get-port has a proper CLI.

src/get-port.cr

@@ -1,11 +1,33 @@
 require "file_utils"
+require "option_parser"
+
 require "./config.cr"
 
 START_PORT = 49152
 PORTS_CACHE_DIRECTORY = "#{CACHE_DIRECTORY}/ports/"
 
-service = ARGV[0]
-wanted_default_port = ARGV[1]?.try &.to_i
+service = ""
+wanted_default_port : String? = nil
+
+parser = OptionParser.parse do |parser|
+	parser.banner = "usage: get-post <id> [default-port] [options]\n" +
+		"options:\n"
+
+	parser.on "-h", "--help", "Prints this help message." do
+		puts parser
+		exit 0
+	end
+
+	parser.unknown_args do |arg|
+		if arg.size < 1 || arg.size > 2
+			puts parser
+			exit 1
+		end
+
+		service = arg[0]
+		wanted_default_port = arg[1]?
+	end
+end
 
 service_port_file = "#{PORTS_CACHE_DIRECTORY}/#{service.gsub /\//, ":"}"