The difference between PHP $_SERVER[SCRIPT_FILENAME] and __FILE__

PHP $_SERVER['SCRIPT_FILENAME'] and __FILE__

Normally, PHP $_SERVER['SCRIPT_FILENAME'] and __FILE__ will return the full path (absolute path) and file name of the PHP file:

<?php
echo 'SCRIPT_FILENAME 为：',$_SERVER['SCRIPT_FILENAME'];
echo '<br />';
echo '__FILE__ 为：',__FILE__;
?>

The above test code Copy to test.php and access the file (http://127.0.0.1/php/test.php), and get the following results:

SCRIPT_FILENAME 为：E:/web/html/php/test.php
__FILE__ 为：E:\web\html\php\test.php 

Tips: When testing on the Windows platform, path separators may appear in the results as shown above. nuances.

The difference between $_SERVER['SCRIPT_FILENAME'] and __FILE__

Although $_SERVER['SCRIPT_FILENAME'] is very similar to __FILE__, there are still subtle differences between the two when the file is included or require.

Copy the above test code to E:webhtmlphpcommoninc.php, and then include inc.php in the test.php file just now:

<?php
include 'common/inc.php';
?>

When you access the test.php file again at this time, the output result is:

SCRIPT_FILENAME 为：E:/web/html/php/test.php
__FILE__ 为：E:\web\html\php\common\test.php 

You can see both The difference is: $_SERVER['SCRIPT_FILENAME'] reflects the absolute path and file name of the currently executing program; __FILE__ reflects the absolute path and file name of the original file (included file).

The above introduces the difference between PHP $_SERVER[SCRIPT_FILENAME] and __FILE__, including the relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.