#!/bin/env python3
import sys

def auditor(builtins):
    # site.exit is a mutable Quitter instance, so keep the hook state immutable.
    _system_exit = builtins['SystemExit']
    # Call the real str implementation directly.  Audit arguments can contain
    # attacker-created str subclasses whose __str__/__contains__ methods lie.
    _str_contains = builtins['str'].__contains__
    blacklist_patterns = (
        'spawn', 'process', 'os', 'sys', 'cpython', 'fork', 'open',
        'interpreter', 'ctypes', 'compile', 'gc', '__new__', 'import',
    )

    def func(event, args):
        # Security decisions use only CPython's canonical event name.  Calling
        # str() on arbitrary arguments both executes attacker code and lets a
        # str subclass hide the value consumed later by a C API.  Blocking the
        # import event also closes raw extension-loader audit gaps such as
        # directly invoking _posixsubprocess.fork_exec().
        for pattern in blacklist_patterns:
            if _str_contains(event, pattern):
                raise _system_exit(1)

    return func

codes = input('$ ')

code = compile(codes, "<code>", "exec")
sys.addaudithook(auditor(__builtins__.__dict__.copy()))
exec(code,{'__builtins__':{}},{})