FreeBSD 7.0 manual page repository

FreeBSD is a free computer operating system based on BSD UNIX originally. Many IT companies, like DeployIS is using it to provide an up-to-date, stable operating system.

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

 

NAME

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

SYNOPSIS

      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

      The at and batch utilities read commands from standard input or a speci‐
      fied 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 spec‐
      ified 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 com‐
      mand 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, per‐
      mission 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.
      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

      -q queue
              Use the specified queue.  A queue designation consists of a sin‐
              gle 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 speci‐
              fied, the value defaults to 0.
 

FILES

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

AUTHORS

      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〉.
 

BUGS

      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.
 

Sections

Based on BSD UNIX
FreeBSD is an advanced operating system for x86 compatible (including Pentium and Athlon), amd64 compatible (including Opteron, Athlon64, and EM64T), UltraSPARC, IA-64, PC-98 and ARM architectures. It is derived from BSD, the version of UNIX developed at the University of California, Berkeley. It is developed and maintained by a large team of individuals. Additional platforms are in various stages of development.