SLEEP(1)                   OpenBSD Reference 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 num-
     ber of seconds. This number must be positive and may contain a decimal
     fraction.  sleep is commonly used to schedule the execution of other com-
     mands (see below).

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

DIAGNOSTICS
     The sleep utility exits with one of the following values:

     0     On successful completion, or if the signal SIGALRM was received.
     >0    An error occurred.

SEE ALSO
     at(1), nanosleep(2), setitimer(2), alarm(3), sleep(3), usleep(3)

STANDARDS
     The sleep command offers a superset of IEEE Std1003.2 (``POSIX.2'') func-
     tionality.  The handling of fractional arguments is provided as an exten-
     sion to the specification.

OpenBSD 3.0                     April 18, 1994                               1
