Correct Bash and shell script variable capitalization

Question

I run across many shell scripts with variables in all caps, and I\'ve always thought that there is a severe misunderstanding with that. My understanding is that, by convent

Answer 1

If shell variables are going to be exported to the environment, it’s worth considering that the POSIX (Issue 7, 2018 edition) Environment Variable Definition specifies:

Environment variable names used by the utilities in the Shell and Utilities volume of POSIX.1-2017 consist solely of uppercase letters, digits, and the underscore ( _ ) from the characters defined in Portable Character Set and do not begin with a digit.

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The name space of environment variable names containing lowercase letters is reserved for applications. Applications can define any environment variables with names from this name space without modifying the behavior of the standard utilities.