bin/shorturl in shorturl-0.7.0 vs bin/shorturl in shorturl-0.8.0

@@ -1,36 +1,38 @@
 #!/usr/bin/env ruby
 
 require "rubygems"
 require "shorturl"
+require "optparse"
 
-def usage
-  puts "Usage: #$0 <url> [<service>]"
-  puts "Available services:"
-  ShortURL.valid_services.each { |s| puts "\t#{s}" }
-  exit(-1)
+def service_list
+  ShortURL.valid_services.map { |s| s.to_s }.sort.join("\n\t")
 end
 
 def main
-  if ARGV.size < 1
-    usage
+  service = :rubyurl
+  op = OptionParser.new do |opts|
+    opts.banner = "Usage: #{File.basename($0)} [<options>] <url>"
+    opts.on("-h", "--help", "Displays help") { puts opts; exit }
+    opts.on("-s", "--service <service>", String,
+            "Uses <service> instead of RubyURL
+Available services:\n\t" + service_list) { |s| service = s.to_sym }
+    opts.parse!
   end
 
-  url = ARGV[0]
-  service = ARGV[1]
-
-  shorturl = if service.nil?
-               ShortURL.shorten(url)
+  if ARGV.empty?
+    puts op
+    exit(-1)
+  end
+  
+  url = ARGV.shift
+  shorturl = if ShortURL.valid_services.include?(service)
+               ShortURL.shorten(url, service)
              else
-               if ShortURL.valid_services.include?(service.to_sym)
-                 ShortURL.shorten(url, service.to_sym)
-               else
-                 puts "Invalid service"
-                 exit(-1)
-               end
+               puts "Invalid service"
+               exit(-1)
              end
 
-  puts shorturl
-    
+  puts shorturl || "Unable to get shortened URL.  Maybe the URL is already too short?"
 end
 
 main