sleep Command

Purpose

Suspends execution for an interval.

Syntax

sleep Seconds

Description

The sleep command suspends execution of a process for at least the interval that is specified by the Seconds parameter. The amount of time that is specified in the Seconds parameter can range from 1 to MAXINT (2,147,483,647) seconds.

Exit status

This command returns the following exit values:

Table 1. Exit status
Item	Description
0	The execution was successfully suspended for at least `Seconds` seconds, or a `SIGALRM` signal was received.
>0	An error occurred.

Examples

To run a command after a certain amount of time has passed, enter the following command:

(
echo  "SYSTEM SHUTDOWN IN 10 MINUTES!" | wall
sleep 300; echo "SYSTEM SHUTDOWN IN 5 MINUTES!" | wall
sleep 240; echo "SYSTEM SHUTDOWN IN 1 MINUTE!" | wall
sleep 60; shutdown
)&

This command sequence warns all users 10 minutes, 5 minutes, and 1 minute before the system is shut down.

To run a command at regular intervals, enter the following command:
```
while true
do
 date
 sleep 60
done
```
This shell procedure displays the date and time once a minute. To stop it, press the Interrupt key sequence.