#!/usr/bin/env perl
use strict;
use warnings;
use Plack::Request;

sub {
    my $request = Plack::Request->new(+shift);
    # If the URI starts with /success, it is one.
    my $success = $request->path =~ m{\A/success\b};
    [ 200,
      [ "Content-Type" => "text/plain" ],
      [ $success ? 1 : 0 ]
    ]; 
}
##</code><code>##

~>plackup
HTTP::Server::PSGI: Accepting connections at http://0:5000/