gistfile1.pl

#!/usr/local/bin/perl

use strict;
use Carp::REPL qw(repl);

sub {
    my $env = shift;
    my $message= "hello";
    repl(); # $message .= "world"; :q
    [
        200,
        ["Content-Type" => "text/plain"],
        [$message]
    ]
}