winreg

What is winreg?

The winreg npm package is a Node.js library for accessing and manipulating the Windows Registry. It allows you to read, write, and delete registry keys and values, making it useful for applications that need to interact with the Windows operating system at a low level.

What are winreg's main functionalities?

Read a registry key

This feature allows you to read a value from a specified registry key. The code sample demonstrates how to read a value named 'MyValue' from the 'HKEY_CURRENT_USER\Software\MyApp' key.

const Winreg = require('winreg');
const regKey = new Winreg({
  hive: Winreg.HKCU, // HKEY_CURRENT_USER
  key: '\Software\MyApp'
});
regKey.get('MyValue', (err, item) => {
  if (err) console.log('Error:', err);
  else console.log('Value:', item.value);
});

Write a registry key

This feature allows you to write a value to a specified registry key. The code sample demonstrates how to set a string value named 'MyValue' with the data 'MyData' in the 'HKEY_CURRENT_USER\Software\MyApp' key.

const Winreg = require('winreg');
const regKey = new Winreg({
  hive: Winreg.HKCU, // HKEY_CURRENT_USER
  key: '\Software\MyApp'
});
regKey.set('MyValue', Winreg.REG_SZ, 'MyData', (err) => {
  if (err) console.log('Error:', err);
  else console.log('Value written successfully');
});

Delete a registry key

This feature allows you to delete a value from a specified registry key. The code sample demonstrates how to remove a value named 'MyValue' from the 'HKEY_CURRENT_USER\Software\MyApp' key.

const Winreg = require('winreg');
const regKey = new Winreg({
  hive: Winreg.HKCU, // HKEY_CURRENT_USER
  key: '\Software\MyApp'
});
regKey.remove('MyValue', (err) => {
  if (err) console.log('Error:', err);
  else console.log('Value removed successfully');
});

Other packages similar to winreg

windows-registry

The windows-registry package is another alternative for interacting with the Windows Registry from Node.js. It provides basic functionality for reading and writing registry keys and values. While it is similar to winreg, it may not be as feature-rich or actively maintained.

README

node-winreg

node module that provides access to the Windows Registry through the REG commandline tool

Installation

The following command installs node-winreg.

npm install winreg 

If you prefer to install without the development tools used to generate the HTML documentation (into a production environment for example) you should use the following command.

npm install winreg --production

Note that the development dependencies will not be installed if this package was installed as a dependency of another package.

Documentation

The documentation is generated using jsdoc with the docstrap template. You can view the API documentation online, download the latest documentation or generate it from the sourcecode.

Online Documentation

View the latest docs online.

Download Documentation

To download the latest docs from GIT the following command is used.

npm run-script download-docs

Generate Documentation

To generate the docs from the sources you can use the following command.

npm run-script generate-docs

Note that generating the docs requires the development dependencies to be installed.

Example Usage

Let's start with an example. The code below lists the autostart programs of the current user.

var Registry = require('winreg')
,   regKey = new Registry({                                       // new operator is optional
      hive: Registry.HKCU,                                        // open registry hive HKEY_CURRENT_USER
      key:  '\\Software\\Microsoft\\Windows\\CurrentVersion\\Run' // key containing autostart programs
    })

// list autostart programs
regKey.values(function (err, items /* array of RegistryItem */) {
  if (err)
    console.log('ERROR: '+err);
  else
    for (var i=0; i<items.length; i++)
      console.log('ITEM: '+items[i].name+'\t'+items[i].type+'\t'+items[i].value);
});

Troubleshooting

Access to restricted keys

Since Windows Vista access to certain Registry Hives (HKEY_LOCAL_MACHINE or short HKLM for example) is restricted to processes that run in a security elevated context even if the user that starts the process is an admin. You can start a console within that context by right clicking the console shortcut and selecting the item with the shield icon called "Run as administrator" from the context menu.

Under some rare circumstances access to Registry Hives or particular keys may also be blocked by some antivirus programs or the Windows Group Policy Editor (google for gpedit.msc).

You can also use the regedit.exe tool shipped with Windows to check if you actually have access.

Processing UTF-8 data

The Microsoft Windows console isn't capable of handling UTF-8 encoded text unless you set it up properly. If you see weird question marks for certain characters, it's probhably a problem with the encoding.

By default the console is setup to use an encoding that suits the language of the Windows operating system installation. Windows uses codepages to specify encodings for the console. The codepage is a unique number which is assigned to each encoding.

If you want to query the currently selected codepage you can type the command chcp (w/o parameters). To set a new codepage (UTF-8 for this example) you pass the codepage number as the only argument to chcp. The codepage value for UTF-8 is 65001.

You can easily do this from within your nodejs script by using the child_process.execSync(...) function like the following example shows.

var execSync = require('child_process').execSync;
console.log(execSync('chcp').toString());
console.log(execSync('chcp 65001').toString());

An even better approach would be to extract and store the value returned by a call to chcp prior setting the console to UTF-8 and resetting the codepage after your script is done.

License

This project is released under BSD 2-Clause License.

Copyright (c) 2016, Paul Bottin All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.