# @ohos.fileio (File Management)
The **fileio** module provides APIs for file storage and management, including basic file management, directory management, file information statistics, and stream read and write.
> **NOTE**
> - The initial APIs of this module are supported since API version 6. 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.fs](js-apis-file-fs.md).
## Modules to Import
```ts
import fileio from '@ohos.fileio';
```
## Guidelines
Before using the APIs provided by this module to perform operations on a file or directory, obtain the application sandbox path of the file or directory as follows:
```ts
import UIAbility from '@ohos.app.ability.UIAbility';
import window from '@ohos.window';
export default class EntryAbility extends UIAbility {
onWindowStageCreate(windowStage: window.WindowStage) {
let context = this.context;
let pathDir = context.filesDir;
}
}
```
For details about how to obtain the application sandbox path, see [Obtaining Application File Paths](../../application-models/application-context-stage.md#obtaining-application-file-paths).
## fileio.stat
stat(path: string): Promise<Stat>
Obtains file information. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.stat](js-apis-file-fs.md#stat) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | -------------------------- |
| path | string | Yes | Application sandbox path of the file.|
**Return value**
| Type | Description |
| ---------------------------- | ---------- |
| Promise<[Stat](#stat)> | Promise used to return the file information obtained.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "test.txt";
fileio.stat(filePath).then((stat: fileio.Stat) => {
console.info("getFileInfo succeed, the size of file is " + stat.size);
}).catch((err: BusinessError) => {
console.info("getFileInfo failed with error:" + err);
});
```
## fileio.stat
stat(path: string, callback: AsyncCallback<Stat>): void
Obtains file information. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.stat](js-apis-file-fs.md#fsstat-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ---------------------------------- | ---- | ------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| callback | AsyncCallback<[Stat](#stat)> | Yes | Callback invoked to return the file information obtained.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
fileio.stat(pathDir, (err: BusinessError, stat: fileio.Stat) => {
// Example code in Stat
});
```
## fileio.statSync
statSync(path: string): Stat
Obtains file information. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.statSync](js-apis-file-fs.md#fsstatsync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | -------------------------- |
| path | string | Yes | Application sandbox path of the file.|
**Return value**
| Type | Description |
| ------------- | ---------- |
| [Stat](#stat) | File information obtained.|
**Example**
```ts
let stat = fileio.statSync(pathDir);
// Example code in Stat
```
## fileio.opendir
opendir(path: string): Promise<Dir>
Opens a directory. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.listFile](js-apis-file-fs.md#fslistfile) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------------------ |
| path | string | Yes | Application sandbox path of the directory to open.|
**Return value**
| Type | Description |
| -------------------------- | -------- |
| Promise<[Dir](#dir)> | Promise used to return the **Dir** object opened.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let dirPath = pathDir + "/testDir";
fileio.opendir(dirPath).then((dir: fileio.Dir) => {
console.info("opendir succeed");
}).catch((err: BusinessError) => {
console.info("opendir failed with error:" + err);
});
```
## fileio.opendir
opendir(path: string, callback: AsyncCallback<Dir>): void
Opens a file directory. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.listFile](js-apis-file-fs.md#fslistfile-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | -------------------------------- | ---- | ------------------------------ |
| path | string | Yes | Application sandbox path of the directory to open.|
| callback | AsyncCallback<[Dir](#dir)> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
fileio.opendir(pathDir, (err: BusinessError, dir: fileio.Dir) => {
// Example code in Dir struct
// Use read/readSync/close.
});
```
## fileio.opendirSync
opendirSync(path: string): Dir
Opens a directory. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.listFileSync](js-apis-file-fs.md#fslistfilesync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------------------ |
| path | string | Yes | Application sandbox path of the directory to open.|
**Return value**
| Type | Description |
| ----------- | -------- |
| [Dir](#dir) | A **Dir** instance corresponding to the directory.|
**Example**
```ts
let dir = fileio.opendirSync(pathDir);
// Example code in Dir struct
// Use read/readSync/close.
```
## fileio.access
access(path: string, mode?: number): Promise<void>
Checks whether this process can access a file. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.access](js-apis-file-fs.md#fsaccess) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| mode | number | No | Options for accessing the file. You can specify multiple options, separated with a bitwise OR operator (|). The default value is **0**.<br>The options are as follows:<br>- **0**: Check whether the file exists.<br>- **1**: Check whether the process has the execute permission on the file.<br>- **2**: Check whether the process has the write permission on the file.<br>- **4**: Check whether the process has the read permission on the file.|
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
fileio.access(filePath).then(() => {
console.info("Access successful");
}).catch((err: BusinessError) => {
console.info("access failed with error:" + err);
});
```
## fileio.access
access(path: string, mode?: number, callback: AsyncCallback<void>): void
Checks whether this process can access a file. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.access](js-apis-file-fs.md#fsaccess-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| mode | number | No | Options for accessing the file. You can specify multiple options, separated with a bitwise OR operator (|). The default value is **0**.<br>The options are as follows:<br>- **0**: Check whether the file exists.<br>- **1**: Check whether the process has the execute permission on the file.<br>- **2**: Check whether the process has the write permission on the file.<br>- **4**: Check whether the process has the read permission on the file.|
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
fileio.access(filePath, (err: BusinessError) => {
// Do something.
});
```
## fileio.accessSync
accessSync(path: string, mode?: number): void
Checks whether this process can access a file. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.accessSync](js-apis-file-fs.md#fsaccesssync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| mode | number | No | Options for accessing the file. You can specify multiple options, separated with a bitwise OR operator (|). The default value is **0**.<br>The options are as follows:<br>- **0**: Check whether the file exists.<br>- **1**: Check whether the process has the execute permission on the file.<br>- **2**: Check whether the process has the write permission on the file.<br>- **4**: Check whether the process has the read permission on the file.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
try {
fileio.accessSync(filePath);
} catch(eror) {
let err: BusinessError = error as BusinessError;
console.info("accessSync failed with error:" + err);
}
```
## fileio.close<sup>7+</sup>
close(fd: number): Promise<void>
Closes a file. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.close](js-apis-file-fs.md#fsclose) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ------------ |
| fd | number | Yes | File descriptor (FD) of the file to close.|
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
fileio.close(fd).then(() => {
console.info("File closed");
}).catch((err: BusinessError) => {
console.info("close file failed with error:" + err);
});
```
## fileio.close<sup>7+</sup>
close(fd: number, callback: AsyncCallback<void>): void
Closes a file. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.close](js-apis-file-fs.md#fsclose-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | ------------------------- | ---- | ------------ |
| fd | number | Yes | FD of the file to close.|
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
fileio.close(fd, (err: BusinessError) => {
// Do something.
});
```
## fileio.closeSync
closeSync(fd: number): void
Closes a file. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.closeSync](js-apis-file-fs.md#fsclosesync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ------------ |
| fd | number | Yes | FD of the file to close.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
fileio.closeSync(fd);
```
## fileio.copyFile
copyFile(src: string|number, dest: string|number, mode?: number): Promise<void>
Copies a file. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.copyFile](js-apis-file-fs.md#fscopyfile) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | -------------------------- | ---- | ---------------------------------------- |
| src | string\|number | Yes | Path or FD of the file to copy. |
| dest | string\|number | Yes | Path or FD of the new file. |
| mode | number | No | Whether to overwrite the file with the same name in the destination directory. The default value is **0**, which is the only value supported.<br>**0**: overwrite the file with the same name and truncate the part that is not overwritten.|
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let srcPath = pathDir + "srcDir/test.txt";
let dstPath = pathDir + "dstDir/test.txt";
fileio.copyFile(srcPath, dstPath).then(() => {
console.info("File copied");
}).catch((err: BusinessError) => {
console.info("copyFile failed with error:" + err);
});
```
## fileio.copyFile
copyFile(src: string|number, dest: string|number, mode: number, callback: AsyncCallback<void>): void
Copies a file. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.copyFile](js-apis-file-fs.md#fscopyfile-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | -------------------------- | ---- | ---------------------------------------- |
| src | string\|number | Yes | Path or FD of the file to copy. |
| dest | string\|number | Yes | Path or FD of the new file. |
| mode | number | No | Whether to overwrite the file with the same name in the destination directory. The default value is **0**, which is the only value supported.<br>**0**: overwrite the file with the same name and truncate the part that is not overwritten.|
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let srcPath = pathDir + "srcDir/test.txt";
let dstPath = pathDir + "dstDir/test.txt";
fileio.copyFile(srcPath, dstPath, (err: BusinessError) => {
// Do something.
