I'm trying to make a command/environments with a view key value options similar to many other popular packages.
I found description on how to use key value but the examples don't work. Anyway can help to make a minimal key-value configured command my?
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{keyval}
\define@key{my}{foo}{Foo is #1\par}
\define@key{my}{bar}[99]{Bar is #1\par}
\newcommand{\KV@my@foo}[1]{Foo is #1}
\begin{document}
\my{foo=3,bar}
\end{document}


keyvalpackage but if you want to use commands with an@in their names you at least must make@an letter before you use them, see https://tex.stackexchange.com/questions/8351/ – cgnieder May 06 '20 at 08:58keyval. IMHO, the three packages which should be considered nowadays to create new stuff are:l3keys/LaTeX-kernel key=value support (stable, built in),expkv(withexpkv-deforexpkv-cs-- disclaimer: I'm the author; stable, fast, in case ofexpkv-csvery easy for simple things), orpgfkeys(wide spread, versatile, flexible at use-time -- the last might be considered an advantage and a drawback). – Skillmon Jul 30 '23 at 21:01