OS X hidden files

#!/usr/bin/python

import contextlib
import ctypes

cf = ctypes.cdll.LoadLibrary('/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation')

cf.CFShow.argtypes = [ctypes.c_void_p]
cf.CFShow.restype = None

cf.CFRelease.argtypes = [ctypes.c_void_p]
cf.CFRelease.restype = None

cf.CFStringCreateWithBytes.argtypes = [ctypes.c_void_p,
                                       ctypes.c_char_p, ctypes.c_long,
                                       ctypes.c_int, ctypes.c_int]
cf.CFStringCreateWithBytes.restype = ctypes.c_void_p

cf.CFStringGetMaximumSizeOfFileSystemRepresentation.argtypes = [ctypes.c_void_p]
cf.CFStringGetMaximumSizeOfFileSystemRepresentation.restype = ctypes.c_int

cf.CFStringGetFileSystemRepresentation.argtypes = [ctypes.c_void_p,
                                                   ctypes.c_char_p,
                                                   ctypes.c_long]
cf.CFStringGetFileSystemRepresentation.restype = ctypes.c_int

cf.CFURLCreateFromFileSystemRepresentation.argtypes = [ctypes.c_void_p,
                                                       ctypes.c_char_p,
                                                       ctypes.c_long,
                                                       ctypes.c_int]
cf.CFURLCreateFromFileSystemRepresentation.restype = ctypes.c_void_p

cf.CFURLCopyResourcePropertyForKey.argtypes = [ctypes.c_void_p,
                                               ctypes.c_void_p,
                                               ctypes.c_void_p,
                                               ctypes.c_void_p]
cf.CFURLCopyResourcePropertyForKey.restype = ctypes.c_int

cf.CFBooleanGetValue.argtypes = [ctypes.c_void_p]
cf.CFBooleanGetValue.restype = ctypes.c_int

cf.CFURLEnumeratorCreateForDirectoryURL.argtypes = [ctypes.c_void_p,
                                                    ctypes.c_void_p,
                                                    ctypes.c_int,
                                                    ctypes.c_void_p]
cf.CFURLEnumeratorCreateForDirectoryURL.restype = ctypes.c_void_p


cf.CFURLEnumeratorGetNextURL.argtypes = [ctypes.c_void_p,
                                         ctypes.c_void_p,
                                         ctypes.c_void_p]
cf.CFURLEnumeratorGetNextURL.restype = ctypes.c_int

cf.CFURLCopyFileSystemPath.argtypes = [ctypes.c_void_p, ctypes.c_int]
cf.CFURLCopyFileSystemPath.restype = ctypes.c_void_p

# From CFString.h
# http://www.opensource.apple.com/source/CF/CF-744/CFString.h
# The value has been the same from at least 10.2-10.8.
kCFStringEncodingUTF8 = 0x08000100

# Documented here:
# https://developer.apple.com/library/mac/#documentation/CoreFoundation/Reference/CFURLEnumeratorRef/Reference/reference.html
kCFURLEnumeratorSkipInvisibles = 1 << 1

kCFURLEnumeratorSuccess = 1
kCFURLEnumeratorEnd = 2
kCFURLEnumeratorError = 3
kCFURLEnumeratorDirectoryPostOrderSuccess = 4

# Documented here:
# http://developer.apple.com/library/ios/#documentation/CoreFoundation/Reference/CFURLRef/Reference/reference.html
kCFURLPOSIXPathStyle = 0

# This one is a static CFStringRef.
kCFURLIsHiddenKey = ctypes.c_void_p.in_dll(cf, 'kCFURLIsHiddenKey')

@contextlib.contextmanager
def cfreleasing(stuff):
    try:
        yield
    finally:
        for thing in stuff:
            cf.CFRelease(thing)

def cfstr_to_unicode(cfstr):
    count = cf.CFStringGetMaximumSizeOfFileSystemRepresentation(cfstr)
    buf = (ctypes.c_char * count)()
    if cf.CFStringGetFileSystemRepresentation(cfstr, buf, count):
        return buf.value.decode('UTF-8')
    raise OSError('CFStringGetFileSystemRepresentation failed')

def is_hidden(path):
    if not isinstance(path, bytes):
        path = path.encode('UTF-8')
    stuff = []
    with cfreleasing(stuff):
        url = cf.CFURLCreateFromFileSystemRepresentation(None, path, len(path), False)
        stuff.append(url)
        val = ctypes.c_void_p(0)
        ret = cf.CFURLCopyResourcePropertyForKey(url, kCFURLIsHiddenKey,
                                                 ctypes.addressof(val), None)
        if ret:
            result = cf.CFBooleanGetValue(val)
            stuff.append(val)
            return True if result else False
        # TODO: You could pass a CFErrorRef instead of None, and do all the
        # work to wrap that in a Python exception, etc.
        raise OSError('CFURLCopyResourcePropertyForKey failed')

def listdir_skipping_hidden(path):
    if not isinstance(path, bytes):
        path = path.encode('UTF-8')
    stuff = []
    with cfreleasing(stuff):
        url = cf.CFURLCreateFromFileSystemRepresentation(None,
                                                         path, len(path),
                                                         True)
        stuff.append(url)
        enum = cf.CFURLEnumeratorCreateForDirectoryURL(None, url,
                                                       kCFURLEnumeratorSkipInvisibles,
                                                       None)
        stuff.append(enum)
        paths = []
        while True:
            url = ctypes.c_void_p(0)
            ret = cf.CFURLEnumeratorGetNextURL(enum, ctypes.addressof(url), None)
            if ret != kCFURLEnumeratorSuccess:
                break
            path = cf.CFURLCopyFileSystemPath(url, kCFURLPOSIXPathStyle)
            stuff.append(path)
            paths.append(cfstr_to_unicode(path))
        return paths

if __name__ == '__main__':
    import sys
    for arg in sys.argv[1:]:
        print('{}: {}'.format(arg, is_hidden(arg)))
        if arg[-1] == '/':
            for path in listdir_skipping_hidden(arg):
                print('  {}'.format(path))