Even putting aside the ugliness of errno, this is pretty bad. I'm at the point with libc where I try to use as little of it as I can, though I'm not writing a lot of C these days
Just don't make the errors, then you don't have to detect them.
When your app stops issuing these errors, then you won't have to write blog posts complaining that someone elses code can't handle your errors.
Definitely you should never be converting strings to floats ever anyways, see how I'm going on a limb here without any knowledge of your application, but then you know that I'm right because there's no reason why you would ever do that?
That doesn't detect overflows and underflows. Also changes based on locale, which is not thread safe (so you cannot set locale, convert, then unset locale).
https://en.wikipedia.org/wiki/IEEE_754
https://sixlettervariable.blogspot.com/2007/05/vax-floating-...
Gilfoyle: Anything to do with errors is more your vibe"
https://www.youtube.com/watch?v=oyVksFviJVE&t=49
Oh, this one is easy.
Just don't make the errors, then you don't have to detect them.
When your app stops issuing these errors, then you won't have to write blog posts complaining that someone elses code can't handle your errors.
Definitely you should never be converting strings to floats ever anyways, see how I'm going on a limb here without any knowledge of your application, but then you know that I'm right because there's no reason why you would ever do that?
For extra reassurance, initialize foo to NaN or DBL_MAX or something, and verify that it is no longer equal to that value.