# 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.

### 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
// Works as of PHP 4.3.0
set_include_path('/inc');
// Works in all PHP versions
ini_set('include_path', '/inc');
?>`

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()
- get_include_path()
- restore_include_path()
- include()