Use strtoull to convert string to unsigned long long int
Syntax
C strtoull function has the following format.
unsigned long long int strtoull(const char *restrict start, char **restrict end, int radix);Header
C strtoull function is from header file stdlib.h.
Description
C strtoull function is similar to
strtoul() except that it returns an unsigned long long int.
If the result cannot be represented as an unsigned long integer, ULLONG_MAX is returned.
If *start is a number, no conversion takes place and zero is returned.
Example
Convert string to unsigned long long int by using C strtoull function.
#include <stdlib.h>
/*w w w. j a va 2 s.c om*/
int main(void){
char *start, *end;
char a[100];
end = a;
*start= "12341234";
printf("%d", strtoull(start, &end, 8));
}