pid_recvfrom()

int pid_recvfrom ( int $pid, int/string &$buf [ , int $len, int $flags = 0, string &$addr, int &$port ] )

Description

pid_recvfrom() receives $len bytes of the incoming data from UDP socket’s buffer

※ available F/W version : all

Parameters

$pid - the network device’s PID
&$buf - the destination buffer will be saved to
$len - the maximum number of bytes to receive
It receives up to the size of the $buf if this field is omitted (integer: 8 bytes, string: MAX_STRING_LEN)
$flags - This field should be 0
&$addr - the peer host’s IP address
&$port - the peer host’s UDP port number

Return values

Returns the number of bytes received (it can be less than the $len). PHP error on error

Example

<?php
define("MAX_BUF", 100);

$buf = "";
$peer_addr = "";
$peer_port = 0;

$pid = pid_open("/mmap/udp0");
pid_bind($pid, "", 1470);

while(1)
{
    $rlen = pid_recvfrom($pid, $buf, MAX_BUF, 0, $peer_addr, $peer_port);
    if($rlen > 0)
    {
        echo "udp received from $peer_addr:$peer_port ($rlen bytes)\r\n";
        $wlen = pid_sendto($pid, $buf, $rlen, 0, $peer_addr, $peer_port);
        echo "udp echo sent: $wlen bytes\r\n";

        // send data another host
        $wlen = pid_sendto($pid, $buf, $rlen, 0, "10.3.0.52", 2000);
        echo "udp sent to another host: $wlen bytes\r\n";
    }
}
?>

Remarks

None

< pid_recv()

pid_send() >