The hardest tarball

andyc | 4 hours ago

an archive that can be constructed using a single GNU tar invocation, that is extracted in 8 distinct ways depending on what tool you use

Hm interesting, I like these examples. I might call this a "maximum parser differential". Or I also called it a Yahtzee because you're "rolling the dice", and ideally you want the results to be the same, but they are different.

This came up here: comment on A Design Space Exploration of Async/Await

e.g. a (pseudo-code) async-await program that has 4 different behaviors in 4 languages, starting with

async fn write_to_log():
  ...

async fn fire_and_forget():
  ...

And then my own example of a POSIX shell script that has 4 behaviors in 4 shells:

command -v echo ZZZ for
echo status=$?

https://github.com/bashix-spec/bashix/blob/main/yahtzee/4-command.sh

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OK and now I see you have tested this recent parser from Astral:

A fast and secure tar parser for the Rust ecosystem

The goal is reducing uv's exposure to parser differentials and other security risks

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Any other "Yahtzee" examples? In any language or data format

[OP] stabbles | an hour ago

I have this one:

IFS=' :'; a='x '; b=':'; printf '<%s>' $a$b $(echo 'x ')$(echo ':y')

which gives

bash  <x><x><y>
dash  <x><><x><><y>
mksh  <x><><x><y>
zsh   <x :><x><><y>