Show HN: SixLogger, a Simple POSIX-compliant Logger function for shell scripts

Hi HN! I built this very simple logger function that is POSIX-compliant, so it's very portable.

I did it because I wanted to learn a little bit more about POSIX-compliant shell scripts and how I could test if my script is POSIX-compliant. I'm using shellspec with Docker and Vagrant to test this logger function in different OSes, with different shells.

This is one of my first open-source projects, so let me know what you think!