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 at(1)								       at(1)




 NAME
      at, batch - execute batched commands immediately or at a later time

 SYNOPSIS
    Enter commands from standard input to run at a specified time:
      at [-m] [-q queue] -t spectime
      commands
      eof

      at [-m] [-q queue] time [date]
	   [next timeunit | +count timeunit]
      commands
      eof

    Enter commands from a file to run at a specified time:
      at -f job-file [-m] [-q queue] -t spectime

      at -f job-file [-m] [-q queue] time [date]
	   [next timeunit | +count timeunit]

    List scheduled jobs:
      at -d job-id ...

      at -l [job-id ...]

      at -l -q queue

    Cancel (remove) a scheduled job:
      at -r job-id ...

    Enter commands from standard input to run as a batch process:
      batch
      commands
      eof

    Enter commands from a file to run as a batch process:
      batch <&lt&lt&lt; job-file

 DESCRIPTION
      The at and batch commands schedule jobs for execution by the cron
      daemon (see cron(1M)).

      at schedules a job for execution at a specified time.  at can also
      list (-l) or remove (-r) existing scheduled at and batch jobs.

      batch schedules a job for execution immediately, or as soon as system
      load levels permit.

      You can enter commands into a job in one of the following ways:





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	+  From the keyboard on separate lines immediately after the at or
	   batch command line, followed by the currently defined eof (end-
	   of-file) character to end the input.	 The default eof is Ctrl-D.
	   It can be redefined in your environment (see stty(1)).

	+  With the -f option of the at command to read input from a script
	   file.

	+  From output piped from a preceding command.

    Options and Arguments
      at recognizes the following options and arguments.

	   commands	       One or more HP-UX commands that can be
			       executed as a shell script by at or batch.

	   eof		       End-of-file character.  The default is Ctrl-D
			       unless defined otherwise in your environment.

	   job-file	       The path name of an existing file.

	   job-id	       The job identifier reported by at or batch
			       when the job was originally scheduled.

	   -d job-id ...       Displays the contents of the specified job.
			       An unprivileged user is restricted to display
			       information only on jobs that the user owns.
			       A user with the appropriate privileges is
			       able to display information about all jobs.

	   -f job-file	       Read in the commands contained in job-file
			       instead of using standard input.

	   -l [job-id ...]     List the jobs specified.	 If no job-ids are
			       given, all jobs are listed.

	   -m		       Send mail to the invoking user after the job
			       has run, announcing its completion.  Unless
			       redirected elsewhere within the job, standard
			       output and standard error produced by the job
			       are automatically mailed to the user as well.

	   -q queue	       Submit the specified job to the queue
			       indicated (see queuedefs(4)).  Queues a, b,
			       and d through y can be used.  at uses queue a
			       by default.  batch always uses queue b.	All
			       queues except b require a time or a -t
			       specification.  at -qb is equivalent to
			       batch.





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	   -r job-id ...       Remove the jobs specified by each job-id.

	   -t spectime	       Define the absolute time to start the job.

			       spectime	 A date and time in the format:

					      [[CC]YY]MMDDhhmm [ . ss ]

					 where the decimal digit pairs are
					 as follows:

					 CC   The first two digits of the
					      year (19, 20).
					 YY   The second two digits of the
					      year (69-99, 00-68).  See
					      WARNINGS.
					 MM   The month of the year (01-12).
					 DD   The day of the month (01-31).
					 hh   The hour of the day (00-23).
					 mm   The minute of the hour
					      (00-59).
					 ss   The second of the minute
					      (00-61).

					 If both CC and YY are omitted, the
					 default is the current year.

					 If CC is omitted and YY is in the
					 range 69-99, CC defaults to 19.
					 Otherwise, CC defaults to 20.

					 The range for ss provides for two
					 leap seconds.	If ss is 60 or 61,
					 and the resulting time, as affected
					 by the TZ environment variable,
					 does not refer to a leap second,
					 the time is set to the whole minute
					 following mm.

					 If ss is omitted, it defaults to
					 00.

	   time [date]	       Define the base time for starting the job.

			       time	 A time specified as one, two, or
					 four digits.  One- and two-digit
					 numbers represent hours; four
					 digits represent hours and minutes.

					 Alternately, time can be specified
					 as two numbers separated by a colon



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					 (:), a single quote ('), the letter
					 h (h), a period (.), or a comma
					 (,).  Spaces may be present between
					 the separator and digits
					 representing minutes.	If defined
					 in langinfo(5), special time unit
					 characters can be used.

					 am or pm can be appended to
					 indicate morning or afternoon.
					 Otherwise, a 24-hour clock is
					 understood.  For example, 0815,
					 8:15, 8'15, 8h15, 8.15, and 8,15
					 are read as 15 minutes after eight
					 in the morning.  The suffixes zulu
					 and utc can be used to specify
					 Coordinated Universal Time (UTC),
					 equivalent to Greenwich Mean Time
					 (GMT).

