Following my previous post on “How to Create a Prompt With Timeout in Bash ”, we will now see how to create a timer (countdown) in Bash using the built-in $SECONDS variable.
The $SECONDS variable holds in the number of seconds the script has been running. So it can easily be used to create a timer inside your script in Bash.
$ bash -c 'while true ; do echo -en "\r${SECONDS}s elapsed" ; sleep 1 ; done'
203s elapsed
