raw zeromq wire protocol in php

zeromq_wire_protocol.php

<?php
// ZMTP/2.0 http://rfc.zeromq.org/spec:15
// ZMTP/1.0 http://rfc.zeromq.org/spec:13

$fp = fsockopen("127.0.0.1", 5559, $errno, $errstr, 1);
if (!$fp) {
	return;
}

stream_set_timeout($fp, 0, 500);

$str = str_repeat('abc123', mt_rand(1,100));
$msg = '{"num":'.strlen($str).',"string":"'.$str.'"}';
$length = strlen($msg);

echo $msg . PHP_EOL;
echo $length . PHP_EOL;

// ZMTP/2.0 vs. ZMTP/1.0
if (fread($fp, 1) == 0xff) {
	$version = 2;

	// server greeting (ff 00 00 00 00 00 00 00 01 7f)
	fread($fp, 9);

	// client greeting, length, PUSH
	$s = pack('CCCCCCCCCCCC', 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x7f, 0x01, 0x08);
	fwrite($fp, $s, 12);

	// server length, PULL (01, 07)
	$s = fread($fp, 2);

	// server final short (00 00)
	$s = fread($fp, 2);

	if ($length < 255) {
		fwrite($fp, pack('N', $length), 4);
		fwrite($fp, $msg, $length);
	} else {
		fwrite($fp, pack('CCCNN', 0x00, 0x00, 0x02, 0x00, $length), 1 + 1 + 1 + 4 + 4 + $length);
		fwrite($fp, $msg, $length);
	}

} else {
	$version = 1;

	// server greeting (01 00)
	fread($fp, 1);

	// client greeting
	$s = pack('CC', 0x01, 0x00);
	fwrite($fp, $s, 2);

	if ($length < 255) {
		fwrite($fp, pack('CC', $length + 1, 0x00), 2);
		fwrite($fp, $msg, $length);
		fwrite($fp, pack('C', 0), 1);
	} else {
		fwrite($fp, pack('CNNC', 0xff, 0x00, $length + 1, 0x00), 1 + 4 + 4 + 1);
		fwrite($fp, $msg, $length);
		fwrite($fp, pack('C', 0), 1);
	}
}

fclose($fp);