Node.js fs.openSync()方法
原文:https://www.geeksforgeeks.org/node-js-fs-opensync-method/
fs.openSync()方法是 fs 模块的内置应用编程接口，用于返回代表文件描述符的整数值。
语法:
fs.openSync( path, flags, mode )
参数:该方法接受三个参数，如上所述，如下所述:
- Path: The path to save the file. Its type is string, buffer or web address.
- Flag: It holds strings or numerical values. Its default value is "r".
- mode: Save the string or integer value, with the default value of 0o666.
返回值:返回一个代表文件描述符的数字。
下面的例子说明了 fs.openSync()方法在 Node.js 中的使用:
例 1:
// Node.js program to demonstrate the
// fs.openSync() method
// Including fs module
var fs = require('fs');
// Defining filename
var filename = './myfile';
// Calling openSync method
// with its parameters
var res = fs.openSync(filename, 'r');
// Prints output
console.log(res);
输出:
23
这里，标志“r”表示文件已经被创建，它读取创建的文件。
例 2:
// Node.js program to demonstrate the
// fs.openSync() method
// Including fs module
var fs = require('fs');
// Defining path
var path = require('path');
// Calling openSync method with
// all its parameters
var fd = fs.openSync(path.join(
process.cwd(), 'input.txt'), 'w', 0o666);
// This will append the content
// of file created above
fs.writeSync(fd, 'GeeksforGeeks');
// Setting timeout
setTimeout(function () {
// Its printed after the file is closed
console.log('closing file now');
// closing file descriptor
fs.closeSync(fd);
}, 10000);
console.log("Program done!");
输出:
Program done!
closing file now
这里，标记“w”表示文件被创建或覆盖。
参考:https://nodejs . org/API/fs . html # fs _ fs _ opensync _ path _ flags _ mode
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