SLEEP(1) BSD 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 seconds. It is usually used to schedule the exe-cution execution
cution of other commands (see EXAMPLES below).
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.
EXAMPLES
To schedule the execution of a command for x number seconds later:
(sleep 1800; sh command_file >& errors)&
This incantation would wait a half hour before running the script command_file. (See the at(1) util-ity.) utility.)
ity.)
To reiteratively run a command (with the csh(1)):
while (1)
if (! -r zzz.rawdata) then
sleep 300
else
foreach i (`ls *.rawdata`)
sleep 70
awk -f collapse_data $i >> results
end
break
endif
end
The scenario for a script such as this 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 the file zzz.rawdata, when the file is found, then another portion
processing is done courteously by sleeping for 70 seconds in between each awk job.
SEE ALSO
setitimer(2), sleep(3), at(1)
STANDARDS
The sleep command is expected to be IEEE Std 1003.2 (``POSIX.2'') compatible.
BSD April 18, 1994 BSD
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