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I have the following script to execute "xset led" command on keypress but I cannot make it work for the command does not actually execute. Here is the script:

#!/bin/bash
res=$(echo "$(xset q)" | tr ";" "Scroll Lock")
if [[ $res == *"Scroll Lock: on"* ]]; then
    echo $(xset led on)
else
    echo $(xset led off)
fi

However when I execute echo $(xset led on) in the shell it works. Executing the script above outputs an empty line, though.

Burgi
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Любомир Борисов
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  • I would normally put `$res` in quotes for comparison and use a single equals sign, i.e. `if [ "$res" = *"Scroll Lock: on"* ]; then ... fi`, but it seems like your script should work regardless. Oh, but `tr` will only take the first character from `Scroll Lock`, not the whole thing! – wvxvw Nov 07 '17 at 09:26
  • I am new to the bash script but $res somehow contains what I need - the if-else statement works as expected but I don't know how to fire xset led on/off so that my keyboard backlight will turn of or on respectively. – Любомир Борисов Nov 07 '17 at 13:47
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    Well, if that's all you need, you don't need to call `xset` inside a subshell, you could replace `echo $(xset led on)` with just `xset led on` with virtually the same effect. Also, you might want to put `set +x` before anything in your script to make Bash log every line it executes: this way you will know when something breaks. – wvxvw Nov 07 '17 at 14:11
  • [What is wrong with `echo $(stuff)`?](https://superuser.com/q/1352850/432690) – Kamil Maciorowski Mar 09 '20 at 16:42

1 Answers1

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The problem was actually in executing the wrong command in the if-else statement. When the backlight is on I executed xset led on instead of off. A rookie mistake was

Любомир Борисов
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