#rlundo

rlundo grants interactive interpreters magical undo powers! Some interpreters work without requiring compiling a new readline library:

$ python rlundo python
$ python rlundo ipython

You can undo using ctrl+c

The goal is for this to work with any interpreter, as in

$ python rlundo /usr/bin/irb

which will work if you compile the modified readline library with

cd rlundoable
make -f Makefileosx

There are three major parts to this project:

• rlundoable - a patch for readline that makes it fork to save state
• rewrite.py - rewinds the terminal state to how it was at the last prompt
• undoableINTERPRETER - alternative scripts for running specific interactive interpreters so that they have undo

##rlundoable

try it with

$ python rlundo /usr/bin/irb

##rewrite.py

try it with

$ python rewrite.py

and then in another terminal run

nc localhost 4242

to save terminal states, and

nc localhost 4243

to restore previous terminal states

##Running the tests

• clone the repo, create a virtual environment
• pip install nose
• install tmux 1.9a or 2.1 (master). 1.8 is too early, 2.0 has a regression.
• nosetests test in the root directory
• or try RLUNDO_USE_EXISTING_TMUX_SESSION=1 nosetests test while you have a tmux session open to watch the tests which use tmux run

Thanks to

• John Hergenroeder for help with fixing race conditions with terminal rewriting
• John Connor for discussion and Python 3 fixes
• Agustín Benassi for ipython support, improved terminal rewriting, memory monitoring work and much more
• Joe Jean for work on Travis tests

##License

Copyright 2015 Thomas Ballinger

Released under GPL3, like GNU readline.

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/.