คุณสมบัติของโปรแกรม · การแสดงสิทธิ์ POSIX

def permission_text(mode):
    if type(mode) is not int or not 0 <= mode <= 0o7777:
        raise ValueError("permission bits only")
    out = []
    for shift in (6, 3, 0):
        bits = (mode >> shift) & 7
        out.extend(c if bits & bit else "-"
                   for c, bit in zip("rwx", (4, 2, 1)))
    for pos, bit, mark in ((2, 0o4000, "s"), (5, 0o2000, "s"), (8, 0o1000, "t")):
        if mode & bit: out[pos] = mark if out[pos] == "x" else mark.upper()
    return "".join(out)