});
```
## fileio.copyFileSync
copyFileSync(src: string|number, dest: string|number, mode?: number): void
Copies a file. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.copyFileSync](js-apis-file-fs.md#fscopyfilesync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | -------------------------- | ---- | ---------------------------------------- |
| src | string\|number | Yes | Path or FD of the file to copy. |
| dest | string\|number | Yes | Path or FD of the new file. |
| mode | number | No | Whether to overwrite the file with the same name in the destination directory. The default value is **0**, which is the only value supported.<br>**0**: overwrite the file with the same name and truncate the part that is not overwritten.|
**Example**
```ts
let srcPath = pathDir + "srcDir/test.txt";
let dstPath = pathDir + "dstDir/test.txt";
fileio.copyFileSync(srcPath, dstPath);
```
## fileio.mkdir
mkdir(path: string, mode?: number): Promise<void>
Creates a directory. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.mkdir](js-apis-file-fs.md#fsmkdir) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the directory. |
| mode | number | No | Permission on the directory to create. You can specify multiple permissions, separated using a bitwise OR operator (|). The default value is **0o775**.<br>- **0o775**: The owner has the read, write, and execute permissions, and other users have the read and execute permissions.<br>- **0o700**: The owner has the read, write, and execute permissions.<br>- **0o400**: The owner has the read permission.<br>- **0o200**: The owner has the write permission.<br>- **0o100**: The owner has the execute permission.<br>- **0o070**: The user group has the read, write, and execute permissions.<br>- **0o040**: The user group has the read permission.<br>- **0o020**: The user group has the write permission.<br>- **0o010**: The user group has the execute permission.<br>- **0o007**: Other users have the read, write, and execute permissions.<br>- **0o004**: Other users have the read permission.<br>- **0o002**: Other users have the write permission.<br>- **0o001**: Other users have the execute permission.|
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let dirPath = pathDir + '/testDir';
fileio.mkdir(dirPath).then(() => {
console.info("Directory created");
}).catch((error: BusinessError) => {
console.info("mkdir failed with error:" + error);
});
```
## fileio.mkdir
mkdir(path: string, mode: number, callback: AsyncCallback<void>): void
Creates a directory. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.mkdir](js-apis-file-fs.md#fsmkdir-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the directory. |
| mode | number | No | Permission on the directory to create. You can specify multiple permissions, separated using a bitwise OR operator (|). The default value is **0o775**.<br>- **0o775**: The owner has the read, write, and execute permissions, and other users have the read and execute permissions.<br>- **0o700**: The owner has the read, write, and execute permissions.<br>- **0o400**: The owner has the read permission.<br>- **0o200**: The owner has the write permission.<br>- **0o100**: The owner has the execute permission.<br>- **0o070**: The user group has the read, write, and execute permissions.<br>- **0o040**: The user group has the read permission.<br>- **0o020**: The user group has the write permission.<br>- **0o010**: The user group has the execute permission.<br>- **0o007**: Other users have the read, write, and execute permissions.<br>- **0o004**: Other users have the read permission.<br>- **0o002**: Other users have the write permission.<br>- **0o001**: Other users have the execute permission.|
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let dirPath = pathDir + '/testDir';
fileio.mkdir(dirPath, (err: BusinessError) => {
console.info("Directory created");
});
```
## fileio.mkdirSync
mkdirSync(path: string, mode?: number): void
Creates a directory. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.mkdirSync](js-apis-file-fs.md#fsmkdirsync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the directory. |
| mode | number | No | Permission on the directory to create. You can specify multiple permissions, separated using a bitwise OR operator (|). The default value is **0o775**.<br>- **0o775**: The owner has the read, write, and execute permissions, and other users have the read and execute permissions.<br>- **0o700**: The owner has the read, write, and execute permissions.<br>- **0o400**: The owner has the read permission.<br>- **0o200**: The owner has the write permission.<br>- **0o100**: The owner has the execute permission.<br>- **0o070**: The user group has the read, write, and execute permissions.<br>- **0o040**: The user group has the read permission.<br>- **0o020**: The user group has the write permission.<br>- **0o010**: The user group has the execute permission.<br>- **0o007**: Other users have the read, write, and execute permissions.<br>- **0o004**: Other users have the read permission.<br>- **0o002**: Other users have the write permission.<br>- **0o001**: Other users have the execute permission.|
**Example**
```ts
let dirPath = pathDir + '/testDir';
fileio.mkdirSync(dirPath);
```
## fileio.open<sup>7+</sup>
open(path: string, flags?: number, mode?: number): Promise<number>
Opens a file. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.open](js-apis-file-fs.md#fsopen) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| flags | number | No | Option for opening the file. You must specify one of the following options. By default, the file is open in read-only mode.<br>- **0o0**: Open the file in read-only mode.<br>- **0o1**: Open the file in write-only mode.<br>- **0o2**: Open the file in read/write mode.<br>In addition, you can specify the following options, separated using a bitwise OR operator (|). By default, no additional option is specified.<br>- **0o100**: If the file does not exist, create it. If you use this option, you must also specify **mode**.<br>- **0o200**: If **0o100** is added and the file already exists, throw an exception.<br>- **0o1000**: If the file exists and is open in write-only or read/write mode, truncate the file length to 0.<br>- **0o2000**: Open the file in append mode. New data will be appended to the file (added to the end of the file).<br>- **0o4000**: If **path** points to a named pipe (also known as a FIFO), block special file, or character special file, perform non-blocking operations on the open file and in subsequent I/Os.<br>- **0o200000**: If **path** does not point to a directory, throw an exception.<br><br/>- **0o400000**: If **path** points to a symbolic link, throw an exception.<br>- **0o4010000**: Open the file in synchronous I/O mode.|
| mode | number | No | Permissions on the file. You can specify multiple permissions, separated using a bitwise OR operator (|). The default value is **0o660**.<br>- **0o660**: The owner and user group have the read and write permissions.<br>- **0o700**: The owner has the read, write, and execute permissions.<br>- **0o400**: The owner has the read permission.<br>- **0o200**: The owner has the write permission.<br>- **0o100**: The owner has the execute permission.<br>- **0o070**: The user group has the read, write, and execute permissions.<br>- **0o040**: The user group has the read permission.<br>- **0o020**: The user group has the write permission.<br>- **0o010**: The user group has the execute permission.<br>- **0o007**: Other users have the read, write, and execute permissions.<br>- **0o004**: Other users have the read permission.<br>- **0o002**: Other users have the write permission.<br>- **0o001**: Other users have the execute permission.|
**Return value**
| Type | Description |
| --------------------- | ----------- |
| Promise<number> | Promise used to return the FD of the opened file.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
fileio.open(filePath, 0o1, 0o0200).then((number: number) => {
console.info("File opened");
}).catch((err: BusinessError) => {
console.info("open file failed with error:" + err);
});
```
## fileio.open<sup>7+</sup>
open(path: string, flags: number, mode: number, callback: AsyncCallback<number>): void
Opens a file. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.open](js-apis-file-fs.md#fsopen-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------------- | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| flags | number | No | Option for opening the file. You must specify one of the following options. By default, the file is open in read-only mode.<br>- **0o0**: Open the file in read-only mode.<br>- **0o1**: Open the file in write-only mode.<br>- **0o2**: Open the file in read/write mode.<br>In addition, you can specify the following options, separated using a bitwise OR operator (|). By default, no additional option is specified.<br>- **0o100**: If the file does not exist, create it. If you use this option, you must also specify **mode**.<br>- **0o200**: If **0o100** is added and the file already exists, throw an exception.<br>- **0o1000**: If the file exists and is open in write-only or read/write mode, truncate the file length to 0.<br>- **0o2000**: Open the file in append mode. New data will be appended to the file (added to the end of the file).<br>- **0o4000**: If **path** points to a named pipe (also known as a FIFO), block special file, or character special file, perform non-blocking operations on the open file and in subsequent I/Os.<br>- **0o200000**: If **path** does not point to a directory, throw an exception.<br><br/>- **0o400000**: If **path** points to a symbolic link, throw an exception.<br>- **0o4010000**: Open the file in synchronous I/O mode.|
| mode | number | No | Permissions on the file. You can specify multiple permissions, separated using a bitwise OR operator (|). The default value is **0o660**.<br>- **0o660**: The owner and user group have the read and write permissions.<br>- **0o700**: The owner has the read, write, and execute permissions.<br>- **0o400**: The owner has the read permission.<br>- **0o200**: The owner has the write permission.<br>- **0o100**: The owner has the execute permission.<br>- **0o070**: The user group has the read, write, and execute permissions.<br>- **0o040**: The user group has the read permission.<br>- **0o020**: The user group has the write permission.<br>- **0o010**: The user group has the execute permission.<br>- **0o007**: Other users have the read, write, and execute permissions.<br>- **0o004**: Other users have the read permission.<br>- **0o002**: Other users have the write permission.<br>- **0o001**: Other users have the execute permission.|
| callback | AsyncCallback<number> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
fileio.open(filePath, 0, (err: BusinessError, fd: number) => {
// Do something.
});
```
## fileio.openSync
openSync(path: string, flags?: number, mode?: number): number
Opens a file. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.openSync](js-apis-file-fs.md#fsopensync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| flags | number | No | Option for opening the file. You must specify one of the following options. By default, the file is open in read-only mode.<br>- **0o0**: Open the file in read-only mode.<br>- **0o1**: Open the file in write-only mode.<br>- **0o2**: Open the file in read/write mode.<br>In addition, you can specify the following options, separated using a bitwise OR operator (|). By default, no additional option is specified.<br>- **0o100**: If the file does not exist, create it. If you use this option, you must also specify **mode**.<br>- **0o200**: If **0o100** is added and the file already exists, throw an exception.<br>- **0o1000**: If the file exists and is open in write-only or read/write mode, truncate the file length to 0.<br>- **0o2000**: Open the file in append mode. New data will be appended to the file (added to the end of the file).<br>- **0o4000**: If **path** points to a named pipe (also known as a FIFO), block special file, or character special file, perform non-blocking operations on the open file and in subsequent I/Os.<br>- **0o200000**: If **path** does not point to a directory, throw an exception.<br><br/>- **0o400000**: If **path** points to a symbolic link, throw an exception.<br>- **0o4010000**: Open the file in synchronous I/O mode.|
| mode | number | No | Permissions on the file. You can specify multiple permissions, separated using a bitwise OR operator (|). The default value is **0o660**.<br>- **0o660**: The owner and user group have the read and write permissions.<br>- **0o640**: The owner has the read and write permissions, and the user group has the read permission.<br>- **0o700**: The owner has the read, write, and execute permissions.<br>- **0o400**: The owner has the read permission.<br>- **0o200**: The owner has the write permission.<br>- **0o100**: The owner has the execute permission.<br>- **0o070**: The user group has the read, write, and execute permissions.<br>- **0o040**: The user group has the read permission.<br>- **0o020**: The user group has the write permission.<br>- **0o010**: The user group has the execute permission.<br>- **0o007**: Other users have the read, write, and execute permissions.<br>- **0o004**: Other users have the read permission.<br>- **0o002**: Other users have the write permission.<br>- **0o001**: Other users have the execute permission.<br>The file permissions on newly created files are affected by umask, which is set as the process starts. Currently, the modification of umask is not open.|
**Return value**
| Type | Description |
| ------ | ----------- |
| number | FD of the file opened.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath, 0o102, 0o640);
```
```ts
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath, 0o102, 0o666);
fileio.writeSync(fd, 'hello world');
let fd1 = fileio.openSync(filePath, 0o2002);
fileio.writeSync(fd1, 'hello world');
class Option {
offset: number = 0;
length: number = 4096;
position: number = 0;
}
let option = new Option();
option.position = 0;
let buf = new ArrayBuffer(4096)
let num = fileio.readSync(fd1, buf, option);
console.info("num == " + num);
```
## fileio.read
read(fd: number, buffer: ArrayBuffer, options?: { offset?: number; length?: number; position?: number; }): Promise<ReadOut>
Reads data from a file. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.read](js-apis-file-fs.md#fsread) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| ------- | ----------- | ---- | ------------------------------------------------------------ |
| fd | number | Yes | FD of the file to read. |
| buffer | ArrayBuffer | Yes | Buffer used to store the file data read. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. This parameter is optional. The default value is **0**.<br>- **length** (number): length of the data to read. This parameter is optional. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. This parameter is optional. By default, data is read from the current position.<br>Constraints: offset + length <= Buffer size|
**Return value**
| Type | Description |
| ---------------------------------- | ------ |
| Promise<[ReadOut](#readout)> | Promise used to return the data read.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
import buffer from '@ohos.buffer';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath, 0o102, 0o640);
let arrayBuffer = new ArrayBuffer(4096);
fileio.read(fd, arrayBuffer).then((readResult: fileio.ReadOut) => {
console.info("Read file data successfully");
let buf = buffer.from(arrayBuffer, 0, readResult.bytesRead);
console.log(`The content of file: ${buf.toString()}`);
fileio.closeSync(fd);
}).catch((err: BusinessError) => {
console.info("read file data failed with error:" + err);
});
```
## fileio.read
read(fd: number, buffer: ArrayBuffer, options: { offset?: number; length?: number; position?: number; }, callback: AsyncCallback<ReadOut>): void
Reads data from a file. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.read](js-apis-file-fs.md#fsread-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | ---------------------------------------- | ---- | ---------------------------------------- |
| fd | number | Yes | FD of the file to read. |
| buffer | ArrayBuffer | Yes | Buffer used to store the file data read. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. This parameter is optional. The default value is **0**.<br>- **length** (number): length of the data to read. This parameter is optional. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. This parameter is optional. By default, data is read from the current position.<br>Constraints: offset + length <= Buffer size |
| callback | AsyncCallback<[ReadOut](#readout)> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
import buffer from '@ohos.buffer';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath, 0o102, 0o640);
let arrayBuffer = new ArrayBuffer(4096);
fileio.read(fd, arrayBuffer, (err: BusinessError, readResult: fileio.ReadOut) => {
if (readResult) {
console.info("Read file data successfully");
let buf = buffer.from(arrayBuffer, 0, readResult.bytesRead);
console.info(`The content of file: ${buf.toString()}`);
}
fileio.closeSync(fd);
});
```
## fileio.readSync
readSync(fd: number, buffer: ArrayBuffer, options?: { offset?: number; length?: number; position?: number; }): number
Reads data from a file. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.readSync](js-apis-file-fs.md#fsreadsync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ------- | ----------- | ---- | ---------------------------------------- |
| fd | number | Yes | FD of the file to read. |
| buffer | ArrayBuffer | Yes | Buffer used to store the file data read. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. This parameter is optional. The default value is **0**.<br>- **length** (number): length of the data to read. This parameter is optional. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. This parameter is optional. By default, data is read from the current position.<br>Constraints: offset + length <= Buffer size |
**Return value**
| Type | Description |
| ------ | -------- |
| number | Length of the data read.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath, 0o2);
let buf = new ArrayBuffer(4096);
let num = fileio.readSync(fd, buf);
```
## fileio.rmdir<sup>7+</sup>
rmdir(path: string): Promise<void>
Deletes a directory. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.rmdir](js-apis-file-fs.md#fsrmdir) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | -------------------------- |
| path | string | Yes | Application sandbox path of the directory.|
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let dirPath = pathDir + '/testDir';
fileio.rmdir(dirPath).then(() => {
console.info("Directory deleted");
}).catch((err: BusinessError) => {
console.info("rmdir failed with error:" + err);
});
```
## fileio.rmdir<sup>7+</sup>
rmdir(path: string, callback: AsyncCallback<void>): void
Deletes a directory. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.rmdir](js-apis-file-fs.md#fsrmdir-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | -------------------------- |
| path | string | Yes | Application sandbox path of the directory.|
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let dirPath = pathDir + '/testDir';
fileio.rmdir(dirPath, (err: BusinessError) => {
// Do something.
