This file is indexed.

/usr/lib/ruby/1.8/open-uri.rb is in libruby1.8 1.8.7.352-2ubuntu1.6.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
require 'uri'
require 'stringio'
require 'time'

module Kernel
  private
  alias open_uri_original_open open # :nodoc:

  # makes possible to open various resources including URIs.
  # If the first argument respond to `open' method,
  # the method is called with the rest arguments.
  #
  # If the first argument is a string which begins with xxx://,
  # it is parsed by URI.parse.  If the parsed object respond to `open' method,
  # the method is called with the rest arguments.
  #
  # Otherwise original open is called.
  #
  # Since open-uri.rb provides URI::HTTP#open, URI::HTTPS#open and
  # URI::FTP#open,
  # Kernel[#.]open can accepts such URIs and strings which begins with
  # http://, https:// and ftp://.
  # In these case, the opened file object is extended by OpenURI::Meta.
  def open(name, *rest, &block) # :doc:
    if name.respond_to?(:open)
      name.open(*rest, &block)
    elsif name.respond_to?(:to_str) &&
          %r{\A[A-Za-z][A-Za-z0-9+\-\.]*://} =~ name &&
          (uri = URI.parse(name)).respond_to?(:open)
      uri.open(*rest, &block)
    else
      open_uri_original_open(name, *rest, &block)
    end
  end
  module_function :open
end

# OpenURI is an easy-to-use wrapper for net/http, net/https and net/ftp.
#
#== Example
#
# It is possible to open http/https/ftp URL as usual like opening a file:
#
#   open("http://www.ruby-lang.org/") {|f|
#     f.each_line {|line| p line}
#   }
#
# The opened file has several methods for meta information as follows since
# it is extended by OpenURI::Meta.
#
#   open("http://www.ruby-lang.org/en") {|f|
#     f.each_line {|line| p line}
#     p f.base_uri         # <URI::HTTP:0x40e6ef2 URL:http://www.ruby-lang.org/en/>
#     p f.content_type     # "text/html"
#     p f.charset          # "iso-8859-1"
#     p f.content_encoding # []
#     p f.last_modified    # Thu Dec 05 02:45:02 UTC 2002
#   }
#
# Additional header fields can be specified by an optional hash argument.
#
#   open("http://www.ruby-lang.org/en/",
#     "User-Agent" => "Ruby/#{RUBY_VERSION}",
#     "From" => "foo@bar.invalid",
#     "Referer" => "http://www.ruby-lang.org/") {|f|
#     # ...
#   }
#
# The environment variables such as http_proxy, https_proxy and ftp_proxy
# are in effect by default.  :proxy => nil disables proxy.
#
#   open("http://www.ruby-lang.org/en/raa.html", :proxy => nil) {|f|
#     # ...
#   }
#
# URI objects can be opened in a similar way.
#
#   uri = URI.parse("http://www.ruby-lang.org/en/")
#   uri.open {|f|
#     # ...
#   }
#
# URI objects can be read directly. The returned string is also extended by
# OpenURI::Meta.
#
#   str = uri.read
#   p str.base_uri
#
# Author:: Tanaka Akira <akr@m17n.org>

module OpenURI
  Options = {
    :proxy => true,
    :progress_proc => true,
    :content_length_proc => true,
    :http_basic_authentication => true,
  }

  def OpenURI.check_options(options) # :nodoc:
    options.each {|k, v|
      next unless Symbol === k
      unless Options.include? k
        raise ArgumentError, "unrecognized option: #{k}"
      end
    }
  end

  def OpenURI.scan_open_optional_arguments(*rest) # :nodoc:
    if !rest.empty? && (String === rest.first || Integer === rest.first)
      mode = rest.shift
      if !rest.empty? && Integer === rest.first
        perm = rest.shift
      end
    end
    return mode, perm, rest
  end

  def OpenURI.open_uri(name, *rest) # :nodoc:
    uri = URI::Generic === name ? name : URI.parse(name)
    mode, perm, rest = OpenURI.scan_open_optional_arguments(*rest)
    options = rest.shift if !rest.empty? && Hash === rest.first
    raise ArgumentError.new("extra arguments") if !rest.empty?
    options ||= {}
    OpenURI.check_options(options)

    unless mode == nil ||
           mode == 'r' || mode == 'rb' ||
           mode == File::RDONLY
      raise ArgumentError.new("invalid access mode #{mode} (#{uri.class} resource is read only.)")
    end

    io = open_loop(uri, options)
    if block_given?
      begin
        yield io
      ensure
        io.close
      end
    else
      io
    end
  end

