Perl how to detect if running under Fast CGI FCGI

Question

How to detect inside Perl script if it is called under FCGI or CGI. I want to detect if running under FCGI then load the FCGI modules, something like this at the top of the script:

if ($ENV{FCGI}) {
    use FCGI;
    use MyFCGIHandler;
}

I know I can do something like this:

use FCGI;
my $request = FCGI::Request();

#Returns whether or not the program was run as a FastCGI.
$isfcgi = $req->IsFastCGI();

But this means I have to load the FCGI module and call its Request and isFastCGI methods to check which is not good if app is not running under FCGI.

Answer 1

Found this at PerlMonks:

#!/usr/bin/perl

use strict;
use warnings;

use CGI::Fast qw(:standard);

sub mode
{
        my $h=$CGI::Fast::Ext_Request;
        if (defined($h) && ref($h) && $h->IsFastCGI()) {
                return 'FastCGI';
        } else {
                return 'CGI';
        }
}

while (CGI::Fast->new()) {
        print
                header(),
                start_html('CGI or FastCGI?'),
                h1('CGI or FastCGI?'),
                p('This application runs in ',mode(),' mode.'),
                end_html();
}