inotify.py 文件源码

def load_inotify():
    ''' Initialize the inotify library '''
    global _inotify
    if _inotify is None:
        if hasattr(sys, 'getwindowsversion'):
            # On windows abort before loading the C library. Windows has
            # multiple, incompatible C runtimes, and we have no way of knowing
            # if the one chosen by ctypes is compatible with the currently
            # loaded one.
            raise INotifyError('INotify not available on windows')
        if sys.platform == 'darwin':
            raise INotifyError('INotify not available on OS X')
        if not hasattr(ctypes, 'c_ssize_t'):
            raise INotifyError('You need python >= 2.7 to use inotify')
        name = find_library('c')
        if not name:
            raise INotifyError('Cannot find C library')
        libc = ctypes.CDLL(name, use_errno=True)
        for function in ('inotify_add_watch', 'inotify_init1', 'inotify_rm_watch'):
            if not hasattr(libc, function):
                raise INotifyError('libc is too old')
        # inotify_init1()
        prototype = ctypes.CFUNCTYPE(ctypes.c_int, ctypes.c_int, use_errno=True)
        init1 = prototype(('inotify_init1', libc), ((1, 'flags', 0),))

        # inotify_add_watch()
        prototype = ctypes.CFUNCTYPE(ctypes.c_int, ctypes.c_int, ctypes.c_char_p, ctypes.c_uint32, use_errno=True)
        add_watch = prototype(('inotify_add_watch', libc), (
            (1, 'fd'), (1, 'pathname'), (1, 'mask')))

        # inotify_rm_watch()
        prototype = ctypes.CFUNCTYPE(ctypes.c_int, ctypes.c_int, ctypes.c_int, use_errno=True)
        rm_watch = prototype(('inotify_rm_watch', libc), (
            (1, 'fd'), (1, 'wd')))

        # read()
        prototype = ctypes.CFUNCTYPE(ctypes.c_ssize_t, ctypes.c_int, ctypes.c_void_p, ctypes.c_size_t, use_errno=True)
        read = prototype(('read', libc), (
            (1, 'fd'), (1, 'buf'), (1, 'count')))
        _inotify = (init1, add_watch, rm_watch, read)
    return _inotify