I did miss that until I read your post, looking up behavior that your program relies in a language standard seems easy to me to because I _have_ to as a C programmer, a lot, for the reasons you and the post mentioned. I totally agree with you, and nearly all of the C footguns in the article.

That being said I'm still doubling down on my post:

"who knows" if argv is const? Me, because I program for a standard of C that guarantees that that it's not const and that it's pointers and the strings it pointers to are both modifiable.

And "who knows" if toupper returns an error because "It's a C API! Anything is possible!"

Also me, because I program for a standard of C where toupper returns what you gave it, or it gives you a single character back that _might_be_different_ based on the host computer's language.

Not defending toupper and towupper, but it is explicitly unreliable in the C standard I program to.

If I naively wrote a case-insensitive file manager in Rust, wchar_t C, or C with ICU, could operations on the following files be reliable on a German computer and on a English computer? If they are reliable, then is it correct to the point where either person wouldn't overwrite a file on accident? If the Rust one overwrites files, is it a smaller fuckywuky since Rust programers value "safety, correctness, and performance"?

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