Some code for working with /var/folders temp folders on macOS via ctypes

temp_folders.py

import glob, os.path, pwd, os
from ctypes import CDLL, byref, create_string_buffer, c_uint32
from ctypes.util import find_library
libsys = CDLL(find_library('C'))

def user_temp_dir(uid):
    path_buffer = create_string_buffer(1024)
    result = libsys.__user_local_dirname(c_uint32(uid), 0, byref(path_buffer), 1024)
    return path_buffer.value.rsplit('/0/',1)[0]

def validate_var_folders():
    # needs to be run as root
    temp_folders = [x for x in glob.glob('/var/folders/*/*') if os.path.isdir(x)]
    all_known_users = pwd.getpwall()
    # calculate temp folder path for all known users
    user_paths = dict()
    uids = set()
    for user in all_known_users:
        uid = user.pw_uid
        uids.add(uid)
        gid = user.pw_gid
        path = user_temp_dir(uid)
        user_paths[path] = (uid, gid)
    # loop over the folders we saw
    calculated_folders = user_paths.keys()
    for folder in temp_folders:
        folder_info = os.stat(folder)
        if not folder in calculated_folders:
            print "Unknown user for temp folder:", folder
            print "Current ownership: uid: %d, gid: %d" % (folder_info.st_uid, folder_info.st_gid)
            if folder_info.st_uid in uids:
                print "Diagnosis: User with uid %d exists, but wrong GeneratedUID (likely different user / not in use - check inside it?)\n" % folder_info.st_uid
            else:
                print "Diagnosis: No such user with uid %d, probably safe to delete\n" % folder_info.st_uid
        else:
            print "Known user for temp folder:", folder
            print "Current ownership: uid: %d, gid: %d" % (folder_info.st_uid, folder_info.st_gid)
            seen_uid, seen_gid = user_paths[folder]
            if seen_uid != folder_info.st_uid:
                print "Diagnosis: Ownership (uid) appears to be wrong! Should be: %d\n" % seen_uid
            elif seen_gid != folder_info.st_gid:
                print "Diagnosis: Group (gid) appears to be wrong! Should be: %d\n" % seen_gid
            else:
                print "Diagnosis: Looks good!\n"