You can check if a directory exists using the file_exists() function. file_exists(\'http://www.example.com/path/to/directory/\'); It returns boolean TRUE if the directory exists; boolean FALSE otherwise. Incorporting this function with a searching algorithym will make a successful directory search engine. Alternatively, you can make the engine very simple, and check if the exact directory name exists.
These are the search engines and directories, which provides search results for Yahoo.BingYahoo directoryGoogleWikipediaDmoz
A search directory is an online site that helps you find websites on a specific topic. There are very general directories like DMOZ to niche subject directories and local search directories as well.
search engines and directories
Human powered directories are special types of search engines, organized into subject categories. The directories are smaller than most search engines and do not contain full text of the webpage they link to. Such directories are good when a user is interested in a general topic of search.
Yes you can make a search engine in php it works pretty good i built one my self
Yahoo Directory
Google!
Mixed Results
What i believe is you asked wrong.. did you mean "How do you detect virus by PHP?"? if yes then: It's out of php availabilities.. you going to need a virus database.. and if you mean finding out what client have for antivirus then i should tell you I'm not sure it's possible too.. (by php) but if you use Java Applets you may find out by searching directories :)
A quick search of PHP currency gave me this1 Philippine peso = 0.0229 US dollars"
results come from the Yahoo Directory
You'd need PHP and mySQL knowledge for this. Search Google for "Free PHP Comment Scripts".