Another way to bypass the annoying thing with telnet, that send each character as a string ,is to check if the response is "\r\n", that is the string that telnet sends when the user presses enter.
Here is an example:
<?php
error_reporting(E_ALL);
set_time_limit(0);
ob_implicit_flush();
$address = '127.0.0.1';
$port = 100;
if (($sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)) === false) {
echo "socket_create() failed: reason: " . socket_strerror(socket_last_error()) . "\n";
}
if (socket_bind($sock, $address, $port) === false) {
echo "socket_bind() failed: reason: " . socket_strerror(socket_last_error($sock)) . "\n";
}
else
echo 'Socket ' . $address . ':' . $port . " has been opened\n";
if (socket_listen($sock, 5) === false) {
echo "socket_listen() failed: reason: " . socket_strerror(socket_last_error($sock)) . "\n";
}
else
echo "Listening for new clients..\n";
$client_id = 0;
do {
if (($msgsock = socket_accept($sock)) === false) {
echo "socket_accept() failed: reason: " . socket_strerror(socket_last_error($sock)) . "\n";
break;
}
else {
$client_id += 1;
echo "Client #" .$client_id .": Connect\n";
}
$msg = "\nWelcome to the PHP Test Server. \n" .
"To quit, type 'quit'. To shut down the server type 'shutdown'.\n";
socket_write($msgsock, $msg, strlen($msg));
$cur_buf = '';
do {
if (false === ($buf = socket_read($msgsock, 2048))) {
echo "socket_read() failed: reason: " . socket_strerror(socket_last_error($msgsock)) . "\n";
break 2;
}
if ($buf == "\r\n") {
if ($cur_buf == 'quit') {
echo 'Client #' .$client_id .': Disconnect' . "\n";
break;
}
if ($cur_buf == 'shutdown') {
socket_close($msgsock);
break 2;
}
$talkback = "Unknown command: " . str_replace("\r\n", '\r\n', $cur_buf) ."\n";
socket_write($msgsock, $talkback, strlen($talkback));
echo 'Client #' .$client_id .': ' . $cur_buf . "\n";
$cur_buf = '';
}
else $cur_buf .= $buf;
} while (true);
socket_close($msgsock);
} while (true);
socket_close($sock);
?>
