PHP method to obtain the real IP address of the machine and example code

function getLocalIP() {
 $preg = "/\A((([0-9]?[0-9])|(1[0-9]{2})|(2[0-4][0-9])|(25[0-5]))\.){3}(([0-9]?[0-9])|(1[0-9]{2})|(2[0-4][0-9])|(25[0-5]))\Z/";
//获取操作系统为win2000/xp、win7的本机IP真实地址
 exec("ipconfig", $out, $stats);
 if (!empty($out)) {
  foreach ($out AS $row) {
   if (strstr($row, "IP") && strstr($row, ":") && !strstr($row, "IPv6")) {
    $tmpIp = explode(":", $row);
    if (preg_match($preg, trim($tmpIp[1]))) {
     return trim($tmpIp[1]);
    }
   }
  }
 }
//获取操作系统为linux类型的本机IP真实地址
 exec("ifconfig", $out, $stats);
 if (!empty($out)) {
  if (isset($out[1]) && strstr($out[1], 'addr:')) {
   $tmpArray = explode(":", $out[1]);
   $tmpIp = explode(" ", $tmpArray[1]);
   if (preg_match($preg, trim($tmpIp[0]))) {
    return trim($tmpIp[0]);
   }
  }
 }
 return '127.0.0.1';
}