Linux showkey utility inside a bash script not returning data

Question

I am bit puzzled, when I run this showkey -a command on shell, the command is run and I can interact with it in realtime.

See below

timeout 10 /usr/bin/showkey -a

Press any keys - Ctrl-D will terminate this program

t   116 0164 0x74
a    97 0141 0x61
s   115 0163 0x73
d   100 0144 0x64
f   102 0146 0x66
g   103 0147 0x67
j   106 0152 0x6a
f   102 0146 0x66
k   107 0153 0x6b
l   108 0154 0x6c
d   100 0144 0x64

Now when I add this command in a shell script, I do not see any output, or in other words I cannot interact with script or command that is run inside the script.

Here is my bash script.

#!/bin/bash
timeout 10 /usr/bin/showkey -a
exit 0

When I run this script, it waits for 10 seconds and exit to the shell. How can I make it show keys pressed, codes and interact with the user.

The reason I want this because the script has to execute many tasks before coming to keyboard testing and after keyboard test there are various other tasks that the scripts performs. I couldn't find any answers anywhere, so as a last resort I had to ask this question here. I hope someone can help.

Answer 1

The command showkey reads from console device. If you start showkey from a subshell, you have to redirect stdin:

#!/usr/bin/env bash
/usr/bin/showkey -a </dev/stdin

In case you want to use timeout, just allow the command showkey to read from the TTY and get TTY signals:

#!/usr/bin/env bash
timeout --foreground 10 /usr/bin/showkey -a </dev/stdin