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Friday 1 January 2010

at man page

User Commands                                               at(1)



NAME
     at, batch - execute commands at a later time

SYNOPSIS
     /usr/bin/at [-c | -k | -s]  [-m] [-f file]  [-p project]  [-
     q queuename] -t time

     /usr/bin/at [-c | -k | -s]  [-m] [-f file]  [-p project]  [-
     q queuename] timespec...

     /usr/bin/at -l [-p project] [-q queuename] [ at_job_id. ..]

     /usr/bin/at -r at_job_id. ..

     /usr/bin/batch [-p project]

     /usr/xpg4/bin/at [-c | -k | -s]  [-m] [-f file] [-p project]
     [-q queuename] -t time

     /usr/xpg4/bin/at [-c | -k | -s]  [-m] [-f file] [-p project]
     [-q queuename] timespec...

     /usr/xpg4/bin/at -l [-p project] [-q queuename] [ at_job_id.
     ..]

     /usr/xpg4/bin/at -r at_job_id. ..

     /usr/xpg4/bin/batch [-p project]

DESCRIPTION
  at
     The at utility reads commands from standard input and groups
     them together as an at-job, to be executed at a later time.

     The at-job is executed  in  a  separate  invocation  of  the
     shell,  running in a separate process group with no control-
     ling  terminal,  except  that  the  environment   variables,
     current   working   directory,   file   creation  mask  (see
     umask(1)), and system resource limits (for sh and ksh  only,
     see  ulimit(1)) in effect when the at utility is executed is
     retained and used when the at-job is executed.

     When the at-job is submitted, the  at_job_id  and  scheduled
     time  are  written  to  standard  error. The at_job_id is an
     identifier  that  is   a   string   consisting   solely   of
     alphanumeric   characters  and  the  period  character.  The
     at_job_id  is  assigned  by  the  system  when  the  job  is
     scheduled such that it uniquely identifies a particular job.

     User notification and the processing of the  job's  standard
     output and standard error are described under the -m option.




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User Commands                                               at(1)



     Users are permitted to use at and batch (see below) 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  a   user   with   the
     solaris.jobs.user  authorization is allowed to submit a job.
     If only at.deny exists and is empty, global usage is permit-
     ted. The at.allow and at.deny files consist of one user name
     per line.

     cron and at jobs are not be executed if the  user's  account
     is  locked. Only accounts which are not locked as defined in
     shadow(4) will have their job or process executed.

  batch
     The batch utility reads commands to be executed at  a  later
     time.

     Commands of the forms:

     /usr/bin/batch [-p project]
     /usr/xpg4/bin/batch [-p project]

     are respectively equivalent to:

     /usr/bin/at -q b [-p project] now
     /usr/xpg4/bin/at -q b -m [-p project] now

     where queue b is a special at queue, specifically for  batch
     jobs.  Batch  jobs  are  submitted  to  the  batch queue for
     immediate execution. Execution  of  submitted  jobs  can  be
     delayed  by limits on the number of jobs allowed to run con-
     currently. See queuedefs(4).

OPTIONS
     If the -c, -k, or -s options are not  specified,  the  SHELL
     environment  variable  by  default determines which shell to
     use.

     For /usr/xpg4/bin/at and /usr/xpg4/bin/batch,  if  SHELL  is
     unset or NULL, /usr/xpg4/bin/sh is used.

     For usr/bin/at and /usr/bin/batch,  if  SHELL  is  unset  or
     NULL, /bin/sh is used.

     The following options are supported:

     -c              C shell. csh(1) is used to execute  the  at-
                     job.






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User Commands                                               at(1)



     -k              Korn shell. ksh(1) is used  to  execute  the
                     at-job.



     -s              Bourne shell. sh(1) is used to  execute  the
                     at-job.



     -f file         Specifies the path of a file to be  used  as
                     the  source  of the at-job, instead of stan-
                     dard input.



     -l              (The letter ell.) Reports all jobs scheduled
                     for   the  invoking  user  if  no  at_job_id
                     operands are specified.  If  at_job_ids  are
                     specified,   reports  only  information  for
                     these jobs.



     -m              Sends mail to the invoking  user  after  the
                     at-job  has  run, announcing its completion.
                     Standard output and standard error  produced
                     by  the  at-job  are  mailed  to the user as
                     well, unless redirected elsewhere.  Mail  is
                     sent even if the job produces no output.

                     If -m is not used, the job's standard output
                     and  standard  error is provided to the user
                     by means of mail, unless they are redirected
                     elsewhere;  if  there  is  no such output to
                     provide, the user is  not  notified  of  the
                     job's completion.



     -p project      Specifies under  which  project  the  at  or
                     batch  job  is  run.  When  used with the -l
                     option, limits the search to that particular
                     project.  Values  for project is interpreted
                     first as a project name, and then as a  pos-
                     sible  project  ID,  if entirely numeric. By
                     default, the user's current project is used.



