fxlibc/src/stdlib/strtoull.c

#include "stdlib_p.h"
#include <errno.h>

unsigned long long int strtoull(char const * restrict ptr,
	char ** restrict endptr, int base)
{
	unsigned long long n = 0;
	if(endptr)
		*endptr = (char *)ptr;

	struct __scanf_input in = { .str = ptr, .fp = NULL };
	__scanf_start(&in);
	int err = __strto_int(&in, base, NULL, (long long *)&n, true, INT_MAX);
	__scanf_end(&in);

	if(err != 0)
		errno = (err == EOF) ? EINVAL : err;
	if(err != EINVAL && endptr)
		*endptr = (char *)in.str;
	return n;
}