rfc1580.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

   on hypertext, which offers a means of moving from document to
   document (usually called to navigate) within a network of
   information.

   Hypertext documents are linked to each other through a selected set
   of words. For example, when a new word, or a new concept, is
   introduced in a text, hypertext makes it possible to point to another
   document which gives more details about it. The reader can open the
   second document by selecting the unknown word or concept and the
   relevant section is displayed. The second document may also contain
   links to further details. The reader need not know where the
   referenced document is, and there is no need to type a command to
   display it, or to browse it to find the right paragraph.
   Cross-references may be defined in the same document. A collection of
   documents is a database.

   If you were reading this document on a hypertext system, instead of
   this all too short explanation about hypertext, you would have a
   selectable pointer to a complete hypertext information web with
   examples and more pointers to other definitions.

   For instance, in the first document you might read:

   -----------------------------------------------------------------

   The  WorldWideWeb (W3)  is a  wide-area "hypermedia"  information
   retrieval initiative aiming  to give universal access  to a large
   universe of documents.

   -----------------------------------------------------------------



EARN Staff                                                     [Page 12]

RFC 1580            Guide to Network Resource Tools           March 1994


   Selecting hypermedia will display the following explanation for you:

   -----------------------------------------------------------------

                          WHAT IS HYPERTEXT
   Hypertext is text which is not constrained to be linear.

   Hypertext is text which contains "links" to other texts. The term
   was coined by "Ted Nelson" around 1965 (see "History").

   HyperMedia is a term used  for hypertext which is not constrained
   to  be text:  it can  include  graphics, video  and "sound",  for
   example. Apparently Ted Nelson was the first to use this term too.

   -----------------------------------------------------------------

   Then you can learn more about links and Nelson. Indeed, the links in
   WWW are not confined to text only, so the term hypermedia is more
   accurate.  For example, the link to Nelson might point to a file
   containing a picture of Ted Nelson. The picture would be displayed on
   your screen if you have a suitable configuration.

   Also, special documents (indexes) in the WWW information space can be
   search for given keyword(s). The result is a document which contains
   links to the documents found.

   World-Wide Web uses hypertext over the network: the linked documents
   may be located at various sites. WWW can handle different text
   formats and various information organizations. WWW also provides
   access to many of the other tools described in this guide.

3.2. Who can use World-Wide Web

   WWW uses the client-server model to provide access to the information
   universe. You must be on the international TCP/IP network (the
   Internet) in order to use a client on your computer to access WWW. If
   you are on the Internet, but don't have a WWW client on your
   computer, you can still enter the World-Wide Web. Several sites offer
   public interactive access to WWW clients (see the Remote clients
   section under How to get to World-Wide Web below).

   If you have e-mail access only, or if you are not on the Internet
   then you can not fully exploit the vast potential of WWW. However, a
   mail-robot is available at the address: [e-mail] which
   gives e-mail access to WWW-accessible [e-mail] files.
   (see E-mail access section under How to get to World-Wide Web below).





EARN Staff                                                     [Page 13]

RFC 1580            Guide to Network Resource Tools           March 1994


3.3. How to get to World-Wide Web

   Users access the World-Wide Web facilities via a client called a
   browser. This interface provides transparent access to the WWW
   servers.  If a local WWW client is not available on your computer,
   you may use a client at a remote site. Thus, an easy way to start
   with WWW is to access a remote client.

   3.3.1. Local clients

      Usage of a local client is encouraged since it provides better
      performance and better response time than a remote client.

      Public domain clients for accessing WWW servers are available for:
      Macintosh, MS-DOS, VMS, VM/CMS, MVS, NeXT, Unix, X-Windows. The
      clients are available for anonymous FTP from info.cern.ch in the
      directory /pub/www. All these platforms support a simple line mode
      browser. In addition, graphical clients are available for:
      Macintosh, Windows, X-Windows, NeXT and Unix. See the list of
      freely available client software in Appendix A.

   3.3.2. Remote clients

      To access a remote WWW client, telnet to the client site. If you
      are new to WWW, you should telnet to info.cern.ch. No login is
      needed. You will immediately enter the WWW line mode browser. Some
      publicly accessible clients feature locally developed clients.
      Most remote clients are at sites with WWW servers with information
      on specific areas. After you telnet to the client site, at the
      login: prompt enter www, no password is needed. The following
      remote client sites are available:

      +---------------------------------------------------------------+
      |                                                               |
      |  Site                   Country          Server Specialization|
      |                                                               |
      +---------------------------------------------------------------+
      |  vms.huji.ac.il         Israel            Environment         |
      |  info.cern.ch           Switzerland (CERN) High-energy physics|
      |  fatty.law.cornell.edu  USA               Law                 |
      |  ukanaix.cc.ukans.edu   USA               History             |
      |  www.njit.edu           USA                                   |
      |                                                               |
      +---------------------------------------------------------------+

      CERN is the entry point to find information about WWW itself and
      to have an overview of the Web with a catalogue of the databases
      sorted by subject.