     -q queuename    Specifies in which queue to schedule  a  job
                     for   submission.  When  used  with  the  -l



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User Commands                                               at(1)



                     option, limits the search to that particular
                     queue.  Values  for queuename are limited to
                     the lower  case  letters  a  through  z.  By
                     default,  at-jobs  are scheduled in queue a.
                     In contrast, queue b is reserved  for  batch
                     jobs.  Since  queue  c  is reserved for cron
                     jobs, it can not be used with the -q option.



     -r at_job_id    Removes  the   jobs   with   the   specified
                     at_job_id   operands  that  were  previously
                     scheduled by the at utility.



     -t time         Submits the job to be run at the time speci-
                     fied by the time option-argument, which must
                     have the format as specified by the touch(1)
                     utility.



OPERANDS
     The following operands are supported:

     at_job_id       The name reported by a  previous  invocation
                     of  the  at  utility at the time the job was
                     scheduled.



     timespec        Submit the job to be run  at  the  date  and
                     time specified. All of the timespec operands
                     are interpreted as if they were separated by
                     space  characters and concatenated. The date
                     and time are interpreted  as  being  in  the
                     timezone  of  the user (as determined by the
                     TZ variable), unless a timezone name appears
                     as part of time below.

                     In the "C" locale, the  following  describes
                     the  three  parts  of the time specification
                     string. All of the values from  the  LC_TIME
                     categories  in the "C" locale are recognized
                     in a case-insensitive manner.


                     time            The time can be specified as
                                     one,  two  or  four  digits.
                                     One- and  two-digit  numbers
                                     are   taken   to  be  hours,



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User Commands                                               at(1)



                                     four-digit  numbers  to   be
                                     hours  and minutes. The time
                                     can alternatively be  speci-
                                     fied    as    two    numbers
                                     separated by a colon,  mean-
                                     ing  hour:minute.  An  AM/PM
                                     indication   (one   of   the
                                     values  from  the am_pm key-
                                     words in the LC_TIME  locale
                                     category)   can  follow  the
                                     time; otherwise,  a  24-hour
                                     clock  time is understood. A
                                     timezone name of  GMT,  UCT,
                                     or  ZULU  (case insensitive)
                                     can follow to  specify  that
                                     the  time  is in Coordinated
                                     Universal    Time.     Other
                                     timezones  can  be specified
                                     using  the  TZ   environment
                                     variable. The time field can
                                     also be one of the following
                                     tokens in the "C" locale:

                                     midnight Indicates the  time
                                              12:00 am (00:00).





                                     noon     Indicates the  time
                                              12:00 pm.



                                     now      Indicate        the
                                              current   day   and
                                              time.  Invoking  at
                                              now  submits an at-
                                              job for potentially
                                              immediate execution
                                              (that  is,  subject
                                              only to unspecified
                                              scheduling delays).




                     date            An  optional  date  can   be
                                     specified  as either a month
                                     name (one of the values from
                                     the mon or abmon keywords in



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User Commands                                               at(1)



                                     the LC_TIME locale category)
                                     followed  by  a  day  number
                                     (and  possibly  year  number
                                     preceded  by  a  comma) or a
                                     day of the week (one of  the
                                     values from the day or abday
                                     keywords  in   the   LC_TIME
                                     locale  category).  Two spe-
                                     cial days are recognized  in
                                     the "C" locale:

                                     today    Indicates       the
                                              current day.




                                     tomorrow Indicates  the  day
                                              following       the
                                              current day.



                                     If no date is  given,  today
                                     is assumed if the given time
                                     is greater than the  current
                                     time,    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.


                     increment       The optional increment is  a
                                     number  preceded  by  a plus
                                     sign (+) and suffixed by one
                                     of  the  following: minutes,
                                     hours, days, weeks,  months,
                                     or   years.   (The  singular
                                     forms  are  also  accepted.)
                                     The    keyword    next    is
                                     equivalent to  an  increment
                                     number  of + 1. For example,
                                     the following are equivalent
                                     commands:


                                     at 2pm + 1 week
                                     at 2pm next week





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User Commands                                               at(1)



USAGE
     The format of the at command line shown here  is  guaranteed
     only for the "C" locale. Other locales are not supported for
     midnight, noon, now, mon, abmon, day, abday,  today,  tomor-
     row, minutes, hours, days, weeks, months, years, and next.

     Since the commands run in a separate shell invocation,  run-
     ning  in a separate process group with no controlling termi-
     nal, open file descriptors,  traps  and  priority  inherited
     from the invoking environment are lost.

