Gopher Service

Gopher is client/server–oriented software that uses a simple protocol to search for and retrieve files from Gopher servers on the Internet. The Gopher service was developed by the University of Minnesota in 1991 to overcome some limitations of the FTP service. Gopher has an easier-to-use interface and also allows administrators to create links to other computers or services, to annotate files and directories, and to create custom menus.

Gopher is not just an Internet tool. Many organizations use Gopher on their local area network to help people within the organization find the information they need quickly and efficiently.

The user of the Gopher client can download files, switch directories, or link to other Gopher servers by using a series of menus. The Gopher server generates menus, links, and annotations by using a series of tag files.

Gopher presents information in a hierarchical structure. Depending on which client software is used and what selections are available on the Gopher server, the user can choose how to view information—for example, as a text file, as a Microsoft Word for Windows document, or in a particular language.

A Gopher client presents the individual user with directory lists. If the user chooses a subdirectory from the displayed list, the listing for that subdirectory is displayed. If the user chooses a file, it is downloaded. Each directory and file can be on a different Gopher server.

You can also configure a Gopher server to search local Wide Area Information Server (WAIS) databases.

Gopher uses TCP as its transport protocol for all communication and data exchanges between the client and the server. Internet Information Server communicates with Windows Sockets, then Windows Sockets communicates with TCP.

TCP is a connection-oriented protocol (that is, the communications session is established between the client and the server before data is transmitted). However, unlike FTP, Gopher does not maintain the connection between requests; this is also known as a stateless connection.

For a description of TCP connection features, see Table 1.6, earlier in this chapter.