You can also add several paths in one set_include_path separating them by ':'.
ex : set_include_path('/home/mysite/includes1:/home/mysite/includes2')
set_include_path
(PHP 4 >= 4.3.0, PHP 5)
set_include_path — Sets the include_path configuration option
Description
string set_include_path
( string
$new_include_path
)Sets the include_path configuration option for the duration of the script.
Return Values
Returns the old include_path on
success or FALSE
on failure.
Examples
Example #1 set_include_path() example
<?php
// Works as of PHP 4.3.0
set_include_path('/usr/lib/pear');
// Works in all PHP versions
ini_set('include_path', '/usr/lib/pear');
?>
Example #2 Adding to the include path
Making use of the PATH_SEPARATOR
constant, it is
possible to extend the include path regardless of the operating system.
In this example we add /usr/lib/pear to the end of the existing include_path.
<?php
$path = '/usr/lib/pear';
set_include_path(get_include_path() . PATH_SEPARATOR . $path);
?>
See Also
- ini_set() - Sets the value of a configuration option
- get_include_path() - Gets the current include_path configuration option
- restore_include_path() - Restores the value of the include_path configuration option
- include - include

koenig at electronova dot net ¶
6 years ago
cloxy at cloxy dot com ¶
9 months ago
If you want to include files with their absolute path without changing the current include path, you can use the magic constant __DIR__ . For example:
<?php include(__DIR__.'/file.php'); ?>
It is available since PHP 5.3.
francois r vespa ¶
1 year ago
include_path is not taking in consideration by very commonly used functions such as file_exists(), the following hack can come handy to override that
<?php
function suchFile($file) // like file_exists() but takes in consideration include_path
{
if(!file_exists($file))
{
$paths=explode(PATH_SEPARATOR,get_include_path());
foreach($paths as $p)
if(file_exists(preg_replace('%/$%','',$p)."/$file"))
return true;
return false;
}
else
return true;
}
?>
joel at pittet dot ca ¶
2 years ago
Seems set_include_path wasn't working for me.
The problem was i didn't have .: in my include_path
Which seemed to stop the set_include_path().
mateusz at bkfmyjnie dot pl ¶
2 years ago
It seems you can't really set empty inlude_path. First, set_include_path('') does exactly nothing (successfully), and second, '.' is always implicitly appended to the include path by PHP itself, as noted in comments below.
However, you can:
set_include_path(PATH_SEPARATOR); // note no quotes around the PATH_SEPARATOR; it's a string on its own
or, more explicit:
set_include_path('.');
Both seems to have the same result.
ricardo dot ferro at gmail dot com ¶
4 years ago
Two functions to help:
<?php
function add_include_path ($path)
{
foreach (func_get_args() AS $path)
{
if (!file_exists($path) OR (file_exists($path) && filetype($path) !== 'dir'))
{
trigger_error("Include path '{$path}' not exists", E_USER_WARNING);
continue;
}
$paths = explode(PATH_SEPARATOR, get_include_path());
if (array_search($path, $paths) === false)
array_push($paths, $path);
set_include_path(implode(PATH_SEPARATOR, $paths));
}
}
function remove_include_path ($path)
{
foreach (func_get_args() AS $path)
{
$paths = explode(PATH_SEPARATOR, get_include_path());
if (($k = array_search($path, $paths)) !== false)
unset($paths[$k]);
else
continue;
if (!count($paths))
{
trigger_error("Include path '{$path}' can not be removed because it is the only", E_USER_NOTICE);
continue;
}
set_include_path(implode(PATH_SEPARATOR, $paths));
}
}
?>
chris-r3i ¶
5 years ago
Can be useful to check the value of the constant PATH_SEPARATOR.
<?php
if ( ! defined( "PATH_SEPARATOR" ) ) {
if ( strpos( $_ENV[ "OS" ], "Win" ) !== false )
define( "PATH_SEPARATOR", ";" );
else define( "PATH_SEPARATOR", ":" );
}
?>
For older versions of php, PATH_SEPARATOR is not defined.
If it is so, we must check what kind of OS is on the web-server and define PATH_SEPARATOR properly
df a t dougfelton d o t c o m ¶
7 years ago
In order to use .htaccess files to set the include path, PHP must be installed as an Apache module. If PHP is compiled as a CGI binary, you can set the include path in a custom php.ini file (if, for example, you're being hosted somewhere and don't have access to the main php.ini file. Note that custom php.ini files don't affect subdirectories in the way that .htaccess files do, so you'll need to put your custom php.ini file in any subdirectories as well.
r dot s dot goldsmith at far-blue dot co dot uk ¶
8 years ago
If you want to set the paths php uses to find included files on a directory by directory level, you can do so in Apache's .htaccess file. Add the line:
php_value include_path "<first path to look>:<second path>:<etc>:."
to the .htaccess file. This will replace any paths set in your environment or the php.ini file so remember to include the path to php's own libraries as, usually, the first option!
V.useful tip given to me by the 'php guy' at Edinburgh Uni's Computing Support.
parks at vecinc dot com ¶
3 years ago
If you find that this function is failing for you, and you're not sure why, you may have set your php include path in your sites's conf file in Apache (this may be true of .htaccess as well)
So to get it to work, comment out any "php_value include_path" type lines in your Apache conf file, and you should be able to set it now in your php code.
ChanibaL.net ¶
4 years ago
The files are included in order of the inclusion path, in this example, the directory structure is as follows:
.
|-- index.php
|-- t1
| |-- a
| `-- b
`-- t2
|-- b
`-- c
<?php
set_include_path('t1'.PATH_SEPARATOR.'t2');
include 'a'; // includes from T1
include 'b'; // includes from T1
include 'c'; // includes from T2
?>
Note that the include path affects only include/require functions.
<?php
var_dump(file_exists('a')); // false
var_dump(fopen('b', 'r')); // file not found
?>
junya at xs4all dot nl ¶
7 years ago
When you use .htaccess to set the include path, don't forget Apache directive 'AllowOverride Options' or 'AllowOverride All' is also needed.