strtoull and long long arithmetic
c, long-integer, string
Solution
Do you have `<stdlib.h>` included?
I can reproduce on MacOS X if I omit `<stdlib.h>`.
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
unsigned long long ns = strtoll("123110724001300", (char **)NULL, 10);
printf("%llu\n", ns);
return(0);
}
Omit the header, I get your result. Include the header, I get the correct answer.
Both 32-bit and 64-bit compiles.
As noted in the comments, in the absence of a declaration for strtoll(), the compiler treats it as a function returning int.
To see more of what goes on, look at the hex outputs:
123110724001300 0x00006FF7_F2F8DE14 Correct
18446744073490980372 0xFFFFFFFF_F2F8DE14 Incorrect
Manually inserted underscores...
Problem
Can anyone explain the output of this program and how I can fix it? ``` unsigned long long ns = strtoull("123110724001300", (char **)NULL, 10); fprintf(stderr, "%llu\n", ns); // 18446744073490980372 ```