console.info("Directory deleted");
});
```
## fileio.rmdirSync<sup>7+</sup>
rmdirSync(path: string): void
Deletes a directory. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.rmdirSync](js-apis-file-fs.md#fsrmdirsync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | -------------------------- |
| path | string | Yes | Application sandbox path of the directory.|
**Example**
```ts
let dirPath = pathDir + '/testDir';
fileio.rmdirSync(dirPath);
```
## fileio.unlink
unlink(path: string): Promise<void>
Deletes a file. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.unlink](js-apis-file-fs.md#fsunlink) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | -------------------------- |
| path | string | Yes | Application sandbox path of the file.|
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
fileio.unlink(filePath).then(() => {
console.info("File deleted");
}).catch((error: BusinessError) => {
console.info("remove file failed with error:" + error);
});
```
## fileio.unlink
unlink(path: string, callback: AsyncCallback<void>): void
Deletes a file. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.unlink](js-apis-file-fs.md#fsunlink-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | -------------------------- |
| path | string | Yes | Application sandbox path of the file.|
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
fileio.unlink(filePath, (err: BusinessError) => {
console.info("File deleted");
});
```
## fileio.unlinkSync
unlinkSync(path: string): void
Deletes a file. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.unlinkSync](js-apis-file-fs.md#fsunlinksync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | -------------------------- |
| path | string | Yes | Application sandbox path of the file.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
fileio.unlinkSync(filePath);
```
## fileio.write
write(fd: number, buffer: ArrayBuffer|string, options?: { offset?: number; length?: number; position?: number; encoding?: string; }): Promise<number>
Writes data into a file. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.write](js-apis-file-fs.md#fswrite) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ------- | ------------------------------- | ---- | ---------------------------------------- |
| fd | number | Yes | FD of the file to write. |
| buffer | ArrayBuffer\|string | Yes | Data to write. It can be a string or data from a buffer. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. This parameter is optional. The default value is **0**.<br>- **length** (number): length of the data to write. This parameter is optional. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. This parameter is optional. By default, data is written from the current position.<br>- **encoding** (string): format of the data to be encoded when the data is a string. The default value is **'utf-8'**, which is the only value supported.<br>Constraints: offset + length <= Buffer size|
**Return value**
| Type | Description |
| --------------------- | -------- |
| Promise<number> | Promise used to return the length of the data written.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath, 0o100 | 0o2, 0o666);
fileio.write(fd, "hello, world").then((number: number) => {
console.info("write data to file succeed and size is:" + number);
}).catch((err: BusinessError) => {
console.info("write data to file failed with error:" + err);
});
```
## fileio.write
write(fd: number, buffer: ArrayBuffer|string, options: { offset?: number; length?: number; position?: number; encoding?: string; }, callback: AsyncCallback<number>): void
Writes data to a file. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.write](js-apis-file-fs.md#fswrite-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | ------------------------------- | ---- | ---------------------------------------- |
| fd | number | Yes | FD of the file to write. |
| buffer | ArrayBuffer\|string | Yes | Data to write. It can be a string or data from a buffer. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. This parameter is optional. The default value is **0**.<br>- **length** (number): length of the data to write. This parameter is optional. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. This parameter is optional. By default, data is written from the current position.<br>- **encoding** (string): format of the data to be encoded when the data is a string. The default value is **'utf-8'**, which is the only value supported.<br>Constraints: offset + length <= Buffer size|
| callback | AsyncCallback<number> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath, 0o100 | 0o2, 0o666);
fileio.write(fd, "hello, world", (err: BusinessError, bytesWritten: number) => {
if (bytesWritten) {
console.info("write data to file succeed and size is:" + bytesWritten);
}
});
```
## fileio.writeSync
writeSync(fd: number, buffer: ArrayBuffer|string, options?: { offset?: number; length?: number; position?: number; encoding?: string; }): number
Writes data to a file. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.writeSync](js-apis-file-fs.md#fswritesync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ------- | ------------------------------- | ---- | ---------------------------------------- |
| fd | number | Yes | FD of the file to write. |
| buffer | ArrayBuffer\|string | Yes | Data to write. It can be a string or data from a buffer. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. This parameter is optional. The default value is **0**.<br>- **length** (number): length of the data to write. This parameter is optional. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. This parameter is optional. By default, data is written from the current position.<br>- **encoding** (string): format of the data to be encoded when the data is a string. The default value is **'utf-8'**, which is the only value supported.<br>Constraints: offset + length <= Buffer size|
**Return value**
| Type | Description |
| ------ | -------- |
| number | Length of the data written in the file.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath, 0o100 | 0o2, 0o666);
let num = fileio.writeSync(fd, "hello, world");
```
## fileio.hash
hash(path: string, algorithm: string): Promise<string>
Calculates the hash value of a file. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [hash.write](js-apis-file-hash.md#hashhash) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| --------- | ------ | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| algorithm | string | Yes | Algorithm used to calculate the hash value. The value can be **md5**, **sha1**, or **sha256**. **sha256** is recommended for security purposes.|
**Return value**
| Type | Description |
| --------------------- | -------------------------- |
| Promise<string> | Promise used to return the hash value. The hash value is a hexadecimal string consisting of digits and uppercase letters.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
fileio.hash(filePath, "sha256").then((str: string) => {
console.info("calculate file hash succeed:" + str);
}).catch((err: BusinessError) => {
console.info("calculate file hash failed with error:" + err);
});
```
## fileio.hash
hash(path: string, algorithm: string, callback: AsyncCallback<string>): void
Calculates the hash value of a file. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [hash.write](js-apis-file-hash.md#hashhash-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| --------- | --------------------------- | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| 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.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
fileio.hash(filePath, "sha256", (err: BusinessError, hashStr: string) => {
if (hashStr) {
console.info("calculate file hash succeed:" + hashStr);
}
});
```
## fileio.chmod<sup>7+</sup>
chmod(path: string, mode: number): Promise<void>
Changes file permissions. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| mode | number | Yes | Permissions on the file. You can specify multiple permissions, separated using a bitwise OR operator (|).<br>- **0o700**: The owner has the read, write, and execute permissions.<br>- **0o400**: The owner has the read permission.<br>- **0o200**: The owner has the write permission.<br>- **0o100**: The owner has the execute permission.<br>- **0o070**: The user group has the read, write, and execute permissions.<br>- **0o040**: The user group has the read permission.<br>- **0o020**: The user group has the write permission.<br>- **0o010**: The user group has the execute permission.<br>- **0o007**: Other users have the read, write, and execute permissions.<br>- **0o004**: Other users have the read permission.<br>- **0o002**: Other users have the write permission.<br>- **0o001**: Other users have the execute permission.|
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
fileio.chmod(filePath, 0o700).then(() => {
console.info("File permissions changed");
}).catch((err: BusinessError) => {
console.info("chmod failed with error:" + err);
});
```
## fileio.chmod<sup>7+</sup>
chmod(path: string, mode: number, callback: AsyncCallback<void>): void
Changes file permissions. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| mode | number | Yes | Permissions on the file. You can specify multiple permissions, separated using a bitwise OR operator (|).<br>- **0o700**: The owner has the read, write, and execute permissions.<br>- **0o400**: The owner has the read permission.<br>- **0o200**: The owner has the write permission.<br>- **0o100**: The owner has the execute permission.<br>- **0o070**: The user group has the read, write, and execute permissions.<br>- **0o040**: The user group has the read permission.<br>- **0o020**: The user group has the write permission.<br>- **0o010**: The user group has the execute permission.<br>- **0o007**: Other users have the read, write, and execute permissions.<br>- **0o004**: Other users have the read permission.<br>- **0o002**: Other users have the write permission.<br>- **0o001**: Other users have the execute permission.|
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
fileio.chmod(filePath, 0o700, (err: BusinessError) => {
// Do something.
});
```
## fileio.chmodSync<sup>7+</sup>
chmodSync(path: string, mode: number): void
Changes file permissions. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| mode | number | Yes | Permissions on the file. You can specify multiple permissions, separated using a bitwise OR operator (|).<br>- **0o700**: The owner has the read, write, and execute permissions.<br>- **0o400**: The owner has the read permission.<br>- **0o200**: The owner has the write permission.<br>- **0o100**: The owner has the execute permission.<br>- **0o070**: The user group has the read, write, and execute permissions.<br>- **0o040**: The user group has the read permission.<br>- **0o020**: The user group has the write permission.<br>- **0o010**: The user group has the execute permission.<br>- **0o007**: Other users have the read, write, and execute permissions.<br>- **0o004**: Other users have the read permission.<br>- **0o002**: Other users have the write permission.<br>- **0o001**: Other users have the execute permission.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
fileio.chmodSync(filePath, 0o700);
```
## fileio.fstat<sup>7+</sup>
fstat(fd: number): Promise<Stat>
Obtains file information based on an FD. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.stat](js-apis-file-fs.md#fsstat) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ------------ |
| fd | number | Yes | FD of the target file.|
**Return value**
| Type | Description |
| ---------------------------- | ---------- |
| Promise<[Stat](#stat)> | Promise used to return the detailed file information obtained.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
fileio.fstat(fd).then((stat: fileio.Stat) => {
console.info("fstat succeed, the size of file is " + stat.size);
}).catch((err: BusinessError) => {
console.info("fstat failed with error:" + err);
});
```
## fileio.fstat<sup>7+</sup>
fstat(fd: number, callback: AsyncCallback<Stat>): void
Obtains file information based on an FD. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.stat](js-apis-file-fs.md#fsstat-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | ---------------------------------- | ---- | ---------------- |
| fd | number | Yes | FD of the target file. |
| callback | AsyncCallback<[Stat](#stat)> | Yes | Callback invoked to return the file information obtained.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
fileio.fstat(fd, (err: BusinessError) => {
// Do something.
