rfc2396.txt

C/C++语言的CGI接口库

9. References

   [RFC2277] Alvestrand, H., "IETF Policy on Character Sets and
             Languages", BCP 18, RFC 2277, January 1998.

   [RFC1630] Berners-Lee, T., "Universal Resource Identifiers in WWW: A
             Unifying Syntax for the Expression of Names and Addresses
             of Objects on the Network as used in the World-Wide Web",
             RFC 1630, June 1994.

   [RFC1738] Berners-Lee, T., Masinter, L., and M. McCahill, Editors,
             "Uniform Resource Locators (URL)", RFC 1738, December 1994.

   [RFC1866] Berners-Lee T., and D. Connolly, "HyperText Markup Language
             Specification -- 2.0", RFC 1866, November 1995.

   [RFC1123] Braden, R., Editor, "Requirements for Internet Hosts --
             Application and Support", STD 3, RFC 1123, October 1989.

   [RFC822]  Crocker, D., "Standard for the Format of ARPA Internet Text
             Messages", STD 11, RFC 822, August 1982.

   [RFC1808] Fielding, R., "Relative Uniform Resource Locators", RFC
             1808, June 1995.

   [RFC2046] Freed, N., and N. Borenstein, "Multipurpose Internet Mail
             Extensions (MIME) Part Two: Media Types", RFC 2046,
             November 1996.




Berners-Lee, et. al.        Standards Track                    [Page 24]

RFC 2396                   URI Generic Syntax                August 1998


   [RFC1736] Kunze, J., "Functional Recommendations for Internet
             Resource Locators", RFC 1736, February 1995.

   [RFC2141] Moats, R., "URN Syntax", RFC 2141, May 1997.

   [RFC1034] Mockapetris, P., "Domain Names - Concepts and Facilities",
             STD 13, RFC 1034, November 1987.

   [RFC2110] Palme, J., and A. Hopmann, "MIME E-mail Encapsulation of
             Aggregate Documents, such as HTML (MHTML)", RFC 2110, March
             1997.

   [RFC1737] Sollins, K., and L. Masinter, "Functional Requirements for
             Uniform Resource Names", RFC 1737, December 1994.

   [ASCII]   US-ASCII. "Coded Character Set -- 7-bit American Standard
             Code for Information Interchange", ANSI X3.4-1986.

   [UTF-8]   Yergeau, F., "UTF-8, a transformation format of ISO 10646",
             RFC 2279, January 1998.































Berners-Lee, et. al.        Standards Track                    [Page 25]

RFC 2396                   URI Generic Syntax                August 1998


10. Authors' Addresses

   Tim Berners-Lee
   World Wide Web Consortium
   MIT Laboratory for Computer Science, NE43-356
   545 Technology Square
   Cambridge, MA 02139

   Fax: [phone]
   EMail: [e-mail]


   Roy T. Fielding
   Department of Information and Computer Science
   University of California, Irvine
   Irvine, CA  92697-3425

   Fax: [phone]
   EMail: [e-mail]


   Larry Masinter
   Xerox PARC
   3333 Coyote Hill Road
   Palo Alto, CA 94034

   Fax: [phone]
   EMail: [e-mail]























Berners-Lee, et. al.        Standards Track                    [Page 26]

RFC 2396                   URI Generic Syntax                August 1998


A. Collected BNF for URI

      URI-reference = [ absoluteURI | relativeURI ] [ "#" fragment ]
      absoluteURI   = scheme ":" ( hier_part | opaque_part )
      relativeURI   = ( net_path | abs_path | rel_path ) [ "?" query ]

      hier_part     = ( net_path | abs_path ) [ "?" query ]
      opaque_part   = uric_no_slash *uric

      uric_no_slash = unreserved | escaped | ";" | "?" | ":" | "@" |
                      "&" | "=" | "+" | "$" | ","

      net_path      = "//" authority [ abs_path ]
      abs_path      = "/"  path_segments
      rel_path      = rel_segment [ abs_path ]

      rel_segment   = 1*( unreserved | escaped |
                          ";" | "@" | "&" | "=" | "+" | "$" | "," )

      scheme        = alpha *( alpha | digit | "+" | "-" | "." )

