gat: execute the given command every time the working dir changes

gat

#! /usr/bin/env ruby

#
# Example usage:
#
# 1> $ cd github.com/anthonybishopric/gotcha
# 1> $ gat go test # begin listening to this directory
# 
# 2> $ cd github.com/anthonybishopric/gotcha
# 2> $ touch README.md
# PASS
# ok  	github.com/anthonybishopric/gotcha	0.016s
 
require 'rb-fsevent'
require 'optparse'

options = {}

opts = OptionParser.new do |opts|
        opts.banner = "Run a command when contents in this directory change.\nUsage: gat [-n|--no-clear] <command>"
        opts.on("-n", "--[no-]clear", "Don't clear the screen before execution") do |n|
                options[:no_clear] = n
        end
        opts.on_tail("-h", "--help", "Show help") do
                puts opts
                exit
        end

end
opts.parse!


command = ARGV.join(" ")
if command == ""
        puts opts
        exit 1
end

unless options[:no_clear]
        command = "clear && #{command}"
end

fsevent = FSEvent.new
fsevent.watch Dir.pwd do |directories|
        system command
end
fsevent.run