string getservbyport ( int $port , string $protocol )   */ $services=array('80','21','22','23','25','143');      //定义数组 foreach($services as $service)         //循环读取内容 {   $protocol=getservbyport($service,'tcp');       //返回端口号对应的协议   echo $service.":".$protocol."<br/>n";       //输出结果 }   /* int getservbyname ( string $service , string $protocol ) */   $services=array('http','ftp','ssh','telnet','imap', 'smtp','nicname','gopher','finger','pop3','www');       //定义一个数组 foreach($services as $service)          //循环读取内容 {   $port=getservbyname($service,'tcp');        //获取数组元素对应端口   echo $service.":".$port."<br/>n";         //输出结果 }