Gopher (protocol)

{{short descrile |- | style="background: #FFD; color:black; vertical-align: middle; text-align: center; " class="partial table-partial"| 7 || Gopher full-text search |- | style="background: #FFD; color:black; vertical-align: middle; text-align: center; " class="partial table-partial"| 8 || Telnet |- | style="background: #FFD; color:black; vertical-align: middle; text-align: center; " class="partial table-partial"| 9 || Binary file |- | style="background: #FFD; color:black; vertical-align: middle; text-align: center; " class="partial table-partial"| + || Mirror or alternate server (for load balancing or in case of primary server downtime) |- | style="background: #FFD; color:black; vertical-align: middle; text-align: center; " class="partial table-partial"| g || GIF file |- | style="background: #FFD; color:black; vertical-align: middle; text-align: center; " class="partial table-partial"| I || Image file |- | style="background: #FFD; color:black; vertical-align: middle; text-align: center; " class="partial table-partial"| T || Telnet 3270 |- ! colspan="2" style="background:#FFB; color:black;vertical-align:middle;text-align:center; " class="table-partial"|gopher+ types |- | style="background: #FFD; color:black; vertical-align: middle; text-align: center; " class="partial table-partial"| : || Bitmap image |- | style="background: #FFD; color:black; vertical-align: middle; text-align: center; " class="partial table-partial"| ; || Movie file |- | style="background: #FFD; color:black; vertical-align: middle; text-align: center; " class="partial table-partial"| < || Sound file |- ! colspan="2" style="background: #8FD; color:black; vertical-align: middle; text-align: center; " class="partial table-partial"|Non-canonical types |- |style="background:#adffe6; text-align:center" | d || Doc. Seen used alongside PDF and .DOC files |- | style="background:#adffe6; text-align:center" | h || HTML file |- | style="background:#adffe6; text-align:center" | i || Informational message, widely used. |- | style="background:#adffe6; text-align:center" | p || image file "(especially the png format)" | |- | style="background:#adffe6; text-align:center" | r || document rtf file "rich text Format") | |- | style="background:#adffe6; text-align:center" | s || Sound file (especially the WAV format) | |- | style="background:#adffe6; text-align:center" | P || document pdf file "Portable Document Format") | |- | style="background:#adffe6; text-align:center" | X || document xml file "eXtensive Markup Language" ) |}

Here is an example gopher session where the user requires a gopher menu (/Reference on the first line):

/Reference
1CIA World Factbook     /Archives/mirrors/textfiles.com/politics/CIA    gopher.quux.org 70
0Jargon 4.2.0   /Reference/Jargon 4.2.0 gopher.quux.org 70      +
1Online Libraries       /Reference/Online Libraries     gopher.quux.org 70     +
1RFCs: Internet Standards       /Computers/Standards and Specs/RFC      gopher.quux.org 70
1U.S. Gazetteer /Reference/U.S. Gazetteer       gopher.quux.org 70      +
iThis file contains information on United States        fake    (NULL)  0
icities, counties, and geographical areas.  It has      fake    (NULL)  0
ilatitude/longitude, population, land and water area,   fake    (NULL)  0
iand ZIP codes. fake    (NULL)  0
i       fake    (NULL)  0
iTo search for a city, enter the city's name.  To search        fake    (NULL) 0
ifor a county, use the name plus County -- for instance,        fake    (NULL) 0
iDallas County. fake    (NULL)  0

The gopher menu sent back from the server, is a sequence of lines each of which describes an item that can be retrieved. Most clients will display these as hypertext links, and so allow the user to navigate through gopherspace by following the links. This menu includes a text resource (itemtype 0 on the third line), multiple links to submenus (itemtype 1, on the second line as well as lines 4-6) and a non-standard information message (from line 7 on), broken down to multiple lines by providing dummy values for selector, host and port.

External links

Historically, to create a link to a Web server, "GET /" was used as a pseudo-selector to emulate an HTTP GET request. John Goerzen created an addition to the Gopher protocol, commonly referred to as "URL links", that allows links to any protocol that supports URLs. For example, to create a link to http://gopher.quux.org/, the item type is h, the display string is the title of the link, the item selector is "URL:http://gopher.quux.org/", and the domain and port are that of the originating Gopher server (so that clients that do not support URL links will query the server and receive an HTML redirection page).

Gopher+

Gopher+ is a forward compatible enhancement to the Gopher protocol. Gopher+ works by sending metadata between the client and the server. The enhancement was never widely adopted by Gopher servers.

The client sends a tab followed by a +. A Gopher+ server will respond with a status line followed by the content the client requested. An item is marked as supporting Gopher+ in the Gopher directory listing by a tab + after the port (this is the case of some of the items in the example above).

Other features of Gopher+ include:

• Item attributes, which can include the items
  • Administrator
  • Last date of modification
  • Different views of the file, like PostScript or plain text, or different languages
  • Abstract, or description of the item
• Interactive queries

Client software

Gopher clients

These are clients, libraries, and utilities primarily designed to access gopher resources.

Client	Updated	License	Language	Type	Notes
ACID	2021	?	C	GUI (Windows)	Supports page cache, TFTP and has G6 extension.
Bombadillo	2022	GPLv3	Go	TUI (Linux, BSD, OSX)	Supports Gopher, Gemini, Finger
cURL	2022		C	CLI
elpher	2022	G