HomePHP Page 2 - Using PHP classes to navigate distributed whois databases
Overview of the whois landscape - PHP
Whois services changed radically this year with the introductionof competition at the registrar level in the .com/.net/.orgnamespace and with it the advent of the SRS (Shared Registry System). Find out how to navigate the new whois in your PHP scripts.
Excepting for the moment .com/.net/.org, most TLD's have a whoisserver somewhere listening on port 43 where you can connect toit, give it a domain name, and get a record back for that domainname if it exists. The formats of the returned record vary acrossdifferent servers.
The .com/.net/.org namespace is a little more convoluted. We have thecentral registry database at whois.nsiregistry.net which contains aminimal record for all domains in this namespace, and then eachregistrar operates it's own whois server with more complete recordsfor only the domains they administer. Further, each registrar has it'sown whois output format for their own records.
The result of all this is One Big Mess. Depending on whether you wantto look up a ccTLD or a gTLD (generic TLD), and if the latter, whothe registrar is and where their whois server is; trying to createa script to integrate this kind of functionality into your websitecan be, in a word, nightmarish.