[TxMt] Properly escaping characters in ruby script

Well I rewrote my little script in Ruby and have had mostly success, but I need some help escaping things properly. Here's what I'm having trouble with:

#!/usr/bin/env ruby

arg = STDIN.read arg.chomp! arg.gsub!('\', '\') arg.gsub!("'", '\'') arg.gsub!(""","\"") arg.gsub!('`', '\`') system("pointfree ""+arg+""")

This is intended to enclose text selected in TextMate in quotation marks, and then escape all of the following characters within the the quotes, and then use that as the argument to pointfree. What's wrong with how I'm doing it?

Sorry for all of the questions, Ian