父文件夹包含的文件，另一个文件夹包含的文件

Question

The title is hard to understand, but my question is easy:

I have:

config.php

include('config_mysql.php');
include('language/english.php');

then I have: index.php

include('config.php');

and then: /ajax/ajax_vote.php

include('../config.php');

Why index.php includes both config_mysql.php and language/english.php but ajax/ajax_vote.php only includes the config_mysql.php ?

Answer 1

The base folder for include() is allways the base folder of the original script, so the include() s inside an include() d script will be non-intuitive:

ajax/ajax_vote.php will (try to) include

ajax/../config.php
  -> ajax/sonfig_mysql.php
     ajax/language/english.php

You might want to look at

$BASEDIR=dirname(__FILE__);
include("$BASEDIR/config_mysql.php");
include("$BASEDIR/language/english.php");

and friends.

Answer 2

The reason is, the language/english.php is not in the same directory as config.php . Also, the /ajax/ajax_vote.php is somewhere outside from the root folder.

But still, PHP manages to include files correctly. I don't understand why the /ajax/ajax_vote.php is not including the file language/english.php . Correct me if I misunderstood the question.

Answer 3

What Eugen said is true, this is because of the base path not being the same as your included script.

Also it seems from my tests (because I encountered a similar problem) that php include() will store another temporary include_path when including files, this is why ajax_vote.php could include config_mysql.php. To convince yourself, try to move config_mysql.php to your ajax folder: it will work the same, and config.php will be able to include it (but only when executing ajax_vote.php, NOT index.php!). In this case, you have two include paths: '/ajax/' and '/'.

However, when you use a path (not merely a filename to include, but also specify a folder in your string), the include path is only based on the executing script (eg: only '/ajax/').

You can fix this behaviour by doing:

include(dirname(__FILE__).'/language/english.php'); // don't forget the prepended '/'

Or just:

include('/language/english.php'); // here again the prepended '/'

However I warn you that I don't fully understand yet why the second method works, you may be safer by using the first one with dirname().

/EDIT: I just found out that include('/path/to/file') is probably a bug on Windows OSes: on Windows it's equal to dirname(__ FILE__ ), but on UNIX it's equal to root path. So dirname(__ FILE__ ) is definately more reliable.