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Function Reference/validate file

Description

Used to prevent directory traversal attacks, or to test a filename against a whitelist.

Usage

<?php validate_file( $file, $allowed_files ); ?>

Parameters

$file
(string) (required) The file path.
Default: None
$allowed_files
(array) (optional) An array of allowed files
Default: null

Return Values

(0) 
$file represents a valid relative path. You must treat it as a relative path after validating.
(1) 
$file is invalid and contains either '..' or './'
(2) 
$file is invalid and contains ':' after the first character.
(3) 
$file is invalid and is not in the $allowed_file list.

Examples

$path = 'uploads/2012/12/my_image.jpg';
echo validate_file( $path ); // echoes 0 (valid path)

$path = '../../wp-content/uploads/2012/12/my_image.jpg';
echo validate_file( $path ); // echoes 1 (invalid path)

Notes

Be careful making boolean interpretations of the result, since false (0) indicates the filename has passed validation, whereas true (> 0) indicates failure.

Changelog

Source File

validate_file() is located in wp-includes/functions.php.

Related

See the Data Validation article for an in-depth discussion of input and output sanitization.

See also index of Function Reference and index of Template Tags.
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