PHP 读取MAC地址

代码：

<?php

class GetMacAddress {
	var $return_array = array();
	var $mac_addr;

	function _construct($os_type) {
		switch (strtolower($os_type)) {
			case   "linux":
			$this->forLinux();
			break;
			default:
			$this->forWindows();
			break;
		}

		$temp_array = array();
		foreach ($this->return_array as $value) {
			if (preg_match("/[0-9a-f][0-9a-f][:-]"."[0-9a-f][0-9a-f][:-]"."[0-9a-f][0-9a-f][:-]"
			               ."[0-9a-f][0-9a-f][:-]"."[0-9a-f][0-9a-f][:-]"."[0-9a-f][0-9a-f]/i", $value, $temp_array)) {
				$this->mac_addr = $temp_array[0];
				break;
			}
		}

		unset($temp_array);
		return $this->mac_addr;
	}

	function forWindows() {
		@exec("ipconfig /all", $this->return_array);

		if ($this->return_array) {
			return $this->return_array;
		} else {
			$ipconfig = $_SERVER["SystemRoot"]."\system32\ipconfig.exe";
			if (is_file($ipconfig)) {
				@exec($ipconfig." /all", $this->return_array);
			} else {
				@exec($_SERVER["WINDIR"]."\system\ipconfig.exe /all", $this->return_array);
			}
			return $this->return_array;
		}
	}

	function forLinux() {
		@exec("ifconfig  -a", $this->return_array);
		return $this->return_array;
	}
}

$mac = new GetMacAddress(null);
echo $mac->mac_addr;

?>