use IO::Socket;
use strict;

my ($server, $client, $input, $pid, $kid, %kids);

$server = IO::Socket::INET->new(
    Proto     => 'tcp',
    LocalPort => 8000,
    Listen    => 1,
    Reuse     => 1
);
die "Can't set up server" unless $server;
print "Server accepting connections.\n";

$pid = $$;
MAIN: while ($client = $server->accept()) {
    $client->autoflush(1);
    defined (my $kid = fork) or die "Cannot fork: $!\n";

    if ($kid) {
        $kids{$kid} = 1;
    }
    else {
        while (1) {
            $input = uc getInput($client);
            chomp $input;
            
            if ($input eq 'KILL') {
                `kill $pid`;
                exit;
            }
            if ($input eq 'EXIT') {
                exit;
            }
            if ($input eq 'DATE') {
                sendOutput($client, time());
            }
            else {
                sendOutput($client, $input);
            }
        }
    }
    close $client;
}

### Get input from socket
sub getInput {
    my $handle = $_[0];
    my $input;

    while (<$handle>) {
        last if !m/\S/;
        $input .= $_;
    }
    return $input;
}

### Send to socket
sub sendOutput {
    my ($handle, $output) = @_;

    $output .= "\n" if $output !~ /\n$/;
    print $handle $output;
    print $handle "\n";
}
[download]

use IO::Socket;
use strict;

my $location = '123.456.123.456:8000';

my ($sock, $out);

$sock = new IO::Socket::INET (
    PeerAddr => $location,
    Proto => 'tcp',
);

die "Could not create socket: $!\n" unless $sock;

while (1) {
    sendInput($sock, getInput('Enter a command'));
    $out = getOutput($sock);
    last if !$out;
    print $out;
}
close($sock);

### Query user for input
sub getInput {
    my ($query, $null) = @_;
    my $in;

    do {
        print "$query : ";
        chomp($in = <STDIN>);
    } while !$null && !$in;
    return $in;
}

### Send to socket
sub sendInput {
    my ($handle, $inp) = @_;

    $inp .= "\n" if $inp !~ /\n$/;
    print $handle $inp;
    print $handle "\n";
}

### Get result
sub getOutput {
    my $handle = $_[0];
    my $output;

    while (<$handle>) {
        last if !m/\S/;
        $output .= $_;
    }
    return $output;
}
[download]