validity.py 文件源码

def effectivelyReadable(self):
        uid = os.getuid()
        euid = os.geteuid()
        gid = os.getgid()
        egid = os.getegid()

        # This is probably true most of the time, so just let os.access()
        # handle it.  Avoids potential bugs in the rest of this function.
        if uid == euid and gid == egid:
            return os.access(self.name, os.R_OK)

        st = os.stat(self.name)

        # This may be wrong depending on the semantics of your OS.
        # i.e. if the file is -------r--, does the owner have access or not?
        if st.st_uid == euid:
            return st.st_mode & stat.S_IRUSR != 0

        # See comment for UID check above.
        groups = os.getgroups()
        if st.st_gid == egid or st.st_gid in groups:
            return st.st_mode & stat.S_IRGRP != 0

        return st.st_mode & stat.S_IROTH != 0