Node.js fs.filehandle.chown()方法
原文:https://www . geesforgeks . org/node-js-fs-file handle-chown-method/
fs.filehandle.chown() 方法是文件系统模块中类 fs.filehandle 的内置应用编程接口，用于更改特定文件的所有权。
语法:
const filehandle.chown(uid, gid)
参数:该方法接受两个参数，如上所述，如下所述:
- uid: :代表用户 id。
- gid: 表示组标识符。
返回值:该方法返回一个不包含任何值的待定承诺。
下面的程序说明了 fs.filehandle.chown() 方法的使用。 示例 1: 文件名:index.js
java 描述语言
// Node.js program to demonstrate the
// filehandle.chown() method
const fs = require('fs');
const fsPromises = fs.promises;
console.log("content of file before operation :- "
+ (fs.readFileSync('example.txt')));
// Initiating asyncrionise function
async function funct() {
// Initializing filehandle
let filehandle = null;
try {
// Creating and initiating filehandle
filehandle = await
fsPromises.open('example.txt', 'r+');
// Modifying the file ownership
// by using chown() method
const prom = filehandle.chown(1, 1);
} finally {
if (filehandle) {
// Close the file if it is opened.
console.log("ownership is changed"
+ " successfully");
console.log("content of file after"
+ " operation :- " +
(fs.readFileSync('example.txt')));
await filehandle.close();
}
}
}
funct().catch(console.error);
运行程序前的目录结构:
运行程序后的目录结构:
使用以下命令运行 index.js 文件:
node index.js
输出:
content of file before operation :- Content of example.txt file
ownership is changed successfully
content of file after operation :- Content of example.txt file
示例 2: 文件名:index.js
java 描述语言
// Node.js program to demonstrate the
// filehandle.chown() method
const fs = require('fs');
const fsPromises = fs.promises;
// Data for the new file
let data = "This is a file containing "
+ "a collection of books.";
// Name of the file to be created
let file = "books.txt";
// Creating the new file 'books.txt'
fs.writeFile(file, data, (err) => {
// Cathing error
if (err) {
console.log(err);
}
});
// Using fs.exists() method
fs.exists(file, (exists) => {
if (exists) {
console.log("content of file"
+ " before operation :- " +
(fs.readFileSync(file)));
}
});
// Initiating asyncrionise function
async function funct() {
// Initializing filehandle
let filehandle = null;
try {
// Creating and initiating
// filehandle
filehandle = await
fsPromises.open(file, 'r+');
// Modifying the file ownership
// by using chown() method
const prom = filehandle.chown(1, 1);
} finally {
if (filehandle) {
// Close the file if it is opened.
console.log("ownership is changed");
console.log("content of file "
+ "after operation :- " +
(fs.readFileSync(file)));
await filehandle.close();
}
}
}
funct().catch(console.error);
运行程序前的目录结构:
运行程序后的目录结构:
使用以下命令运行 index.js 文件:
node index.js
输出:
content of file before operation :- This is a file containing a collection of books.
ownership is changed
content of file after operation :- This is a file containing a collection of books.
参考: https://nodejs . org/dist/latest-v 12 . x/docs/API/fs . html # fs _ file handle _ chown _ uid _ GID
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