Converts a string to an unsigned long long integer.
#include <stdlib.h>
uint64_t strtoull (
const char *ptr,
char **endptr,
int base);
(IN) Points to the string to be converted.
(OUT) Points to the first unrecognized character.
(IN) Specifies the number base to use.
If successful, returns the converted value. Otherwise, returns one of the following:
If the correct value would cause overflow, returns ULLONG_MAX and sets errno to ERANGE.
If base is out of range, returns 0 and sets errno to ENIVAL.
If the input string cannot be converted, returns 0 and sets errno to ENIVAL.
The strtoull function converts the string pointed to by ptr to an unsigned long long integer. The function recognizes a string containing optional whitespace characters, followed by a sequence of digits and letters. The conversion ends at the first unrecognized character. A pointer to that character is stored in the object to which endptr points if endptr is not NULL.
If base is zero, the first characters determine the base used for the conversion. If the first characters are 0x or 0X, the digits are treated as hexadecimal. If the first character is 0, the digits are treated as octal. Otherwise, the digits are treated as decimal.
If base is not zero, it must have a value of between 2 and 36. The letters a through z and A through Z represent the values 10 through 35. Only those letters whose designated values are less than base are permitted. If the value of base is 16, the characters 0x or 0X can optionally precede the sequence of letters and digits.