<?php
$address = '0.0.0.0';
$port = $argv[1] ?? 8071;
$listen = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
if (false === $listen) errhandle(__LINE__);
//ctrl+c重启时 能立马重启,要在bind,listen之前
if (true !== socket_set_option($listen, SOL_SOCKET, SO_REUSEADDR, 1)) errhandle(__LINE__);;

if (true !== socket_bind($listen, '0.0.0.0', $port)) errhandle(__LINE__);;
if (true !== socket_listen($listen, 5)) errhandle(__LINE__);;  //待连接队列长度
//socket_set_nonblock($listen);

echo "Server linsten on:{$address}:$port" . PHP_EOL;

while (true) {
    //连接socket，处理连接的接入
    $sock_client = socket_accept($listen);
    if (false === $sock_client) {
        errhandle(__LINE__,false);
        continue;
    }
    processClientConn($sock_client);
}

//处理已经连入的连接
function processClientConn($sock_client)
{
    if (socket_getpeername($sock_client, $clinet_addr, $client_port)) {
        echo "New client " . intval($sock_client) . " come from  {$clinet_addr}:$client_port" . PHP_EOL;
        sayWelcome($sock_client);
    }
    while (true) {
        //接收到不少于len
        $len = socket_recv($sock_client, $buf, 2048, 0);
        if ($len === false) {
            echo "no data" . PHP_EOL;
            continue;
        } elseif ($len === 0) {
            errhandle(__LINE__,false);
            socket_shutdown($sock_client);
            break;
        } else {
            echo "recv=" . var_export($buf,1) . ",len=" . $len . PHP_EOL;
            $trimBuf=trim($buf);
            if ($trimBuf == 'quit') {
                socket_shutdown($sock_client);
                break;
            }
        }
    }
}

function errhandle($line_num,$exit=true)
{
    echo $line_num.":".socket_last_error() . ":" . socket_strerror(socket_last_error()) . PHP_EOL;
    if($exit){
        exit();
    }

}
function sayWelcome($client)
{
    $buf = date("H:i:s") . " welcome to server! you id:" . intval($client) . PHP_EOL;
    socket_write($client, $buf, strlen($buf));
}