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sleep(1)
NAME
  sleep - Suspends execution for at least the specified time

SYNOPSIS
  sleep seconds

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  sleep:  XCU5.0

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

OPTIONS
  None

OPERANDS
  seconds
      Non-negative integer specifying the number of seconds for which
      execution is to be suspended.

DESCRIPTION
  The sleep command suspends execution of a process for at least the interval
  specified by seconds, which can range from 0 to 2,147,483,647 seconds.
  Depending on system activity, the actual time of suspension may be longer.
  See the sleep(3) reference page.

  [Tru64 UNIX]	seconds can be entered as a non-negative decimal, octal, or
  hexadecimal value.

NOTES
  If sleep receives a SIGALARM signal before process execution has resumed,
  sleep takes one of the following actions:

   1.  Terminates normally with a 0 (zero) exit status.	 (See the sleep(3)
       reference page for more information.)

   2.  Ignores the signal

   3.  Performs default processing

EXIT STATUS
  The following exit values are returned:

  0   Execution was successfully suspended for at least the requested time,
      or a SIGALARM signal was received.

  >0  An error occurred.

EXAMPLES
   1.  To display a message at 4-minute intervals for 20 minutes, create a
       shell script called remind containing the following:

	    for i
	    do
	    sleep 240; echo $i
	    sleep 240; echo $i
	    sleep 240; echo $i
	    sleep 240; echo $i
	    sleep 240; echo $i
	    done

       To display the message Try calling NHK at 4-minute intervals, enter:
	    remind 'Try calling NHK'

   2.  To run a command at regular intervals, create a shell script
       containing the following:

	    while true
	    do
		    date
		    sleep 60
	    done

       This displays the date and time once a minute.

   3.  To execute a command after a specified interval, enter the following;
	    (sleep 3600; echo Time\'s up) &

       This displays the message "Time's up" after one hour.

ENVIRONMENT VARIABLES
  The following environment variables affect the execution of sleep:

  LANG
      Provides a default value for the internationalization variables that
      are unset or null. If LANG is unset or null, the corresponding value
      from the default locale is used.	If any of the internationalization
      variables contain an invalid setting, the utility behaves as if none of
      the variables had been defined.

  LC_ALL
      If set to a non-empty string value, overrides the values of all the
      other internationalization variables.

  LC_CTYPE
      Determines the locale for the interpretation of sequences of bytes of
      text data as characters (for example, single-byte as opposed to
      multibyte characters in arguments).

  LC_MESSAGES
      Determines the locale for the format and contents of diagnostic
      messages written to standard error.

  NLSPATH
      Determines the location of message catalogues for the processing of
      LC_MESSAGES.

SEE ALSO
  Commands:  wait(1)

  Functions:  alarm(3), pause(3), sigaction(2), sleep(3)

  Standards:  standards(5)

Index for Section 1

Alphabetical listing for S

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