Gopher
Click on the red underlined text to get to the source
...
The Internet Gopher protocol is designed primarily to act as a
distributed document delivery system. While documents (and services ...
... 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 ...
... hierarchy of items and directories much like a file system. In fact,
the Gopher interface is designed to resemble a file system since a
...
... (b) A file-system style hierarchy can be expressed in a simple
syntax. The syntax used for the internet Gopher protocol is
easily understandable, and was designed to make debugging servers
and clients ...
... Telnet to simulate an internet
Gopher client's requests and observe the responses from a server.
Special purpose software tools ...
... activity: browsing through the directory hierarchy.
(c) Since Gopher originated in a University setting, one of the
goals was for departments to have the option of publishing
information from their inexpensive desktop ...
... file system on the user's desktop machine to the directory
structure published via the Gopher protocol, the problem of
writing server software for slow desktop systems is minimized.
...
... A detailed BNF rendering of the internet Gopher syntax is available
in the appendix...but a close reading of the appendix may not be
necessary to understand the internet ...
... in the appendix...but a close reading of the appendix may not be
necessary to understand the internet Gopher protocol.
...
...
In essence, the Gopher protocol consists of a client connecting to a
server and sending the server a selector (a line of text, which may
...
... client/server interaction; more
complex interactions are dealt with later. Assume that a "well-
known" Gopher server (this may be duplicated, details are discussed
later) listens at a well known port for the campus (much like a
...
... for retrieval. The first character of the line is really defining
the type of item described on this line. In nearly every case, the
Gopher client software will give the users some sort of idea about
what type of item this is (by displaying an icon, a short text tag ...
... port at which to
connect. If there are yet other tab delimited fields, the basic
Gopher client should ignore them. A CR LF ...
... In the example, line 1 describes a document the user will see as
"About internet Gopher". To retrieve this document, the client
software must send the retrieval string: "Stuff:About us" to
rawBits.micro.umn.edu at port ...
... the administrators of the top-level Gopher server, much the same way
as they register a machine name with the campus domain ...
... They may indeed place links to any servers they desire in their own
server, thus creating a customized view of thethe Gopher information
universe; links can of course point back at the top-level ...
... node is
merely one convenient, well-known point of entry. A set of Gopher
servers linked in this manner may function as a campus-wide
information system.
...
... services
anywhere on the internet. Viewed in this manner, Gopher can be seen
as an Internet-wide information system.
...
... It is recommended that every server administrator have a document
called something like: "About Bogus University's Gopher server" as
the first item in their server's top level directory. In this
...
... directory (character '1'), or a search (character '7'). This is the
base set of item types in the Gopher protocol. It is desirable for
clients to be able to use different services ...
... anticipate all future needs and hard-wire them in the basic Internet
Gopher protocol; it keeps the basic protocol extremely simple. In
spite of this simplicity, the scheme has the capability to expand and
change with the times by adding an agreed upon type-character for a
...
... service
of course have to know nothing about Internet Gopher; they can just
be off-the shelf CSO, X.500, or other servers. We do not however,
...
... encourage arbitrary or machine-specific proliferation of service
types in the basic Gopher protocol.
...
...
On the other hand, subsets of other document retrieval schemes may be
mapped onto the Gopher protocol by means of "gateway-servers".
Examples of such servers include Gopher ...
... Gopher protocol by means of "gateway-servers".
Examples of such servers include Gopher-to-FTP gateways, Gopher ...
... Gopher-to-
archie gateways, Gopher-to-WAIS gateways, etc. There are a number of
advantages of such mechanisms. First, a relatively powerful server
...
...
There are two special server types (beyond the normal Gopher server)
also discussed below:
...
... search servers
maintain full-text indexes on the contents of text documents held
by some subset of Gopher servers. Such a "full-text search
server" responds to client requests ...
... the campus phone-book servers at the University of Minnesota used the
CSO protocol and it seemed simplest to just engulf them. The index-
server is however very much a Gopher in spirit, albeit with a slight
twist in the meaning of the selector-string. Index servers are a
natural place to incorperate gateways ...
... A full-text search server is a special-purpose server that knows
about the Gopher scheme for retrieving documents. These servers
maintain a full-text index of the contents of plain text documents on
Gopher ...
... Gopher scheme for retrieving documents. These servers
maintain a full-text index of the contents of plain text documents on
Gopher servers in some specified domain. A Gopher full-text search ...
... Gopher servers in some specified domain. A Gopher full-text search
server was implemented using several NeXTstations because it was easy
...
... search engine, is also available and
currently an optional part of the UNIX gopher server. In addition,
at least one implementation of the gopher server incorperates a
...
... UNIX gopher server. In addition,
at least one implementation of the gopher server incorperates a
gateway to WAIS servers by presenting the WAIS servers to gopherspace
...
... gateway to WAIS servers by presenting the WAIS servers to gopherspace
as full-text search servers. The gopher<->WAIS gateway servers does
the work of translating from gopher ...
... gopher<->WAIS gateway servers does
the work of translating from gopher protocol to WAIS so unmodified
gopher clients ...
... the work of translating from gopher protocol to WAIS so unmodified
gopher clients can access WAIS servers via the gateway server.
...
... new
protocols that will be hidden behind new document-types. The
internet Gopher philosophy is:
...
... Fully Qualified Domain Name as defined in RFC 1034std13.
(e.g., gopher.micro.umn.edu) Hosts that have a CR-LF ...
... range [0..65535]; port 70 is officially assigned
to gopher.
DirEntity ::= Type User_Name Tab Selector Tab Host ...