fs module - fs.open()

open(): 

To create a file, to write to a file, or to read a file the fs.open() method is used.

Syntax:

    

    fs.open(filename, options, callback);

Example:

    

    var fs = require("fs");

    fs.open("mynewfile2.txt", "w", function (err, file) {

      if (err) throw err;

      console.log("Saved!");

    });

FLAG	DESCRIPTION
r	To open a file to read and throw an exception if the file doesn’t exist.
r+	Open file to read and write. Throw an exception if the file doesn’t exist.
rs+	Open file in synchronous mode to read and write.
w	Open file for writing. File is created if it doesn’t exist.
wx	It is the same as ‘w’ but fails if the path exists.
w+	Open file to read and write. File is created if it doesn’t exist.
wx+	It is the same as ‘w+’ but fails if the path exists.
a	Open file to append. File is created if it doesn’t exist.
ax	It is the same as ‘a’ but fails if the path exists.
a+	Open file for reading and appending. File is created if it doesn’t exist.
ax+	It is the same as ‘a+’ but fails if the path exists.

fs.openSync():

    

    fs.openSync(path, options);

    // 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);