I had some issues with the Kubernetes filter in fluent-bit. And I believed that its unescape_string function might be the problem.

Now I wanted to fix it but really don't have any experience in programming C ...

This is my approach for unescaping a JSON string.

Every transition between two states reads another char from the input buffer.

1. Move it out of the scratch incubator
2. Make a library of it (.h file) and put the main method somewhere else
3. Write test cases
4. Use it together with JSMN and write something cool.

1. Support Unicode on top of the Basic multilingual plane
2. Escape UTF-8 with bit shifting. Devide and modulo works but the former is easier to read and probably faster. See https://github.com/akheron/jansson/blob/master/src/utf.c
3. Replace camelCase with under_scores in variable names.
4. More code comments
5. Format the code according to how they do it at fluent-bit