tools.py 文件源码

def check_access(filename, write_required=True):
    """
    Checks if user has read and optionaly write access to specified file.
    Uses acl first and possix file permisions if acl cannot be used.
    Returns true only if user has both required access rights.
    """
    if HAVE_POSIX1E:
        for pset in posix1e.ACL(file=filename):
            if pset.tag_type == posix1e.ACL_USER and pset.qualifier == os.geteuid():
                if pset.permset.test(posix1e.ACL_READ) and (not write_required or pset.permset.test(posix1e.ACL_WRITE)):
                    return True
            if pset.tag_type == posix1e.ACL_GROUP and pset.qualifier in os.getgroups():
                if pset.permset.test(posix1e.ACL_READ) and (not write_required or pset.permset.test(posix1e.ACL_WRITE)):
                    return True
    if write_required:
        return os.access(filename, os.R_OK | os.W_OK)
    return os.access(filename, os.R_OK)