use strict; use warnings; use Win32::API; use Win32::API::Callback; use constant WH_KEYBOARD => 2; use constant LEFT_SHIFT => 0xA0; my $get_thread_id = Win32::API->new('kernel32', 'int GetCurrentThreadId()'); my $get_key_state = Win32::API->new('user32', 'GetKeyState', 'I', 'I'); my $set_hook = Win32::API->new('user32', 'SetWindowsHookEx', 'IKII', 'I'); my $call_next = Win32::API->new('user32', 'CallNextHookEx', 'IIII', 'I'); my $unhook_hook = Win32::API->new( 'user32', 'BOOL UnhookWindowsHookEx(int hookHandle)' ); my $hook; my $n = 0; my $callback = Win32::API::Callback->new( sub { $n++; my $next = $call_next->Call($hook, @_); return $next; }, 'III', 'I', ); my $thread_id = $get_thread_id->Call(); print "Thread ID: $thread_id\n"; $hook = $set_hook->Call(WH_KEYBOARD, $callback, 0, $thread_id); for (0 .. 9) { printf "%1d : %3d, %4d\n", $_, $n, $get_key_state->Call( LEFT_SHIFT ) || 0; sleep 1; } my $rv = $unhook_hook->Call($hook);