Various blocking and non-blocking IO demos

echo.php

<?php

$ss = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

$iface = '0.0.0.0';
$port =  5432;

socket_set_option($ss, SOL_SOCKET, SO_REUSEADDR, 1);
socket_bind($ss, $iface, $port) or die("Could not bind\n");
socket_listen($ss, 1);
print "Listening on $iface:$port\n";

while (true) {
	$cs = socket_accept($ss);
	socket_getpeername($cs, $addr, $port);
	print "Client connected $addr:$port\n";

	while (true) {
		$ok = socket_recv($cs, $data, 1024, 0);
		if (!$ok) {
			break;
		}
		socket_send($cs, $data, 1024, 0);
		print "$data";
	}
	print "Closing client socket\n";
	socket_close($cs);
}

print "Closing master socket\n";
socket_close($ss);

nbchat.php

<?php

$ss = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

$iface = '0.0.0.0';
$port =  5432;

socket_set_option($ss, SOL_SOCKET, SO_REUSEADDR, 1);
socket_bind($ss, $iface, $port) or die("Could not bind\n");
socket_listen($ss, 1);
print "Listening on $iface:$port\n";

$clients = array();
$sendbuf = array();
$wantswrite = array();
$nicks = array();

while (true) {
	$ws = $wantswrite;
	$rs = $clients;
	$rs[] = $ss;

	$len = socket_select($rs, $ws, $xs, 10);

	if ($len === 0) {
		foreach ($clients as $client) {
			$wantswrite[$client] = $client;
			$sendbuf[$client] = "<server heart beat>\n";
			print "Buffering to send to client #$client: $data";
		}
	}

	foreach ($rs as $cs) {
		if ($cs == $ss) {
			$cs = socket_accept($ss);
			socket_getpeername($cs, $addr, $port);
			print "Connected: client #$cs $addr:$port\n";
			$clients[$cs] = $cs;
			$wantswrite[$cs] = $cs;
			$sendbuf[$cs] = "You are connected to the chat room."
				. " Type 'quit' to quit.\n\nPlease enter your name: "; 
			print "Buffering to send to client #$cs: $data";
		} else {
			$ok = socket_recv($cs, $data, 1024, 0);
			if ($data == '') {
				print "Closing: client #$cs\n";
				socket_close($cs);
				unset($clients[$cs]);
				unset($nicks[$cs]);
			} else {
				if (empty($nicks[$cs])) {
					$nicks[$cs] = trim($data);
					$wantswrite[$cs] = $cs;
					$sendbuf[$cs] = "You are now known as $data"; 
					print "Buffering to send to client #$cs: $data";
				} else {
					$message = $nicks[$cs] . ': ' . $data;
					if (trim($data) == 'quit') {
						$message = $nicks[$cs] . " has left the channel.\n";
						print "Closing: client #$cs\n";
						socket_close($cs);
						unset($clients[$cs]);
						unset($nicks[$cs]);
					}
					foreach ($clients as $client) {
						$wantswrite[$client] = $client;
						$sendbuf[$client] = $message;
						print "Buffering to send to client #$client: $data";
					}
				}
			}
		}
	}

	foreach ($ws as $cs) {
		$data = $sendbuf[$cs];
		print "Sending data to client #$cs: $data";
		socket_send($cs, $data, 1024, 0);
		unset($sendbuf[$cs]);
		unset($wantswrite[$cs]);
	}
}

print "Closing master socket\n";
socket_close($ss);

nbecho.php

<?php

$ss = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

$iface = '0.0.0.0';
$port =  5432;

socket_set_option($ss, SOL_SOCKET, SO_REUSEADDR, 1);
socket_bind($ss, $iface, $port) or die("Could not bind\n");
socket_listen($ss, 1);
print "Listening on $iface:$port\n";

$clients = array();
$sendbuf = array();
$wantswrite = array();

while (true) {
	$ws = $wantswrite;
	$rs = $clients;
	$rs[] = $ss;

	socket_select($rs, $ws, $xs, 10);

	foreach ($rs as $cs) {
		if ($cs == $ss) {
			$cs = socket_accept($ss);
			socket_getpeername($cs, $addr, $port);
			print "Connected: client #$cs $addr:$port\n";
			$clients[$cs] = $cs;
		} else {
			$ok = socket_recv($cs, $data, 1024, 0);
			if ($data == '') {
				print "Closing: client #$cs\n";
				socket_close($cs);
				unset($clients[$cs]);
			} else {
				$wantswrite[$cs] = $cs;
				$sendbuf[$cs] = $data;
				print "Buffering to send to client #$cs: $data";
			}
		}
	}

	foreach ($ws as $cs) {
		$data = $sendbuf[$cs];
		print "Sending data to client #$cs: $data";
		socket_send($cs, $data, 1024, 0);
		unset($sendbuf[$cs]);
		unset($wantswrite[$cs]);
	}
}

print "Closing master socket\n";
socket_close($ss);