php - $absolutePath = realpath(__DIR__) 中的 "realpath"是多余的吗？ __DIR__ 总是规范的绝对路径吗？

Question

做这样的事情是不是一种感觉

 $dir = realpath(dirname(__FILE__));
 // or for php 5.3+:
 $dir = realpath(__DIR__)

或者像 DIR 和 FILE 这样的魔术常量总是返回绝对路径，所以 realpath 是多余的？

Answer 1

您不需要realpath()。

__FILE__ 的文档:

The full path and filename of the file. If used inside an include, the name of the included file is returned. Since PHP 4.0.2, __FILE__ always contains an absolute path with symlinks resolved whereas in older versions it contained relative path under some circumstances.

所以 __FILE__ 返回一个绝对路径 => realpath() 不必要的

如果你使用 __DIR__:

The directory of the file. If used inside an include, the directory of the included file is returned. This is equivalent to dirname(__FILE__). This directory name does not have a trailing slash unless it is the root directory. (Added in PHP 5.3.0.)

__DIR__ 也返回绝对路径，因为 dirname() 没有截断 __FILE__ 路径的绝对部分 => < em>realpath() 不必要