Linux / UNIX: Bash Script Sleep or Delay a Specified Amount of Time

Posted on in Categories , , last updated August 8, 2017

How do I pause for 5 seconds or 2 minutes in my bash shell script on a Linux or Unix-like systems?

You need to use the sleep command to add delay for a specified amount of time. The syntax is as follows for gnu/bash sleep command:

sleep NUMBER[SUFFIX]

Where SUFFIX may be:

  1. s for seconds (the default)
  2. m for minutes.
  3. h for hours.
  4. d for days.

Please note that the sleep command in BSD family of operating systems (such as FreeBSD) or macOS X does NOT take any suffix arguments (m/h/d). It only takes arguments in seconds.

Examples

To sleep for 5 seconds, use:
sleep 5
To sleep for 2 minutes, use:
sleep 2m
To sleep for 3 hours, use:
sleep 3h
To sleep for 5 days, use:
sleep 5d
To sleep for 1.5 seconds:
sleep 1.5
To sleep for .5 seconds:
sleep .5
The most common usage are as follows:

## run commmand1, sleep for 1 minute and finally run command2 ## 
command1 && sleep 1m && command2
 
## sleep in bash for loop ##
for i in {1..10}
do
  do_something_here
  sleep 5s
done
 
## run while loop to display date and hostname on screen ##
while [ : ]
do
    clear
    tput cup 5 5
    date
    tput cup 6 5
    echo "Hostname : $(hostname)"
    sleep 1
done

Sample outputs from last while loop:

Animated gif.01: Sleep command in action
Animated gif.01: Sleep command in action

sleep Command Bash Script Example

Here is a simple example:

#!/bin/bash
echo "Hi, I'm sleeping for 5 seconds..."
sleep 5  
echo "all Done."

In this example, create the lock directory. I’m using [/\\:.-] here to ensure that we don’t use the same name that we are using for the .o file. Also, base the name on the expected object file name, since that is what matters with a parallel build.

...
...
lockdir=`echo "$cofile" | sed -e 's|[/\\:.-]|_|g'`.d
while true; do
  if mkdir "$lockdir" >/dev/null 2>&1; then
    break
  fi
  sleep 1
done
....
..
....

How can I pause my bash shell script for 5 second before continuing?

Use the read command:
read -p "text" -t 5
read -p "Waiting five secs for Cloudflare to clear cache...." -t 5
echo "Generating pdf file now ...."

Sample outputs:
Waiting five secs for Cloudflare to clear cache....
Generating pdf file now ....

Where,

  • -p "text" : Show the text without a trailing newline before time out.
  • -t N : Set time out to 5 seconds.

For more info see bash command man page:
$ man bash
$ man sleep
$ help read

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on Twitter, Facebook, Google+.

10 comment

  1. with the command ‘sleep’ , for more information use the manual pages of sleep by ‘man sleep’.

    sleep 5s ; echo ‘end test sleep 5sec’
    sleep 1m; echo ‘end test sleep 1min’

    best regards

  2. There is two types of sleep command – a shell built in and the /bin/seep. Both bash built-in and /bin/sleep take the suffixes, however the built in for mksh (which is on android) does not take suffixes. It’s is the same distinction between /usr/bin/time and shell built-in time

  3. watch also would be handy:
    watch runs command repeatedly, displaying its output and errors (the first screenfull). This allows you to watch the program output change over time. By default, the program is run every 2 seconds. By default, watch will run until interrupted.

  4. Hi,

    I have a scenario that files for a day comes in the interval of 5-6 hour which is not exactly fixed some times may vary much and I have to keep eyes on them before executing my process.
    Can we schedule my process in such a way that it invokes multiple times if it fails in its previous attempt. Once it executed won’t be invoked again for the day.

    Thanks in Advance…!!!

    Regards,
    mytechskill

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