Bash Read Escaped Characters and Normal Characters

Question

I want to read in bash when any key is pressed, be it arrow key, number, letter, or punctuation, without pressing enter.

This is the closest that I have come up with, besides that when an escaped key is pressed, it spills over into the next input. Also, escaped keys will read but not echo.

#!/bin/bash

read -r -n 1 -d $'\n' -p 'input> ' line
echo -en "\n"
echo "$line"

Answer 1

A bit hacky/dirty way, but should work for user interactive shells...

read -n1 -s -p 'input> ' line; read -t 0.1 -n2 -s line2
line="$line$line2"

Now, it's up to you to convert <ESC>[A to string <UP> or not.

NOTE: It would most likely fail, if the stdin is redirected (say, from pipe/file...)