Please put this into synopsys of 'plackup' $ SCRIPT_NAME='/' REQUEST_METHOD='GET' SERVER_NAME='www.test' SERVER_PORT='5000' plackup -s CGI t.pl

Also:

https://github.com/plack/Plack/issues/598
https://github.com/plack/Plack/issues/147
https://github.com/plack/Plack/pull/159/files
https://github.com/plack/Plack/pull/217
https://github.com/plack/Plack/pull/235

In recent years we've seen an explosion of powerful web technologies in Perl not at the least due to the creation of the PSGI specification.

Plack provides the Plack::Middleware class that makes the process of modifying the response easier, and along with Plack::Util helps us deal with the slightly more complex cases where there's a callback for a response from our inner class:

Plack::Test

Another great thing about abstracting away the actual webserver that our PSGI application is talking to is that we don't actually have to have a real webserver at the outer layer at all! If we just want to test our application we can do this in process by just sending input to the anonymous subroutine and examining the return values.

Moving from an old CGI application to Plack/PSGI in CGI mode and to running it in the Starman application server.

From its start, Perl comes with most (Unix) core operating system trickery like forks, events and signals. So, you can implement real performing daemons for interesting tasks.

We will get into various features which show how straight-forward it is to implement an Apache-like webserver, with VirtualHosts, proxies, etc.

But we start by discussing many options how to set-up servers: processes, event-loops, and so on... before we reach to HTTP-servers processing requests.

Any::Daemon

• Use Apache as your front end ~30:00

A modernisation of this using Plack is straightforwardly equivalent:

#!/usr/bin/env perl
use strict;
use warnings;
use Plack::Request;
use Encode::Simple;
use JSON::MaybeXS;

my $app = sub {
    my $req = Plack::Request->new($_[0]);
    my $input = eval { decode 'UTF-8', $req->parameters->{'input'} };
    [ 200, [ 'Content-Type', 'application/json; charset=UTF-8' ], [ encode_json { output => uc $input } ] ];
};

This is now a full PSGI app and as such gains all the same additional deployment options of the Mojolicious example. To deploy it as a CGI script you add this line at the bottom:

use Plack::Handler::CGI; Plack::Handler::CGI->new->run($app);

In all it takes about twice as long to load as the CGI.pm example, compared to the Mojolicious example taking about 7× as long. In exchange you get all the benefits of the PSGI ecosystem – without losing any of the strengths of deploying as a CGI script, unlike the Mojolicious example.