  def OpenURI.open_loop(uri, options) # :nodoc:
    case opt_proxy = options.fetch(:proxy, true)
    when true
      find_proxy = lambda {|u| u.find_proxy}
    when nil, false
      find_proxy = lambda {|u| nil}
    when String
      opt_proxy = URI.parse(opt_proxy)
      find_proxy = lambda {|u| opt_proxy}
    when URI::Generic
      find_proxy = lambda {|u| opt_proxy}
    else
      raise ArgumentError.new("Invalid proxy option: #{opt_proxy}")
    end

    uri_set = {}
    buf = nil
    while true
      redirect = catch(:open_uri_redirect) {
        buf = Buffer.new
        uri.buffer_open(buf, find_proxy.call(uri), options)
        nil
      }
      if redirect
        if redirect.relative?
          # Although it violates RFC2616, Location: field may have relative
          # URI.  It is converted to absolute URI using uri as a base URI.
          redirect = uri + redirect
        end
        unless OpenURI.redirectable?(uri, redirect)
          raise "redirection forbidden: #{uri} -> #{redirect}"
        end
        if options.include? :http_basic_authentication
          # send authentication only for the URI directly specified.
          options = options.dup
          options.delete :http_basic_authentication
        end
        uri = redirect
        raise "HTTP redirection loop: #{uri}" if uri_set.include? uri.to_s
        uri_set[uri.to_s] = true
      else
        break
      end
    end
    io = buf.io
    io.base_uri = uri
    io
  end

  def OpenURI.redirectable?(uri1, uri2) # :nodoc:
    # This test is intended to forbid a redirection from http://... to
    # file:///etc/passwd.
    # However this is ad hoc.  It should be extensible/configurable.
    uri1.scheme.downcase == uri2.scheme.downcase ||
    (/\A(?:http|ftp)\z/i =~ uri1.scheme && /\A(?:http|ftp)\z/i =~ uri2.scheme)
  end

  def OpenURI.open_http(buf, target, proxy, options) # :nodoc:
    if proxy
      raise "Non-HTTP proxy URI: #{proxy}" if proxy.class != URI::HTTP
    end

    if target.userinfo && "1.9.0" <= RUBY_VERSION
      # don't raise for 1.8 because compatibility.
      raise ArgumentError, "userinfo not supported.  [RFC3986]"
    end

    require 'net/http'
    klass = Net::HTTP
    if URI::HTTP === target
      # HTTP or HTTPS
      if proxy
        klass = Net::HTTP::Proxy(proxy.host, proxy.port)
      end
      target_host = target.host
      target_port = target.port
      request_uri = target.request_uri
    else
      # FTP over HTTP proxy
      target_host = proxy.host
      target_port = proxy.port
      request_uri = target.to_s
    end

    http = klass.new(target_host, target_port)
    if target.class == URI::HTTPS
      require 'net/https'
      http.use_ssl = true
      http.verify_mode = OpenSSL::SSL::VERIFY_PEER
      store = OpenSSL::X509::Store.new
      store.set_default_paths
      http.cert_store = store
    end

    header = {}
    options.each {|k, v| header[k] = v if String === k }

    resp = nil
    http.start {
      req = Net::HTTP::Get.new(request_uri, header)
      if options.include? :http_basic_authentication
        user, pass = options[:http_basic_authentication]
        req.basic_auth user, pass
      end
      http.request(req) {|response|
        resp = response
        if options[:content_length_proc] && Net::HTTPSuccess === resp
          if resp.key?('Content-Length')
            options[:content_length_proc].call(resp['Content-Length'].to_i)
          else
            options[:content_length_proc].call(nil)
          end
        end
        resp.read_body {|str|
          buf << str
          if options[:progress_proc] && Net::HTTPSuccess === resp
            options[:progress_proc].call(buf.size)
          end
        }
      }
    }
    io = buf.io
    io.rewind
    io.status = [resp.code, resp.message]
    resp.each {|name,value| buf.io.meta_add_field name, value }
    case resp
    when Net::HTTPSuccess
    when Net::HTTPMovedPermanently, # 301
         Net::HTTPFound, # 302
         Net::HTTPSeeOther, # 303
         Net::HTTPTemporaryRedirect # 307
      throw :open_uri_redirect, URI.parse(resp['location'])
    else
      raise OpenURI::HTTPError.new(io.status.join(' '), io)
    end
  end

  class HTTPError < StandardError
    def initialize(message, io)
      super(message)
      @io = io
    end
    attr_reader :io
  end

  class Buffer # :nodoc:
    def initialize
      @io = StringIO.new
      @size = 0
    end
    attr_reader :size

