NAME

sleep − Suspends execution for a specified time

SYNOPSIS

sleep seconds

DESCRIPTION

The sleep command suspends execution of a process for the interval specified by seconds, which can range from 0 to 2,147,483,647 seconds. 

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

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. 

RELATED INFORMATION

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