Skip to content


Subversion checkout URL

You can clone with
Download ZIP
Extras missing from node's fs module
JavaScript C++ Other


Extras not included in Node's fs module.


Install via npm:

npm install fs-ext


fs-ext imports all of the methods from the core 'fs' module, so you don't need two objects.

var fs = require('fs-ext');
var fd = fs.openSync('foo.txt', 'r');
fs.flock(fd, 'ex', function (err) {
    if (err) {
        return console.log("Couldn't lock file");
    // file is locked

For an advanced example checkout example.js.


fs.flock(fd, flags, [callback])

Asynchronous flock(2). No arguments other than a possible error are passed to the callback. Flags can be 'sh', 'ex', 'shnb', 'exnb', 'un' and correspond to the various LOCK_SH, LOCK_EX, LOCK_SH|LOCK_NB, etc.

fs.flockSync(fd, flags)

Synchronous flock(2). Throws an exception on error.

fs.fcntl(fd, cmd, [arg], [callback])

Asynchronous fcntl(2).

callback will be given two arguments (err, result).

The supported commands are:

  • 'getfd' ( F_GETFD )
  • 'setfd' ( F_SETFD )

Requiring this module adds FD_CLOEXEC to the constants module, for use with F_SETFD.

fs.fcntlSync(fd, flags)

Synchronous fcntl(2). Throws an exception on error., offset, whence, [callback])

Asynchronous lseek(2).

callback will be given two arguments (err, currFilePos).

whence can be 0 (SEEK_SET) to set the new position in bytes to offset, 1 (SEEK_CUR) to set the new position to the current position plus offset bytes (can be negative), or 2 (SEEK_END) to set to the end of the file plus offset bytes (usually negative or zero to seek to the end of the file).

fs.seekSync(fd, offset, whence)

Synchronous lseek(2). Throws an exception on error. Returns current file position.

fs.utime(path [, atime, mtime] [, callback])

Asynchronous utime(2).

Arguments atime and mtime are in seconds as for the system call. Note that the number value of Date() is in milliseconds, so to use the 'now' value with fs.utime() you would have to divide by 1000 first, e.g.

Just like for utime(2), the absence of the atime and mtime means 'now'.

fs.utimeSync(path [, atime, mtime])

Synchronous version of utime(). Throws an exception on error.

Something went wrong with that request. Please try again.