Bash - detect key pressed

In this short article, we want to show how to handle pressed key without waiting to rerun key / enter key confirmation under Bash.

Quick solution:

read -r -s -n 1 input

echo "$input"

Where:

• -r disables waiting to type new line character to end read command (Return / Enter key is not required),
• -s does not display typed characters,
• -n 1 expects to type one character.

Alternatively you can use short version too: read -rsn1 input

Practical example

In this section, we want to show how to create a simple menu that doesn't require to pres Return / Enter key after the option is typed.

example menu.sh file:

#!/bin/bash

echo '1. Message'
echo '2. User'
echo '3. Exit'
echo
echo 'Select one option [1-3]'
echo

while true;
do
	read -r -s -n 1 input

	case "$input" in
		"1")
			echo "Selected 1 [1. Message]"
			;;
		"2")
			echo "Selected 2 [2. User]"
			;;
		"3")
			echo "Selected 3 [3. Exit]"
			exit 0
			;;
	esac
done