					 The special names midnight, noon,
					 and now are also recognized.

			       date	 A day of the week (fully spelled
					 out or abbreviated) or a date
					 consisting of a day, a month, and
					 optionally a year.  The day and
					 year fields must be numeric, and
					 the month can be either fully
					 spelled out, abbreviated, or
					 numeric.  The fields in the date
					 string are separated by punctuation
					 marks such as slash (/), hyphen (-
					 ), period (.), and comma (,).	If
					 defined in langinfo(5), special
					 date unit characters can be
					 present.  A field having a value
					 greater than 31 is treated as the
					 year field and the remaining two
					 fields in the date string are
					 treated as month and day fields.
					 Otherwise, if a given date is
					 ambiguous (such as 2/5 or 2/5/10),
					 the D_T_FMT string (if defined in
					 langinfo(5)) is used to resolve the
					 ambiguity.

					 Two special days, today and
					 tomorrow, are also recognized.	 If
					 no date is given, today is assumed
					 if the given time is greater than



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					 the current time; 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.
					 Two-digit years in the range 69 to
					 99 are expanded to 1969 to 1999; in
					 the range 00 to 68, to 2000 to
					 2068.

	   next timeunit |  + count timeunit

			       Delay the execution date and time by a
			       specific number of time units after the base
			       time specified by time [date].

			       count	 A decimal number.  next is
					 equivalent to +1.

			       timeunit	 A time unit, one of the following:
					 minutes, hours, days, weeks,
					 months, or years, or their singular
					 forms.

    How Jobs Are Processed
      When a job is accepted, at and batch print a message to standard error
      in the form:

	   job job-id at execution-date

      where job-id is the job identifier in the form jobnumber.queue, such
      as 756284400.a, and execution-date is the date and time when the job
      will be released for execution.

      If your login shell is not the POSIX shell (/usr/bin/sh), the commands
      also print a warning message:

	   warning: commands will be executed using /usr/bin/sh

      at jobs default to queue a.  batch jobs always go in queue b.  See the
      -q option.

      An at or batch job consists of a two-part script stored in
      /var/spool/cron/atjobs that can be executed by the POSIX shell.

      The first part sets up the environment to match the environment when
      the at or batch command was issued.  This includes the current shell
      environment variables, current directory, umask, and ulimit (see
      ulimit(2), umask(1), and proto(4)).  Open file descriptors, traps, and
      priority are lost.



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 at(1)								       at(1)




      The second part consists of the commands that you entered.

      When cron dispatches the job, it starts a POSIX shell to execute the
      script.

      The number of jobs executing from a queue at any time is controlled by
      parameters in the file /var/adm/cron/queuedefs (see queuedefs(4)).

      Standard output and standard error from the job are mailed to the user
      unless they are redirected elsewhere within the job.

      Scheduled jobs are immune to the SIGHUP hangup signal, and remain
      scheduled if the user logs off.

      Users are permitted to use the at and batch commands if their user
      names appear in the file /usr/lib/cron/at.allow.	If that file does
      not exist, users can use at and batch if their names do not appear in
      the file /usr/lib/cron/at.deny.  If neither file exists, only
      superuser is allowed to submit jobs.  If only at.deny exists but is
      empty, all users can use at and batch.  The allow/deny files consist
      of one user name per line.

      All users can list and remove their own jobs.  Users with appropriate
      privileges can list and remove jobs other than their own.

 EXTERNAL INFLUENCES
    Environment Variables
      LC_TIME determines the format and contents of date and time strings.

      LC_MESSAGES determines the language in which messages are displayed.

      LC_MESSAGES also determines the language in which the words days,
      hours, midnight, minutes, months, next, noon, now, today, tomorrow,
      weeks, years, and their singular forms can also be specified.

      IF LC_TIME or LC_MESSAGES is not specified in the environment or is
      set to the empty string, the value of LANG is used as a default for
      each unspecified or empty variable.  If LANG is not specified or is
      set to the empty string, a default of "C" (see lang(5)) is used
      instead of LANG.

      If any internationalization variable contains an invalid setting, all
      internationalization variables default to "C" (see environ(5)).

    International Code Set Support
      Single- and multi-byte character code sets are supported.

 RETURN VALUE
      The exit code is set to one of the following:





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	    0	Successful completion
	    1	Failure

 DIAGNOSTICS
      at produces self-explanatory messages for syntax errors and out-of-
      range times.

      warning: commands will be executed using /usr/bin/sh

	   If your login shell is not the POSIX shell (/usr/bin/sh), at and
	   batch produce a warning message as a reminder that at and batch
	   jobs are executed using /usr/bin/sh.

