The problem in that snippet is that `printf` could have altered the `errno` set ...

signa11 · on Oct 17, 2023

crap, i definitely meant to write `printf(...)` there !

my typical usage for such scenarios i.e. when i know that callee might alter errno etc. is to

        int save_errno = errno;

        do_foo(...);

        if (errno == ...) {
          ...
        }

wrapping libc into something that (maybe) does better seems like such a sisyphean task to me.

burntsushi · on Oct 17, 2023

This thread isn't talking about how to fix the errno problem generally. It's talking about the existence of a problem in the first place. Fixing it would be a whole different can of worms, and indeed, sisyphean sounds about right.

Notice how this entire thread was started by someone asking why errno was problematic. This is just about understanding.

signa11 · on Oct 18, 2023

> Notice how this entire thread was started by someone asking why errno was problematic. This is just about understanding.

yes, you are absolutely right. this is just about understanding and how easy it is to miss what is hidden just one-level away.