Why are shell script variables named in capital letters?

Question

bash

What is the reason for this phenomenon, and what are the advantages of this approach? except for the unity of variable naming in the system. All commands are written in lowercase

Answer 1

Upper case for global variables (a) makes them easier to keep track of and (b) reduces the chance of conflicts with local variables.
Search Google for something like "shell variable naming convention" for details.
Here you will also find:
- stackoverflow.com/a/673940/2743554
- unix.stackexchange.com/a/42849
- https://google-styleguide.googlecode.com/svn/trunk...
etc.