url-formats

<entry-title>URL formats</entry-title>

URLs are often defined and represented in various systems as a set of various pieces/parts. This page documents the implicit formats from those systems.

URL specification

The URL specification is perhaps the most canonical source for the names of the different parts of a URL.

1994 http://www.w3.org/Addressing/URL/url-spec.txt

Names are quoted literally, dropping any "The" prefix and "part" suffix.

• PrePrefix - e.g. "URL:". The portion before the "http".
• Scheme - e.g. "http"
• :
• Internet protocol parts
  • // (until the following /)
  • user name (if present, followed by an @ after optional password (see next field)).
  • password (if present, preceded by a :)
  • internet domain name - e.g. "www.w3.org"
  • port number (if present, preceded by a :)
• Path
  • search
• fragmentid - "the hash sign and following"

HTTP

The HTTP specification has a few notes about the format/portions of HTTP URLs.

1996 http://www.ietf.org/rfc/rfc1945.txt - 3.2.1 General Syntax

• URI
  • absoluteURI
    • scheme
    • :
    • relativeURI
      • net_path
        • //
        • net_loc
        • abs_path
          • /
          • rel_path
            • path
              • fsegment
              • segment (zero or more, if present, preceded by /)
            • params (if present, preceded by ;)
            • query (if present, preceded by ?)
  • fragment (if present, preceded by #)

Also:

• http_URL
  • http://
  • host
  • port (if present, preceded by :)
  • abs_path (as defined above)

Canonicalization:

• host is lowercased
• :port is omitted if the port is 80
• empty abs_path is replaced with /

CGI

• http://tools.ietf.org/html/rfc3875
• http://en.wikipedia.org/wiki/Common_Gateway_Interface - has example: http://example.com/cgi-bin/printenv.pl/ponylove?q=20%C001er&moar=kitties

Terms:

• script-URI
  • scheme same as SERVER_PROTOCOL
  • ://
  • server-name - SERVER_NAME
  • :
  • server-port - SERVER_PORT
  • script-path same as SCRIPT_NAME
  • extra-path same as PATH_INFO
  • ?
  • query-string - QUERY_STRING

Environment variables:

• SERVER_PROTOCOL - not the protocol scheme, e.g. "HTTP/1.1"
• HTTP_HOST - e.g "example.com"
• SERVER_PORT - e.g. "80"
• REMOTE_USER
• PATH - not the URL path, but to the web server on the system
• REQUEST_URI - e.g. "/cgi-bin/printenv.pl/ponylove?q=20%C001er&moar=kitties"
  • SCRIPT_NAME - e.g. "/cgi-bin/printenv.pl"
  • PATH_INFO - e.g. "/ponylove"
  • QUERY_STRING - e.g. "q=20%C001er&moar=kitties"

related

• url