GoldenDict-ng is a dictionary program that I have been starting to use more often lately. It has a pretty cool feature that monitors your system clipboard that automatically pops up a window and looks up the copied text. Unfortunately, this feature is only available for X11 if you’re a Linux user.

Thankfully, we can port this feature fairly easily by utilizing existing programs that you may already have installed on your machine right now!

Basic approach

The wl-paste command from wl-clipboard has a --watch flag that allows you to run a command with the copied text passed in as input. That alone already makes things a lot easier. Now we just need a command that transfers the copied text to GoldenDict. We can “create” a command by writing a shell script. Here is a simple example:

read query
goldendict -s "$query"

This script simply reads the standard input (which will be our copied text) and send it to GoldenDict. Now to start clipboard monitoring, you just run:

wl-paste --watch sh /path/to/script.sh

This is working but it could be better. In case you don’t want to look up words on the dictionary anymore, you may want to be able to easily disable the script or enable it again. So it is a wise idea to implement some form of control over the script.

The simpliest approach to this is to use a file to save the script’ state. Basically, we’ll make the script to look into a file and decide whether or not the script should send the copied text to GoldenDict:

STATEFILE="/path/to/statefile"

# If state file doesn't yet exist, create it.
if [ ! -f $STATEFILE ]; then
	touch $STATEFILE
fi

# Fetch the content of the state file
STATUS=$(<$STATEFILE)

# If the content matches our conditions, then send the query
if [ "$STATUS" == "1" ]; then
	goldendict -s "$query"
fi

Integration with Waybar

Unless you’re a true minimalist, you should have a desktop panel available on your screen. I use Waybar as my panel and I’ll be using it to control the script because the panel doesn’t hide from you.

The idea is to add a button that toggles the script between two states: enable or disable. By using the custom module, we can easily do that, but not without some modifications to our script since Waybar needs some output in order to print something.

I’m gonna be honest here, but I kinda suck at Bash and I don’t really want to bother myself crawling on Stack Overflow so I rewrote the script to Ruby instead:

STATE_FILE_PATH = "/path/to/statefile"

print_status = false
new_status = ""

# Create state file if not yet exists
unless File.exist? STATE_FILE_PATH
  File.new(STATE_FILE_PATH, "wx").close
end

# Load the initial status
status = File.read(STATE_FILE_PATH)

# Loop through each command line arguments and evaluate them
ARGV.each do |arg|
  case arg
  when "-0"
    # Disable
    new_status = "0"
  when "-1"
    # Enable
    new_status = "1"
  when "-t"
    # Toggle
    if status == "1"
      new_status = "0"
    else
      new_status = "1"
    end
  when "-s"
    print_status = true
  end
end

# If the user wants to assign new states, open up the
# file and do so.
unless new_status.empty?
  state_file = File.open(STATE_FILE_PATH, "w+")
  state_file.write(new_status)
  state_file.flush
  state_file.close
end

# Read the new status
status = File.read(STATE_FILE_PATH)

if print_status
  # Write your own conditions here
  puts "󰺂" if status == "1"
  puts "󰪗" unless status == "1"
else
  if status == "1"
    input = gets
    unless input == nil  # In case clipboard is empty
      IO.popen("goldendict -s #{input}")
    end
  end
end

Some explanation for the arguments here:

• -0: Set state to 0 (disable)
• -1: Set state to 1 (enable)
• -t: Switch state between 0 and 1
• -s: Prints an icon that indicates the state
• nothing: Asks for input and send it to GoldenDict if state is 1

Now let’s create our Waybar module and assign it to somewhere on your panel. I put it to the left of my system tray:

...

"modules-right": [
  ...
  "custom/goldendict",
  "tray",
  ...
],

...

"custom/goldendict": {
  "format": "{}",
  "exec": "ruby /path/to/script -s",
  "on-click": "ruby /path/to/script -t",
  "interval": "once",
},

Don’t forget the main part of the story: run wl-paste -w ruby /path/to/script to trigger the script on every clipboard changes (you should run this on boot). And your panel should now look something like this after a restart. Also try clicking the icon to switch the state and copy some text:

A book icon sitting next to the system tray

A popup for 現在

I kept this very simple because this feature could be done by GoldenDict itself and a fix for Wayland could pop up at any time. Our next goal is to improve GoldenDict for Japanese text.