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Win32::Registry - Query the Windows registry using the Windows API


use Win32::Registry::Subkeys;
my $hive = 'HKEY_LOCAL_MACHINE';
my $key  = 'SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths';
my @array  = get-subkeys( $hive, $key );


Win32::Registry uses the NativeCall module to execute WinAPI functions to extract information from the registry.

Native Call Functions

The following Windows API native call functions are currently supported:

RegCloseKey(int32) is native("Kernel32.dll") returns int32 is export {*};

RegGetValueW(int32, CArray[WCHAR], CArray[WCHAR], int32, int32, CArray[uint16], int32 is rw) is native("Kernel32.dll") returns int32 is export {*};

RegOpenKeyExW(int32, WCHARS, int32, int32, int32 is rw) is native("Kernel32.dll") returns int32 is export {*};

RegQueryInfoKeyW(int32, int32, int32, int32, int32 is rw, int32 is rw, int32, int32, int32, int32, int32, int32) returns int32 is native('kernel32') is export {*};


get-hkey-handle(Str:D $hive)

Returns the handle for a hive name. Hive names can be shortened to leave off the HKEY_ bit at the beginning. Capitlization is ignored.

my $handle = get-hkey-handler('hkey_local_machine);
my $handle = get-hkey-handler('local_machine); # same as above

get-hkey(Str:D $h)

Returns the name of a hive, if found. Dies otherwise.

my $handle = get-hkey('local_machine');
say $handle; # OUTPUT: hkey_local_machine

key-exists(Str:D $key)

Test to see if a key exists in the registry. Accepts a string representing a path to a registry key. Returns a boolean value.

my $exists = key-exists('hkey_local_machine\SOFTWARE\Microsoft\Windows \CurrentVersion \App Paths');

close-key(Int:D $key-handle)

Closes an open key. Accepts a handle to an already open key. Returns boolean value based on success of operation. False will be returned if the key was already closed.

$key-exists = key-exists('hkey_local_machine\SOFTWARE\Microsoft\Windows \CurrentVersion \App Paths');

wstr(Str $str)

Converts a string into a wide characgter string, suitable for passing to a Windows API native call function. Returns the original string in a native CArray[WCHAR] object that is terminated with a null character.

multi sub open-key(Str:D $key)

multi sub open-key(Int:D $hkey-handle, Str:D $key)

Opens a registry key. Returns the key's handle. Dies if key does not exist.

my $handle = open-key('local_machine', 'SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths' );
my $handle = open-key('hkey_local_machine\SOFTWARE\Microsoft\Windows \CurrentVersion\App Paths' );


See the documentation for the individual submodules for further details.


Steve Dondley s@dondley.com


Copyright 2022 Steve Dondley

This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.