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:

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read -r -s -n 1 input

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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

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:

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#!/bin/bash

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echo '1. Message'

echo '2. User'

echo '3. Exit'

echo

echo 'Select one option [1-3]'

echo

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while true;

do

    read -r -s -n 1 input

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    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

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