Thread: Matching substr() results

1) ' delimits character literals, not string literals.

2) || tests completely independent conditions. Your if statement, if it used string literals, would test
if the initial 3 characters of userInput are "cd "
OR
if the string literal "Cd " evaluates to true
OR
if the string literal "cD " evaluates to true
OR
if the string literal "CD " evaluates to true.

You should get some string-to-lower function, apply it to the substring, and simply compare once against "cd ". There's one in Boost. (Or this one.)

Originally Posted by FlyingIsFun1217

Alright, thanks for pointing out the ' and " difference. Guess I was too tired, and forgot to check!

With the string-to-lower function, would that be collecting input, and lowercasing it all?

Thanks again, always very helpful here!
FlyingIsFun1217

You don't want to lower-case all of the input, just the command that you need to compare case-insensitively [in fact, you may also use a case-insensitive compare, but that's likely to just lower-case the strign anyways].

The reason you don't just lowercase the whole thing is that some commands may differentiate between options that are upper case and options that are lower-case. gcc for example do not treat -C and -c as the same thing, nor -e and -E or -s and -S. Likewise, it's nice to be able to use mixed case when creating filenames and directory names - even if the OS doesn't make the difference into different files, it's easier to read if the case is "what you expect".

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