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UDP client

A datagram client. After connect(), the kernel locks the peer address; read() / write() then behave like a stream socket and talk only to that peer.

Quick reference

use InitPHP\Socket\Socket;
use InitPHP\Socket\Enum\Transport;

$client = Socket::client(Transport::UDP, '127.0.0.1', 9000);
$client->connect();

$client->write('ping');
echo $client->read(65535);

$client->disconnect();

Flags

Both read() and write() accept an optional int $flags argument:

Flag set Sensible places
MSG_OOB, MSG_PEEK, MSG_WAITALL, MSG_DONTWAIT read()
MSG_OOB, MSG_EOR, MSG_EOF, MSG_DONTROUTE write()

Leave them at 0 unless you are sure you need them.

Caveats

  • No retransmits. A successful write() only proves the OS accepted the packet for sending. Datagram loss is silent.
  • No connection state. disconnect() only closes the local socket; the peer has no way to learn the client is gone.
  • Packet size. UDP over IPv4 maxes out at 65 507 bytes of payload. Stay under MTU (≈1472 bytes on Ethernet) to avoid fragmentation.