A ruby clone of ack (http://betterthangrep.com/) that uses Ruby multiline regexps.

ack.rb

#!/usr/bin/env ruby
require 'find'

usage = <<EOF
Usage: ack.rb <regexp> <directory or filename>
The regular expression can be across multiple lines, and is _not_ escaped by default.
For example:
  ack.rb 'end\\nend' .
will find all files in the current directory that have two 'end' statements across two lines

ack.rb is inspired by (but much less featureful than) ack (http://betterthangrep.com/)
EOF

abort usage unless ARGV.size == 2

regexp = Regexp.new(ARGV[0])
puts "Using regexp: #{regexp}"
filename = ARGV[1]

Find.find(filename) do |file|
  next if File.directory? file

  begin
    File.open(file) do |f|
      f.read(nil, s = "")
      i = regexp =~ s
      if i
        puts "*** File: #{file}"
        puts s[i-200..i+200]
      end
    end
  rescue
    puts "Cannot open file #{file}"
  end
end