    StringMax = 10240
    def <<(str)
      @io << str
      @size += str.length
      if StringIO === @io && StringMax < @size
        require 'tempfile'
        io = Tempfile.new('open-uri')
        io.binmode
        Meta.init io, @io if @io.respond_to? :meta
        io << @io.string
        @io = io
      end
    end

    def io
      Meta.init @io unless @io.respond_to? :meta
      @io
    end
  end

  # Mixin for holding meta-information.
  module Meta
    def Meta.init(obj, src=nil) # :nodoc:
      obj.extend Meta
      obj.instance_eval {
        @base_uri = nil
        @meta = {}
      }
      if src
        obj.status = src.status
        obj.base_uri = src.base_uri
        src.meta.each {|name, value|
          obj.meta_add_field(name, value)
        }
      end
    end

    # returns an Array which consists status code and message.
    attr_accessor :status

    # returns a URI which is base of relative URIs in the data.
    # It may differ from the URI supplied by a user because redirection.
    attr_accessor :base_uri

    # returns a Hash which represents header fields.
    # The Hash keys are downcased for canonicalization.
    attr_reader :meta

    def meta_add_field(name, value) # :nodoc:
      @meta[name.downcase] = value
    end

    # returns a Time which represents Last-Modified field.
    def last_modified
      if v = @meta['last-modified']
        Time.httpdate(v)
      else
        nil
      end
    end

    RE_LWS = /[\r\n\t ]+/n
    RE_TOKEN = %r{[^\x00- ()<>@,;:\\"/\[\]?={}\x7f]+}n
    RE_QUOTED_STRING = %r{"(?:[\r\n\t !#-\[\]-~\x80-\xff]|\\[\x00-\x7f])*"}n
    RE_PARAMETERS = %r{(?:;#{RE_LWS}?#{RE_TOKEN}#{RE_LWS}?=#{RE_LWS}?(?:#{RE_TOKEN}|#{RE_QUOTED_STRING})#{RE_LWS}?)*}n

    def content_type_parse # :nodoc:
      v = @meta['content-type']
      # The last (?:;#{RE_LWS}?)? matches extra ";" which violates RFC2045.
      if v && %r{\A#{RE_LWS}?(#{RE_TOKEN})#{RE_LWS}?/(#{RE_TOKEN})#{RE_LWS}?(#{RE_PARAMETERS})(?:;#{RE_LWS}?)?\z}no =~ v
        type = $1.downcase
        subtype = $2.downcase
        parameters = []
        $3.scan(/;#{RE_LWS}?(#{RE_TOKEN})#{RE_LWS}?=#{RE_LWS}?(?:(#{RE_TOKEN})|(#{RE_QUOTED_STRING}))/no) {|att, val, qval|
          val = qval.gsub(/[\r\n\t !#-\[\]-~\x80-\xff]+|(\\[\x00-\x7f])/) { $1 ? $1[1,1] : $& } if qval
          parameters << [att.downcase, val]
        }
        ["#{type}/#{subtype}", *parameters]
      else
        nil
      end
    end

    # returns "type/subtype" which is MIME Content-Type.
    # It is downcased for canonicalization.
    # Content-Type parameters are stripped.
    def content_type
      type, *parameters = content_type_parse
      type || 'application/octet-stream'
    end

    # returns a charset parameter in Content-Type field.
    # It is downcased for canonicalization.
    #
    # If charset parameter is not given but a block is given,
    # the block is called and its result is returned.
    # It can be used to guess charset.
    #
    # If charset parameter and block is not given,
    # nil is returned except text type in HTTP.
    # In that case, "iso-8859-1" is returned as defined by RFC2616 3.7.1.
    def charset
      type, *parameters = content_type_parse
      if pair = parameters.assoc('charset')
        pair.last.downcase
      elsif block_given?
        yield
      elsif type && %r{\Atext/} =~ type &&
            @base_uri && /\Ahttp\z/i =~ @base_uri.scheme
        "iso-8859-1" # RFC2616 3.7.1
      else
        nil
      end
    end

    # returns a list of encodings in Content-Encoding field
    # as an Array of String.
    # The encodings are downcased for canonicalization.
    def content_encoding
      v = @meta['content-encoding']
      if v && %r{\A#{RE_LWS}?#{RE_TOKEN}#{RE_LWS}?(?:,#{RE_LWS}?#{RE_TOKEN}#{RE_LWS}?)*}o =~ v
        v.scan(RE_TOKEN).map {|content_coding| content_coding.downcase}
      else
        []
      end
    end
  end

