The Shell Toolkit (shtk) is an application toolkit for programmers
writing POSIX-compliant shell scripts.

shtk provides a collection of reusable modules that work on a wide
variety of operating systems and shell interpreters.  The included
modules aid developers in implementing usable and consistent CLI
interfaces, interacting with processes, parsing configuration files and
manipulating higher-level data types among other things.

shtk-based scripts are "built" by using the included shtk(1) utility,
which adds the necessary machinery to the scripts so that they can
trivially import and use the modular interfaces of shtk.

WWW: https://github.com/jmmv/shtk/