RFC 1436 (rfc1436) - Page 2 of 16

The Internet Gopher Protocol (a distributed document search and retrieval protocol)

RFC 1436                         Gopher                       March 1993


   While documents (and services) reside on many servers, Gopher client
   software presents users with a hierarchy of items and directories
   much like a file system.  The Gopher interface is designed to
   resemble a file system since a file system is a good model for
   organizing documents and services; the user sees what amounts to one
   big networked information system containing primarily document items,
   directory items, and search items (the latter allowing searches for
   documents across subsets of the information base).

   Servers return either directory lists or documents.  Each item in a
   directory is identified by a type (the kind of object the item is),
   user-visible name (used to browse and select from listings), an
   opaque selector string (typically containing a pathname used by the
   destination host to locate the desired object), a host name (which
   host to contact to obtain this item), and an IP port number (the port
   at which the server process listens for connections). The user only
   sees the user-visible name.  The client software can locate and
   retrieve any item by the trio of selector, hostname, and port.

   To use a search item, the client submits a query to a special kind of
   Gopher server: a search server.  In this case, the client sends the
   selector string (if any) and the list of words to be matched. The
   response yields "virtual directory listings" that contain items
   matching the search criteria.

   Gopher servers and clients exist for all popular platforms.  Because
   the protocol is so sparse and simple, writing servers or clients is
   quick and straightforward.

1.  Introduction

   The Internet Gopher protocol is designed primarily to act as a
   distributed document delivery system.  While documents (and services)
   reside on many servers, Gopher client software presents users with a
   hierarchy of items and directories much like a file system.  In fact,
   the Gopher interface is designed to resemble a file system since a
   file system is a good model for locating documents and services.  Why
   model a campus-wide information system after a file system?  Several
   reasons:

      (a) A hierarchical arrangement of information is familiar to many
      users.  Hierarchical directories containing items (such as
      documents, servers, and subdirectories) are widely used in
      electronic bulletin boards and other campus-wide information
      systems. People who access a campus-wide information server will
      expect some sort of hierarchical organization to the information
      presented.




Anklesari, McCahill, Lindner, Johnson, Torrey & Alberti