使用 Node.js 写入文件
🌐 Writing files with Node.js
写入文件
🌐 Writing a file
在 Node.js 中写入文件最简单的方法是使用 fs.writeFile() API。
🌐 The easiest way to write to files in Node.js is to use the fs.writeFile() API.
const = ('node:fs');
const = 'Some content!';
.('/Users/joe/test.txt', , => {
if () {
.();
} else {
// file written successfully
}
});
同步写入文件
🌐 Writing a file synchronously
或者，你可以使用同步版本 fs.writeFileSync()：
🌐 Alternatively, you can use the synchronous version fs.writeFileSync():
const = ('node:fs');
const = 'Some content!';
try {
.('/Users/joe/test.txt', );
// file written successfully
} catch () {
.();
}
你也可以使用 fs/promises 模块提供的基于 Promise 的 fsPromises.writeFile() 方法：
🌐 You can also use the promise-based fsPromises.writeFile() method offered by the fs/promises module:
const = ('node:fs/promises');
async function () {
try {
const = 'Some content!';
await .('/Users/joe/test.txt', );
} catch () {
.();
}
}
();
默认情况下，如果文件已存在，此 API 将替换文件的内容。
🌐 By default, this API will replace the contents of the file if it does already exist.
你可以通过指定一个标志来修改默认设置：
fs.writeFile('/Users/joe/test.txt', content, { : 'a+' }, => {});
你可能会使用的标志是
🌐 The flags you'll likely use are
| Flag | Description | File gets created if it doesn't exist |
|---|---|---|
r+ | This flag opens the file for reading and writing | ❌ |
w+ | This flag opens the file for reading and writing and it also positions the stream at the beginning of the file | ✅ |
a | This flag opens the file for writing and it also positions the stream at the end of the file | ✅ |
a+ | This flag opens the file for reading and writing and it also positions the stream at the end of the file | ✅ |
- 你可以在 fs 文档 中找到有关标志的更多信息。
向文件追加内容
🌐 Appending content to a file
当你不想用新内容覆盖文件，而是想向文件中添加内容时，将内容附加到文件会非常方便。
🌐 Appending to files is handy when you don't want to overwrite a file with new content, but rather add to it.
示例
🌐 Examples
向文件末尾添加内容的一个方便方法是 fs.appendFile()（以及它的同步版本 fs.appendFileSync()）：
🌐 A handy method to append content to the end of a file is fs.appendFile() (and its fs.appendFileSync() counterpart):
const = ('node:fs');
const = 'Some content!';
.('file.log', , => {
if () {
.();
} else {
// done!
}
});
使用 Promise 的示例
🌐 Example with Promises
这是一个 fsPromises.appendFile() 示例：
🌐 Here is a fsPromises.appendFile() example:
const = ('node:fs/promises');
async function () {
try {
const = 'Some content!';
await .('/Users/joe/test.txt', );
} catch () {
.();
}
}
();