      authority     = server | reg_name

      reg_name      = 1*( unreserved | escaped | "$" | "," |
                          ";" | ":" | "@" | "&" | "=" | "+" )

      server        = [ [ userinfo "@" ] hostport ]
      userinfo      = *( unreserved | escaped |
                         ";" | ":" | "&" | "=" | "+" | "$" | "," )

      hostport      = host [ ":" port ]
      host          = hostname | IPv4address
      hostname      = *( domainlabel "." ) toplabel [ "." ]
      domainlabel   = alphanum | alphanum *( alphanum | "-" ) alphanum
      toplabel      = alpha | alpha *( alphanum | "-" ) alphanum
      IPv4address   = 1*digit "." 1*digit "." 1*digit "." 1*digit
      port          = *digit

      path          = [ abs_path | opaque_part ]
      path_segments = segment *( "/" segment )
      segment       = *pchar *( ";" param )
      param         = *pchar
      pchar         = unreserved | escaped |
                      ":" | "@" | "&" | "=" | "+" | "$" | ","

      query         = *uric

      fragment      = *uric



Berners-Lee, et. al.        Standards Track                    [Page 27]

RFC 2396                   URI Generic Syntax                August 1998


      uric          = reserved | unreserved | escaped
      reserved      = ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" |
                      "$" | ","
      unreserved    = alphanum | mark
      mark          = "-" | "_" | "." | "!" | "~" | "*" | "'" |
                      "(" | ")"

      escaped       = "%" hex hex
      hex           = digit | "A" | "B" | "C" | "D" | "E" | "F" |
                              "a" | "b" | "c" | "d" | "e" | "f"

      alphanum      = alpha | digit
      alpha         = lowalpha | upalpha

      lowalpha = "a" | "b" | "c" | "d" | "e" | "f" | "g" | "h" | "i" |
                 "j" | "k" | "l" | "m" | "n" | "o" | "p" | "q" | "r" |
                 "s" | "t" | "u" | "v" | "w" | "x" | "y" | "z"
      upalpha  = "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" | "I" |
                 "J" | "K" | "L" | "M" | "N" | "O" | "P" | "Q" | "R" |
                 "S" | "T" | "U" | "V" | "W" | "X" | "Y" | "Z"
      digit    = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" |
                 "8" | "9"





























Berners-Lee, et. al.        Standards Track                    [Page 28]

RFC 2396                   URI Generic Syntax                August 1998


B. Parsing a URI Reference with a Regular Expression

   As described in Section 4.3, the generic URI syntax is not sufficient
   to disambiguate the components of some forms of URI.  Since the
   "greedy algorithm" described in that section is identical to the
   disambiguation method used by POSIX regular expressions, it is
   natural and commonplace to use a regular expression for parsing the
   potential four components and fragment identifier of a URI reference.

   The following line is the regular expression for breaking-down a URI
   reference into its components.

      ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
       12            3  4          5       6  7        8 9

   The numbers in the second line above are only to assist readability;
   they indicate the reference points for each subexpression (i.e., each
   paired parenthesis).  We refer to the value matched for subexpression
   <n> as $<n>.  For example, matching the above expression to

      http://www.ics.uci.edu/pub/ietf/uri/#Related

   results in the following subexpression matches:

      $1 = http:
      $2 = http
      $3 = //www.ics.uci.edu
      $4 = www.ics.uci.edu
      $5 = /pub/ietf/uri/
      $6 = <undefined>
      $7 = <undefined>
      $8 = #Related
      $9 = Related

   where <undefined> indicates that the component is not present, as is
   the case for the query component in the above example.  Therefore, we
   can determine the value of the four components and fragment as

      scheme    = $2
      authority = $4
      path      = $5
      query     = $7
      fragment  = $9

   and, going in the opposite direction, we can recreate a URI reference
   from its components using the algorithm in step 7 of Section 5.2.





Berners-Lee, et. al.        Standards Track                    [Page 29]

RFC 2396                   URI Generic Syntax                August 1998


C. Examples of Resolving Relative URI References

   Within an object with a well-defined base URI of

      http://a/b/c/d;p?q

   the relative URI would be resolved as follows:

C.1.  Normal Examp