Ah, I had posted a golfed silly gawk webserver here some time ago. It uses gawk's built in tcp.
https://news.ycombinator.com/item?id=22085459
Pretty printed: https://gist.github.com/tyingq/4e568425e2e68e6390f3105e58878...
neat! i was aware of bash's built-in tcp client at /dev/tcp, but gawk being able to function as a tcp server is way cooler. Thanks for that bit of knowledge :>
Actually, bash has now a loadable builtin to listen on tcp socket. I wrote a script and the patch. https://github.com/dzove855/Bash-web-server
The patch is now included in bash 5.2