Well, then this is interesting to me aswell :) Wanted to be able of doing this while back... Gotta check it out more...

Found this on my hd. Not working properly.. dunno why exactly:

#!/usr/bin/env perl

use Data::Dumper;

use strict;
use warnings;
#use diagnostics;

use Win32::API;
use Win32::API::Callback;

sub FILE_FLAG_BACKUP_SEMANTICS { 0x02000000 }

sub WH_KEYBOARD { 2 }
sub WH_KEYBOARD_LL { 13 }

sub DWORD_SIZE { 4 }


#my $kernel32 = 'kernel32.dll';
#my $advapi32 = 'advapi32.dll';
# HHOOK SetWindowsHookEx(
#
#     int idHook,
#     HOOKPROC lpfn,
#     HINSTANCE hMod,
#     DWORD dwThreadId
# );

# lpfn
#     [in] Pointer to the hook procedure. If the dwThreadId parameter 
+is zero or specifies
#          the identifier of a thread created by a different process, 
+the lpfn parameter must point
#          to a hook procedure in a dynamic-link library (DLL). Otherw
+ise, lpfn can point to a hook
#          procedure in the code associated with the current process.
# hMod
#     [in] Handle to the DLL containing the hook procedure pointed to 
+by the lpfn parameter.
#          The hMod parameter must be set to NULL if the dwThreadId pa
+rameter specifies a thread
#          created by the current process and if the hook procedure is
+ within the code associated
#          with the current process.
# dwThreadId
#     [in] Specifies the identifier of the thread with which the hook 
+procedure is to be associated.
#          If this parameter is zero, the hook procedure is associated
+ with all existing threads
#          running in the same desktop as the calling thread.


# LRESULT CALLBACK LowLevelKeyboardProc(
#     int nCode,
#     WPARAM wParam,
#     LPARAM lParam
# );

my $user32   = 'user32.dll';


my $callback = Win32::API::Callback->new(
    sub { my($a, $b) = @_; return $a+$b; },
    "INN", "N",
  );


my $SetWindowsHookEx = new Win32::API($user32,
                                     'SetWindowsHookEx',
                                     'IPNN', 'I');


print Dumper($SetWindowsHookEx);
if (!$SetWindowsHookEx) {
    print $^E . "\n";
    print Win32::GetLastError();
    exit;
}


my $idHook = WH_KEYBOARD_LL;
my $lpfn = \&hello; #pack("L", 0);
my $hMod = 0;
my $dwThreadId = 0;

my $ok = $SetWindowsHookEx->Call(
                    $idHook,
                    $lpfn,
                    $hMod,
                    $dwThreadId
                    ) or die $^E;

print Win32::GetLastError();

sub hello {

}
[download]

"Doesn't work to set a non-local hook without a modulereferense (handle) at globalKeysWin32.pl line 79, <DATA> line 164."
Whatever that means... may be helpfull? Please tell me if you make it work!

Ace