julp

require 'Win32API'
 
module Win32
 
    INVALID_HANDLE_VALUE = -1
    INFINITE = 0xFFFFFFFF
    WAIT_OBJECT_0 = 0x00000000
    WAIT_TIMEOUT = 0x00000102
    WAIT_FAILED = 0xFFFFFFFF
    FILE_NOTIFY_CHANGE_FILE_NAME   = 0x00000001
    FILE_NOTIFY_CHANGE_DIR_NAME    = 0x00000002
    FILE_NOTIFY_CHANGE_ATTRIBUTES  = 0x00000004
    FILE_NOTIFY_CHANGE_SIZE        = 0x00000008
    FILE_NOTIFY_CHANGE_LAST_WRITE  = 0x00000010
    FILE_NOTIFY_CHANGE_LAST_ACCESS = 0x00000020
    FILE_NOTIFY_CHANGE_CREATION    = 0x00000040
    FILE_NOTIFY_CHANGE_SECURITY    = 0x00000100
 
    FindFirstChangeNotification = Win32API.new('kernel32', 'FindFirstChangeNotification', 'PIL', 'L')
    FindNextChangeNotification = Win32API.new('kernel32', 'FindNextChangeNotification', 'L', 'I')
    WaitForMultipleObjects = Win32API.new('kernel32', 'WaitForMultipleObjects', 'LPIL', 'L')
    WaitForSingleObject = Win32API.new('kernel32', 'WaitForSingleObject', 'LL', 'L')
    CloseHandle = Win32API.new('kernel32', 'CloseHandle', 'L', 'L')
 
    module Event
 
        def self.FindChangeNotification(directory = '.', watch_subtree = false)
            h = FindFirstChangeNotification.Call(
                directory, (watch_subtree ? 1 : 0), 
                FILE_NOTIFY_CHANGE_LAST_WRITE |
                FILE_NOTIFY_CHANGE_CREATION # |
                #FILE_NOTIFY_CHANGE_FILE_NAME
            )
            return nil if h == INVALID_HANDLE_VALUE
 
            begin
                loop {
                    wait_start = Time.now
                    return nil if WAIT_FAILED == WaitForSingleObject.Call(h, INFINITE)
                    if block_given?
                        yield if Time.now - wait_start > 0.1
                    else
                        return true
                    end
                    return nil if 0 == FindNextChangeNotification.Call(h)
                }
            ensure
                CloseHandle.call(h)
            end
        end
 
    end
 
end
 
Win32::Event::FindChangeNotification('C:/AMP/apache/conf') {
    puts "changed"
}