fs.writeFile(file, data[, options], callback)

• file <string> | <Buffer> | <URL> | <integer> 文件名或文件描述符

  ¥file <string> | <Buffer> | <URL> | <integer> filename or file descriptor

• data <string> | <Buffer> | <TypedArray> | <DataView>

• options <Object> | <string>

  • encoding <string> | <null> 默认值：'utf8'

    ¥encoding <string> | <null> Default: 'utf8'

  • mode <integer> 默认值：0o666

    ¥mode <integer> Default: 0o666

  • flag <string> 参见 支持文件系统 flags。默认值：'w'。

    ¥flag <string> See support of file system flags. Default: 'w'.

  • flush <boolean> 如果所有数据都成功写入文件，并且 flush 是 true，则使用 fs.fsync() 来刷新数据。默认值：false。

    ¥flush <boolean> If all data is successfully written to the file, and flush is true, fs.fsync() is used to flush the data. Default: false.

  • signal <AbortSignal> 允许中止正在进行的 writeFile

    ¥signal <AbortSignal> allows aborting an in-progress writeFile

• callback <Function>

  • err <Error> | <AggregateError>

当 file 是文件名时，将数据异步地写入文件，如果文件已存在则替换该文件。data 可以是字符串或缓冲区。

¥When file is a filename, asynchronously writes data to the file, replacing the file if it already exists. data can be a string or a buffer.

当 file 是文件描述符时，其行为类似于直接调用 fs.write()（推荐）。请参阅以下有关使用文件描述符的说明。

¥When file is a file descriptor, the behavior is similar to calling fs.write() directly (which is recommended). See the notes below on using a file descriptor.

如果 data 是缓冲区，则忽略 encoding 选项。

¥The encoding option is ignored if data is a buffer.

mode 选项仅影响新创建的文件。有关详细信息，请参阅 fs.open()。

¥The mode option only affects the newly created file. See fs.open() for more details.

import { writeFile } from 'node:fs';
import { Buffer } from 'node:buffer';

const data = new Uint8Array(Buffer.from('Hello Node.js'));
writeFile('message.txt', data, (err) => {
  if (err) throw err;
  console.log('The file has been saved!');
}); 拷贝

如果 options 是字符串，则它指定编码：

¥If options is a string, then it specifies the encoding:

import { writeFile } from 'node:fs';

writeFile('message.txt', 'Hello Node.js', 'utf8', callback); 拷贝

在同一个文件上多次使用 fs.writeFile() 而不等待回调是不安全的。对于这种情况，建议使用 fs.createWriteStream()。

¥It is unsafe to use fs.writeFile() multiple times on the same file without waiting for the callback. For this scenario, fs.createWriteStream() is recommended.

与 fs.readFile 类似 - fs.writeFile 是一种便捷方法，它在内部执行多个 write 调用以写入传递给它的缓冲区。对于性能敏感的代码，则考虑使用 fs.createWriteStream()。

¥Similarly to fs.readFile - fs.writeFile is a convenience method that performs multiple write calls internally to write the buffer passed to it. For performance sensitive code consider using fs.createWriteStream().

可以使用 <AbortSignal> 取消 fs.writeFile()。取消是 "最大努力"，可能仍有一些数据要写入。

¥It is possible to use an <AbortSignal> to cancel an fs.writeFile(). Cancelation is "best effort", and some amount of data is likely still to be written.

import { writeFile } from 'node:fs';
import { Buffer } from 'node:buffer';

const controller = new AbortController();
const { signal } = controller;
const data = new Uint8Array(Buffer.from('Hello Node.js'));
writeFile('message.txt', data, { signal }, (err) => {
  // When a request is aborted - the callback is called with an AbortError
});
// When the request should be aborted
controller.abort(); 拷贝

中止正在进行的请求不会中止单个操作系统请求，而是中止内部缓冲的 fs.writeFile 执行。

¥Aborting an ongoing request does not abort individual operating system requests but rather the internal buffering fs.writeFile performs.