});
```
## fileio.fstatSync<sup>7+</sup>
fstatSync(fd: number): Stat
Obtains file status information based on an FD. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.statSync](js-apis-file-fs.md#fsstatsync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ------------ |
| fd | number | Yes | FD of the target file.|
**Return value**
| Type | Description |
| ------------- | ---------- |
| [Stat](#stat) | Detailed file information obtained.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
let stat = fileio.fstatSync(fd);
```
## fileio.ftruncate<sup>7+</sup>
ftruncate(fd: number, len?: number): Promise<void>
Truncates a file based on an FD. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.truncate](js-apis-file-fs.md#fstruncate) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ---------------- |
| fd | number | Yes | FD of the file to truncate. |
| len | number | No | File length, in bytes, after truncation.|
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
fileio.ftruncate(fd, 5).then(() => {
console.info("File truncated");
}).catch((err: BusinessError) => {
console.info("truncate file failed with error:" + err);
});
```
## fileio.ftruncate<sup>7+</sup>
ftruncate(fd: number, len?: number, callback: AsyncCallback<void>): void
Truncates a file based on an FD. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.truncate](js-apis-file-fs.md#fstruncate-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | ------------------------- | ---- | ---------------- |
| fd | number | Yes | FD of the file to truncate. |
| len | number | No | File length, in bytes, after truncation.|
| callback | AsyncCallback<void> | Yes | Callback that returns no value. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
let len = 5;
fileio.ftruncate(fd, 5, (err: BusinessError) => {
// Do something.
});
```
## fileio.ftruncateSync<sup>7+</sup>
ftruncateSync(fd: number, len?: number): void
Truncates a file based on an FD. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.truncateSync](js-apis-file-fs.md#fstruncatesync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ---------------- |
| fd | number | Yes | FD of the file to truncate. |
| len | number | No | File length, in bytes, after truncation.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
let len = 5;
fileio.ftruncateSync(fd, len);
```
## fileio.truncate<sup>7+</sup>
truncate(path: string, len?: number): Promise<void>
Truncates a file based on a file path. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.truncate](js-apis-file-fs.md#fstruncate) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | -------------------------------- |
| path | string | Yes | Application sandbox path of the file to truncate. |
| len | number | No | File length, in bytes, after truncation.|
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let len = 5;
fileio.truncate(filePath, len).then(() => {
console.info("File truncated");
}).catch((err: BusinessError) => {
console.info("truncate file failed with error:" + err);
});
```
## fileio.truncate<sup>7+</sup>
truncate(path: string, len?: number, callback: AsyncCallback<void>): void
Truncates a file based on a file path. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.truncate](js-apis-file-fs.md#fstruncate-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | -------------------------------- |
| path | string | Yes | Application sandbox path of the file to truncate. |
| len | number | No | File length, in bytes, after truncation.|
| callback | AsyncCallback<void> | Yes | Callback that returns no value. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let len = 5;
fileio.truncate(filePath, len, (err: BusinessError) => {
// Do something.
});
```
## fileio.truncateSync<sup>7+</sup>
truncateSync(path: string, len?: number): void
Truncates a file based on a file path. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.truncateSync](js-apis-file-fs.md#fstruncatesync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | -------------------------------- |
| path | string | Yes | Application sandbox path of the file to truncate. |
| len | number | No | File length, in bytes, after truncation.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let len = 5;
fileio.truncateSync(filePath, len);
```
## fileio.readText<sup>7+</sup>
readText(filePath: string, options?: { position?: number; length?: number; encoding?: string; }): Promise<string>
Reads the text content of a file. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.readText](js-apis-file-fs.md#fsreadtext) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------ | ---- | ------------------------------------------------------------ |
| filePath | string | Yes | Application sandbox path of the file to read. |
| options | Object | No | The options are as follows:<br>- **position** (number): position of the data to read in the file. This parameter is optional. By default, data is read from the current position.<br>- **length** (number): length of the data to read. This parameter is optional. The default value is the buffer length minus the offset.<br>- **encoding** (string): format of the data to be encoded.<br>It is valid only when the data is of the string type.<br>The default value is **'utf-8'**, which is the only value supported.|
**Return value**
| Type | Description |
| --------------------- | ---------- |
| Promise<string> | Promise used to return the file content read.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
fileio.readText(filePath).then((str: string) => {
console.info("readText succeed:" + str);
}).catch((err: BusinessError) => {
console.info("readText failed with error:" + err);
});
```
## fileio.readText<sup>7+</sup>
readText(filePath: string, options: { position?: number; length?: number; encoding?: string; }, callback: AsyncCallback<string>): void
Reads the text content of a file. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.readText](js-apis-file-fs.md#fsreadtext-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | --------------------------- | ---- | ------------------------------------------------------------ |
| filePath | string | Yes | Application sandbox path of the file to read. |
| options | Object | No | The options are as follows:<br>- **position** (number): position of the data to read in the file. This parameter is optional. By default, data is read from the current position.<br>- **length** (number): length of the data to read. This parameter is optional. The default value is the buffer length minus the offset.<br>- **encoding**: format of the data to be encoded. The default value is **'utf-8'**, which is the only value supported.|
| callback | AsyncCallback<string> | Yes | Callback invoked to return the content read. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
class Option {
length: number = 4096;
position: number = 0;
encoding: string = 'utf-8';
}
let option = new Option();
option.position = 1;
option.encoding = 'utf-8';
fileio.readText(filePath, option, (err: BusinessError, str: string) => {
// Do something.
});
```
## fileio.readTextSync<sup>7+</sup>
readTextSync(filePath: string, options?: { position?: number; length?: number; encoding?: string; }): string
Reads the text of a file. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.readTextSync](js-apis-file-fs.md#fsreadtextsync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------ | ---- | ------------------------------------------------------------ |
| filePath | string | Yes | Application sandbox path of the file to read. |
| options | Object | No | The options are as follows:<br>- **position** (number): position of the data to read in the file. This parameter is optional. By default, data is read from the current position.<br>- **length** (number): length of the data to read. This parameter is optional. The default value is the buffer length minus the offset.<br>- **encoding** (string): format of the data to be encoded.<br>It is valid only when the data is of the string type.<br>The default value is **'utf-8'**, which is the only value supported.|
**Return value**
| Type | Description |
| ------ | -------------------- |
| string | File content read.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
class Option {
length: number = 4096;
position: number = 0;
encoding: string = 'utf-8';
}
let option = new Option();
option.position = 1;
option.length = 3;
let str = fileio.readTextSync(filePath, option);
```
## fileio.lstat<sup>7+</sup>
lstat(path: string): Promise<Stat>
Obtains information about a symbolic link that is used to refer to a file or directory. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.lstat](js-apis-file-fs.md#fslstat) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | -------------------------------------- |
| path | string | Yes | Application sandbox path of the target file.|
**Return value**
| Type | Description |
| ---------------------------- | ---------- |
| Promise<[Stat](#stat)> | Promise used to return the symbolic link information obtained. For details, see **stat**.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
fileio.lstat(filePath).then((stat: fileio.Stat) => {
console.info("get link status succeed, the size of file is" + stat.size);
}).catch((err: BusinessError) => {
console.info("get link status failed with error:" + err);
});
```
## fileio.lstat<sup>7+</sup>
lstat(path: string, callback: AsyncCallback<Stat>): void
Obtains information about a symbolic link that is used to refer to a file or directory. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.lstat](js-apis-file-fs.md#fslstat-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ---------------------------------- | ---- | -------------------------------------- |
| path | string | Yes | Application sandbox path of the target file.|
| callback | AsyncCallback<[Stat](#stat)> | Yes | Callback invoked to return the symbolic link information obtained. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
fileio.lstat(filePath, (err: BusinessError, stat: fileio.Stat) => {
// Do something.
});
```
## fileio.lstatSync<sup>7+</sup>
lstatSync(path: string): Stat
Obtains information about a symbolic link that is used to refer to a file or directory. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.lstatSync](js-apis-file-fs.md#fslstatsync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | -------------------------------------- |
| path | string | Yes | Application sandbox path of the target file.|
**Return value**
| Type | Description |
| ------------- | ---------- |
| [Stat](#stat) | File information obtained.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let stat = fileio.lstatSync(filePath);
```
## fileio.rename<sup>7+</sup>
rename(oldPath: string, newPath: string): Promise<void>
Renames a file. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.rename](js-apis-file-fs.md#fsrename) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| ------- | ------ | ---- | ---------------------------- |
| oldPath | string | Yes | Application sandbox path of the file to rename.|
| newPath | string | Yes | Application sandbox path of the file renamed. |
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let srcFile = pathDir + "/test.txt";
let dstFile = pathDir + '/new.txt';
fileio.rename(srcFile, dstFile).then(() => {
console.info("File renamed");
}).catch((err: BusinessError) => {
console.info("rename failed with error:" + err);
});
```
## fileio.rename<sup>7+</sup>
rename(oldPath: string, newPath: string, callback: AsyncCallback<void>): void
Renames a file. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.rename](js-apis-file-fs.md#fsrename-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | ---------------------------- |
| oldPath | string | Yes | Application sandbox path of the file to rename.|
| newPath | string | Yes | Application sandbox path of the file renamed. |
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let srcFile = pathDir + "/test.txt";
let dstFile = pathDir + '/new.txt';
fileio.rename(srcFile, dstFile, (err: BusinessError) => {
});
```
## fileio.renameSync<sup>7+</sup>
renameSync(oldPath: string, newPath: string): void
Renames a file. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.renameSync](js-apis-file-fs.md#fsrenamesync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| ------- | ------ | ---- | ---------------------------- |
| oldPath | string | Yes | Application sandbox path of the file to rename.|
| newPath | string | Yes | Application sandbox path of the file renamed. |
**Example**
```ts
let srcFile = pathDir + "/test.txt";
let dstFile = pathDir + '/new.txt';
fileio.renameSync(srcFile, dstFile);
```
## fileio.fsync<sup>7+</sup>
fsync(fd: number): Promise<void>
Synchronizes a file. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.fsync](js-apis-file-fs.md#fsfsync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ------------ |
| fd | number | Yes | FD of the file to synchronize.|
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
fileio.fsync(fd).then(() => {
console.info("Data flushed");
}).catch((err: BusinessError) => {
console.info("sync data failed with error:" + err);
});
```
## fileio.fsync<sup>7+</sup>
fsync(fd: number, callback: AsyncCallback<void>): void
Synchronizes a file. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.fsync](js-apis-file-fs.md#fsfsync-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | ------------------------- | ---- | --------------- |
| fd | number | Yes | FD of the file to synchronize. |
| Callback | AsyncCallback<void> | Yes | Callback invoked to return the result.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
fileio.fsync(fd, (err: BusinessError) => {
// Do something.
