open-uri.rb

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      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.
    #
    # [:proxy_http_basic_authentication]
    #  Synopsis:
    #    :proxy_http_basic_authentication => ["http://proxy.foo.com:8000/", "proxy-user", "proxy-password"]
    #    :proxy_http_basic_authentication => [URI.parse("http://proxy.foo.com:8000/"), "proxy-user", "proxy-password"]
    #   
    #  If :proxy option is specified, the value should be an Array with 3 elements.
    #  It should contain a proxy URI, a proxy user name and a proxy password.
    #  The proxy URI should be a String, an URI or nil.
    #  The proxy user name and password should be a String.
    #
    #  If nil is given for the proxy URI, this option is just ignored.
    #
    #  If :proxy and :proxy_http_basic_authentication is specified, 
    #  ArgumentError is raised.
    #
    # [: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| ... }
    #
    # [:read_timeout]
    #  Synopsis:
    #    :read_timeout=>nil     (no timeout)
    #    :read_timeout=>10      (10 second)
    #
    #  :read_timeout option specifies a timeout of read for http connections.
    #
    # 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[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