Module: HTML5::Sniffer

Defined in:
lib/html5/sniffer.rb

Instance Method Summary collapse

Instance Method Details

#html_or_feed(str) ⇒ Object

4.7.4



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# File 'lib/html5/sniffer.rb', line 4

def html_or_feed str
  s = str[0, 512] # steps 1, 2
  pos = 0

  while pos < s.length
    case s[pos]
    when 0x09, 0x20, 0x0A, 0x0D # tab, space, LF, CR
      pos += 1
    when  0x3C # "<"
      pos += 1
      if s[pos..pos+2] == "!--" # [0x21, 0x2D, 0x2D]
        pos += 3
        until s[pos..pos+2] == "-->" or pos >= s.length
          pos += 1
        end
        pos += 3
      elsif s[pos] == 0x21 # "!"
        pos += 1
        until s[pos] == 0x3E or pos >= s.length # ">"
          pos += 1 
        end
        pos += 1
      elsif s[pos] == 0x3F # "?"
        until s[pos..pos+1] == "?>" or pos >= s.length # [0x3F, 0x3E]
          pos +=  1
        end
        pos += 2
      elsif s[pos..pos+2] == "rss"   # [0x72, 0x73, 0x73]
        return "application/rss+xml"
      elsif s[pos..pos+3] == "feed"  # [0x66, 0x65, 0x65, 0x64]
        return "application/atom+xml"
      elsif s[pos..pos+6] == "rdf:RDF" # [0x72, 0x64, 0x66, 0x3A, 0x52, 0x44, 0x46]
        raise NotImplementedError
      end
    else
      break
    end
  end
  "text/html"
end