> 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.
This module provides file storage functions. It provides JS I/O APIs, including basic file management APIs, basic directory management APIs, statistical APIs for obtaining file information, and streaming APIs for reading and writing files.
Provides file storage and management capabilities, including basic file management, file directory management, file information statistics, and stream read and write.
## Modules to Import
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...
@@ -14,22 +14,14 @@ import fileio from '@ohos.fileio';
## Guidelines
Before using the APIs provided by this module to perform operations on a file or directory, obtain the path of the application sandbox. For details, see [getOrCreateLocalDir of the Context module](js-apis-Context.md).
Application sandbox path of a file or directory = Application directory + File name or directory name
For example, if the application directory obtained by using **getOrCreateLocalDir** is **dir** and the file name is **xxx.txt**, the application sandbox path of the file is as follows:
```js
letpath=dir+"/xxx.txt";
```
The file descriptor is as follows:
```js
letfd=fileio.openSync(path);
Before using the APIs provided by this module to perform operations on files or directories, obtain the path of the application sandbox as follows:
| path | string | Yes | Application sandbox path of the target file. |
| 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 current process has the execute permission on the file.<br>- **2**: check whether the current process has the write permission on the file.<br>- **4**: check whether the current process has the read permission on the file.|
| path | string | Yes | Application sandbox path of the target file. |
| 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 current process has the execute permission on the file.<br>- **2**: check whether the current process has the write permission on the file.<br>- **4**: check whether the current process has the read permission on the file.|
| callback | AsyncCallback<void> | Yes | Callback invoked when the file is asynchronously checked. |
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@@ -255,7 +247,7 @@ Synchronously checks whether the current process can access the specified file.
| path | string | Yes | Application sandbox path of the target file. |
| 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 current process has the execute permission on the file.<br>- **2**: check whether the current process has the write permission on the file.<br>- **4**: check whether the current process has the read permission on the file.|
**Example**
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@@ -272,7 +264,7 @@ Synchronously checks whether the current process can access the specified file.
close(fd: number):Promise<void>
Asynchronously closes a file. This API uses a promise to return the result.
Closes a file. This API uses a promise to return the result asynchronously.
| path | string | Yes | Application sandbox path of the directory to create. |
| 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.|
| path | string | Yes | Application sandbox path of the directory to create. |
| 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 when the directory is created asynchronously. |
**Example**
```js
fileio.mkdir(path,function(err){
console.info("mkdir successfully");
console.info("mkdir succeed");
});
```
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...
@@ -521,7 +513,7 @@ Synchronously creates a directory.
| path | string | Yes | Application sandbox path of the directory to create. |
| 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**
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@@ -534,26 +526,26 @@ Synchronously creates a directory.
| path | string | Yes | Application sandbox path of the target file. |
| 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** points 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 **0o666**.<br>- **0o666**: The owner, user group, and other users have the read and write permissions on the file.<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> | File descriptor of the file opened.|
| Promise<number> | Promise used to return the file descriptor of the file opened.|
| path | string | Yes | Application sandbox path of the target file. |
| path | string | Yes | Application sandbox path of the file. |
| flags | number | Yes | 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** points 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 | Yes | Permissions on the file. You can specify multiple permissions, separated using a bitwise OR operator (|). The default value is **0o666**.<br>- **0o666**: The owner, user group, and other users have the read and write permissions on the file.<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 when the file is open asynchronously. |
| path | string | Yes | Application sandbox path of the target file. |
| 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** points 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 **0o666**.<br>- **0o666**: The owner, user group, and other users have the read and write permissions on the file.<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.|
| mode | number | No | Permissions on the file. You can specify multiple permissions, separated using a bitwise OR operator (|). The default value is **0o666**.<br>- **0o666**: The owner, user group, and other users have the read and write permissions on the file.<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.|
| path | string | Yes | Application sandbox path of the target file. |
| 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.|
| Promise<string> | Promise used to return the hash value of the file. The hash value is a hexadecimal string consisting of digits and uppercase letters.|
| Promise<string> | Promise used to return the hash value obtained. The hash value is a hexadecimal string consisting of digits and uppercase letters.|
| path | string | Yes | Application sandbox path of the target file. |
| 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. The hash value is a hexadecimal string consisting of digits and uppercase letters.|
| 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.|
| path | string | Yes | Application sandbox path of the target file. |
| 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.|
| path | string | Yes | Application sandbox path of the target file. |
| 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 when the file permissions are changed asynchronously. |
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@@ -1062,14 +1062,14 @@ Asynchronously changes the file permissions based on its path. This API uses a c
chmodSync(path: string, mode: number): void
Synchronously changes the file permissions based on its path.
