GNU Ed 2.0 (python version)

ed.py

#!/usr/bin/env python

# GNU Ed 2.0 (python version)
#
# Copyright (C) 1994 Andrew L. Moore.
# Copyright (C) 2014 Free Software Foundation, Inc.
# Copyright (C) 2014 dx
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import signal

def what(*args):
    if args:
        print("")
    print("?")

for x in dir(signal):
    if x.startswith("SIG"):
        try:
            signal.signal(getattr(signal, x), what)
        except:
            pass

try:
    input = raw_input
except:
    pass

while True:
    try:
        input()
    except:
        pass
    what()