Pre-commit hook to add newlines and remove trailing whitespace

gistfile1.rb

#!/usr/bin/env ruby

files = `git diff-index --name-status --cached HEAD | grep -v ^D | cut -c3-`
unless files == ''
  files.split("\n").each do |f|
    # Only examine known text files
    if f =~ /.(conf|css|erb|html|haml|scss|css|js|json|log|properties|rb|ru|txt|xml|yml)$/ && f =~ /^tapjoyads\/(app|test|lib|public|db\/migrate|config)\//
      # Add a linebreak to the file if it doesn't have one
      if `tail -c1 #{f}` != "\n"
        `echo >> #{f}`
        `git add #{f}`
      end
      # Remove trailing whitespace if it exists
      if system %(grep -q "[[:blank:]]$" #{f})
        `sed -i "" -e $'s/[ \t]*$//g' #{f}`
        `git add #{f}`
      end
    end
  end
end