program to parse rfc2822 type data

rfcparser.rb

#!/usr/bin/env ruby -w
#*******************************************************#
# This is a sample program which reads a data file
# into a hash.
# The format can be either:
#      Key: value
#
#      Key: <<ENDHERE
#        ... any kind of multiline
#      ENDHERE
#
#      Description:
#      Some data comes here.
#      Multiline data as in RFC2822.
#                                                       #
# The motive for this is that yaml coughs if the multiline
# date has data in it that appear like another definition.
# My data is often programming code which will give 
# problems to YAML.
# To test this call this with intro.page
# http://www.benegal.org/files/intro.page
# or test.page
# at http://gist.github.com/226145
# @Author: rkumar
# $Id$  #
#*******************************************************#
def parse_heredoc_to_hash(filename)
  file = File.new(filename, "r");
  myhash=Hash.new
  lastk= nil # last keyword, so we can append to it
  first_line = false
  line = file.gets;
  while line
    # check for heredoc start
    if line =~ /^([_\w]+):\s*<<(.*)$/
      kword=$1;
      delim=$2;
      buffer="";
      line = file.gets;
      # keep reading until you find the end of heredoc
      while line && line !~ /^#{delim}$/
        buffer = buffer + line;
        line = file.gets;
      end
      myhash[kword]=buffer;
      lastk = kword
    elsif line =~ /XXX/ #/^([_\w]+):\s*$/
      kword=$1;
      buffer="";
      line = file.gets;
      # keep reading until you find the end or another tag
      while line && line !~ /^([_\w]+):/
        buffer = buffer + line;
        line = file.gets;
      end
      myhash[kword]=buffer;
      lastk = kword
    else
      # this is a simple, single line assignment
      if line =~ /^([_\w]+):\s*(.*)$/
        myhash[$1]=$2;
        lastk = $1
        first_line = true
      else
        # did not know what to know with this
        # maybe add it to prev item.
        value = myhash[lastk]
        if first_line
          # this is when adding the second line, since REGEXP eats up EOL.
          value = value + "\n" +  line
        else
          value = value + line
        end
        myhash[lastk] = value
        first_line = false
      end
    end
    line = file.gets;
  end
  return myhash;
end # def

# java's main method !!
if __FILE__ == $0
  require 'pp'
  filename=ARGV[0];
  myhash = parse_heredoc_to_hash(filename)
  print "==========\n"
  pp myhash
  print "\n==========\n"
end