loadavg statistics on Darwin using sysctl(3)

loadavg.c

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/sysctl.h>

int main(int argc, char const* argv[])
{
  struct loadavg load;
  size_t size = sizeof(load);
  if (sysctlbyname("vm.loadavg", &load, &size, 0, 0) == -1) {
    fprintf(stderr, "failed in sysctl\n");
    return 1;
  }
  printf("loadavg1: %lf\nloadavg5: %lf\nloadavg15: %lf\n",
      (double)load.ldavg[0]/load.fscale,
      (double)load.ldavg[1]/load.fscale,
      (double)load.ldavg[2]/load.fscale);
  return 0;
}