EARN Staff                                                     [Page 14]

RFC 1580            Guide to Network Resource Tools           March 1994


      3.3.2.1. E-mail access

         In order to get a file, send mail to [e-mail] with
         a SEND command. The SEND command returns the document with the
         given WWW address, subject to certain restrictions. Hypertext
         documents are formatted to 72 character width, with links
         numbered. A separate list at the end of the file gives the
         document-addresses of the related documents.

         If the document is hypertext, its links will be marked by
         numbers in brackets, and a list of document addresses by number
         will be appended to the message. In this way, you can navigate
         through the web, more or less. A good file to start with would
         be:
      http://info.cern.ch./hypertext/DataSources/bySubject/Overview.html

         Note that, despite the name listserv in the address of this
         mail robot, it is not a LISTSERV server.

         A note of caution from the WWW developers and maintainers:

         "As the robot gives potential mail access to a *vast* amount of
         information, we must emphasise that the service should not be
         abused.  Examples of appropriate use would be:

         * Accessing any information about W3 itself;
         * Accessing any CERN and/or physics-related or network
           development related information;

         Examples of INappropriate use would be:

         * Attempting to retrieve binaries or tar files or anything more
           than directory listings or short ASCII files from FTP archive
           sites;
         * Reading Usenet newsgroups which your site doesn't receive;
         * Repeated automatic use.

         There is currently a 1000 line limit on any returned file. We
         don't want to overload other people's mail relays or our
         server. We reserve the right to withdraw the service at any
         time. We are currently monitoring all use of the server, so
         your reading will not initially enjoy privacy.

         Enjoy!"

         The W3 team at CERN ([e-mail])





EARN Staff                                                     [Page 15]

RFC 1580            Guide to Network Resource Tools           March 1994


3.4. Using World-Wide Web

   When using a graphical interface, you access the WWW functions by
   pressing mouse buttons. In particular, references are highlighted or
   underlined words. To follow a link, click on the associated
   reference.

   The line mode browser is a more simple user interface: references are
   numbers in square brackets next to words. Type the number and hit the
   RETURN key to follow a reference. For example, here is the beginning
   of the Subject Catalogue you get on the CERN server:

   -----------------------------------------------------------------

         The World-Wide Web Virtual Library: Subject Catalogue
                         WWW VIRTUAL LIBRARY

   This is  the subject catalogue.  See also arrangement  by service
   type[1]. Mail  [e-mail] to  add pointers  to this
   list.

   Aeronautics     Mailing list archive index[2]. See also NASA LaRC[3]

   Agriculture[4]  Separate list, see also Almanac mail servers[5].

   Astronomy and Astrophysics
                   Abstract Indexes[6] at NASA, Astrophysics work at
                   FNAL[7],   Princeton's[8]   Sloane  Digital   Sky
                   Survey,  the  STELAR   project,  Space  Telescope
                   Electronic Information System[9], the Southampton
                   University  Astronomy   Group[10],  the  National
                   Solar Observatory[11],  Astrophysics work  at the
                   AHPCRC[12]. See also: space[13].

   Bio Sciences[14] Separate list.

   Computing[15]   Separate list.

   1-81, Back, <RETURN> for more, Quit, or Help:

   -----------------------------------------------------------------

   The following commands are available within WWW. Some are disabled
   when not applicable (e.g., Find is enabled only when the current
   document is an index). Angle brackets (<>) indicate an optional
   parameter.





EARN Staff                                                     [Page 16]

RFC 1580            Guide to Network Resource Tools           March 1994


   Help
      gives a list of available commands depending on the context, and
      the hypertext address of the current document.

   Manual
      displays the on-line manual.

   Quit
      exits WWW.

   Up, Down
      scrolls up or down one page in the current document.

   Top, BOttom
      goes to the top or the bottom of the current document.

   Back
      goes back to the document you were reading before.

   HOme
      goes back to the first document you were reading.

   Next, Previous
      goes to the next or previous document in the list of pointers from
      the document that led to the current one.

   List
      gives a numbered list of the links from the current document. To
      follow a link, type in the number.

   Recall <number>
      if number is omitted, gives a numbered list of the documents you
      have visited.

      To display one specific document, re-issue the command with
      number.

   <Find> keyword
      queries the current index with the supplied keyword(s). A list of
      matching entries is displayed with possibly links to further
      details.  Find can be omitted if the first keyword does not
      conflict with another WWW command. Multiple keywords are separated
      by blanks.

   Go docaddress
      goes to the document represented by the given hypertext address,
      which is interpreted relatively to the current document.




EARN Staff                                                     [Page 17]

RFC 1580            Guide to Network Resource Tools           March 1994


   Extra command available on Unix versions only: