Try to build and run this program, it could be a reproducer for your
problem:
#include <stdlib.h>
#include <stdio.h>
int main()
{
const char *s = "001 GLX";
char *p;
long int l = strtol(s, &p, 10);
long long ll = strtoll(s, &p, 10);
printf("%ld %lld\n", l, ll);
}