PHP path related dirname, realpath, __FILE__, dirnamerealpath_PHP tutorial

PHP path related dirname, realpath, __FILE__, dirnamerealpath

​For example: the program root directory is in: E:wampwww

1. __FILE__ The absolute path of the current file

If called in index.php, it will return E:wampwwwindex.php

Let’s take a look at the directory structure of the program root directory

If __FILE__ is called in c_system_base.php it returns:

E:wampwwwzb_systemfunctionc_system_base.php

2.dirname Returns the parent directory of the current directory or the directory where the current file is located (without / at the end)

Generally used in conjunction with __FILE__

If dirname(__FILE__) is called in c_system_base.php, it will return

E:wampwwwzb_systemfunction (the file returns to the directory where it is located)

If dirname(dirname(__FILE__)) is called, it returns

E:wampwwwzb_system (the directory returns to the upper directory)

realpath() method returns the absolute path of the current file or the path relative to the root directory

If realpath(__FILE__) is called in c_system_base.php, it will return

E:wampwwwzb_systemfunctionc_system_base.php

realpath('/') Return to disk root directory E:

realpath('./') Return to the root directory E:wampwww

realpath('../') Returns the superior directory relative to the program root directory

can also be used in conjunction with dirname, usually adding several relative paths../ (add / in front, that is: /../)

realpath(dirname(__FILE__)) Return E:wampwwwzb_systemfunction

realpath(dirname(__FILE__).'/../') returns E:wampwwwzb_system

realpath(dirname(__FILE__).'/../../') Return E:wampwww