 EXAMPLES
      The following commands show three different ways to run a POSIX shell
      script file named delayed-job five minutes from now:

	   at -f delayed-job now + 5 minutes
	   cat delayed-job | at now + 5 minutes
	   at now + 5 minutes <&lt&lt&lt;delayed-job

      Run a typical HP-UX command (nroff in this case) when system load
      levels permit, and redirect standard output and standard error to
      files:

	   batch
	   nroff source-file >&gt&gt&gt;output-file 2>&gt&gt&gt;error-file
	   eof	   (the default is Ctrl-D)

      Run a job contained in future in the home directory at 12:20 a.m. on
      December 27, 2013:

	   at -f $HOME/future -t201312271220.00

      Redirect standard error to a pipe (useful in a shell procedure).	Note
      that the sequence of the output redirection specifications is
      significant.  Standard error is redirected to where standard output is
      going; standard output is redirected to a file; the original "standard
      output" (which now consists of the former standard error) is piped to
      the mail program.

	   batch <&lt&lt&lt;<&lt&lt&lt;!!	 (sets eof temporarily to !!)
	   nroff input-file 2>&gt&gt&gt;&&amp&amp&amp;1 1>&gt&gt&gt; output-file | mail loginid
	   !!

      Run a job contained in jobfile in the home directory at 5:00 a.m. next
      Tuesday:

	   at -f $HOME/jobfile 5am tuesday next week





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      Run the same job at 5:00 a.m. one week from next Tuesday (i.e., 2
      Tuesdays in advance):

	   at -f $HOME/jobfile 5am tuesday + 2 weeks

      Add a command to the file named weekly-run in directory jobs in the
      home directory so that it automatically reschedules itself every time
      it runs.	This example reschedules itself every Thursday at 1900 (7:00
      p.m.):

	   echo "sh $HOME/jobs/weekly-run" | at 1900 thursday next week

      The following commands show several forms recognized by at and include
      native language usage:

	   at 0815 Jan 24
	   at 8:15 Jan 24
	   at 9:30am tomorrow
	   at now + 1 day
	   at -f job 5 pm Friday
	   at 17:40 Tor.	      # in Danish
	   at 17h46 demain	      # in French
	   at 5:30 26. Feb. 1988      # in German
	   at 12:00 26-02	      # in Finnish

 WARNINGS
      If the date argument begins with a number and the time argument is
      also numeric without a suffix, the time argument should be a four-
      digit number that can be correctly interpreted as hours and minutes.

      If you use both next and +count within a single at command, the first
      operator is accepted and the trailing operator is silently ignored.

      If you use both -t and time ...  in the same command, the first
      specified is accepted and the second is silently ignored.

      If the FIFO used to communicate with cron fills up, at is suspended
      until cron has read sufficient messages from the FIFO to make room for
      the message at is trying to write.  This condition can occur if at is
      writing messages faster than cron can process them or if cron is not
      executing.

      Scheduled processes are run in the background.  Any script file that
      calls itself will cause the user or the system to run out of available
      processes.

      If the execution-time request for a job duplicates the execution time
      of a currently scheduled job, the new job time is set to the next
      available second.





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      at will not schedule jobs whose start time precedes the current Epoch
      (00:00:00 January 1, 1970 UTC).

      at will not schedule jobs beyond the year 2037.

 DEPENDENCIES
    HP Process Resource Manager
      If the optional HP Process Resource Management (PRM) software is
      installed and configured, jobs are launched in the initial process
      resource group of the user that scheduled the job.  The user's initial
      group is determined at the time the job is started, not when the job
      is scheduled.  If the user's initial group is not defined, the job
      runs in the user default group (PRMID=1).	 See prmconfig(1) for a
      description of how to configure HP PRM, and prmconf(4) for a
      description of how the user's initial process resource group is
      determined.

 AUTHOR
      at was developed by AT&T and HP.

 FILES
      /usr/bin/sh			 POSIX shell
      /var/adm/cron			 Main cron directory
      /var/adm/cron/.proto		 This file contains a set of shell
					 commands which are added to the at
					 job file to make the environment
					 for the at job same as the current
					 environment. See proto(4).
      /usr/lib/cron/at.allow		 List of allowed users
      /usr/lib/cron/at.deny		 List of denied users
      /var/adm/cron/queuedefs		 Scheduling information
      /var/spool/cron/atjobs		 Spool area

 SEE ALSO
      crontab(1), kill(1), mail(1), nice(1), ps(1), sh(1), stty(1),
      cron(1M), proto(4), queuedefs(4).

      HP Process Resource Manager:
	   prmconfig(1), prmconf(4) in HP Process Resource Manager User's
	   Guide.

 STANDARDS CONFORMANCE
      at: SVID2, SVID3, XPG2, XPG3, XPG4

      batch: SVID2, SVID3, XPG2, XPG3, XPG4









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