});
```
## fileio.fsyncSync<sup>7+</sup>
fsyncSync(fd: number): void
Synchronizes a file. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.fsyncSync](js-apis-file-fs.md#fsfsyncsync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ------------ |
| fd | number | Yes | FD of the file to synchronize.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
fileio.fsyncSync(fd);
```
## fileio.fdatasync<sup>7+</sup>
fdatasync(fd: number): Promise<void>
Synchronizes the data of a file. This API uses a promise to return the result. **fdatasync()** is similar to **fsync()**, but does not flush modified metadata unless that metadata is needed.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.fdatasync](js-apis-file-fs.md#fsfdatasync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ------------ |
| fd | number | Yes | FD of the file to synchronize.|
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
fileio.fdatasync(fd).then(() => {
console.info("Data flushed");
}).catch((err: BusinessError) => {
console.info("sync data failed with error:" + err);
});
```
## fileio.fdatasync<sup>7+</sup>
fdatasync(fd: number, callback: AsyncCallback<void>): void
Synchronizes the data of a file. This API uses an asynchronous callback to return the result. **fdatasync()** is similar to **fsync()**, but does not flush modified metadata unless that metadata is needed.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.fdatasync](js-apis-file-fs.md#fsfdatasync-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | ------------------------------- | ---- | ----------------- |
| fd | number | Yes | FD of the file to synchronize. |
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
fileio.fdatasync (fd, (err: BusinessError) => {
// Do something.
});
```
## fileio.fdatasyncSync<sup>7+</sup>
fdatasyncSync(fd: number): void
Synchronizes the data of a file. This API returns the result synchronously. **fdatasync()** is similar to **fsync()**, but does not flush modified metadata unless that metadata is needed.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.fdatasyncSync](js-apis-file-fs.md#fsfdatasyncsync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ------------ |
| fd | number | Yes | FD of the file to synchronize.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
let stat = fileio.fdatasyncSync(fd);
```
## fileio.symlink<sup>7+</sup>
symlink(target: string, srcPath: string): Promise<void>
Creates a symbolic link based on a file path. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.symlink](js-apis-file-fs.md#fssymlink) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| ------- | ------ | ---- | ---------------------------- |
| target | string | Yes | Application sandbox path of the target file. |
| srcPath | string | Yes | Application sandbox path of the symbolic link.|
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let srcFile = pathDir + "/test.txt";
let dstFile = pathDir + '/test';
fileio.symlink(srcFile, dstFile).then(() => {
console.info("Symbolic link created");
}).catch((err: BusinessError) => {
console.info("symlink failed with error:" + err);
});
```
## fileio.symlink<sup>7+</sup>
symlink(target: string, srcPath: string, callback: AsyncCallback<void>): void
Creates a symbolic link based on a file path. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.symlink](js-apis-file-fs.md#fssymlink-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | -------------------------------- |
| target | string | Yes | Application sandbox path of the target file. |
| srcPath | string | Yes | Application sandbox path of the symbolic link. |
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let srcFile = pathDir + "/test.txt";
let dstFile = pathDir + '/test';
fileio.symlink(srcFile, dstFile, (err: BusinessError) => {
// Do something.
});
```
## fileio.symlinkSync<sup>7+</sup>
symlinkSync(target: string, srcPath: string): void
Creates a symbolic link based on a file path. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.symlinkSync](js-apis-file-fs.md#fssymlinksync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| ------- | ------ | ---- | ---------------------------- |
| target | string | Yes | Application sandbox path of the target file. |
| srcPath | string | Yes | Application sandbox path of the symbolic link.|
**Example**
```ts
let srcFile = pathDir + "/test.txt";
let dstFile = pathDir + '/test';
fileio.symlinkSync(srcFile, dstFile);
```
## fileio.chown<sup>7+</sup>
chown(path: string, uid: number, gid: number): Promise<void>
Changes the file owner based on a file path. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | -------------------------- |
| path | string | Yes | Application sandbox path of the file.|
| uid | number | Yes | New user ID (UID). |
| gid | number | Yes | New group ID (GID). |
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let stat = fileio.statSync(filePath);
fileio.chown(filePath, stat.uid, stat.gid).then(() => {
console.info("File owner changed");
}).catch((err: BusinessError) => {
console.info("chown failed with error:" + err);
});
```
## fileio.chown<sup>7+</sup>
chown(path: string, uid: number, gid: number, callback: AsyncCallback<void>): void
Changes the file owner based on a file path. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | ------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| uid | number | Yes | New UID. |
| gid | number | Yes | New GID. |
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let stat = fileio.statSync(filePath)
fileio.chown(filePath, stat.uid, stat.gid, (err: BusinessError) => {
// Do something.
});
```
## fileio.chownSync<sup>7+</sup>
chownSync(path: string, uid: number, gid: number): void
Changes the file owner based on its path. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | -------------------------- |
| path | string | Yes | Application sandbox path of the file.|
| uid | number | Yes | New UID. |
| gid | number | Yes | New GID. |
**Example**
```ts
let filePath = pathDir + "/test.txt";
let stat = fileio.statSync(filePath)
fileio.chownSync(filePath, stat.uid, stat.gid);
```
## fileio.mkdtemp<sup>7+</sup>
mkdtemp(prefix: string): Promise<string>
Creates a temporary directory. The folder name is created by replacing a string (specified by **prefix**) with six randomly generated characters. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.mkdtemp](js-apis-file-fs.md#fsmkdtemp) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ------ | ------ | ---- | --------------------------- |
| prefix | string | Yes | String to be replaced with six randomly generated characters to create a unique temporary directory.|
**Return value**
| Type | Description |
| --------------------- | ---------- |
| Promise<string> | Promise used to return the directory created.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
fileio.mkdtemp(pathDir + "/XXXXXX").then((pathDir: string) => {
console.info("mkdtemp succeed:" + pathDir);
}).catch((err: BusinessError) => {
console.info("mkdtemp failed with error:" + err);
});
```
## fileio.mkdtemp<sup>7+</sup>
mkdtemp(prefix: string, callback: AsyncCallback<string>): void
Creates a temporary directory. The folder name is created by replacing a string (specified by **prefix**) with six randomly generated characters. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.mkdtemp](js-apis-file-fs.md#fsmkdtemp-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | --------------------------- | ---- | --------------------------- |
| prefix | string | Yes | String to be replaced with six randomly generated characters to create a unique temporary directory.|
| callback | AsyncCallback<string> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
fileio.mkdtemp(pathDir + "/XXXXXX", (err: BusinessError, res: string) => {
// Do something.
});
```
## fileio.mkdtempSync<sup>7+</sup>
mkdtempSync(prefix: string): string
Creates a temporary directory. The folder name is created by replacing a string (specified by **prefix**) with six randomly generated characters. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.mkdtempSync](js-apis-file-fs.md#fsmkdtempsync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ------ | ------ | ---- | --------------------------- |
| prefix | string | Yes | String to be replaced with six randomly generated characters to create a unique temporary directory.|
**Return value**
| Type | Description |
| ------ | ---------- |
| string | Unique path generated.|
**Example**
```ts
let res = fileio.mkdtempSync(pathDir + "/XXXXXX");
```
## fileio.fchmod<sup>7+</sup>
fchmod(fd: number, mode: number): Promise<void>
Changes file permissions based on an FD. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ---------------------------------------- |
| fd | number | Yes | FD of the target file. |
| mode | number | Yes | Permissions on the file. You can specify multiple permissions, separated using a bitwise OR operator (|).<br>- **0o700**: The owner has the read, write, and execute permissions.<br>- **0o400**: The owner has the read permission.<br>- **0o200**: The owner has the write permission.<br>- **0o100**: The owner has the execute permission.<br>- **0o070**: The user group has the read, write, and execute permissions.<br>- **0o040**: The user group has the read permission.<br>- **0o020**: The user group has the write permission.<br>- **0o010**: The user group has the execute permission.<br>- **0o007**: Other users have the read, write, and execute permissions.<br>- **0o004**: Other users have the read permission.<br>- **0o002**: Other users have the write permission.<br>- **0o001**: Other users have the execute permission.|
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
let mode: number = 0o700;
fileio.fchmod(fd, mode).then(() => {
console.info("File permissions changed");
}).catch((err: BusinessError) => {
console.info("chmod failed with error:" + err);
});
```
## fileio.fchmod<sup>7+</sup>
fchmod(fd: number, mode: number, callback: AsyncCallback<void>): void
Changes file permissions based on an FD. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | ------------------------------- | ---- | ---------------------------------------- |
| fd | number | Yes | FD of the target file. |
| mode | number | Yes | Permissions on the file. You can specify multiple permissions, separated using a bitwise OR operator (|).<br>- **0o700**: The owner has the read, write, and execute permissions.<br>- **0o400**: The owner has the read permission.<br>- **0o200**: The owner has the write permission.<br>- **0o100**: The owner has the execute permission.<br>- **0o070**: The user group has the read, write, and execute permissions.<br>- **0o040**: The user group has the read permission.<br>- **0o020**: The user group has the write permission.<br>- **0o010**: The user group has the execute permission.<br>- **0o007**: Other users have the read, write, and execute permissions.<br>- **0o004**: Other users have the read permission.<br>- **0o002**: Other users have the write permission.<br>- **0o001**: Other users have the execute permission.|
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
let mode: number = 0o700;
fileio.fchmod(fd, mode, (err: BusinessError) => {
// Do something.
