How can I get the active (focused) window in OSX?

Question

I want my console to beep when a task finishes in a terminal I'm not watching.

I actually have it all worked out in Linux:

function beeper_preexec {
  focus_window=`xdotool getwindowfocus`
} 

function beeper_precmd {
  retval=$?

  if [[ $focus_window -ne `xdotool getwindowfocus` ]]; then
    if [[ $retval -ne 0 ]]; then
      beep -f 329.6
    else
      beep
    fi
  fi
} 

function beeper_setup {
  add-zsh-hook precmd beeper_precmd
  add-zsh-hook preexec beeper_preexec
}

Does anyone know something I can use to replace xdotool getwindowfocus on OS X? I don't particularly care if it returns the PID or window id, it just needs to change when the focused window switches.

Answer 1

I'm not exactly sure how I would approach this, but I did a small amount of research and it seems that you can use AppleScript to get the current window title and then compare that to the expected window title of Terminal.

From: MacOSX: get foremost window title

global frontApp, frontAppName, windowTitle

set windowTitle to ""
tell application "System Events"
    set frontApp to first application process whose frontmost is true
    set frontAppName to name of frontApp
    tell process frontAppName
        tell (1st window whose value of attribute "AXMain" is true)
            set windowTitle to value of attribute "AXTitle"
        end tell
    end tell
end tell

return {frontAppName, windowTitle}