Re: avoid atoi, when possible; int overflow -> heap corruption

"Morten Welinder" [off-list ref] wrote:

quoted

There are about 20 uses of atoi, and most calls can return
a usable result in spite of an invalid input -- just because
atoi returns the same thing for "99" as "99-and-any-suffix".
It would be better not to ignore invalid inputs.

atoi has undefined behaviour for "99-and-any-suffix".  You might
get lucky and get back 99, but you might also get a random value
or a core dump.

I've never heard of that.
POSIX says that atoi(str) is equivalent to:

    (int) strtol(str, (char **)NULL, 10)
    except that the handling of errors may differ.
    If the value cannot be represented, the behavior is undefined.

Since strtol works fine with such a suffix, and since 99 can be
represented, I don't see why there would be any undefined behavior.

Do you know of an implementation for which `atoi ("99-and-any-suffix")'
does anything other than return 99?