linux下php多进程与可响应http请求的socket server

　　要有多蛋疼才会用php去写http服务器?答案是需要蛋疼到蛋裂的地步。

　　还好哥只是略疼,所以写了非常非常粗糙的一点东西,目的是为了温习下php的socket(tcp)+fork的用法。

　　开始先讲原理，主要是scoket服务利用whilet挂住，socket_accept接收到新的socket连接后，马上fork一个子进程，负责单独和这个连接交互，这里也很简单，无非就是socket_read挂住监听这个连接的请求，发现有则解析并返回，这里说的返回是socket_write往socket连接的句柄写入信息。

　　接着就是代码了,解释再多也不如代码看得实在。

#!/usr/local/php/bin/php
<?php
$host = "192.168.1.50"; $port = 12335; 
set_time_limit(0);
// Socket create
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP) or die("Could not create socket\n"); 
// Bind socket to a port
$result = socket_bind($socket, $host, $port) or die("Could not bind to socket\n"); 
// Start listening for connections 
$result = socket_listen($socket, 3) or die("Could not set up socket listener\n"); 

while( true )
{
    /** waiting a new connection **/
    $newsock = socket_accept( $socket );
    /**
    ***We fork child process for each client
    **/
    if($newsock)
    {
        $child = pcntl_fork();     
        if( $child > 0 )
        {//parent process.
            /** 
            ** Since child process is hanging there. 
            ** so we know that we should close client socket here.
            **/
            socket_close( $newsock );
        }
        else if( $child == 0 )
        {//child process
            /** get address and port of client socket **/ 
            socket_getpeername($newsock,$addr,$port);
            $welcomemsg = "A new clients $addr:$port was entered.".PHP_EOL;
            echo $welcomemsg;
            while( true )
            {
                /** hanging here to wait some messages come from client socket **/
                $msg         = socket_read( $newsock,1024);
                if( $msg === false)
                {
                    /** Client was quited unexpected **/
                    echo "$addr:$port was quited!".PHP_EOL;
                    socket_close( $newsock );
                    posix_kill( posix_getpid(),SIGTERM);
                }    
                else
                {
                    $kill = false;
                    $msg = strtolower(trim($msg));
                    /** Cli hello message **/
                    if(!empty($msg) && $msg != "\x21\x23") echo "$addr:$port request:".$msg.PHP_EOL;
                    /** Do something according to command from client **/
                    switch( $msg )
                    {
                        default :
                            if(preg_match('#^(get|post)\s+/([^\s]*)#i',$msg,$match))
                            {//it's a http request    
                                $page = $match[2] ? $match[2] : 'index.php';
                                ob_start();
                                    include '/var/www/'.$page;
                                    $httpResponse = ob_get_contents();
                                ob_end_clean();
                                //$httpResponse = "<b>Hello browser,成功了!</b>";
                                $msg     = "HTTP/1.1 200\n"
                                          ."Content-type:text/html;charset=utf-8\n"
                                          ."Content-length:".strlen($httpResponse)."\n"
                                          ."Connection:close\n\n"
                                           .$httpResponse;
                                $kill     = true;
                            }
                            else $msg = "Unknow command!";
                        break;
                        case "\x21\x23":
                            $msg = "Welcome $addr:$port";
                        break;

                        case 'q':
                        case 'quit':
                        case 'exit':
                            echo "$addr:$port ask for quit!".PHP_EOL;
                        break;
                    }
                    /** Message send to client socket,
                    *** would kill client socket when wrote action was fail or when we doing a  http response**/
                    if(!socket_write($newsock,$msg,strlen($msg)) || $kill)
                    {
                        echo "$addr:$port was quited!".PHP_EOL;
                        socket_close( $newsock );
                        posix_kill( posix_getpid(),SIGTERM);
                    }
                }    
            }
        }
        else
        {//
            exit('Unable to fork!');    
        }
    }
}
// close sockets 
socket_close($socket);
?>