# FileHelper

> File system helper.

[API reference](/docs/api/index.md) › [yii](/docs/api/yii/index.md) › [helpers](/docs/api/yii/helpers/index.md) › FileHelper

| class | `yii\helpers\FileHelper` |
| --- | --- |
| Extends | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| Since | 2.0 |
| Source | [`framework/helpers/FileHelper.php`](https://github.com/yiisoft/yii2/blob/22.0/framework/helpers/FileHelper.php#L18) |

File system helper.

## Properties

| Property | Type | Description | Defined by |
| --- | --- | --- | --- |
| <span id="property-mimeAliasesFile"></span>[`$mimeAliasesFile`](/docs/api/yii/helpers/basefilehelper/index.md#property-mimeAliasesFile) static | `string` | The path (or alias) of a PHP file containing MIME aliases. Default: `'@yii/helpers/mimeAliases.php'`. Available since 2.0.14. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="property-mimeExtensionsFile"></span>[`$mimeExtensionsFile`](/docs/api/yii/helpers/basefilehelper/index.md#property-mimeExtensionsFile) static | `string` | The path (or alias) of a PHP file containing extensions per MIME type. Default: `'@yii/helpers/mimeExtensions.php'`. Available since 2.0.48. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="property-mimeMagicFile"></span>[`$mimeMagicFile`](/docs/api/yii/helpers/basefilehelper/index.md#property-mimeMagicFile) static | `string` | The path (or alias) of a PHP file containing MIME type information. Default: `'@yii/helpers/mimeTypes.php'`. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |

## Methods

| Method | Description | Defined by |
| --- | --- | --- |
| <span id="method-changeOwnership"></span>[`changeOwnership()`](/docs/api/yii/helpers/basefilehelper/index.md#method-changeOwnership) static | Changes the Unix user and/or group ownership of a file or directory, and optionally the mode. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-copyDirectory"></span>[`copyDirectory()`](/docs/api/yii/helpers/basefilehelper/index.md#method-copyDirectory) static | Copies a whole directory as another one. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-createDirectory"></span>[`createDirectory()`](/docs/api/yii/helpers/basefilehelper/index.md#method-createDirectory) static | Creates a new directory. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-filterPath"></span>[`filterPath()`](/docs/api/yii/helpers/basefilehelper/index.md#method-filterPath) static | Checks if the given file path satisfies the filtering options. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-findDirectories"></span>[`findDirectories()`](/docs/api/yii/helpers/basefilehelper/index.md#method-findDirectories) static | Returns the directories found under the specified directory and subdirectories. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-findFiles"></span>[`findFiles()`](/docs/api/yii/helpers/basefilehelper/index.md#method-findFiles) static | Returns the files found under the specified directory and subdirectories. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-getExtensionByMimeType"></span>[`getExtensionByMimeType()`](/docs/api/yii/helpers/basefilehelper/index.md#method-getExtensionByMimeType) static | Determines the most common extension by given MIME type. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-getExtensionsByMimeType"></span>[`getExtensionsByMimeType()`](/docs/api/yii/helpers/basefilehelper/index.md#method-getExtensionsByMimeType) static | Determines the extensions by given MIME type. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-getMimeType"></span>[`getMimeType()`](/docs/api/yii/helpers/basefilehelper/index.md#method-getMimeType) static | Determines the MIME type of the specified file. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-getMimeTypeByExtension"></span>[`getMimeTypeByExtension()`](/docs/api/yii/helpers/basefilehelper/index.md#method-getMimeTypeByExtension) static | Determines the MIME type based on the extension name of the specified file. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-localize"></span>[`localize()`](/docs/api/yii/helpers/basefilehelper/index.md#method-localize) static | Returns the localized version of a specified file. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-normalizePath"></span>[`normalizePath()`](/docs/api/yii/helpers/basefilehelper/index.md#method-normalizePath) static | Normalizes a file/directory path. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-removeDirectory"></span>[`removeDirectory()`](/docs/api/yii/helpers/basefilehelper/index.md#method-removeDirectory) static | Removes a directory (and all its content) recursively. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-unlink"></span>[`unlink()`](/docs/api/yii/helpers/basefilehelper/index.md#method-unlink) static | Removes a file or symlink in a cross-platform way | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-loadMimeAliases"></span>[`loadMimeAliases()`](/docs/api/yii/helpers/basefilehelper/index.md#method-loadMimeAliases) protected static | Loads MIME aliases from the specified file. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-loadMimeExtensions"></span>[`loadMimeExtensions()`](/docs/api/yii/helpers/basefilehelper/index.md#method-loadMimeExtensions) protected static | Loads MIME extensions from the specified file. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-loadMimeTypes"></span>[`loadMimeTypes()`](/docs/api/yii/helpers/basefilehelper/index.md#method-loadMimeTypes) protected static | Loads MIME types from the specified file. | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="method-normalizeOptions"></span>[`normalizeOptions()`](/docs/api/yii/helpers/basefilehelper/index.md#method-normalizeOptions) protected static |  | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |

## Constants

| Constant | Value | Description | Defined by |
| --- | --- | --- | --- |
| <span id="const-PATTERN_NODIR"></span>[`PATTERN_NODIR`](/docs/api/yii/helpers/basefilehelper/index.md#const-PATTERN_NODIR) | `1` |  | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="const-PATTERN_ENDSWITH"></span>[`PATTERN_ENDSWITH`](/docs/api/yii/helpers/basefilehelper/index.md#const-PATTERN_ENDSWITH) | `4` |  | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="const-PATTERN_MUSTBEDIR"></span>[`PATTERN_MUSTBEDIR`](/docs/api/yii/helpers/basefilehelper/index.md#const-PATTERN_MUSTBEDIR) | `8` |  | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="const-PATTERN_NEGATIVE"></span>[`PATTERN_NEGATIVE`](/docs/api/yii/helpers/basefilehelper/index.md#const-PATTERN_NEGATIVE) | `16` |  | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |
| <span id="const-PATTERN_CASE_INSENSITIVE"></span>[`PATTERN_CASE_INSENSITIVE`](/docs/api/yii/helpers/basefilehelper/index.md#const-PATTERN_CASE_INSENSITIVE) | `32` |  | [`BaseFileHelper`](/docs/api/yii/helpers/basefilehelper/index.md) |