winprefs

macOS users: please see macprefs for an equivalent tool.

This package dumps a registry path to equivalent reg commands. It contains two commands. Save-Preferences creates a batch script composed of reg commands for copying into a script. Write-RegCommands is effectively the same but requires a path argument and only writes to standard output.

By default both commands default to a maximum depth of 20. Save-Preferences defaults to path HKCU:.

Note that by default only HKCU: and HKLM: are mounted in PowerShell. Others need to be mounted and must be under the appropriate name such as HKU for HKEY_USERS.

Keys/values are skipped under these conditions:

• Depth limit (default: 20); this can be changed by passing -MaxDepth LIMIT or -m LIMIT
• Key that cannot be read for any reason such as permissions
• Value contains newlines
• Value has type REG_UNKNOWN

An example of an always skipped key under normal circumstances is HKLM\SECURITY, even if this is run as administrator.

WARNING: If you save an entire tree such as HKLM: to a file and attempt to run said script, you probably will break your OS. The output of this tool is meant for getting a single command at a time, testing it, and then using it in an appropriate script. The author will not be held responsible for any damages.

Installation

Install-Module -Name WinPrefs

Usage

Save-Preferences
# or the alias:
prefs-export

Save-Preferences generates an exec-reg.bat (default name) file and saves to ${env:APPDATA}\prefs-export by default. This can be changed by passing -OutputDirectory DIR (or -o DIR). The file name can be changed by passing -OutputFile FILE (or -f FILE).

The format can be changed with the -Format argument. Accepted format strings:

• It accepts switch -Commit/-c to initialise and commit to a Git repository in the output directory. It also accepts a -DeployKey PATH parameter and will push if this is specified. Any other Git management such as the branch name, etc must be managed in the output directory manually.

Write-RegCommands HKCU:
# or the alias
path2reg HKCU:

Write-RegCommands prints out equivalent reg commands to reproduce the keys/values at the given path. reg command output is escaped for Batch file only. No variables will be present in the output. If you want to use a reg command in PowerShell you need to replace %% with %.

Automated Usage

You can create a scheduled task that will run every 12 hours to backup a registry path. Register-SavePreferencesScheduledTask (winprefs-install-job) can be called multiple times with different -Path arguments. Like Save-Preferences it can automatically commit to a repository and push.

Calling Register-SavePreferencesScheduledTask multiple times with the same -Path argument will not break anything. If a task with the same name already exists, it must be unregistered before its replacement can be made.

Any task can be uninstalled with Unregister-SavePreferencesScheduledTask (winprefs-uninstall-job) with the same -Path argument.

Examples

Save HKEY_LOCAL_MACHINE\Control Panel with a depth of 1

prefs-export -o . -m 1 -Path 'HKCU:\Control Panel\Desktop'
cat exec-reg.bat

Output:

reg add "HKCU\Control Panel\Desktop\Colors" /v "ActiveBorder" /t REG_SZ /d "212 208 200" /f
reg add "HKCU\Control Panel\Desktop\Colors" /v "ActiveTitle" /t REG_SZ /d "10 36 106" /f
REM ...

Export, commit with Git and push with a key

Dump WindowMetrics as C code

Write-RegCommands HKCU:\Environment -Format c

Output:

data = { 0xee, 0xff, 0xff, 0xff, /* ... */}; RegSetKeyValue(HKEY_CURRENT_USER, TEXT("Control Panel\\Desktop\\WindowMetrics"), TEXT("CaptionFont"), REG_BINARY, (LPCVOID)&data, 92);

Dump a single value

Write-RegCommands HKCU:\Environment\OneDrive

Output:

reg add "HKCU\Environment\OneDrive" /v "OneDrive" /t REG_EXPAND_SZ /d "%%USERPROFILE%%\OneDrive" /f

Dump a binary value

Write-RegCommands 'HKCU:\Control Panel\Desktop\WindowMetrics\StatusFont'

Output:

reg add "HKCU\Control Panel\Desktop\WindowMetrics\StatusFont" /v "StatusFont" /t REG_BINARY /d 000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f505152535455565758595a5b /f

Native version

The PowerShell module makes use of the native code with DllImport to get a significant speed increase in making registry queries and performing I/O. A native binary winprefs.exe can also be built that can be used without needing PowerShell installed and it should work with XP and newer. If built as a a 32-bit binary, the native binary should be compatible with Windows 2000 and newer. It even works with Wine.

Usage is similar to the PowerShell version:

Usage: winprefs.exe [OPTION...] [REG_PATH]
 
If a path to a value name is specified, the output directory argument is ignored and the line is
printed to standard output.
 
Options:
  -F, --format=FORMAT Format to output. Options: c, cs, c#, ps, ps1, powershell, reg. Default: reg.
  -K, --deploy-key    Deploy key for committing.
  -c, --commit        Commit changes.
  -d, --debug         Enable debug logging.
  -f, --output-file   Output filename.
  -m, --max-depth=INT Set maximum depth.
  -o, --output-dir    Output directory.
  -h, --help          Display this help and exit.

Note the equivalent format names (case-insensitive):

• C#: cs, c#
• PowerShell: ps, ps1, powershell

Development

Requirements:

• Windows
• Yarn

Building

Visual Studio

On Windows with Visual Studio installed:

mkdir build
cd build
cmake -Wno-dev ..
cmake -G 'Visual Studio 17 2022' --build . -DCMAKE_BUILD_TYPE=Release
cmake --build . --config Release

Using the VS developer environment shell is not required but it may help.

After building winprefs.exe will be in build\native\Release\winprefs.exe.

MinGW

Note: The PowerShell module (C# code) is only buildable with Visual Studio 2022.

mkdir build
cd build
cmake -G Ninja -Wno-dev ..
cmake --build . --config Release --verbose

After building winprefs.exe will be in build/native/winprefs.exe.

Cross-compiling

mkdir build
cd build
cmake -G Ninja -DCMAKE_BUILD_WITH_INSTALL_RPATH=ON -DCMAKE_C_COMPILER=/usr/lib/mingw64-toolchain/bin/x86_64-w64-mingw32-gcc -DCMAKE_SYSTEM_NAME=Windows -Wno-dev ..
cmake --build . --config Release --verbose

You may need to adjust paths above.

After building winprefs.exe will be in build/native/winprefs.exe.

Tasks

• yarn format: to format the project's files.
• yarn qa: Perform a QA check.