unsigned long long strtoull(FAR const char *nptr, FAR char **endptr, int base)
{
unsigned long long accum = 0;
int value;
if (nptr)
{
/* Skip leading spaces */
lib_skipspace(&nptr);
/* Check for unspecified base */
base = lib_checkbase(base, &nptr);
/* Accumulate each "digit" */
while (lib_isbasedigit(*nptr, base, &value))
{
accum = accum*base + value;
nptr++;
}
/* Return the final pointer to the unused value */
if (endptr)
{
*endptr = (char *)nptr;
}
}
return accum;
}
int lib_checkbase(int base, FAR const char **pptr)
{
FAR const char *ptr = *pptr;
/* Check for unspecified base */
if (!base)
{
/* Assume base 10 */
base = 10;
/* Check for leading '0' - that would signify octal or hex (or binary) */
if (*ptr == '0')
{
/* Assume octal */
base = 8;
ptr++;
/* Check for hexadecimal */
if ((*ptr == 'X' || *ptr == 'x') &&
lib_isbasedigit(ptr[1], 16, NULL))
{
base = 16;
ptr++;
}
}
}
/* If it a hexadecimal representation, than discard any leading "0X" or "0x" */
else if (base == 16)
{
if (ptr[0] == '0' && (ptr[1] == 'X' || ptr[1] == 'x'))
{
ptr += 2;
}
}
/* Check for incorrect bases. */
else if (base < 2 || base > 26)
{
return -1; /* Means incorrect base */
}
/* Return the updated pointer and base */
*pptr = ptr;
return base;
}
unsigned long long strtoull(const char *nptr, char **endptr, int base)
{
unsigned long long prev, accum = 0;
int value;
if (nptr) {
/* Skip leading spaces */
lib_skipspace(&nptr);
/* Check for unspecified base */
base = lib_checkbase(base, &nptr);
if (base < 0) {
set_errno(EINVAL);
return 0;
}
/* Accumulate each "digit" */
while (lib_isbasedigit(*nptr, base, &value)) {
prev = accum;
accum = accum * base + value;
nptr++;
/* Check for overflow */
if (accum < prev) {
set_errno(ERANGE);
accum = 0;
break;
}
}
/* Return the final pointer to the unused value */
if (endptr) {
*endptr = (char *)nptr;
}
}
return accum;
}