});
```
## fileio.fchmodSync<sup>7+</sup>
fchmodSync(fd: number, mode: number): void
Changes the file permissions based on an FD. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ---------------------------------------- |
| fd | number | Yes | FD of the target file. |
| mode | number | Yes | Permissions on the file. You can specify multiple permissions, separated using a bitwise OR operator (|).<br>- **0o700**: The owner has the read, write, and execute permissions.<br>- **0o400**: The owner has the read permission.<br>- **0o200**: The owner has the write permission.<br>- **0o100**: The owner has the execute permission.<br>- **0o070**: The user group has the read, write, and execute permissions.<br>- **0o040**: The user group has the read permission.<br>- **0o020**: The user group has the write permission.<br>- **0o010**: The user group has the execute permission.<br>- **0o007**: Other users have the read, write, and execute permissions.<br>- **0o004**: Other users have the read permission.<br>- **0o002**: Other users have the write permission.<br>- **0o001**: Other users have the execute permission.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
let mode: number = 0o700;
fileio.fchmodSync(fd, mode);
```
## fileio.createStream<sup>7+</sup>
createStream(path: string, mode: string): Promise<Stream>
Creates a stream based on a file path. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.createStream](js-apis-file-fs.md#fscreatestream) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| mode | string | Yes | - **r**: Open a file for reading. The file must exist.<br>- **r+**: Open a file for both reading and writing. The file must exist.<br>- **w**: Open a file for writing. If the file exists, clear its content. If the file does not exist, create a file.<br>- **w+**: Open a file for both reading and writing. If the file exists, clear its content. If the file does not exist, create a file.<br>- **a**: Open a file in append mode for writing at the end of the file. If the file does not exist, create a file. If the file exists, write data to the end of the file (the original content of the file is reserved).<br>- **a+**: Open a file in append mode for reading or updating at the end of the file. If the file does not exist, create a file. If the file exists, write data to the end of the file (the original content of the file is reserved).|
**Return value**
| Type | Description |
| --------------------------------- | --------- |
| Promise<[Stream](#stream)> | Promise used to return the stream opened.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
fileio.createStream(filePath, "r+").then((stream: fileio.Stream) => {
console.info("Stream created");
}).catch((err: BusinessError) => {
console.info("createStream failed with error:" + err);
});
```
## fileio.createStream<sup>7+</sup>
createStream(path: string, mode: string, callback: AsyncCallback<Stream>): void
Creates a stream based on a file path. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.createStream](js-apis-file-fs.md#fscreatestream-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | --------------------------------------- | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| mode | string | Yes | - **r**: Open a file for reading. The file must exist.<br>- **r+**: Open a file for both reading and writing. The file must exist.<br>- **w**: Open a file for writing. If the file exists, clear its content. If the file does not exist, create a file.<br>- **w+**: Open a file for both reading and writing. If the file exists, clear its content. If the file does not exist, create a file.<br>- **a**: Open a file in append mode for writing at the end of the file. If the file does not exist, create a file. If the file exists, write data to the end of the file (the original content of the file is reserved).<br>- **a+**: Open a file in append mode for reading or updating at the end of the file. If the file does not exist, create a file. If the file exists, write data to the end of the file (the original content of the file is reserved).|
| callback | AsyncCallback<[Stream](#stream)> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
fileio.createStream(filePath, "r+", (err: BusinessError, stream: fileio.Stream) => {
// Do something.
});
```
## fileio.createStreamSync<sup>7+</sup>
createStreamSync(path: string, mode: string): Stream
Creates a stream based on a file path. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.createStreamSync](js-apis-file-fs.md#fscreatestreamsync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------------------------------------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| mode | string | Yes | - **r**: Open a file for reading. The file must exist.<br>- **r+**: Open a file for both reading and writing. The file must exist.<br>- **w**: Open a file for writing. If the file exists, clear its content. If the file does not exist, create a file.<br>- **w+**: Open a file for both reading and writing. If the file exists, clear its content. If the file does not exist, create a file.<br>- **a**: Open a file in append mode for writing at the end of the file. If the file does not exist, create a file. If the file exists, write data to the end of the file (the original content of the file is reserved).<br>- **a+**: Open a file in append mode for reading or updating at the end of the file. If the file does not exist, create a file. If the file exists, write data to the end of the file (the original content of the file is reserved).|
**Return value**
| Type | Description |
| ------------------ | --------- |
| [Stream](#stream) | Stream opened.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let ss = fileio.createStreamSync(filePath, "r+");
```
## fileio.fdopenStream<sup>7+</sup>
fdopenStream(fd: number, mode: string): Promise<Stream>
Opens a stream based on an FD. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.fdopenStream](js-apis-file-fs.md#fsfdopenstream) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ---------------------------------------- |
| fd | number | Yes | FD of the target file. |
| mode | string | Yes | - **r**: Open a file for reading. The file must exist.<br>- **r+**: Open a file for both reading and writing. The file must exist.<br>- **w**: Open a file for writing. If the file exists, clear its content. If the file does not exist, create a file.<br>- **w+**: Open a file for both reading and writing. If the file exists, clear its content. If the file does not exist, create a file.<br>- **a**: Open a file in append mode for writing at the end of the file. If the file does not exist, create a file. If the file exists, write data to the end of the file (the original content of the file is reserved).<br>- **a+**: Open a file in append mode for reading or updating at the end of the file. If the file does not exist, create a file. If the file exists, write data to the end of the file (the original content of the file is reserved).|
**Return value**
| Type | Description |
| --------------------------------- | --------- |
| Promise<[Stream](#stream)> | Promise used to return the stream opened.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
fileio.fdopenStream(fd, "r+").then((stream: fileio.Stream) => {
console.info("Stream opened");
}).catch((err: BusinessError) => {
console.info("openStream failed with error:" + err);
});
```
## fileio.fdopenStream<sup>7+</sup>
fdopenStream(fd: number, mode: string, callback: AsyncCallback<Stream>): void
Opens a stream based on an FD. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.fdopenStream](js-apis-file-fs.md#fsfdopenstream-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | ---------------------------------------- | ---- | ---------------------------------------- |
| fd | number | Yes | FD of the target file. |
| mode | string | Yes | - **r**: Open a file for reading. The file must exist.<br>- **r+**: Open a file for both reading and writing. The file must exist.<br>- **w**: Open a file for writing. If the file exists, clear its content. If the file does not exist, create a file.<br>- **w+**: Open a file for both reading and writing. If the file exists, clear its content. If the file does not exist, create a file.<br>- **a**: Open a file in append mode for writing at the end of the file. If the file does not exist, create a file. If the file exists, write data to the end of the file (the original content of the file is reserved).<br>- **a+**: Open a file in append mode for reading or updating at the end of the file. If the file does not exist, create a file. If the file exists, write data to the end of the file (the original content of the file is reserved).|
| callback | AsyncCallback<[Stream](#stream)> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
fileio.fdopenStream(fd, "r+", (err: BusinessError, stream: fileio.Stream) => {
// Do something.
});
```
## fileio.fdopenStreamSync<sup>7+</sup>
fdopenStreamSync(fd: number, mode: string): Stream
Opens a stream based on an FD. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.fdopenStreamSync](js-apis-file-fs.md#fsfdopenstreamsync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ---------------------------------------- |
| fd | number | Yes | FD of the target file. |
| mode | string | Yes | - **r**: Open a file for reading. The file must exist.<br>- **r+**: Open a file for both reading and writing. The file must exist.<br>- **w**: Open a file for writing. If the file exists, clear its content. If the file does not exist, create a file.<br>- **w+**: Open a file for both reading and writing. If the file exists, clear its content. If the file does not exist, create a file.<br>- **a**: Open a file in append mode for writing at the end of the file. If the file does not exist, create a file. If the file exists, write data to the end of the file (the original content of the file is reserved).<br>- **a+**: Open a file in append mode for reading or updating at the end of the file. If the file does not exist, create a file. If the file exists, write data to the end of the file (the original content of the file is reserved).|
**Return value**
| Type | Description |
| ------------------ | --------- |
| [Stream](#stream) | Stream opened.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
let ss = fileio.fdopenStreamSync(fd, "r+");
```
## fileio.fchown<sup>7+</sup>
fchown(fd: number, uid: number, gid: number): Promise<void>
Changes the file owner based on an FD. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ------------ |
| fd | number | Yes | FD of the target file.|
| uid | number | Yes | New UID. |
| gid | number | Yes | New GID. |
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
let stat = fileio.statSync(filePath);
fileio.fchown(fd, stat.uid, stat.gid).then(() => {
console.info("File owner changed");
}).catch((err: BusinessError) => {
console.info("chown failed with error:" + err);
});
```
## fileio.fchown<sup>7+</sup>
fchown(fd: number, uid: number, gid: number, callback: AsyncCallback<void>): void
Changes the file owner based on an FD. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | ------------------------- | ---- | --------------- |
| fd | number | Yes | FD of the target file. |
| uid | number | Yes | New UID. |
| gid | number | Yes | New GID. |
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
let stat = fileio.statSync(filePath);
fileio.fchown(fd, stat.uid, stat.gid, (err: BusinessError) => {
// Do something.
});
```
## fileio.fchownSync<sup>7+</sup>
fchownSync(fd: number, uid: number, gid: number): void
Changes the file owner based on an FD. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ---- | ------ | ---- | ------------ |
| fd | number | Yes | FD of the target file.|
| uid | number | Yes | New UID. |
| gid | number | Yes | New GID. |
**Example**
```ts
let filePath = pathDir + "/test.txt";
let fd = fileio.openSync(filePath);
let stat = fileio.statSync(filePath);
fileio.fchownSync(fd, stat.uid, stat.gid);
```
## fileio.lchown<sup>7+</sup>
lchown(path: string, uid: number, gid: number): Promise<void>
Changes the file owner (owner of the symbolic link, not the file referred to by the symbolic link) based on a file path. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | -------------------------- |
| path | string | Yes | Application sandbox path of the file.|
| uid | number | Yes | New UID. |
| gid | number | Yes | New GID. |
**Return value**
| Type | Description |
| ------------------- | ---------------------------- |
| Promise<void> | Promise that returns no value.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let stat = fileio.statSync(filePath);
fileio.lchown(filePath, stat.uid, stat.gid).then(() => {
console.info("File owner changed");
}).catch((err: BusinessError) => {
console.info("chown failed with error:" + err);
});
```
## fileio.lchown<sup>7+</sup>
lchown(path: string, uid: number, gid: number, callback: AsyncCallback<void>): void
Changes the file owner (owner of the symbolic link, not the file referred to by the symbolic link) based on a file path. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------- | ---- | ------------------------------ |
| path | string | Yes | Application sandbox path of the file. |
| uid | number | Yes | New UID. |
| gid | number | Yes | New GID. |
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let stat = fileio.statSync(filePath);
fileio.lchown(filePath, stat.uid, stat.gid, (err: BusinessError) => {
// Do something.