  # Mixin for HTTP and FTP URIs.
  module OpenRead
    # OpenURI::OpenRead#open provides `open' for URI::HTTP and URI::FTP.
    #
    # OpenURI::OpenRead#open takes optional 3 arguments as:
    # OpenURI::OpenRead#open([mode [, perm]] [, options]) [{|io| ... }]
    #
    # `mode', `perm' is same as Kernel#open.
    #
    # However, `mode' must be read mode because OpenURI::OpenRead#open doesn't
    # support write mode (yet).
    # Also `perm' is just ignored because it is meaningful only for file
    # creation.
    #
    # `options' must be a hash.
    #
    # Each pairs which key is a string in the hash specify a extra header
    # field for HTTP.
    # I.e. it is ignored for FTP without HTTP proxy.
    #
    # The hash may include other options which key is a symbol:
    #
    # [:proxy]
    #  Synopsis:
    #    :proxy => "http://proxy.foo.com:8000/"
    #    :proxy => URI.parse("http://proxy.foo.com:8000/")
    #    :proxy => true
    #    :proxy => false
    #    :proxy => nil
    #   
    #  If :proxy option is specified, the value should be String, URI,
    #  boolean or nil.
    #  When String or URI is given, it is treated as proxy URI.
    #  When true is given or the option itself is not specified,
    #  environment variable `scheme_proxy' is examined.
    #  `scheme' is replaced by `http', `https' or `ftp'.
    #  When false or nil is given, the environment variables are ignored and
    #  connection will be made to a server directly.
    #
    # [:http_basic_authentication]
    #  Synopsis:
    #    :http_basic_authentication=>[user, password]
    #
    #  If :http_basic_authentication is specified,
    #  the value should be an array which contains 2 strings:
    #  username and password.
    #  It is used for HTTP Basic authentication defined by RFC 2617.
    #
    # [:content_length_proc]
    #  Synopsis:
    #    :content_length_proc => lambda {|content_length| ... }
    # 
    #  If :content_length_proc option is specified, the option value procedure
    #  is called before actual transfer is started.
    #  It takes one argument which is expected content length in bytes.
    # 
    #  If two or more transfer is done by HTTP redirection, the procedure
    #  is called only one for a last transfer.
    # 
    #  When expected content length is unknown, the procedure is called with
    #  nil.
    #  It is happen when HTTP response has no Content-Length header.
    #
    # [:progress_proc]
    #  Synopsis:
    #    :progress_proc => lambda {|size| ...}
    #
    #  If :progress_proc option is specified, the proc is called with one
    #  argument each time when `open' gets content fragment from network.
    #  The argument `size' `size' is a accumulated transfered size in bytes.
    #
    #  If two or more transfer is done by HTTP redirection, the procedure
    #  is called only one for a last transfer.
    #
    #  :progress_proc and :content_length_proc are intended to be used for
    #  progress bar.
    #  For example, it can be implemented as follows using Ruby/ProgressBar.
    #
    #    pbar = nil
    #    open("http://...",
    #      :content_length_proc => lambda {|t|
    #        if t && 0 < t
    #          pbar = ProgressBar.new("...", t)
    #          pbar.file_transfer_mode
    #        end
    #      },
    #      :progress_proc => lambda {|s|
    #        pbar.set s if pbar
    #      }) {|f| ... }
    #
    # OpenURI::OpenRead#open returns an IO like object if block is not given.
    # Otherwise it yields the IO object and return the value of the block.
    # The IO object is extended with OpenURI::Meta.
    def open(*rest, &block)
      OpenURI.open_uri(self, *rest, &block)
    end

    # OpenURI::OpenRead#read([options]) reads a content referenced by self and
    # returns the content as string.
    # The string is extended with OpenURI::Meta.
    # The argument `options' is same as OpenURI::OpenRead#open.
    def read(options={})
      self.open(options) {|f|
        str = f.read
        Meta.init str, f
        str
      }
    end
  end
end

