PHP5.3中新增的魔术常量
来源：PHP5.3中新增的魔术常量__DIR__ 我们知道PHP中提供了一个魔术常量(magic constant) __FILE__，用来指向当前执行的PHP脚本。但PHP没有直接提供该脚本所在目录的常量。也就是说如果我们要得到当前PHP脚本所在的目录，需要使用dirname()这个函数： ?php $
来源：PHP5.3中新增的魔术常量__DIR__
我们知道PHP中提供了一个魔术常量(magic constant)__FILE__，用来指向当前执行的PHP脚本。但PHP没有直接提供该脚本所在目录的常量。也就是说如果我们要得到当前PHP脚本所在的目录，需要使用dirname()这个函数：
<?php
$dir = dirname(__FILE__);
?>
在PHP5.3中，增加了一个新的常量__DIR__，指向当前执行的PHP脚本所在的目录。
例如当前执行的PHP文件为 /www/website/index.php
则__FILE__等于'/www/website/index.php'
而__DIR__等于'/www/website'
现在我们要包含当前文件目录或子目录下的文件，可以直接使用：
<?php
require_once __DIR__ . '/path/to/test.inc.php';
?>
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