Regarding Nested Functions, I found this tutorial Creating Nested Functions, from where I modified my functions to local hopefully this is better now and more memory efficient.

If you're concerned about optimized memory consumption for an 8 line function, then you probably should use something else. (e.g. finely tuned C code) My recommendation: Optimize for readability / maintainability. You like to publish the module so that someone else might use it. This someone else might have an anger management problem, an axe and your address. ;)

Is is to so badly written the module? What is so wrong that would make you not want to use this module?

It's trust related. If I use someone else's code then I must be sure the code is doing what it's supposed to do. Easy to understand code and suitable application of common language idioms help to build that trust. (Hey! I can understand that!) Automated tests are also nice. (Hey! I don't understand it, but it's seems to be working as expected.) Your code simply fails to build that trust.

'Three strikes and you are out:'

1. Trying to reinvent printf, especially even though you already use it.
2. Code that does not seem to be used.
3. Failing to validate user input.

No trust -> that code is not going to end up on any of my machines. I may want to play around with it for educational purposes, but it's not going to be something I rely on.