module URI
  class Generic
    # returns a proxy URI.
    # The proxy URI is obtained from environment variables such as http_proxy,
    # ftp_proxy, no_proxy, etc.
    # If there is no proper proxy, nil is returned.
    #
    # Note that capitalized variables (HTTP_PROXY, FTP_PROXY, NO_PROXY, etc.)
    # are examined too.
    #
    # But http_proxy and HTTP_PROXY is treated specially under CGI environment.
    # It's because HTTP_PROXY may be set by Proxy: header.
    # So HTTP_PROXY is not used.
    # http_proxy is not used too if the variable is case insensitive.
    # CGI_HTTP_PROXY can be used instead.
    def find_proxy
      name = self.scheme.downcase + '_proxy'
      proxy_uri = nil
      if name == 'http_proxy' && ENV.include?('REQUEST_METHOD') # CGI?
        # HTTP_PROXY conflicts with *_proxy for proxy settings and
        # HTTP_* for header information in CGI.
        # So it should be careful to use it.
        pairs = ENV.reject {|k, v| /\Ahttp_proxy\z/i !~ k }
        case pairs.length
        when 0 # no proxy setting anyway.
          proxy_uri = nil
        when 1
          k, v = pairs.shift
          if k == 'http_proxy' && ENV[k.upcase] == nil
            # http_proxy is safe to use because ENV is case sensitive.
            proxy_uri = ENV[name]
          else
            proxy_uri = nil
          end
        else # http_proxy is safe to use because ENV is case sensitive.
          proxy_uri = ENV.to_hash[name]
        end
        if !proxy_uri
          # Use CGI_HTTP_PROXY.  cf. libwww-perl.
          proxy_uri = ENV["CGI_#{name.upcase}"]
        end
      elsif name == 'http_proxy'
        unless proxy_uri = ENV[name]
          if proxy_uri = ENV[name.upcase]
            warn 'The environment variable HTTP_PROXY is discouraged.  Use http_proxy.'
          end
        end
      else
        proxy_uri = ENV[name] || ENV[name.upcase]
      end

      if proxy_uri && self.host
        require 'socket'
        begin
          addr = IPSocket.getaddress(self.host)
          proxy_uri = nil if /\A127\.|\A::1\z/ =~ addr
        rescue SocketError
        end
      end

      if proxy_uri
        proxy_uri = URI.parse(proxy_uri)
        name = 'no_proxy'
        if no_proxy = ENV[name] || ENV[name.upcase]
          no_proxy.scan(/([^:,]*)(?::(\d+))?/) {|host, port|
            if /(\A|\.)#{Regexp.quote host}\z/i =~ self.host &&
               (!port || self.port == port.to_i)
              proxy_uri = nil
              break
            end
          }
        end
        proxy_uri
      else
        nil
      end
    end
  end

  class HTTP
    def buffer_open(buf, proxy, options) # :nodoc:
      OpenURI.open_http(buf, self, proxy, options)
    end

    include OpenURI::OpenRead
  end

  class FTP
    def buffer_open(buf, proxy, options) # :nodoc:
      if proxy
        OpenURI.open_http(buf, self, proxy, options)
        return
      end
      require 'net/ftp'

      directories = self.path.split(%r{/}, -1)
      directories.shift if directories[0] == '' # strip a field before leading slash
      directories.each {|d|
        d.gsub!(/%([0-9A-Fa-f][0-9A-Fa-f])/) { [$1].pack("H2") }
      }
      unless filename = directories.pop
        raise ArgumentError, "no filename: #{self.inspect}"
      end
      directories.each {|d|
        if /[\r\n]/ =~ d
          raise ArgumentError, "invalid directory: #{d.inspect}"
        end
      }
      if /[\r\n]/ =~ filename
        raise ArgumentError, "invalid filename: #{filename.inspect}"
      end
      typecode = self.typecode
      if typecode && /\A[aid]\z/ !~ typecode
        raise ArgumentError, "invalid typecode: #{typecode.inspect}"
      end

      # The access sequence is defined by RFC 1738
      ftp = Net::FTP.open(self.host)
      # todo: extract user/passwd from .netrc.
      user = 'anonymous'
      passwd = nil
      user, passwd = self.userinfo.split(/:/) if self.userinfo
      ftp.login(user, passwd)
      directories.each {|cwd|
        ftp.voidcmd("CWD #{cwd}")
      }
      if typecode
        # xxx: typecode D is not handled.
        ftp.voidcmd("TYPE #{typecode.upcase}")
      end
      if options[:content_length_proc]
        options[:content_length_proc].call(ftp.size(filename))
      end
      ftp.retrbinary("RETR #{filename}", 4096) { |str|
        buf << str
        options[:progress_proc].call(buf.size) if options[:progress_proc]
      }
      ftp.close
      buf.io.rewind
    end

    include OpenURI::OpenRead
  end
end