Instructions for using the fs.writeFileSync method in node.js_node.js

Method description:

Synchronized version of fs.writeFile() .

Grammar:

Copy code The code is as follows:

fs.writeFileSync(filename, data, [options])

Since this method belongs to the fs module, the fs module needs to be introduced before use (var fs= require(“fs”) )

Receive parameters:

filename (String) File name

data (String | Buffer) The content to be written can be string or buffer data.

options (Object) option array object, including:

· encoding (string) Optional value, default 'utf8', when data is buffer, the value should be ignored.

· mode (Number) File read and write permissions, default value 438

·flag (String) Default value ‘w’

Example:

Copy code The code is as follows:

fs.writeFileSync('message.txt', 'Hello Node');

Source code:

Copy code The code is as follows:

fs.writeFileSync = function(path, data, options) {
if (!options) {
Options = { encoding: 'utf8', mode: 438 /*=0666*/, flag: 'w' };
} else if (util.isString(options)) {
Options = { encoding: options, mode: 438, flag: 'w' };
} else if (!util.isObject(options)) {
Throw new TypeError('Bad arguments');
}
assertEncoding(options.encoding);
var flag = options.flag || 'w';
var fd = fs.openSync(path, flag, options.mode);
if (!util.isBuffer(data)) {
Data = new Buffer('' data, options.encoding || 'utf8');
}
var written = 0;
var length = data.length;
var position = /a/.test(flag) ? null : 0;
try {
while (written < length) {
Written = fs.writeSync(fd, data, written, length - written, position);
position = written;
}
} finally {
fs.closeSync(fd);
}
};