Perl CGI reading both url_param and param reliably

Question

I'm writing a function that will list once all params passed to a CGI script, whether it be through a form sent with POST, the URL string, or both.

There are two functions for this:

param(): Despite the documentation, I have found this to read EITHER POSTed parameters from a form OR URL params only if there are no POST params.

On the other hand, url_param() will ever ONLY read params passed in through the URL string regardless of POST.

---

My function

sub post_and_url_param_keys{
  if(url_param){
    return [url_param, param];
  }else{
    return [param];
}

It can list all parameters if passed in with:

√ POST and URL params

√ POST params only

X URL params only (lists each key twice)

Is there a way to neatly fix this without having to check the name and value of each and every param pair for duplicates?

Answer 1

A slightly improve method would be to check if request_method() eq 'POST'. You may still get duplicate parameter names if you query string and post both contain the same parameter name.