I tried the suggestion and still got nothing back.
client code:

#!/usr/bin/env perl

use IO::Socket;
$remote_port=7071;
$remote_host="localhost ";
$socket = IO::Socket::INET->new(PeerAddr => $remote_host,
                                PeerPort => $remote_port,
                                Proto    => "tcp",
                                Type     => SOCK_STREAM)
    or die "Couldn't connect to $remote_host:$remote_port : $@\n";

$socket->autoflush(1);

# ... do something with the socket
print $socket "ls:/tmp\n";

while (<$socket>) {
        print "$_\n";
}

# and terminate the connection when we're done
close($socket);
[download]

Server code:

#!/usr/bin/env perl

# perl modules
use IO::Socket;
use POSIX qw(:sys_wait_h);
use Sys::Hostname;
use IPC::Open3 qw( open3 );

# get hostname
my $hostname = hostname;

# Port
my $port = "7071";

$SIG{CHLD} = 'IGNORE';

# make socket connection
my $socket = new IO::Socket::INET (
        LocalHost => "$hostname",
        LocalPort => "$port",
        Proto => 'tcp',
        Reuse => 1,
        Listen => SOMAXCONN,
); die "Could not create socket: $!\n" unless $socket;

# allow server to accept clients
while ($client = $socket->accept()) {

        # flush input
        $client->autoflush(1);

        # input from client
        while (<$client>) {
                chomp;

                # read command and put rest in array
                my ($command,@var2) = split(":", $_);
                my $cmd;

                        if ($command eq 'ls'){
                                @cmd = ( 'ls', '-s', '--', @var2 );
                        }

                        # run command
                        if (@cmd) {
                                open(local *C_STDIN, '<', '/dev/null')
+ or die;
                                open(local *C_STDIN, '>&', $client) or
+ die;
                                my $pid = open3('C_STDIN', '>C_STDOUT'
+, 'C_STDOUT', @cmd);
                                waitpid($pid, 0);
                        }
        }

        # close client
        close($client);

        
}

# close socket so it can reused
close($socket);
[download]