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Gopher Protocol

This page explains the Gopher protocol that Astronomo supports alongside Gemini.

What is Gopher?

Gopher is an internet protocol from 1991, predating the World Wide Web. It was designed at the University of Minnesota (whose mascot is a golden gopher) to distribute documents and files across a network.

Design Goals

  • Hierarchical navigation - Menu-based browsing
  • Simple protocol - Easy to implement
  • Efficient - Minimal overhead
  • Text-focused - Primarily serves text content

How It Works

URLs

Gopher URLs follow this format:

gopher://host[:port]/Tselector
  • host - Server hostname
  • port - Optional, defaults to 70
  • T - Single-character item type (see below)
  • selector - Resource path

Examples: 

gopher://gopher.floodgap.com/
gopher://gopher.floodgap.com/1/
gopher://gopher.floodgap.com/0/gopher/welcome

Item Types

Gopher uses single-character codes to identify content types:

Type Name Description
0 Text Plain text file
1 Directory Menu of items
7 Search Full-text search query
9 Binary Generic binary file
g GIF GIF image
I Image Other image formats
i Info Informational text (not a link)
h HTML External HTML link

Request/Response

  1. Client opens TCP connection to server (port 70)
  2. Client sends selector string + CRLF
  3. Server sends response data
  4. Connection closes

Unlike Gemini, Gopher connections are unencrypted.

Gopher in Astronomo

Type Indicators

Astronomo displays visual indicators for each item type:

Indicator Meaning
[DIR] Directory listing
[TXT] Text file
[SEARCH] Search input
[BIN] Binary download
[IMG] Image file
[EXT] External link (HTTP/Telnet)

Info lines (i type) display as plain text without indicators.

Gopher menus are converted to Gemtext format for a unified browsing experience:

  • Click or press Enter on directory items to navigate
  • Text files display in a preformatted block
  • Search items prompt for a query term

Search Support

Gopher type 7 (search) items work interactively:

  1. Activate a search link
  2. Enter your query in the modal dialog
  3. Results appear as a new Gopher menu

Binary Downloads

When you activate a binary file link (type 9, g, or I):

  1. The file downloads automatically
  2. Saved to ~/Downloads/ with the original filename
  3. Duplicate filenames are auto-incremented (e.g., file(1).txt)

Gopher vs Gemini

Aspect Gopher Gemini
Year 1991 2019
Encryption None TLS required
Content format Plain text + menus Gemtext
Port 70 1965
Authentication None Client certificates
Inline text styles No No

Both protocols share a philosophy of simplicity over complexity, but Gemini adds modern security (TLS) while maintaining the minimalist approach.

Gopherspace

"Gopherspace" refers to the network of Gopher servers, similar to "Geminispace" for Gemini.

Places to Explore

  • gopher://gopher.floodgap.com/ - Floodgap, a major Gopher hub
  • gopher://gopher.quux.org/ - Quux Gopher server
  • gopher://sdf.org/ - SDF Public Access UNIX System
  • gopher://gopher.club/ - Gopher community

Further Reading