Mastering Node.js - Second Edition

fs.writeFile(path, data, [options], callback)

The fs.writeFile(path, data, [options], callback) method writes the contents of data to the file at path. The data argument can be either a buffer or a string. The following options are available:

• encoding: Defaults to utf8. If data is a buffer, this option is ignored.
• mode: Octal representation of file mode, defaulting to 0666.
• flag: Write flags, defaulting to w.

Usage is straightforward:

fs.writeFile('test.txt', 'A string or Buffer of data', err => {   if (err) {     return console.log(err);   }   // File has been written });