This is a robust self-printing program written in Ruby. It works even if you delete one character anywhere from the code.
How to play
rquine.rb and check if the output is equal to the original code:
$ ruby rquine.rb > rquine2.rb $ diff rquine.rb rquine2.rb
Prepare a script that deletes one character randomly:
$ cat mutate.rb src = ARGF.read src[rand(src.size), 1] = "" print src
Generate a broken program by deleting one character from
$ ruby mutate.rb rquine.rb > broken.rb
Run the broken program:
$ ruby broken.rb > rquine2.rb
You will see the output exactly equal to the original code:
$ diff rquine.rb rquine2.rb
old-rquine.rbis the first version based on a trivial redundancy approach (having two copies of the main code).
flagitious.rbis the smarter version that repairs itself instead of redundancy. It was created by Darren Smith aka. flagitious. Thank you flagitious! (Note that this version only works with 1.8.7.)
rquine.rbis the latest "ascii-art" version based on flagitious's approach. It works with 1.9 or later.
- Perl version (attributed to Shinichiro Hamaji)
Copyright (c) 2014 Yusuke Endoh (@mametter), @hirekoke
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The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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