Question

How can I read the URL parameter in a Perl CGI program?

Answer 1

For GET requests, CGI parses the specified parameters and makes them available via the param() method.

For POST requests, param() will return the parameters from the postdata, but any parameters specified via a query string in the URL itself are still available from the url_param() method. (This is can be helpful when a POST request is larger than $CGI::POST_MAX; in that case, CGI just discards the postdata, but you can arrange to have query string parameters that identify what kind of request it was to provide a good error message.)

For ISINDEX style requests, the keywords requested are available via the keywords() method, as well as via param() in a faux “keywords” parameter.

Update: in case you meant something other than the parameters by “URL Parameter”, the url() method provides all or parts of the requested URL; see OBTAINING THE SCRIPT’S URL.