EXAMPLES
  at
     Example 1: Typical Sequence at a Terminal

     This sequence can be used at a terminal:

     $ at -m 0730 tomorrow
     sort < file >outfile
     <EOT>

     Example 2: Redirecting Output

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

     $ at now + 1 hour <<!
     diff file1 file2 2>&1 >outfile | mailx mygroup

     Example 3: Self-rescheduling a Job

     To have a job reschedule itself,  at  can  be  invoked  from
     within  the  at-job.  For  example,  this "daily-processing"
     script named my.daily runs every day (although crontab is  a
     more appropriate vehicle for such work):

     # my.daily runs every day
     at now tomorrow < my.daily
     daily-processing

     Example 4: Various Time and Operand Presentations

     The spacing of the three portions of the "C" locale timespec
     is quite flexible as long as there are no ambiguities. Exam-
     ples of various times and operand presentations include:

     at 0815am Jan 24
     at 8 :15amjan24
     at now "+ 1day"
     at 5 pm FRIday
     at '17



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User Commands                                               at(1)



          utc+
          30minutes'

  batch
     Example 5: Typical Sequence at a Terminal

     This sequence can be used at a terminal:

     $ batch
     sort <file >outfile
     <EOT>

     Example 6: Redirecting Output

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

     $ batch <<!
     diff file1 file2 2>&1 >outfile | mailx mygroup
     !

ENVIRONMENT VARIABLES
     See environ(5) for descriptions of the following environment
     variables  that  affect the execution of at and batch: LANG,
     LC_ALL, LC_CTYPE,  LC_MESSAGES,  NLSPATH, and LC_TIME.

     DATEMSK         If the environment variable DATEMSK is  set,
                     at uses its value as the full path name of a
                     template file containing format strings. The
                     strings  consist  of  format  specifiers and
                     text characters that are used to  provide  a
                     richer set of allowable date formats in dif-
                     ferent languages by appropriate settings  of
                     the  environment  variable  LANG or LC_TIME.
                     The list of allowable format  specifiers  is
                     located  in the getdate(3C) manual page. The
                     formats described in  the  OPERANDS  section
                     for the time and date arguments, the special
                     names  noon,  midnight,  now,  next,  today,
                     tomorrow, and the increment argument are not
                     recognized when DATEMSK is set.



     SHELL           Determine a name of a command interpreter to
                     be  used  to invoke the at-job. If the vari-
                     able is unset or NULL, sh is used. If it  is
                     set  to a value other than sh, the implemen-
                     tation uses that shell; a warning diagnostic
                     is printed telling which shell will be used.




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User Commands                                               at(1)



     TZ              Determine the timezone. The job is submitted
                     for  execution  at  the  time  specified  by
                     timespec or -t time relative to the timezone
                     specified  by  the TZ variable.  If timespec
                     specifies a timezone, it  overrides  TZ.  If
                     timespec  does not specify a timezone and TZ
                     is unset or  NULL,  an  unspecified  default
                     timezone is used.



EXIT STATUS
     The following exit values are returned:

     0        The at utility successfully submitted,  removed  or
              listed a job or jobs.



     >0       An  error  occurred,  and  the  job  will  not   be
              scheduled.



FILES
     /usr/lib/cron/at.allow          names  of  users,  one   per
                                     line,   who  are  authorized
                                     access to the at  and  batch
                                     utilities



     /usr/lib/cron/at.deny           names  of  users,  one   per
                                     line,  who are denied access
                                     to the at and  batch  utili-
                                     ties



ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

  /usr/bin/at











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User Commands                                               at(1)



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWcsu                     |
    |_____________________________|_____________________________|
    | CSI                         | Not enabled                 |
    |_____________________________|_____________________________|
    | Interface Stability         | Standard                    |
    |_____________________________|_____________________________|


  /usr/xpg4/bin/at
     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWxcu4                    |
    |_____________________________|_____________________________|
    | CSI                         | Not enabled                 |
    |_____________________________|_____________________________|
    | Interface Stability         | Standard                    |
    |_____________________________|_____________________________|


  /usr/bin/batch
     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWesu                     |
    |_____________________________|_____________________________|
    | CSI                         | Enabled                     |
    |_____________________________|_____________________________|
    | Interface Stability         | Standard                    |
    |_____________________________|_____________________________|


  /usr/xpg4/bin/batch
     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWxcu4                    |
    |_____________________________|_____________________________|
    | CSI                         | Enabled                     |
    |_____________________________|_____________________________|
    | Interface Stability         | Standard                    |
    |_____________________________|_____________________________|


SEE ALSO
     auths(1),  crontab(1),  csh(1),  date(1),   ksh(1),   sh(1),
     touch(1),   ulimit(1),   umask(1),   cron(1M),  getdate(3C),
     auth_attr(4),   shadow(4),   queuedefs(4),    attributes(5),
     environ(5), standards(5)



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User Commands                                               at(1)



NOTES
     Regardless of queue used, cron(1M) has a limit of  100  jobs
     in execution at any time.

     There can be delays in cron at job execution. In some cases,
     these  delays  can  compound to the point that cron job pro-
     cessing appears to be hung. All jobs  are  executed  eventu-
     ally.  When the delays are excessive, the only workaround is
     to kill and restart cron.














































SunOS 5.10          Last change: 13 Apr 2005                   11

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