Much longer than Brian’s submission but here goes:
#!/usr/bin/env ruby -w
require ‘getoptlong’
require “net/http”
require “base64”
opts = GetoptLong.new([ ‘–help’, ‘-h’, GetoptLong::NO_ARGUMENT],
[ ‘–path’, ‘-p’, GetoptLong::REQUIRED_ARGUMENT],
[ ‘–url’, ‘-u’, GetoptLong::REQUIRED_ARGUMENT],
[ ‘–debug’, ‘-d’, GetoptLong::NO_ARGUMENT])
def print_usage_and_exit
puts “Usage: #{File.basename($PROGRAM_NAME)} [switches] message-id”
puts " -p directory set save directory to directory"
puts " -u url set url to use to url"
puts " -d display all decoded data as it is read"
exit 0
end
class String
def strip_html
string.dup.strip_html!
end
def decode_quoted_printable
decoded_string = gsub(/=…/) { |code| code[1…2].hex.chr }
strip_last = decoded_string.rstrip
strip_last[-1] == ?= ? strip_last.chop! : decoded_string
end
def strip_html!
gsub!(/<.?>/, ‘’)
gsub!(/&.?;/) do |match|
case match
when “&” then ‘&’
when “”" then ‘"’
when “>” then ‘>’
when “<” then ‘<’
when /&#\d+;/ then match[/(\d)+/].to_i.chr
when /&#x[0-9a-fA-F]+;/ then match[/[0-9a-fA-F]+/].hex.chr
else match
end
end
self
end
end
class WaitingState
def process(line)
return self unless line =~ /^–/
HeaderReadingState.new(line.strip)
end
end
WAITING_STATE = WaitingState.new
State reading content description
class HeaderReadingState
def initialize(line)
@line = line.strip
@data = {}
@entry = nil
end
def process(line)
line.strip!
# Ignore this attachment if we only have content lines.
return WAITING_STATE if line[@line]
# Switch to reading attachment-data when we encounter an empty
line.
return AttachmentParsingState.new(@line, @data) if line.empty?
# If we have an entry-header, handle this.
if line =~ /.*:/
@entry = line.slice!(/^.*:/)
@entry.chop!
end
# Invalid attachment
return WAITING_STATE if @entry.nil? && !line.empty?
unless line.empty? then
entry = @entry.downcase
data = line.strip
if data[-1] == ?;
# More data on next line, so just chop the ; and keep the
same entry
data.chop!
else
# Last data for this entry, so make sure next line has an
entry.
@entry = nil
end
# Data for each entry is stored as an array.
@data[entry] = (@data[entry] || []) + data.split(/;/).collect
{ |part| part.strip }
end
# Stay in this state
self
end
end
State for reading attachment content.
class AttachmentParsingState
IDENTITY_DECODING = lambda { |string| string }
QUOTED_PRINTABLE_DECODING = lambda { |string|
string.decode_quoted_printable }
BASE64_DECODING = lambda { |string| Base64.decode64(string) }
ENCODINGS = { ‘base64’ => BASE64_DECODING,
‘quoted-printable’ => QUOTED_PRINTABLE_DECODING }
def initialize(line, data)
@line = line
# Determine the encoding of the content.
encoding = ((data["content-transfer-encoding"] || []).first ||
“none”).downcase
# Select a decoding and default to identity decoding.
@decoding = ENCODINGS[encoding.downcase]
# Check content-disposition if this is an attachement.
# If so, extract the filename.
disposition = data["content-disposition"]
if disposition
@filename = parse_filename(disposition)
puts "Found attachment #{@filename} with encoding '#
{encoding}’." if @filename
puts “No decoder found for ‘#{encoding}’ - decoding turned
off.” unless @decoding
else
@filename = nil
end
@data = ""
end
Parse out a possible filename from content-disposition.
def parse_filename(disposition)
return nil unless disposition.member?(“attachment”)
filename = disposition.find("") { |value| value =~ /filename/ }
filename.slice!(“filename=”)
filename.strip!
filename = eval(filename) if filename =~ /".*"/
filename.empty? ? nil : filename
end
def store_attachment
if @filename then
filename = File.join($file_path, @filename)
if File.exist? filename
puts “Extraction done: #{filename} already exists - skipping.”
else
File.open(filename, “w+”) { |file| file.print @data }
puts “Extraction done: Attachment saved as ‘#{filename}’”
end
end
end
Process a line
def process(line)
if line[@line]
# store the data we got this far.
store_attachment
# We hit a delimiter, so go back to header reading state.
return HeaderReadingState.new(line)
end
# Decode and store data.
decoded = @decoding ? @decoding.call(line) : line
print decoded if $debug
@data << decoded
# stay in this state
self
end
end
def save_attachment(host, path, index)
state = WAITING_STATE
Net::HTTP.get(host, path + index.to_s).strip_html!.each do |str|
state = state.process(str)
end
end
$file_path = “.”
$debug = false
host = “blade.nagaokaut.ac.jp”
path = “/cgi-bin/scat.rb/ruby/ruby-talk/”
opts.each do |opt, arg|
case opt
when ‘–help’
print_usage_and_exit
when ‘–path’
if File.directory?(arg)
$file_path = arg
else
puts “Illegal path ‘#{arg}’ - Aborting.”
exit 0
end
when ‘–debug’
$debug = true
when ‘–url’
url = arg.gsub(/.:///, ‘’)
path = url[//.$/]
path += “/” unless path[-1] == ?/
url.slice!(path)
host = url
end
end
print_usage_and_exit if ARGV.length != 1
message_id = ARGV.first.to_i
save_attachment(host, path, message_id)
