FWIW dash is 20K lines of C code, although it has many fewer features than bash. I use metaprogramming in several places to make the code shorter, so 11K sound

FWIW dash is 20K lines of C code, although it has many fewer features than bash. I use metaprogramming in several places to make the code shorter, so 11K sounds about right for Python vs. C. I think it will be 15K with all the bash features filled out, excluding interactive parts. I use GNU readline and not my own code, so that substantial part isn't counted. The osh/osh.asdl file gives a concise overview of what features are represented and implemented.