wrapper.pl

#!/usr/bin/env perl
use strict;
use warnings qw(all);

use IO::Socket;
use IPC::Run qw(harness pump);

my @command = ('cat');
my ($in, $out, $err);
my $h = harness \@command, \$in, \$out, \$err;

start $h;

my $srv = IO::Socket::INET->new(
    Proto       => 'tcp',
    LocalAddr   => '127.0.0.1',
    LocalPort   => 12345,
    Listen      => SOMAXCONN,
    Reuse       => 1,
) || die "oops: $!";

while (my $cli = $srv->accept()) {
    my $text = <$cli>;

    $in = $text;
    $out = '';
    pump $h until length $out;
    print $cli $out;

    close $cli;
}