What is wrong with "python -m http.server"?
Bashbro, on the other hand, seems to require socat. I wonder if there's any bash-istic method of listening to a port...
But nc is not bash.
https://gist.github.com/alganet/140c7c12d1603c244a01
nc is almost everywhere, you can count on it.
Ultimately, this is a toy, but it can be handy. I originally made it to attempt using for serving config for networked debian unattended installations[1] while automating VM creation, but never went that far.
[1]: https://debian-handbook.info/browse/en-US/stable/sect.automa...
That's a problematic distinction in some situations.
edit:
https://unix.stackexchange.com/questions/49936/dev-tcp-liste...
gives some pointers
In a purpose-built environment there is practically no need for such a feature aside from mischief.