| path | string | Yes | Application sandbox path of the target file. |
| 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**
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@@ -1082,7 +1082,7 @@ Synchronously changes the file permissions based on its path.
fstat(fd: number): Promise<Stat>
Asynchronously obtains file information based on the file descriptor. This API uses a promise to return the result.
Obtains file information based on the file descriptor. This API uses a promise to return the result asynchronously.
| 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. By default, data is read from the current position.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- **encoding** (string): format of the data (string) to be encoded. The default value is **utf-8**, which is the only value supported.|
| callback | AsyncCallback<string> | Yes | Callback invoked when the file is read asynchronously. |
| options | Object | No | The options are as follows:<br>- **position** (number): position of the data to read in the file. By default, data is read from the current position.<br>- **length** (number): length of the data to read. The default value is the buffer length minus the offset.<br>- **encoding**: format of the string to be encoded. The default value is **utf-8**, which is the only value supported.|
| callback | AsyncCallback<string> | Yes | Callback used to return the content read. |
**Example**
```js
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@@ -1392,7 +1392,7 @@ Synchronously reads the text of a file.
lstat(path: string): Promise<Stat>
Asynchronously obtains link information. This API uses a promise to return the result.
Obtains link information. This API uses a promise to return the result asynchronously.
| fd | number | Yes | File descriptor of the file to synchronize.|
| fd | number | Yes | File descriptor of the file to flush.|
**Example**
```js
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@@ -1671,24 +1671,24 @@ Synchronizes a file in synchronous mode.
fdatasync(fd: number): Promise<void>
Asynchronously synchronizes data in a file. This API uses a promise to return the result.
Flushes data of a file to disk. This API uses a promise to return the result asynchronously. **fdatasync()** is similar to **fsync()**, but does not flush modified metadata unless that metadata is needed.
| path | string | Yes | Application sandbox path of the target file. |
| 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**
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@@ -2054,7 +2054,7 @@ Asynchronously opens a stream based on the file path. This API uses a promise to
| path | string | Yes | Application sandbox path of the target file. |
| 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](#stream7)> | Yes | Callback invoked when the stream is open asynchronously. |
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@@ -2095,7 +2095,7 @@ Synchronously opens a stream based on the file path.
| path | string | Yes | Application sandbox path of the target file. |
| 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**
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@@ -2113,7 +2113,7 @@ Synchronously opens a stream based on the file path.
Asynchronously changes the file owner based on the file path, changes the owner of the symbolic link (not the referenced file), and returns the result in a promise.
Changes the file owner (owner of the symbolic link, not the file referred to by the symbolic link) based on the file path. This API uses a promise to return the result asynchronously.
Asynchronously changes the file owner based on the file path, changes the owner of the symbolic link (not the referenced file), and returns the result in a callback.
Changes the file owner (owner of the symbolic link, not the file referred to by the symbolic link) based on the file path. This API uses an asynchronous callback to return the result.
| filename | string | Yes | Application sandbox path of the target file. |
| filename | 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**
| Name | Description |
| -------------------- | ---------- |
| [Watcher](#watcher7) | Instance for listening for a file change event.|
| [Watcher](#watcher7) | Promise used to return the **Watcher** instance.|
**Example**
```js
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@@ -2549,7 +2549,7 @@ Listens for the changes of a file. You can call the **Watcher.stop()** method sy
stop(): Promise<void>
Asynchronously stops **watcher**. This API uses a promise to return the result.
