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 Std 1003.2 (``POSIX.2'') functionality. The handling of fractional arguments is provided as an extension to the specification. OpenBSD 3.5 April 18, 1994 1