30.4 Archie, WAIS, Gopher, Veronica, and WWW

The tools that we described in the previous two sections ”Finger, Whois, and a white pages service ”are for locating information on people. Other tools exist to locate files and documents, and this section gives an overview of these tools. We only provide an overview, because examining the details of each tool is beyond the scope of this book. Methods are given for accessing these tools across the Internet, and you are encouraged to do so, to find which tool can help you. Additional tools are continually being developed. [Obraczka, Danzig, and Li 1993] provide an overview of resource discovery services on the Internet.

Archie

Many of the resources used in this text were obtained using anonymous FTP. The problem is finding which FTP site has the program we want. Sometimes we don't even know the exact filename, but we know some keywords that probably appear in the filename.

Archie provides a directory of thousands of FTP servers across the Internet. We can access this directory by logging into an Archie server and searching for files whose name contains a specified regular expression. The output is a list of servers with matching filenames. We then use anonymous FTP to that site to fetch the file.

There are many Archie servers across the world. One starting point is to use Telnet to ds.internic.net , login as archie, and execute the command servers. This provides a list of all the Archie servers, and their location.

WAIS: Wide Area Information Servers

Archie helps us locate filenames that contain keywords, but sometimes we're looking for a file or database that contains a keyword. That is, we want to search for a file that contains a keyword, not a filename containing a keyword.

WAIS knows about hundreds of databases that contain information on both computer- related topics and other general topics. To use WAIS we select the databases to search and specify the keywords. To try WAIS Telnet to quake.think.com and login as wais.

Gopher

Gopher is a menu-driven front end to other Internet resource services, such as Archie, WAIS, and anonymous FTP. Gopher is one of the easiest to use, since its user interface is the same, regardless of which resource service it's using.

To use Gopher, Telnet into is.internic.net and login as gopher.

Veronica: Very Easy Rodent-Oriented Netwide Index to Computerized Archives

Just as Archie is an index of anonymous FTP servers, Veronica is an index of titles of Gopher items. A Veronica search typically searches hundreds of Gopher servers.

To access Veronica we must go through a Gopher client. Select the Gopher menu item "Beyond InterNIC: Virtual Treasures of the Internet" and then select Veronica from the next menu.

WWW: World Wide Web

World Wide Web lets us browse a large, worldwide set of services and documents using a tool called hypertext. As information is displayed, certain keywords are highlighted, and we can select more information on those keywords.

To access WWW, Telnet to info .cern.ch .