[DOC]: Document Environment Variables

[adam-grant-hendry]

Can the documentation please be updated to incorporate a running list of environment variables that cleo reads and/or sets? I ran a simple python script (see below) to identify such variables and these would be as listed below:

ANSICON
TERM_PROGRAM
SHELL
COLORTERM
TERM

We will want to add FORCE_COLOR and NO_COLOR to this list as well once PR #343 is merged.

find_used_env_vars.py

import os
import re

def find_used_env_vars(filename):
    used_env_vars = set()

    with open(filename) as file:
        content = file.read()
        matches = re.findall(r'os\.environ\[[\'"]([A-Z_]+)[\'"]\]', content)
        used_env_vars.update(matches)

        matches = re.findall(r'os\.environ\.get\([\'"]([A-Z_]+)[\'"]\)', content)
        used_env_vars.update(matches)

        matches = re.findall(r'os\.getenv\([\'"]([A-Z_]+)[\'"]\)', content)
        used_env_vars.update(matches)

        matches = re.findall(r'os\.getenvb\([\'"]([A-Z_]+)[\'"]\)', content)
        used_env_vars.update(matches)

    return used_env_vars

def main():
    result = set()

    for root, _, files in os.walk('.'):
        for file in files:
            if file.endswith('.py'):
                file_path = os.path.join(root, file)
                result.update(find_used_env_vars(file_path))

    with open('output.txt', 'w') as output_file:
        for var in result:
            output_file.write(var + '\n')

if __name__ == "__main__":
    main()

[Secrus]

I have added this to the list in #251 I'm going to close this to avoid duplication.