AT(1)                                                       AT(1)



     NAME
          at, batch - execute commands at a later time

     SYNOPSIS
          at time [ date ] [ + increment ]
          at -r job...
          at -l [ job ... ]

          batch

     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 executed, while jobs queued with batch
          will execute when system load level permits.  at may be used
          with the following options:

          -r   Removes jobs previously scheduled with at.

          -l   Reports all jobs scheduled for the invoking user.

          Standard output and standard error output are mailed to the
          user unless they are redirected elsewhere.  The shell
          environment variables, current directory, umask, and ulimit
          are retained when the commands are executed.  Open file
          descriptors, traps, and priority are lost.

          Users are permitted to use at if their name appears in the
          file /usr/lib/cron/at.allow.  If that file does not exist,
          the file /usr/lib/cron/at.deny is checked to determine if
          the user should be denied access to at. If neither file
          exists, only root is allowed to submit a job.  If at.deny is
          empty, global usage is permitted.  The allow/deny files
          consist of one user name per line.  These files can only be
          modified by the superuser.

          The time may be specified as 1, 2, or 4 digits.  One and two
          digit numbers 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 indicate 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



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     AT(1)                                                       AT(1)



          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 following:  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 a batch job.  It is almost equivalent to
          ``at now'', but not quite.  For one, it goes into a
          different queue.  For another, ``at now'' will respond with
          the error message too late.

          at -r removes jobs previously scheduled by at or batch.  The
          job number is the number given to you previously by the at
          or batch command.  You can also get job numbers by typing at
          -l.  You can only remove your own jobs unless you are the
          super-user.

     EXAMPLES
          The at and batch commands read from standard input the
          commands to be executed at a later time.  sh(1) provides
          different ways of specifying standard input.  Within your
          commands, it may be useful to redirect standard output.

          This sequence can be used at a terminal:
                    batch
                    sort filename >outfile
                    <control-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 <<!
                    sort filename 2>&1 >outfile | mail loginid
                    !

          To have a job reschedule itself, invoke at from within the
          shell procedure, by including code similar to the following
          within the shell file:
                    echo "sh shellfile" | at 1900 thursday next week





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     AT(1)                                                       AT(1)



     FILES
               /usr/lib/cron  main cron directory
               /usr/lib/cron/at.allowlist of allowed users
               /usr/lib/cron/at.denylist of denied users
               /usr/lib/cron/queuescheduling information
               /usr/spool/cron/atjobsspool area

     SEE ALSO
          kill(1), mail(1), nice(1), ps(1), sh(1), sort(1).
          cron(1M) in the System Administrator's Reference Manual.

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

     ORIGIN
          AT&T V.3






































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