});
```
## fileio.lchownSync<sup>7+</sup>
lchownSync(path: string, uid: number, gid: number): void
Changes the file owner based on a file path and changes the owner of the symbolic link (not the referenced file). This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | -------------------------- |
| path | string | Yes | Application sandbox path of the file.|
| uid | number | Yes | New UID. |
| gid | number | Yes | New GID. |
**Example**
```ts
let filePath = pathDir + "/test.txt";
let stat = fileio.statSync(filePath);
fileio.lchownSync(filePath, stat.uid, stat.gid);
```
## fileio.createWatcher<sup>7+</sup>
createWatcher(filename: string, events: number, callback: AsyncCallback<number>): Watcher
Listens for file or directory changes. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | --------------------------------- | ---- | ------------------------------------------------------------ |
| filePath | string | Yes | Application sandbox path of the file. |
| events | number | Yes | - **1**: The file or directory is renamed.<br>- **2**: The file or directory is modified.<br>- **3**: The file or directory is modified and renamed.|
| callback | AsyncCallback<number> | Yes | Called each time a change is detected. |
**Return value**
| Type | Description |
| -------------------- | ---------- |
| [Watcher](#watcher7) | Promise used to return the result.|
**Example**
```js
let filePath = pathDir + "/test.txt";
fileio.createWatcher(filePath, 1, (err, event) => {
console.info("event: " + event + "errmsg: " + JSON.stringify(err));
});
```
## Readout
Obtains the file read result. This class applies only to the **read()** method.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
| Name | Type | Readable | Writable | Description |
| --------- | ---------- | ---- | ---- | ----------------- |
| bytesRead | number | Yes | Yes | Length of the data read. |
| offset | number | Yes | Yes | Position of the buffer to which the data will be read in reference to the start address of the buffer.|
| buffer | ArrayBuffer | Yes | Yes | Buffer for storing the data read. |
## Stat
Provides detailed file information. Before calling a method of the **Stat** class, use the [stat()](#fileiostat) method synchronously or asynchronously to create a **Stat** instance.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stat](js-apis-file-fs.md#stat) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
### Attributes
| Name | Type | Readable | Writable | Description |
| ------ | ------ | ---- | ---- | ---------------------------------------- |
| dev | number | Yes | No | Major device number. |
| ino | number | Yes | No | File identifier, which varies with files on the same device. |
| mode | number | Yes | No | File type and permissions. The first four bits indicate the file type, and the last 12 bits indicate the permissions. The bit fields are described as follows:<br>- **0o170000**: mask used to obtain the file type.<br>- **0o140000**: The file is a socket.<br>- **0o120000**: The file is a symbolic link.<br>- **0o100000**: The file is a regular file.<br>- **0o060000**: The file is a block device.<br>- **0o040000**: The file is a directory.<br>- **0o020000**: The file is a character device.<br>- **0o010000**: The file is a named pipe (FIFO).<br>- **0o0700**: mask used to obtain the owner permissions.<br>- **0o0400**: The owner has the permission to read a regular file or a directory entry.<br>- **0o0200**: The owner has the permission to write a regular file or create and delete a directory entry.<br>- **0o0100**: The owner has the permission to execute a regular file or search for the specified path in a directory.<br>- **0o0070**: mask used to obtain the user group permissions.<br>- **0o0040**: The user group has the permission to read a regular file or a directory entry.<br>- **0o0020**: The user group has the permission to write a regular file or create and delete a directory entry.<br>- **0o0010**: The user group has the permission to execute a regular file or search for the specified path in a directory.<br>- **0o0007**: mask used to obtain the permissions of other users.<br>- **0o0004**: Other users have the permission to read a regular file or a directory entry.<br>- **0o0002**: Other users have the permission to write a regular file or create and delete a directory entry.<br>- **0o0001**: Other users have the permission to execute a regular file or search for the specified path in a directory.|
| nlink | number | Yes | No | Number of hard links in the file. |
| uid | number | Yes | No | ID of the file owner. |
| gid | number | Yes | No | ID of the user group of the file. |
| rdev | number | Yes | No | Minor device number. |
| size | number | Yes | No | File size, in bytes. This parameter is valid only for regular files. |
| blocks | number | Yes | No | Number of blocks occupied by a file. Each block is 512 bytes. |
| atime | number | Yes | No | Time when the file was last accessed. The value is the number of seconds elapsed since 00:00:00 on January 1, 1970. |
| mtime | number | Yes | No | Time when the file content was last modified. The value is the number of seconds elapsed since 00:00:00 on January 1, 1970. |
| ctime | number | Yes | No | Time when the file metadata was last modified. The value is the number of seconds elapsed since 00:00:00 on January 1, 1970. |
### isBlockDevice
isBlockDevice(): boolean
Checks whether this file is a block special file. A block special file supports access by block only, and it is cached when accessed.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stat.isBlockDevice](js-apis-file-fs.md#isblockdevice) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------- | ---------------- |
| boolean | Whether the file is a block special file.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let isBLockDevice = fileio.statSync(filePath).isBlockDevice();
```
### isCharacterDevice
isCharacterDevice(): boolean
Checks whether this file is a character special file. A character special file supports random access, and it is not cached when accessed.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stat.isCharacterDevice](js-apis-file-fs.md#ischaracterdevice) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------- | ----------------- |
| boolean | Whether the file is a character special file.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let isCharacterDevice = fileio.statSync(filePath).isCharacterDevice();
```
### isDirectory
isDirectory(): boolean
Checks whether this file is a directory.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stat.isDirectory](js-apis-file-fs.md#isdirectory) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------- | ------------- |
| boolean | Whether the file is a directory.|
**Example**
```ts
let dirPath = pathDir + "/test";
let isDirectory = fileio.statSync(dirPath).isDirectory();
```
### isFIFO
isFIFO(): boolean
Checks whether this file is a named pipe (or FIFO). Named pipes are used for inter-process communication.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stat.isFIFO](js-apis-file-fs.md#isfifo) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------- | --------------------- |
| boolean | Whether the file is an FIFO.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let isFIFO = fileio.statSync(filePath).isFIFO();
```
### isFile
isFile(): boolean
Checks whether this file is a regular file.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stat.isFile](js-apis-file-fs.md#isfile) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------- | --------------- |
| boolean | Whether the file is a regular file.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let isFile = fileio.statSync(filePath).isFile();
```
### isSocket
isSocket(): boolean
Checks whether this file is a socket.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stat.isSocket](js-apis-file-fs.md#issocket) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------- | -------------- |
| boolean | Whether the file is a socket.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let isSocket = fileio.statSync(filePath).isSocket();
```
### isSymbolicLink
isSymbolicLink(): boolean
Checks whether this file is a symbolic link.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stat.isSymbolicLink](js-apis-file-fs.md#issymboliclink) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------- | --------------- |
| boolean | Whether the file is a symbolic link.|
**Example**
```ts
let filePath = pathDir + "/test";
let isSymbolicLink = fileio.statSync(filePath).isSymbolicLink();
```
## Watcher<sup>7+</sup>
Listens for the changes of a file. You can call the **Watcher.stop()** method synchronously or asynchronously to stop the listening.
### stop<sup>7+</sup>
stop(): Promise<void>
Stops the **watcher** instance. This API uses a promise to return the result.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Example**
```js
let filePath = pathDir + "/test.txt";
let watcher = fileio.createWatcher(filePath, 1, (err, event) => {
console.info("event: " + event + "errmsg: " + JSON.stringify(err));
});
watcher.stop().then(() => {
console.info("Watcher stopped");
});
```
### stop<sup>7+</sup>
stop(callback: AsyncCallback<void>): void
Stops the **watcher** instance. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | ------------------------- | ---- | ---------------------- |
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result.|
**Example**
```js
let filePath = pathDir + "/test.txt";
let watcher = fileio.createWatcher(filePath, 1, (err, event) => {
console.info("event: " + event + "errmsg: " + JSON.stringify(err));
});
watcher.stop(() => {
console.info("Watcher stopped");
})
```
## Stream
Provides a stream for file operations. Before calling any API of the **Stream** class, use **createStream()** to create a **Stream** instance synchronously or asynchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stream](js-apis-file-fs.md#stream) instead.
### close<sup>7+</sup>
close(): Promise<void>
Closes the stream. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stream.close](js-apis-file-fs.md#close) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------------------- | ------------- |
| Promise<void> | Promise used to return the result.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let ss = fileio.createStreamSync(filePath, "r+");
ss.close().then(() => {
console.info("File stream closed");
}).catch((err: BusinessError) => {
console.info("close fileStream failed with error:" + err);
});
```
### close<sup>7+</sup>
close(callback: AsyncCallback<void>): void
Closes this stream. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stream.close](js-apis-file-fs.md#close-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | ------------------------- | ---- | ------------- |
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let ss = fileio.createStreamSync(filePath, "r+");
ss.close((err: BusinessError) => {
// Do something.
});
```
### closeSync
closeSync(): void
Closes this stream. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stream.closeSync](js-apis-file-fs.md#closesync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Example**
```ts
let filePath = pathDir + "/test.txt";
let ss = fileio.createStreamSync(filePath, "r+");
ss.closeSync();
```
### flush<sup>7+</sup>
flush(): Promise<void>
Flushes this stream. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stream.flush](js-apis-file-fs.md#flush) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------------------- | ------------- |
| Promise<void> | Promise used to return the result.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let ss = fileio.createStreamSync(filePath, "r+");
ss.flush().then(() => {
console.info("Stream flushed");
}).catch((err: BusinessError) => {
console.info("flush failed with error:" + err);
});
```
### flush<sup>7+</sup>
flush(callback: AsyncCallback<void>): void
Flushes this stream. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stream.flush](js-apis-file-fs.md#flush-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | ------------------------- | ---- | -------------- |
| callback | AsyncCallback<void> | Yes | Callback invoked to return the result.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let ss = fileio.createStreamSync(filePath, "r+");
ss.flush((err: BusinessError) => {
// Do something.
});
```
### flushSync<sup>7+</sup>
flushSync(): void
Flushes this stream. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stream.flushSync](js-apis-file-fs.md#flushsync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Example**
```ts
let filePath = pathDir + "/test.txt";
let ss = fileio.createStreamSync(filePath, "r+");
ss.flushSync();
```
### write<sup>7+</sup>
write(buffer: ArrayBuffer|string, options?: { offset?: number; length?: number; position?: number; encoding?: string; }): Promise<number>
Writes data into the stream. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stream.write](js-apis-file-fs.md#write) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ------- | ------------------------------- | ---- | ---------------------------------------- |
| buffer | ArrayBuffer\|string | Yes | Data to write. It can be a string or data from a buffer. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. This parameter is optional. The default value is **0**.<br>- **length** (number): length of the data to write. This parameter is optional. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. This parameter is optional. By default, data is written from the current position.<br>- **encoding** (string): format of the data to be encoded when the data is a string. The default value is **'utf-8'**, which is the only value supported.<br>Constraints: offset + length <= Buffer size |
**Return value**
| Type | Description |
| --------------------- | -------- |
| Promise<number> | Promise used to return the length of the data written.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let ss = fileio.createStreamSync(filePath, "r+");
class Option {
offset: number = 0;
length: number = 4096;
position: number = 0;
encoding: string = 'utf-8';
}
let option = new Option();
option.offset = 1;
option.length = 5;
option.position = 5;
ss.write("hello, world", option).then((number: number) => {
console.info("write succeed and size is:" + number);
}).catch((err: BusinessError) => {
console.info("write failed with error:" + err);
});
```
### write<sup>7+</sup>
write(buffer: ArrayBuffer|string, options: { offset?: number; length?: number; position?: number; encoding?: string; }, callback: AsyncCallback<number>): void
Writes data to this stream. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stream.write](js-apis-file-fs.md#write-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory| Description |
| -------- | ------------------------------- | ---- | ------------------------------------------------------------ |
| buffer | ArrayBuffer\|string | Yes | Data to write. It can be a string or data from a buffer. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. This parameter is optional. The default value is **0**.<br>- **length** (number): length of the data to write. This parameter is optional. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. This parameter is optional. By default, data is written from the current position.<br>- **encoding** (string): format of the data to be encoded when the data is a string. The default value is **'utf-8'**, which is the only value supported.<br>Constraints: offset + length <= Buffer size|
| callback | AsyncCallback<number> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
let filePath = pathDir + "/test.txt";
let ss = fileio.createStreamSync(filePath, "r+");
class Option {
offset: number = 0;
length: number = 4096;
position: number = 0;
encoding: string = 'utf-8';
}
let option = new Option();
option.offset = 1;
option.length = 5;
option.position = 5;
ss.write("hello, world", option, (err: BusinessError, bytesWritten: number) => {
if (bytesWritten) {
// Do something.
