The **Environment** module provides APIs for obtaining the root directories of the storage and public files.
> **NOTE**
>
> - The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
> - The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.
> - The APIs of this module are system APIs and cannot be called by third-party applications.
> - The APIs of this module support processing of error codes. For details, see [File Management Error Codes](../errorcodes/errorcode-filemanagement.md).
## Modules to Import
```js
importenvironmentfrom'@ohos.environment';
importenvironmentfrom'@ohos.file.environment';
```
## environment.getStorageDataDir
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@@ -30,10 +31,10 @@ Obtains the root directory of the storage. This API uses a promise to return the
The **fileHash** module implements hash processing on files.
> **NOTE**
>
> - The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.
> - The APIs of this module support processing of error codes. For details, see [File Management Error Codes](../errorcodes/errorcode-filemanagement.md).
## Modules to Import
```js
importHashfrom'@ohos.file.hash';
```
## Guidelines
Before using the APIs provided by this module to perform operations on a file or directory, obtain the path of the file or directory in the application sandbox as follows:
| path | string | Yes | Path of the file in the application sandbox. |
| algorithm | string | Yes | Algorithm used to calculate the hash value. The value can be **md5**, **sha1**, or **sha256**. **sha256** is recommended for security purposes.|
| path | string | Yes | Path of the file in the application sandbox. |
| algorithm | string | Yes | Algorithm used to calculate the hash value. The value can be **md5**, **sha1**, or **sha256**. **sha256** is recommended for security purposes.|
| callback | AsyncCallback<string> | Yes | Callback used to return the hash value obtained. The hash value is a hexadecimal string consisting of digits and uppercase letters.|
The **securityLabel** module provides APIs for managing data security levels of files, including obtaining and setting file security levels.
> **NOTE**
>
> - The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.
>- The APIs of this module support processing of error codes. For details, see [File Management Error Codes](../errorcodes/errorcode-filemanagement.md).
Before using the APIs provided by this module to perform operations on files or directories, obtain the path of the file or directory in the application sandbox as follows:
# @ohos.file.statvfs (File System Space Statistics)
The **statfs** module provides APIs for obtaining file system information, including the total number of bytes and the number of idle bytes of the file system.
> **NOTE**
>
> - The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.
> - The APIs of this module support processing of error codes. For details, see [File Management Error Codes](../errorcodes/errorcode-filemanagement.md).
## Modules to Import
```js
importstatvfsfrom'@ohos.file.statvfs';
```
## statvfs.getFreeSize
getFreeSize(path:string):Promise<number>
Obtains the number of free bytes of the specified file system in asynchronous mode. This API uses a promise to return the result.
The statfs module provides APIs for obtaining file system information, including the total number of bytes and the number of idle bytes of the file system.
The **statfs** module provides APIs for obtaining file system information, including the total number of bytes and the number of idle bytes of the file system.
> **NOTE**<br>
> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
> **NOTE**
>
> - The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
>
> - The APIs provided by this module are deprecated since API version 9. You are advised to use [@ohos.file.statvfs](js-apis-file-statvfs.md).
## Modules to Import
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@@ -20,15 +23,15 @@ Obtains the number of free bytes of the specified file system in asynchronous mo
The error codes of the file management subsystem consist of the following:
- Basic file I/O error codes
- User data management error codes
- User file access error codes
- Spatial statistics error codes
The error codes of the file management subsystem consist of the following:<br>- Basic file I/O error codes<br>- User data management error codes<br>- User file access error codes<br>- Spatial statistics error codes
## Basic File I/O Error Codes
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@@ -719,3 +714,41 @@ Fail to notify agent
**Solution**
Check whether the client is normal.
## Error Code Adaptation
The APIs provided by the file management subsystem support exception handling.
Sample code for exception handling in a synchronous API: