Origa.me

Having looked at ruby-growl earlier today, but needing network-wide notifications rather than to individual machines, I hacked the following code together in Ruby using mDNSBrowse (from the Howl project - sadly a dead project replaced more recently by Avahi) to discover and resolve Growl clients on the network:

#!/usr/bin/env ruby
require 'ruby-growl'
require 'optparse'

mdns_browse_cmd = "mDNSBrowse _growl._tcp"
growl_password = "********"

# Kill zombie tasks using ps and kill
# notify() is only called when mDNSBrowse is killed
# Messy, I know, but it works
def kill_tasks(cmd)
	tasks = `ps aux | grep "#{cmd}$"`
	tasks.each_line do |taskrow|
		task = taskrow.split(" ")
		pid = task[1]
		system("kill #{pid}")
	end
end

# The notification method
def notify(host, password, title, message)
	type = "ruby-growl Notification"
	if (/^([0-9]{1,3}\.){3}[0-9]{1,3}$/.match(host))
		g = Growl.new host, "ruby-growl", type, nil, password
		g.notify type, title, message
	end
end

# Read options
title = "Default title"
message = "Default description"
opts = OptionParser.new do |opts|
	opts.banner = "Usage: cmd [options]"
	opts.on("-t" "--title [TITLE]", "Title") do |val|
		title = val
	end
	opts.on("-m" "--message [MESSAGE]", "Message") do |val|
		message = val
	end
end.parse!

# Begin execution here
pid = fork {
	p = IO.popen("#{mdns_browse_cmd} 2>&1")
	p.readlines.each do |line|
		if (line.slice(0,13)=="resolve reply")
			data = line.split(" ")
			ip = data[(data.length-2)]
			notify(ip, growl_password, title, message)
		end
	end
	p.close
}

kill_tasks mdns_browse_cmd

I've called mine 'globalgrowl' and stuck it in /usr/bin (chmod 755). Usage example: globalgrowl -t 'My title' -m 'My Message' Works nicely (and entirely functionally) when called in the init scripts on our Ubuntu office server. A future improvement could be to implement this with all options by copying ruby-growl's script and merging it with the mDNS discovery code from my script above, making all of the functionality of growl available to global notifications.