Node.js fs.futimes() 方法

fs.futimes() 方法用于异步更改给定文件描述符的修改和访问时间戳。可以使用数字、字符串或 Date 对象指定时间戳。如果时间戳无法转换为正确的数字，或者是 NaN、Infinity 或 -Infinity，则会引发错误。

句法：

fs.futimes( fd, atime, mtime, callback )

参数：此方法接受上面提到的四个参数，如下所述：

• fd：它是一个整数，表示必须更改时间戳的文件的文件描述符。
• atime：数字、字符串或日期对象，表示要设置的新访问时间戳。
• mtime：数字、字符串或日期对象，表示要设置的新修改时间戳。
• 回调：它是一个在方法执行时将被调用的函数。
  • err：如果方法失败会抛出一个错误。

下面的示例说明了 Node.js 中的fs.futimes() 方法：

示例 1：

// Node.js program to demonstrate the
// fs.futimes() method
  
// Import the filesystem module
const fs = require('fs');
  
// Get the file descriptor of the file
const fd = fs.openSync("example_file.txt", "r+");
  
console.log("Details before changing time:");
  
// Get the stats object of the file
prevStats = fs.statSync("example_file.txt");
  
// Access the modified and access time of the file
console.log("Modification Time:", prevStats.mtime);
console.log("Access Time:", prevStats.atime);
  
// Get the current time to change the timestamps
let changedModifiedTime = new Date();
let changedAccessTime = new Date();
  
// Use the futimes() function to assign
// the new timestamps to the file descriptor
fs.futimes(fd, changedAccessTime, changedModifiedTime, () => {
  // Get the stats object of the file
  console.log("\nDetails after changing time:");
  
  // Get the stats object of the file
  changedStats = fs.statSync("example_file.txt");
  
  // Access the changed modified and access time of the file
  console.log("Changed Modification Time:", changedStats.mtime);
  console.log("Changed Access Time:", changedStats.atime);
});

输出：

Details before changing time:
Modification Time: 2020-05-25T15:59:10.807Z
Access Time: 2020-05-25T15:59:10.807Z

Details after changing time:
Changed Modification Time: 2020-05-25T16:01:34.915Z
Changed Access Time: 2020-05-25T16:01:34.915Z

示例 2：

// Node.js program to demonstrate the
// fs.futimes() method
  
// Import the filesystem module
const fs = require('fs');
  
// Get the file descriptor of the file
const fd = fs.openSync("example_file.txt", "r+");
  
console.log("Details before changing time:");
  
// Get the stats object of the file
prevStats = fs.statSync("example_file.txt");
  
// Access the modified and access time of the file
console.log("Modification Time:", prevStats.mtime);
console.log("Access Time:", prevStats.atime);
  
// Get the current time to change the timestamps
let changedModifiedTime = new Date("April 01, 2019 04:13:20");
let changedAccessTime = new Date("April 12, 2019 08:12:40");
  
// Use the futimes() function to assign
// the new timestamps to the file descriptor
fs.futimes(fd, changedAccessTime, changedModifiedTime, () => {
  // Get the stats object of the file
  console.log("\nDetails after changing time:");
  
  // Get the stats object of the file
  changedStats = fs.statSync("example_file.txt");
  
  // Access the changed modified and access time of the file
  console.log("Changed Modification Time:", changedStats.mtime);
  console.log("Changed Access Time:", changedStats.atime);
});

输出：

Details before changing time:
Modification Time: 2020-05-25T16:06:28.977Z
Access Time: 2020-05-25T16:06:28.977Z

Details after changing time:
Changed Modification Time: 2019-03-31T22:43:20.000Z
Changed Access Time: 2019-04-12T02:42:40.000Z

参考： https://nodejs.org/api/fs.html#fs_fs_futimes_fd_atime_mtime_callback