Stops the **watcher** instance. This API uses a promise to return the result asynchronously.
@@ -2583,14 +2583,14 @@ Asynchronously stops **watcher**. This API uses a callback to return the result.
## Stream<sup>7+</sup>
File stream. Before calling a method of the **Stream** class, use the **createStream()** method synchronously or asynchronously to create a **Stream** instance.
Provides file stream management. Before calling a method of the **Stream** class, use the **createStream()** method synchronously or asynchronously to create a **Stream** instance.
### close<sup>7+</sup>
close(): Promise<void>
Asynchronously closes the stream. This API uses a promise to return the result.
Closes the stream. This API uses a promise to return the result asynchronously.
@@ -2978,6 +2978,40 @@ Synchronously reads the next directory entry.
```
### close
close(): Promise<void>
Closes a directory. This API uses a promise to return the result asynchronously. After a directory is closed, the file descriptor in Dir will be released and no directory entry can be read from Dir.
Closes a directory. This API uses an asynchronous callback to return the result. After a directory is closed, the file descriptor in Dir will be released and no directory entry can be read from Dir.
@@ -3010,7 +3044,7 @@ Provides information about files and directories. Before calling a method of the
isBlockDevice(): boolean
Checks whether the current directory entry is a block special file. A block special file supports access by block only, and it is cached when accessed.
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.
| path | string | Yes | URI of the directory to query. |
| type | string | Yes | Type of the files to query. The file type can be **file**, **image**, **audio**, or **video**.|
| path | string | Yes | URI of the directory to query. |
| type | string | Yes | Type of the files to query. The file type can be **file**, **image**, **audio**, or **video**.|
| options | Object | No| The options are as follows:<br>- **dev**: See [DevInfo](#devinfo). It is **dev = {name: "local"}** by default if not specified. Currently, only 'local' is supported.<br>- **offset**: position to start the query. The value is a number.<br>- **count**: number of files to query.|
| callback | AsyncCallback<[FileInfo](#fileinfo)[]> | Yes | Callback invoked to return the file information obtained. |
- Error
...
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@@ -145,14 +154,30 @@ Obtains information about the second-level album or files in asynchronous mode.
- Example
```js
// Call listFile() and getRoot() to obtain the file URI.
| filename | string | Yes | Name of the file to create. |
| path | string | Yes | URI of the file to create. |
| filename | string | Yes | Name of the file to create. |
| path | string | Yes | URI of the file to create. |
| options | Object | No| The options are as follows:<br>- **dev**: See [DevInfo](#devinfo). It is **dev = {name: "local"}** by default if not specified. Currently, only 'local' is supported.|
| callback | AsyncCallback<[FileInfo](#fileinfo)[]> | Yes | Callback invoked to return the file information obtained. |
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@@ -230,7 +255,7 @@ Creates a file in the specified path in asynchronous mode. This API uses a callb
```js
// Create a file.
// Call listFile() and getRoot() to obtain the file URI.
> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
This module provides information related to the file system. It provides JS APIs to obtain the total number of bytes and the number of idle bytes of the file system.
Obtains file system information, including the total number of bytes and the number of idle bytes of the file system.
## Modules to Import
```js
importstatfsfrom'@ohos.statfs';
```
## Guidelines
Before using the APIs provided by this module to perform operations on a file or directory, obtain the path of the application sandbox. For details, see [getOrCreateLocalDir of the Context module](js-apis-Context.md).
Application sandbox path of a file or directory = Application directory + File name or directory name
For example, if the application directory obtained by using **getOrCreateLocalDir** is **dir** and the file name is **xxx.txt**, the application sandbox path of the file is as follows:
```js
letpath=dir+"xxx.txt";
```
## statfs.getFreeBytes
getFreeBytes(path:string):Promise<number>
...
...
@@ -72,8 +59,12 @@ Obtains the number of free bytes of the specified file system in asynchronous mo
@@ -25,11 +25,11 @@ Encrypts or decrypts data using RSA.