console.info("write succeed and size is:" + bytesWritten);
}
});
```
### writeSync<sup>7+</sup>
writeSync(buffer: ArrayBuffer|string, options?: { offset?: number; length?: number; position?: number; encoding?: string; }): number
Writes data to this stream. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stream.writeSync](js-apis-file-fs.md#writesync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ------- | ------------------------------- | ---- | ---------------------------------------- |
| buffer | ArrayBuffer\|string | Yes | Data to write. It can be a string or data from a buffer. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position of the data to write in reference to the start address of the data. This parameter is optional. The default value is **0**.<br>- **length** (number): length of the data to write. This parameter is optional. The default value is the buffer length minus the offset.<br>- **position** (number): start position to write the data in the file. This parameter is optional. By default, data is written from the current position.<br>- **encoding** (string): format of the data to be encoded when the data is a string. The default value is **'utf-8'**, which is the only value supported.<br>Constraints: offset + length <= Buffer size |
**Return value**
| Type | Description |
| ------ | -------- |
| number | Length of the data written in the file.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let ss = fileio.createStreamSync(filePath,"r+");
class Option {
offset: number = 0;
length: number = 4096;
position: number = 0;
encoding: string = 'utf-8';
}
let option = new Option();
option.offset = 1;
option.length = 5;
option.position = 5;
let num = ss.writeSync("hello, world", option);
```
### read<sup>7+</sup>
read(buffer: ArrayBuffer, options?: { position?: number; offset?: number; length?: number; }): Promise<ReadOut>
Reads data from the stream. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stream.read](js-apis-file-fs.md#read) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ------- | ----------- | ---- | ---------------------------------------- |
| buffer | ArrayBuffer | Yes | Buffer used to store the file read. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. This parameter is optional. The default value is **0**.<br>- **length** (number): length of the data to read. This parameter is optional. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. This parameter is optional. By default, data is read from the current position.<br>Constraints: offset + length <= Buffer size |
**Return value**
| Type | Description |
| ---------------------------------- | ------ |
| Promise<[ReadOut](#readout)> | Promise used to return the data read.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
import buffer from '@ohos.buffer';
let filePath = pathDir + "/test.txt";
let ss = fileio.createStreamSync(filePath, "r+");
let arrayBuffer = new ArrayBuffer(4096);
class Option {
offset: number = 0;
length: number = 4096;
position: number = 0;
}
let option = new Option();
option.offset = 1;
option.length = 5;
option.position = 5;
ss.read(arrayBuffer, option).then((readResult: fileio.ReadOut) => {
console.info("Read data successfully");
let buf = buffer.from(arrayBuffer, 0, readResult.bytesRead);
console.info(`The content of file: ${buf.toString()}`);
}).catch((err: BusinessError) => {
console.info("read data failed with error:" + err);
});
```
### read<sup>7+</sup>
read(buffer: ArrayBuffer, options: { position?: number; offset?: number; length?: number; }, callback: AsyncCallback<ReadOut>): void
Reads data from this stream. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stream.read](js-apis-file-fs.md#read-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | ---------------------------------------- | ---- | ---------------------------------------- |
| buffer | ArrayBuffer | Yes | Buffer used to store the file read. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. This parameter is optional. The default value is **0**.<br>- **length** (number): length of the data to read. This parameter is optional. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. This parameter is optional. By default, data is read from the current position.<br>Constraints: offset + length <= Buffer size |
| callback | AsyncCallback<[ReadOut](#readout)> | Yes | Callback invoked to return the result. |
**Example**
```ts
import { BusinessError } from '@ohos.base';
import buffer from '@ohos.buffer';
let filePath = pathDir + "/test.txt";
let ss = fileio.createStreamSync(filePath, "r+");
let arrayBuffer = new ArrayBuffer(4096);
class Option {
offset: number = 0;
length: number = 4096;
position: number = 0;
}
let option = new Option();
option.offset = 1;
option.length = 5;
option.position = 5;
ss.read(arrayBuffer, option, (err: BusinessError, readResult: fileio.ReadOut) => {
if (readResult.bytesRead) {
console.info("Read data successfully");
let buf = buffer.from(arrayBuffer, 0, readResult.bytesRead);
console.info(`The content of file: ${buf.toString()}`);
}
});
```
### readSync<sup>7+</sup>
readSync(buffer: ArrayBuffer, options?: { position?: number; offset?: number; length?: number; }): number
Reads data from this stream. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.Stream.readSync](js-apis-file-fs.md#readsync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| ------- | ----------- | ---- | ---------------------------------------- |
| buffer | ArrayBuffer | Yes | Buffer used to store the file read. |
| options | Object | No | The options are as follows:<br>- **offset** (number): position to store the data read in the buffer in reference to the start address of the buffer. This parameter is optional. The default value is **0**.<br>- **length** (number): length of the data to read. This parameter is optional. The default value is the buffer length minus the offset.<br>- **position** (number): position of the data to read in the file. This parameter is optional. By default, data is read from the current position.<br>Constraints: offset + length <= Buffer size |
**Return value**
| Type | Description |
| ------ | -------- |
| number | Length of the data read.|
**Example**
```ts
let filePath = pathDir + "/test.txt";
let ss = fileio.createStreamSync(filePath, "r+");
class Option {
offset: number = 0;
length: number = 4096;
position: number = 0;
}
let option = new Option();
option.offset = 1;
option.length = 5;
option.position = 5;
let buf = new ArrayBuffer(4096)
let num = ss.readSync(buf, option);
```
## Dir
Manages directories. Before calling a method of the **Dir** class, use the **opendir()** method synchronously or asynchronously to create a **Dir** instance.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.listFile](js-apis-file-fs.md#fslistfile) instead.
### read
read(): Promise<Dirent>
Reads the next directory entry. This API uses a promise to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.listFile](js-apis-file-fs.md#fslistfile) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| -------------------------------- | ------------- |
| Promise<[Dirent](#dirent)> | Promise used to return the result.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
dir.read().then((dirent: fileio.Dirent) => {
console.log("read succeed, the name of dirent is " + dirent.name);
}).catch((err: BusinessError) => {
console.info("read failed with error:" + err);
});
```
### read
read(callback: AsyncCallback<Dirent>): void
Reads the next directory entry. This API uses an asynchronous callback to return the result.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.listFile](js-apis-file-fs.md#fslistfile-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Parameters**
| Name | Type | Mandatory | Description |
| -------- | -------------------------------------- | ---- | ---------------- |
| callback | AsyncCallback<[Dirent](#dirent)> | Yes | Callback invoked to return the result.|
**Example**
```ts
import { BusinessError } from '@ohos.base';
dir.read((err: BusinessError, dirent: fileio.Dirent) => {
if (dirent) {
// Do something.
console.log("read succeed, the name of file is " + dirent.name);
}
});
```
### readSync
readSync(): Dirent
Reads the next directory entry. This API returns the result synchronously.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.listFileSync](js-apis-file-fs.md#fslistfilesync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ----------------- | -------- |
| [Dirent](#dirent) | Directory entry read.|
**Example**
```ts
let dirent = dir.readSync();
```
### close<sup>7+</sup>
close(): Promise<void>
Closes a directory. This API uses a promise to return the result. After a directory is closed, the FD in **Dir** will be released and no directory entry can be read from **Dir**.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.listFile](js-apis-file-fs.md#fslistfile) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Example**
```ts
import { BusinessError } from '@ohos.base';
dir.close().then(() => {
console.info("close dir successfully");
});
```
### close<sup>7+</sup>
close(callback: AsyncCallback<void>): void
Closes a directory. This API uses an asynchronous callback to return the result. After a directory is closed, the FD in **Dir** will be released and no directory entry can be read from **Dir**.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.listFile](js-apis-file-fs.md#fslistfile-1) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Example**
```ts
import { BusinessError } from '@ohos.base';
dir.close((err: BusinessError) => {
console.info("close dir successfully");
});
```
### closeSync
closeSync(): void
Closes a directory. After a directory is closed, the FD in **Dir** will be released and no directory entry can be read from **Dir**.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.listFileSync](js-apis-file-fs.md#fslistfilesync) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Example**
```ts
dir.closeSync();
```
## Dirent
Provides information about files and directories. Before calling a method of the **Dirent** class, use the [dir.read()](#read) method synchronously or asynchronously to create a **Dirent** instance.
> **NOTE**
>
> This API is deprecated since API version 9. Use [fs.listFile](js-apis-file-fs.md#fslistfile) instead.
**System capability**: SystemCapability.FileManagement.File.FileIO
### Attributes
| Name | Type | Readable | Writable | Description |
| ---- | ------ | ---- | ---- | ------- |
| name | string | Yes | No | Directory entry name.|
### isBlockDevice
isBlockDevice(): boolean
Checks whether this directory entry is a block special file. A block special file supports access by block only, and it is cached when accessed.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------- | ---------------- |
| boolean | Whether the directory entry is a block special file.|
**Example**
```ts
let dir = fileio.opendirSync(pathDir);
let isBLockDevice = dir.readSync().isBlockDevice();
```
### isCharacterDevice
isCharacterDevice(): boolean
Checks whether a directory entry is a character special file. A character special file supports random access, and it is not cached when accessed.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------- | ----------------- |
| boolean | Whether the directory entry is a character special file.|
**Example**
```ts
let dir = fileio.opendirSync(pathDir);
let isCharacterDevice = dir.readSync().isCharacterDevice();
```
### isDirectory
isDirectory(): boolean
Checks whether a directory entry is a directory.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------- | ------------- |
| boolean | Whether the directory entry is a directory.|
**Example**
```ts
let dir = fileio.opendirSync(pathDir);
let isDirectory = dir.readSync().isDirectory();
```
### isFIFO
isFIFO(): boolean
Checks whether this directory entry is a named pipe (or FIFO). Named pipes are used for inter-process communication.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------- | --------------- |
| boolean | Whether the directory entry is a FIFO.|
**Example**
```ts
let dir = fileio.opendirSync(pathDir);
let isFIFO = dir.readSync().isFIFO();
```
### isFile
isFile(): boolean
Checks whether a directory entry is a regular file.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------- | --------------- |
| boolean | Whether the directory entry is a regular file.|
**Example**
```ts
let dir = fileio.opendirSync(pathDir);
let isFile = dir.readSync().isFile();
```
### isSocket
isSocket(): boolean
Checks whether a directory entry is a socket.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------- | -------------- |
| boolean | Whether the directory entry is a socket.|
**Example**
```ts
let dir = fileio.opendirSync(pathDir);
let isSocket = dir.readSync().isSocket();
```
### isSymbolicLink
isSymbolicLink(): boolean
Checks whether a directory entry is a symbolic link.
> **NOTE**
>
> This API is deprecated since API version 9.
**System capability**: SystemCapability.FileManagement.File.FileIO
**Return value**
| Type | Description |
| ------- | --------------- |
| boolean | Whether the directory entry is a symbolic link.|
**Example**
```ts
let dir = fileio.opendirSync(pathDir);
let isSymbolicLink = dir.readSync().isSymbolicLink();
```