# set_include_path

(PHP 4 >= 4.3.0, PHP 5, PHP 7)

set_include_path — Sets the include_path configuration option

### Description

set_include_path ( string `$new_include_path` ) : string|false

Sets the include_path configuration option for the duration of the script.

### Parameters

`new_include_path`

  The new value for the include_path

### Return Values

Returns the old include_path on success or `FALSE` on failure.

### Examples

Example #1 set_include_path() example

`<?php
set_include_path('/usr/lib/pear');
// Or using ini_set()
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