use strict;
use Win32::API;

my $tc = Win32::GetTickCount();

Win32::API::Struct->typedef(
  LASTINPUTINFO => qw{
    UINT cbSize; 
    DWORD dwTime; 
  }
);
    
Win32::API->Import("user32", 'BOOL GetLastInputInfo(LPLASTINPUTINFO plii)');

my $li = Win32::API::Struct->new('LASTINPUTINFO');
$li->{cbSize} = $li->sizeof; # MSDN: Must be set to sizeof(LASTINPUTINFO)

GetLastInputInfo($li);
print $li->{dwTime} - $tc, "\n";