Use strtoll() to parse ints

[jasonbking]

Instead of using sscanf() (whose behavior is surprisingly underspecified) to parse integer values, use strtoll() instead. It turns out to be much simpler, and hopefully is more portable.

[jasonbking]

It's not obvious what the AppVeyor failures were -- nothing I pushed should have touched any VS project files. Is there something more specific someone can point me at?

[hawicz]

So how do we know sizeof(long long) == sizeof(int64_t) ?

(the AppVeyor build is probably because I removed the VS project files, and didn't do anything to make it use cmake instead)

[jasonbking]

https://en.wikipedia.org/wiki/C_data_types has the (likely) more digestible version, but includes a link to the relevant standards. tl;dr -- C99 requires that long long can hold at least a 64-bit signed integer. No implementation I'm aware of today uses any integer size larger than that for long long (it'd likely break a lot of stuff), though if there are concerns of that happening, I could have it do something like:

char *end = NULL;
long long val;
errno = 0;
val = stroll(buf, &end, 10);
if (end != buf) {
    if (val > INT64_MAX)
        *retval = INT64_MAX;
   else if (val < INT64_MIN)
       *retval = INT64_MIN;
   else
        *retval = val;
}
return ((val == 0 && errno != 0) || (end == buf)) ? 1 : 0;

or even put the bits capping the value inside a #if sizeof (long long) > sizeof (int64_t) block

[hawicz]

You're right, it's pretty unlikely. Enough so that I'd say instead of code to handle it let's just do a preprocessor check like:

#if SIZEOF_LONG_LONG != SIZEOF_INT64_T
#error The long long type isn't 64-bits
#endif