Read/Write Windows Registry in Node using ffi-napi with a GoLang c-shared DLL.
This was to demo that you can use GoLang c-shared DLL (Go>=1.10) with ffi.
Syntax is inspired from InnoSetup's Pascal Scripting Registry functions.

Example

const regedit = require("regodit"); //commonjs
import regedit from 'regodit'; //esm

(async()=>{

  //promise
  const res = await regedit.promises.RegListAllSubkeys("HKCU","Software/Valve");
  console.log(res);
  
  //sync
  const resSync = regedit.RegListAllSubkeys("HKCU","Software/Valve");
  console.log(resSync);

})().catch(console.error);

Install

npm install regodit

Prequisites: C/C++ build tools (Visual Studio) and Python 2.7 (node-gyp) in order to build ffi-napi.

API

Promise are under the "promises" namespace otherwise sync method

eg:

• promises.RegListAllSubkeys("HKCU","Software/Valve") //Promise
• RegListAllSubkeys("HKCU","Software/Valve") //Sync

RegKeyExists

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key) bool

If the key exists or not.

RegListAllSubkeys

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key) string[] | null

List all subkeys name for a given key (non-recursive).

NB: For a more complete listing see RegExportKey below.

RegListAllValues

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key) string[] | null

List all values name for a given key.

NB: For a more complete listing see RegExportKey below.

RegQueryValueType

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key, string name) string : "NONE"|"SZ"|"EXPAND_SZ"|"BINARY"|"DWORD"|"DWORD_BIG_ENDIAN"|"LINK"|"MULTI_SZ"|"RESOURCE_LIST"|"FULL_RESOURCE_DESCRIPTOR"|"RESOURCE_REQUIREMENTS_LIST"|"QWORD"

Return key/value type.

RegQueryStringValue //REG_SZ & REG_EXPAND_SZ

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key, string name) string | null

Return string value of given key/valueName.

RegQueryStringValueAndExpand //REG_EXPAND_SZ (expands environment-variables)

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key, string name) string | null

Return string value of given key/valueName and expands environment-variable by replacing them with the values defined for the current user.

RegQueryBinaryValue //REG_BINARY

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key, string name) string | null

Return binary value of given key/valueName.

RegQueryIntegerValue //REG_DWORD & REG_QWORD

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key, string name) string | null

Return integer value of given key/valueName.

NB: REG_QWORD is a 64-bit unsigned integer.

RegWriteKey

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key) void

Create given key whether the key already exists or not (subkeys are created if necessary).

RegWriteStringValue

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key, string name, string value) void

Write string value in given key/valueName as 'REG_SZ' (subkeys are created if necessary).

RegWriteExpandStringValue

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key, string name, string value) void

Write string value in given key/valueName as 'REG_EXPAND_SZ' (subkeys are created if necessary).

RegWriteBinaryValue

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key, string name, string value) void

Write binary value in given key/valueName as 'REG_BINARY' (subkeys are created if necessary).

RegWriteDwordValue

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key, string name, string value) void

Write integer value in given key/valueName as 'REG_DWORD' (subkeys are created if necessary).

RegWriteQwordValue

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key, string name, string value) void

Write integer value in given key/valueName as 'REG_QWORD' (subkeys are created if necessary).

RegDeleteKeyValue

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key, string name) void

Delete given key/valueName.

RegDeleteKey

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key) void

Delete given key.

NB: If key has some subkeys then key will not be deleted (see below RegDeleteKeyIncludingSubkeys for this)

RegDeleteKeyIncludingSubkeys

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key) void

Delete given key and all subkeys.

RegExportKey

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key, [obj option]) RegDump{}¹

List all values with their name, content, type and all subkeys from given key recursively (default) or not.
Export it in an object representation (see ¹RegDump) where
subkeys are treated as nested objects including an additional propriety values containing values data if any.

option ⚙️

name	type	default	description
recursive	bool	true	List values recursively
absenceError	bool	true	Throw when a key doesn't exist

Example

const regdump = await regedit.promises.RegExportKey("HKCU","Software/Valve/Steam");
console.log(regdump);

//Console output:

{
  "values": [ //Values of HKCU/Software/Valve/Steam
    {"name": "H264HWAccel","type": "DWORD","data": "1"},
    {"name": "Language","type": "SZ","data": "english"},
    ... //etc
   ],
   "ActiveProcess": { //Subkey ActiveProcess of HKCU/Software/Valve/Steam
    "values": [ //Values of HKCU/Software/Valve/Steam/ActiveProcess
      {"name": "SteamClientDll","type": "SZ","data": "C:\\Program Files (x86)\\Steam\\steamclient.dll"},
      {"name": "SteamClientDll64","type": "SZ","data": "C:\\Program Files (x86)\\Steam\\steamclient64.dll"},
      ... //etc
    ]
   },
    "Apps": { //Subkey Apps of HKCU/Software/Valve/Steam
        "values": [], //Values of HKCU/Software/Valve/Steam/Apps (in this case none)
        "480": { //Subkey 480 of HKCU/Software/Valve/Steam/Apps
          "values": [ //Values of HKCU/Software/Valve/Steam/Apps/480
            {"name": "Name","type": "SZ","data": "Spacewar"}, 
            ... //etc
          ]
        },
        "550": {
          "values": [
            {"name": "Installed","type": "DWORD","data": "0"},
            {"name": "Name","type": "SZ","data": "Left 4 Dead 2"},
            ... //etc
          ]
        },
        ... //etc
    },
    ... //etc
}

RegImportKey

(string root: "HKCR"|"HKCU"|"HKLM"|"HKU"|"HKCC", string key, RegDump{}¹ data, [obj option]) void

Import back to the registry a previously exported key (see RegExportKey and ¹RegDump).
This overwrites existing data if any.

option ⚙️

name	type	default	description
absenceDelete	bool	false	Delete keys in target that exists outside the dump

---

¹RegDump:

interface RegDump {
    values: [ {name: string, type: string, data: string} ...], 
    subkeyName : RegDump{}, ... 
}

Build cgo-dll

Dependencies

• golang.org/x/sys/windows/registry

Run lib/go/dependencies.cmd or
>_ go get golang.org/x/sys/windows/registry

go get requires git for windows installed and in PATH.

cgo requires a gcc compiler installed and in PATH.
Recommended : http://tdm-gcc.tdragon.net/download

Build

Run lib/go/build.cmd or npm run-script build

Manually:

>_ cd src\regodit
>_ go generate
>_ cd ..\
>_ set GOPATH="%~dp0"
>_ go build -buildmode=c-shared -o ..\dist\regodit.dll regodit