DeniX Solutions SRL
newsletter delivery service