Using the Overbite Add-ons for finger and whois (Gopher URLs) ------------------------------------------------------------- Overbite can subsume certain other protocols under the gopher:// handler by manipulating the URL rather than any special logic. A gopher URL is broken down into the following major components: gopher://host.name.invalid:70/1/the/selector ^^^^^^^^^^^^^^^^^ ^^ ^^^^^^^^^^^^^^ \--------+------/ || |\-----+-----/ | || | | host name ------------+ || | +-- selector port number ---------------++ +------- item type The host name and port number designate the server to connect to, and the TCP port to use. The item type is always one character, and is immediately followed by the selector string, which is server-specific and is transmitted directly to the server as is (in this case ``/the/selector''). By changing the selector string and the port number, we can make Overbite "speak" other protocols. Specifically supported are the finger and whois protocols (other protocols may be possible, although Overbite or your browser may restrict the port numbers you can use and/or the command strings you can send). To make a finger request to a server, you will make the URL point to port 79, use an item type of 0 (to specify raw text), and use the desired request as the selector. For example, gopher://floodgap.com:79/0gopher will finger gopher@floodgap.com and report where the mail alias is sent. The selector can be blank, but many finger servers will not respond to a null query. To make a whois request to a server, you will make the URL point to port 43, use an item type of 0 (to specify raw text), and use the desired request as the selector. For example, gopher://org.whois-servers.net:43/0mozilla.org will query for the registration information for mozilla.org. Most whois servers will not respond to a null query. These URLs are advantageous in that other browsers that support Gopher will also support these kinds of requests as a natural consequence of the way Gopher URLs are formed, assuming that those browsers have not blocked access to ports 43 or 79.