bash scripting - read single keystroke including special keys enter and space

Question

Not sure if I should put this on stackoverflow or unix.stackexchange but I found some similar questions here, so here it goes.

I'm trying to create a script to be called by .bashrc that allows me to select one of two options based on a single keystroke. That wouldn't be hard normally but I want the two keys corresponding to the two options to be space and enter.

Here's what I got so far:

#!/bin/bash

SELECT=""
while [[ "$SELECT" != $'\x0a' && "$SELECT" != $'\x20' ]]; do
    echo "Select session type:"
    echo "Press <Enter> to do foo"
    echo "Press <Space> to do bar"
    read -s -N 1 SELECT
    echo "Debug/$SELECT/${#SELECT}"
    [[ "$SELECT" == $'\x0a' ]] && echo "enter" # do foo
    [[ "$SELECT" == $'\x20' ]] && echo "space" # do bar
done

The following output is what I get if I press enter, space, backspace and x:

:~$ bin/sessionSelect.sh
Select session type:
Press <Enter> to start/resume a screen session
Press <Space> for a regular ssh session
Debug//0
Select session type:
Press <Enter> to start/resume a screen session
Press <Space> for a regular ssh session
Debug//0
Select session type:
Press <Enter> to start/resume a screen session
Press <Space> for a regular ssh session
Debug//1
Select session type:
Press <Enter> to start/resume a screen session
Press <Space> for a regular ssh session
Debug/x/1

So both enter and space result in an empty SELECT. No way to distinguish the two. I tried to add -d 'D' to the read options, but that didn't help. Maybe someone can point me in the right direction.

The bash version would be 4.2 btw.

Answer 1

Try setting the read delimiter to an empty string then check the builtin $REPLY variable:

read -d'' -s -n1

For some reason I couldn't get it to work specifying a variable.