sleep



SLEEP(1)                    General Commands Manual                   SLEEP(1)


NAME

     sleep - suspend execution for an interval of time


SYNOPSIS

     sleep seconds


DESCRIPTION

     The sleep utility suspends execution for a minimum of the specified
     number of seconds.  This number must be positive and may contain a
     decimal fraction.  sleep is commonly used to schedule the execution of
     other commands (see below).


ASYNCHRONOUS EVENTS

     SIGALRM     Terminate normally, with a zero exit status.


EXIT STATUS

     The sleep utility exits 0 on success, and >0 if an error occurs.


EXAMPLES

     Wait a half hour before running the script command_file (see also the
     at(1) utility):

           (sleep 1800; sh command_file >& errors)&

     To repetitively run a command (with csh(1)):

           while (! -r zzz.rawdata)
                   sleep 300
           end
           foreach i (*.rawdata)
                   sleep 70
                   awk -f collapse_data $i >> results
           end

     The scenario for such a script might be: a program currently running is
     taking longer than expected to process a series of files, and it would be
     nice to have another program start processing the files created by the
     first program as soon as it is finished (when zzz.rawdata is created).
     The script checks every five minutes for this file.  When it is found,
     processing is done in several steps by sleeping 70 seconds between each
     awk(1) job.

     To monitor the growth of a file without consuming too many resources:

           while true; do
                   ls -l file
                   sleep 5
           done


SEE ALSO

     at(1)


STANDARDS

     The sleep utility is compliant with the IEEE Std 1003.1-2008 ("POSIX.1")
     specification.

     The handling of fractional arguments is provided as an extension to that
     specification.


HISTORY

     A sleep utility appeared in Version 4 AT&T UNIX.

OpenBSD 6.2                     August 16, 2016                    OpenBSD 6.2

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