Sending keyboard input to a program from command-line

Question

How do you send keyboard input to a program?

That is, under a Linux GUI, is there a good manual (programmable) way, or tool, of simulating keyboard input on a running program on Linux, so that I can send from the command-line, e.g., "Control-T" to a Firefox process and "echo 'hello'\n" to a Gnome-Terminal process without actually focusing on each of those processes and typing in directly?

Answer 1

xdotool does have a way of sending keystrokes if limited to a focused window:

WID=`xdotool search "Mozilla Firefox" | head -1`
xdotool windowactivate $WID
xdotool key ctrl+l

Answer 2

It's an old topic, but one still may be looking for this, someone mentioned here solution where window must be activated when using xdotool. However you can specify window and even use xdotool to find it. Here is example I tried to accomplish, change it as you need.

xdotool key --window $(xdotool search --name "Spotify (Premium |Free )?- Linux Preview" | head -n1) ctrl+KP_Down

Answer 3

I've built a Ruby DSL around xdotool to simplify the focusing of windows and simulation of keyboard input. Here's an example, riffing on your original request:

Mani.new(window_manager: :xmonad) do
  window :hello, launch: 'urxvt' do
    run 'echo "hello\n"'
  end

  window :firefox, launch: 'firefox', delay: 1.5 do
    type '{{ctrl+t}}'
  end
end

Answer 4

I found these two programs xmacro and xremote you may take a look, but it seems that they're not well documented.

I also found this utility xvkbd in answer to this question SO Q&A titled: Sending keycode to Xorg + wine with bash script.