/usr/share/doc/libmojolicious-perl/examples/microhttpd.pl is in libmojolicious-perl 2.23-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 | #!/usr/bin/env perl
use Mojo::Base -strict;
# Use bundled libraries
use FindBin;
use lib "$FindBin::Bin/../lib";
# "Kif, I'm feeling the Captain's Itch.
#  I'll get the powder, sir."
use Mojo::IOLoop;
# Buffer for incoming data
my $buffer = {};
# Minimal ioloop example demonstrating how to cheat at HTTP benchmarks :)
Mojo::IOLoop->listen(
  port      => 3000,
  on_accept => sub {
    my ($loop, $id) = @_;
    # Initialize buffer
    $buffer->{$id} = '';
  },
  on_read => sub {
    my ($loop, $id, $chunk) = @_;
    # Append chunk to buffer
    $buffer->{$id} .= $chunk;
    # Check if we got start line and headers (no body support)
    if (index($buffer->{$id}, "\x0d\x0a\x0d\x0a") >= 0) {
      # Clean buffer
      delete $buffer->{$id};
      # Write a minimal HTTP response
      # (the "Hello World!" message has been optimized away!)
      $loop->write($id => "HTTP/1.1 200 OK\x0d\x0a"
          . "Connection: keep-alive\x0d\x0a\x0d\x0a");
    }
  },
  on_error => sub {
    my ($self, $id) = @_;
    # Clean buffer
    delete $buffer->{$id};
  }
) or die "Couldn't create listen socket!\n";
print <<'EOF';
Starting server on port 3000.
Try something like "ab -c 30 -n 100000 -k http://127.0.0.1:3000/" for testing.
On a MacBook Pro 13" this results in about 20k req/s.
EOF
# Start loop
Mojo::IOLoop->start;
1;
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