Node.js fs.realpath() Method

The fs.realPath() method is used to compute the canonical pathname of the given path. It does so by resolving the ., .. and the symbolic links in the path.

Syntax:

fs.realpath( path, options, callback )

Parameters: This method accept three parameters as mentioned above and described below:

• path: It holds the path of the directory that has to be resolved. It can be a String, Buffer or URL.
• options: It is an string or object that can be used to specify optional parameters that will affect the operation. It has one optional parameter:
  • encoding: It is a string which defines the encoding of the resolved path.
• callback: It is the function that would be called when the method is executed.
  • err: It is an error that would be thrown if the operation fails.
  • resolvedPath: It is string or buffer that represents the resolved path.

Below examples illustrate the fs.realPath() method in Node.js:

Example 1: This example uses fs.realPath() method to get the canonical paths of the given path.

// Node.js program to demonstrate the
// fs.realPath() method

// Import the filesystem module
const fs = require('fs');

console.log("Current Directory Path:", __dirname);

// Finding the canonical path
// one directory up
path1 = __dirname + "\\..";

fs.realpath(path1, (error, resolvedPath) => {
  if (error) {
    console.log(error);
  }
  else {
    console.log("One directory up resolved"
      + " path is: ", resolvedPath);
  }
});

// Finding the canonical path
// two directories up
path2 = __dirname + "\\..\\..";

fs.realpath(path2, (error, resolvedPath) => {
  if (error) {
    console.log(error);
  }
  else {
    console.log("Two directories up resolved"
          + " path is:", resolvedPath);
  }
});

Output:

Current Directory Path: G:\tutorials\nodejs-fs-realPath
Two directories up resolved path is: G:\
One directory up resolved path is: G:\tutorials

Example 2: This example uses fs.realPath() method to demonstrate the different encoding type.

// Node.js program to demonstrate the
// fs.realPath() method

// Import the filesystem module
const fs = require('fs');

path = __dirname + "\\..";

// Getting the canonical path in utf8 encoding
fs.realpath(path, {encoding: "utf8"}, (error, resolvedPath) => {
  if (error) {
    console.log(error);
  }
  else {
    console.log("The resolved path is:", resolvedPath);
  }
});

// Getting the canonical path in hex encoding
fs.realpath(path, {encoding: "hex"}, (error, resolvedPath) => {
  if (error) {
    console.log(error);
  }
  else {
    console.log("The resolved path is:", resolvedPath);
  }
});

// Getting the canonical path in base64 encoding
fs.realpath(path, {encoding: "base64"}, (error, resolvedPath) => {
  if (error) {
    console.log(error);
  }
  else {
    console.log("The resolved path is:", resolvedPath);
  }
});

Output:

The resolved path is: G:\tutorials
The resolved path is: 473a5c7475746f7269616c73
The resolved path is: RzpcdHV0b3JpYWxz

Reference: https://nodejs.org/api/fs.html#fs_fs_realpath_path_options_callback