validate_file( string $file, string[] $allowed_files = array() ): int
- Since
- 1.2.0
- Source
wp-includes/functions.php:6243
Description
A return value of 1 means the file path contains directory traversal.
A return value of 2 means the file path contains a Windows drive path.
A return value of 3 means the file is not in the allowed files list.
Compatibility
- WordPress
- since 1.2.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Parameters
$filestring- File path.
$allowed_filesstring[]optional- Array of allowed files. Default empty array.Default:
array()
Return value
int- 0 means nothing is wrong, greater than 0 means something was wrong.
Performance profile
How much work a call to validate_file() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Trivial
- Scaling
- Constant
- Instructions
- 5–46
- Plugin surface
- None
- Called by
- 15
Touches nothing outside its own arguments.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 52.
Nothing here hands control to plugin code.
15 places in core call this, so the cost is paid more often than your own code shows.
What it touches
- regexregular expression over the whole input
preg_match_all()called directly
Further down the call graph this can also reach option, hook, cache, serialize, query and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.
What one call costs · 4 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost validate_file() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 5–7 | none |
is_scalar($file) && $file !== "" && $file === "../" | 18 | wp_normalize_path(), array_map() |
is_scalar($file) && $file !== "" && $file !== "../" | 28–39 | wp_normalize_path(), array_map(), preg_match_all() |
is_scalar($file) && $file !== "" && $file !== "../" && $file | 34–46 | wp_normalize_path(), array_map(), preg_match_all(), mb_substr() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 52 | 5–46 | 10 | |
| 8.5 | 52 | 5–46 | 10 | |
| 8.4 | 52 | 5–46 | 10 | 9 fewer instructions than PHP 8.3 |
| 8.3 | 61 | 5–55 | 10 | |
| 8.2 | 61 | 5–55 | 10 | |
| 8.1 | 61 | 5–55 | 10 | 2 fewer instructions than PHP 7.4 |
| 7.4 | 63 | 7–57 | 10 |
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Uses · 3
- wp_normalize_path()Normalizes a filesystem path.
- str_contains()Polyfill for `str_contains()` function added in PHP 8.0.
- mb_substr()Compat function to mimic mb_substr().
Used by · 15
- WP_Customize_Manager::__construct()Constructor.
- WP_REST_Plugins_Controller::validate_plugin_param()Checks that the "plugin" parameter is a valid path.
- _unzip_file_pclzip()Attempts to unzip an archive using the PclZip library.
- _unzip_file_ziparchive()Attempts to unzip an archive using the ZipArchive class.
- download_url()Downloads a URL to a local temporary file using the WordPress HTTP API.
- get_page_template()Retrieves path of page template in current or parent template.
- get_single_template()Retrieves path of single template in current or parent template. Applies to single Posts, single Attachments, and single custom post types.
- render_block_core_template_part()Renders the `core/template-part` block on the server.
- validate_file_to_edit()Makes sure that the file that was requested to be edited is allowed to be edited.
- validate_plugin()Validates the plugin path.
- wp_ajax_delete_plugin()Handles deleting a plugin via AJAX.
- wp_ajax_update_plugin()Handles updating a plugin via AJAX.
Show all 15
- wp_edit_theme_plugin_file()Attempts to edit a file for a theme or plugin.
- wp_get_active_and_valid_plugins()Retrieves an array of active and valid plugin files.
- wp_get_active_network_plugins()Returns array of network plugin files to be included in global scope.
Source code
function validate_file( $file, $allowed_files = array() ) { if ( ! is_scalar( $file ) || '' === $file ) { return 0; } // Normalize path for Windows servers. $file = wp_normalize_path( $file ); // Normalize path for $allowed_files as well so it's an apples to apples comparison. $allowed_files = array_map( 'wp_normalize_path', $allowed_files ); // `../` on its own is not allowed: if ( '../' === $file ) { return 1; } // More than one occurrence of `../` is not allowed: if ( preg_match_all( '#\.\./#', $file, $matches, PREG_SET_ORDER ) && ( count( $matches ) > 1 ) ) { return 1; } // `../` which does not occur at the end of the path is not allowed: if ( str_contains( $file, '../' ) && '../' !== mb_substr( $file, -3, 3 ) ) { return 1; } // Files not in the allowed file list are not allowed: if ( ! empty( $allowed_files ) && ! in_array( $file, $allowed_files, true ) ) { return 3; } // Absolute Windows drive paths are not allowed: if ( ':' === substr( $file, 1, 1 ) ) { return 2; } return 0;}Changelog
Introduced in 1.2.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 6.9.7 tag, from
src/wp-includes/functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
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