Contribution

• I'd be willing to implement this feature (contributing guide)

Not sure, but I could try if I have time.

Describe the user story

I had typed -d and was surprised to find out it didn't have any effect. Reading the docs, I found out that it must be uppercase -D.

Describe the solution you'd like

I think the case shouldn't matter. There's no conflicting lowercase option anyway. Also, most Unix tools typically prefer to use lowercase shorthand options, reserving uppercase for more rarely used conflicting options.

Same can be for -p, -o, -e etc. And global (which is oddly -g despite being a more cautious option) could also accept -G.

Describe the drawbacks of your solution

Future conflict of two different options sharing the same letter of the alphabet.

However, there are only five shorthand options right now, so we still have 21 unused alphabets. We should be fine.

Describe alternatives you've considered

None.