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| action | string | Yes| Action to perform. The options are as follows:<br>- encrypt<br>- decrypt|
| text | string | Yes| Text to be encrypted or decrypted.<br> The text to be encrypted must be common text that meets the following requirement:<br> Maximum text length = Key length/8 - 66<br>For example, if the key is of 1024 bytes, the text to be encrypted cannot exceed 62 bytes (1024/8 -66 = 62).<br> The text to be decrypted must be binary text encoded in Base64. The default format is used for Base64 encoding.|
| action | string | Yes| Action to perform. The options are as follows:<br>- encrypt<br/>- decrypt|
| text | string | Yes| Text to be encrypted or decrypted.<br> The text to be encrypted must be common text that meets the following requirement:<br> Maximum text length = Key length/8 - 66<br>For example, if the key is of 1024 bytes, the text to be encrypted cannot exceed 62 bytes (1024/8 -66 = 62).<br> The text to be decrypted must be binary text encoded in Base64. The default format is used for Base64 encoding.|
| key | string | Yes| RSA key. The key is used as a public key in encryption and a private key in decryption.|
| transformation | string | No| RSA padding. The default value is **RSA/None/OAEPWithSHA256AndMGF1Padding**.|
| success | Function | No| Called when data is encrypted or decrypted successful.|
| success | Function | No| Called when data is encrypted or decrypted successfully.|
| fail | Function | No| Called when data fails to be encrypted or decrypted.|
| complete | Function | No| Called when the execution is complete.|
...
...
@@ -104,14 +104,14 @@ Encrypts or decrypts data using AES.
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| action | string | Yes| Action to perform. The options are as follows:<br>- encrypt<br>- decrypt|
| text | string | Yes| Text to be encrypted or decrypted.<br> The text to be encrypted must be common text. The text to be decrypted must be binary text encoded in Base64. The default format is used for Base64 encoding.|
| action | string | Yes| Action to perform. The options are as follows:<br>- encrypt<br/>- decrypt|
| text | string | Yes| Text to be encrypted or decrypted.<br> The text to be encrypted must be common text. The text to be decrypted must be binary text encoded in Base64. The default format is used for Base64 encoding.|
| key | string | Yes| Key used for encryption or decryption. It is a string encoded in Base64.|
| transformation | string | No| Encryption mode and padding of the AES algorithm. The default value is **AES/CBC/PKCS5Padding**.|
| iv | string | No| Initialization vector (IV) for AES-based encryption and decryption. The value is a string encoded in Base64. The default value is the key value.|
| ivOffset | string | No| Offset of the IV for AES-based encryption and decryption. The default value is **0**.|
| ivLen | string | No| Length of the IV for AES-based encryption and decryption, in bytes. The default value is **16**.|
| success | Function | No| Called when data is encrypted or decrypted successful.|
| success | Function | No| Called when data is encrypted or decrypted successfully.|
| fail | Function | No| Called when data fails to be encrypted or decrypted.|
| complete | Function | No| Called when the execution is complete.|
> - The APIs of this module are no longer maintained since API version 6. It is recommended that you use [`@ohos.fileio`](js-apis-fileio.md) instead.
> **NOTE**<br/>
> - The APIs of this module are no longer maintained since API version 6. You are advised to use [`@ohos.fileio`](js-apis-fileio.md) instead.
>
> - The initial APIs of this module are supported since API version 3. Newly added APIs will be marked with a superscript to indicate their earliest API version.
...
...
@@ -26,21 +24,21 @@ Moves a specified file to a given location.
| success | Function | No | Called when the source file is moved to the specified location successfully. This function returns the URI of the destination location. |
| fail | Function | No | Called when the operation fails. |
| complete | Function | No | Called when the execution is complete. |
| srcUri | string | Yes| Uniform resource identifier (URI) of the file to move. <br/>The URI can contain a maximum of 128 characters, excluding the following characters: "\*+,:;<=>?[]\|\x7F |
| dstUri | string | Yes| URI of the location to which the file is to move. <br/>The URI can contain a maximum of 128 characters, excluding the following characters: "\*+,:;<=>?[]\|\x7F |
| success | Function | No| Called when the file is moved to the specified location. This API returns the URI of the destination location.|
| fail | Function | No| Called when the file fails to be moved.|
| complete | Function | No| Called when the execution is complete.|
One of the following error codes will be returned if the operation fails.
