os.putEnv accepts invalid key

[juancarlospaco]

os.putEnv accepts keys containing '='. This works, but should not:

import std/os
putEnv "a=b", "BUG"

• https://bugs.python.org/issue4926 / https://bugs.python.org/msg79708

>>> import os
>>> os.putenv("a=b", "BUG")

ValueError: illegal environment variable name

TODO

check whether other env APIs have a similar bug

• os.putEnv
• os.getEnv
• os.existsEnv
• os.delEnv

May or may not read/write/delete the wrong env vars, can be silently destructive to other env vars.

Best practices say that env var key names must be 1 non-empty ASCII string in the range [a-zA-Z0-9_] (DotEnv project docs).

[timotheecour]

this issue is only partially correct

the only thing to fix here is to use c_putenv as done in nim-lang#18530, after which putEnv "a=b", "BUG" will correctly raise

getEnv("foo=bar") should not raise (and doesn't raise currently, nor does it raise in python)

Best practices say that env var key names must be 1 non-empty ASCII string in the range [a-zA-Z0-9_] (DotEnv project docs).

std/os shouldn't impose restrictions, the underlying OS call to c_setenv will already fail for invalid input

[juancarlospaco]

this issue is only partially correct

Ok, feel free to edit it. 👍