| success | Function | No | Called when the source file is copied and saved to the specified location successfully. This function returns the URI of the destination location. |
| fail | Function | No | Called when the operation fails. |
| complete | Function | No | Called when the execution is complete. |
| srcUri | string | Yes| URI of the file to copy.|
| dstUri | string | Yes| URI of the location to which the copy is to be saved.<br>The directory of application resources and URI of the **tmp** type are not supported.|
| success | Function | No| Called when the file is copied and saved to the specified location. This API returns the URI of the destination location.|
| fail | Function | No| Called when the file fails to be copied.|
| complete | Function | No| Called when the execution is complete.|
One of the following error codes will be returned if the operation fails.
| uri | string | Yes | URI of the directory. |
| success | Function | No | Called when the operation is successful. |
| fail | Function | No | Called when the operation fails. |
| complete | Function | No | Called when the execution is complete. |
| uri | string | Yes| URI of the directory. <br/>The URI can contain a maximum of 128 characters, excluding the following characters: "\*+,:;<=>?[]\|\x7F |
| success | Function | No| Called when the file list is obtained.|
| fail | Function | No| Called when the file list fails to be obtained.|
| complete | Function | No| Called when the execution is complete.|
| fileList | Array<FileInfo> | File list. The format of each file is as follows:<br>{<br>uri:'file1',<br>lastModifiedTime:1589965924479,<br>length:10240,<br>type: 'file'<br>} |
**Table1** FileInfo
**Table1** FileInfo
| Name | Type | Description |
| Name| Type| Description|
| -------- | -------- | -------- |
| uri | string | File URI. |
| lastModifiedTime | number | Timestamp when the file is stored the last time, which is the number of milliseconds elapsed since 1970/01/01 00:00:00 GMT. |
| length | number | File size, in bytes. |
| type | string | File type. Available values are as follows:<br/>- **dir**: directory<br/>- **file**: file |
| uri | string | URI of the file.|
| lastModifiedTime | number | Timestamp when the file is saved the last time, which is the number of milliseconds elapsed since 1970/01/01 00:00:00 GMT.|
| length | number | File size, in bytes.|
| type | string | File type. Available values are as follows:<br>- **dir**: directory<br>- **file**: file |
One of the following error codes will be returned if the operation fails.
| recursive | boolean | No | Whether to recursively obtain the file list under a subdirectory. The default value is **false**. |
| success | Function | No | Called when the operation is successful. |
| fail | Function | No | Called when the operation fails. |
| complete | Function | No | Called when the execution is complete. |
| uri | string | Yes| URI of the file.|
| recursive | boolean | No| Whether to recursively obtain the file list under a subdirectory. The default value is **false**.|
| success | Function | No| Called when the file information is obtained.|
| fail | Function | No| Called when the file information fails to be obtained.|
| complete | Function | No| Called when the execution is complete.|
Return values of the **success** callback
Return values of the **success** callback:
| Name | Type | Description |
| Name| Type| Description|
| -------- | -------- | -------- |
| uri | string | File URI. |
| length | number | File size, in bytes. |
| lastModifiedTime | number | Timestamp when the file is stored the last time, which is the number of milliseconds elapsed since 1970/01/01 00:00:00 GMT. |
| type | string | File type. The values are as follows:<br/>- **dir**: directory<br/>- **file**: file |
| subFiles | Array | File list. |
| uri | string | URI of the file.|
| length | number | File size, in bytes.|
| lastModifiedTime | number | Timestamp when the file is saved the last time, which is the number of milliseconds elapsed since 1970/01/01 00:00:00 GMT.|
| type | string | File type. Available values are as follows:<br>- **dir**: directory<br>- **file**: file |
| subFiles | Array | List of files.|
One of the following error codes will be returned if the operation fails.
| position | number | No | Offset to the position where the writing starts. The default value is **0**. |
| append | boolean | No | Whether to enable the append mode. The default value is **false**. If the value is **true**, the **position** parameter will become invalid. |
| success | Function | No | Called when the operation is successful. |
| fail | Function | No | Called when the operation fails. |
| complete | Function | No | Called when the execution is complete. |
| uri | string | Yes| URI of a local file. If it does not exist, a file will be created.|
| buffer | Uint8Array | Yes| Buffer from which the data is derived.|
| position | number | No| Offset to the position where the writing starts. The default value is **0**.|
| append | boolean | No| Whether to enable the append mode. The default value is **false**. If the value is **true**, the **position** parameter will become invalid.|
| success | Function | No| Called when buffer data is written into the file. |
| fail | Function | No| Called when buffer data fails to be written into the file.|
| complete | Function | No| Called when the execution is complete.|
One of the following error codes will be returned if the operation fails.
Error code returned:
| Error Code | Description |
| Error Code| Description|
| -------- | -------- |
| 202 | Invalid parameter. |
| 300 | I/O error. |
| 202 | Incorrect parameters are detected.|
| 300 | An I/O error occurs.|
**Example**
...
...
@@ -347,7 +345,7 @@ export default {
writeArrayBuffer() {
file.writeArrayBuffer({
uri: 'internal://app/test',
buffer: new Uint8Array(8), // The buffer is of the Uint8Array type.
buffer: new Uint8Array(8), // The buffer is of the Uint8Array type.
success: function() {
console.log('call writeArrayBuffer success.');
},
...
...
@@ -364,36 +362,36 @@ export default {
readText(Object): void
Reads text from a specified file.
Reads text from a file. Only text files can be read and written.
| uri | string | Yes | URI of a local file. |
| encoding | string | No | Encoding format. The default format is UTF-8. |
| position | number | No | Position where the reading starts. The default value is the start position of the file. |
| length | number | No | Length of the text to be read (in bytes). The default value is **4096**. |
| success | Function | No | Called when the operation is successful. |
| fail | Function | No | Called when the operation fails. |
| complete | Function | No | Called when the execution is complete. |
| uri | string | Yes| URI of a local file.|
| encoding | string | No| Encoding format. The default format is **UTF-8**.|
| position | number | No| Position where the reading starts. The default value is the start position of the file.|
| length | number | No| Length of the text to read, in bytes. The default value is **4096**.|
| success | Function | No| Called when the text is read successfully.|
| fail | Function | No| Called when the text failed to be read.|
| complete | Function | No| Called when the execution is complete.|
Return values of the **success** callback
Return values of the **success** callback:
| Name | Type | Description |
| Name| Type| Description|
| -------- | -------- | -------- |
| text | string | Text read from the specified file. |
| text | string | Text read from the specified file.|
One of the following error codes will be returned if the operation fails.
| uri | string | Yes | URI of a local file. |
| position | number | No | Position where the reading starts. The default value is the start position of the file. |
| length | number | No | Length of data to read. If this parameter is not set, the reading proceeds until the end of the file. |
| success | Function | No | Called when the operation is successful. |
| fail | Function | No | Called when the operation fails. |
| complete | Function | No | Called when the execution is complete. |
| uri | string | Yes| URI of a local file.|
| position | number | No| Position where the reading starts. The default value is the start position of the file.|
| length | number | No| Length of data to read. If this parameter is not set, the reading proceeds until the end of the file.|
| success | Function | No| Called when the buffer data is read successfully.|
| fail | Function | No| Called when the buffer data fails to be read.|
| complete | Function | No| Called when the execution is complete.|
> - API version 9 is a canary version for trial use. The APIs of this version may be unstable.
> - The APIs of this module are system APIs and cannot be called by third-party applications.
This module provides APIs to implement volume and disk management, including obtaining volume information, mounting and unmounting volumes, partitioning disks, and formatting volumes.
Performs volume and disk management, including obtaining volume information, mounting and unmounting volumes, partitioning disks, and formatting volumes.
## Modules to Import
...
...
@@ -54,7 +54,7 @@ Asynchronously obtains information about all available volumes. This API uses a
