// The code from experts-exchange.com
// http://www.experts-exchange.com/Programming/Programming_Languages/C/Q_10154679.html#1
// To be compiled with gcc -o kstat kstat.c -lkstat

#include <stdio.h>
#include <kstat.h>
#include <sys/sysinfo.h>

#define BYTES_PER_PAGE 8192
#define KBYTE          1024
#define MUL            (BYTES_PER_PAGE/KBYTE)

void print_chain(kstat_ctl_t *kc)
{
 kstat_t *ksp;
 for (ksp = kc->kc_chain; ksp != NULL; ksp = ksp->ks_next) {
   printf("Module: %s Class: %s Name: %s\n", ksp->ks_module, ksp->ks_class, ksp->ks_name);
 }
}

void main(int argc, char*argv[])
{
 kstat_ctl_t    *kc;
 kstat_t        *ksp;
 int            first=1;
 vminfo_t       vmlast,vm;
 cpu_stat_t     statlast, cpu_stat;

 kc  = kstat_open();
 print_chain(kc);
 while(1) {
   ksp = kstat_lookup(kc, "unix", 0, "vminfo");
   if (ksp) {
     kstat_read(kc, ksp, &vm);
     if (!first) {
       printf("---------------------------------\n");
       printf("freemem       =%8llu KByte\n",(vm.freemem-vmlast.freemem)*MUL);
       printf("reserved swap =%8llu KByte\n",(vm.swap_resv-vmlast.swap_resv)*MUL);
       printf("allocated swap=%8llu KByte\n",(vm.swap_alloc-vmlast.swap_alloc)*MUL);
       printf("avail swap    =%8llu KByte\n",(vm.swap_avail-vmlast.swap_avail)*MUL);
       printf("free swap     =%8llu KByte\n",(vm.swap_free-vmlast.swap_free)*MUL);
     }
     vmlast=vm;
   }
   ksp = kstat_lookup(kc, "cpu_stat", 0, "cpu_stat0");
   if (ksp) {
     kstat_read(kc, ksp, &cpu_stat);
     if (!first) {
       printf("stat:syscall  =%8lu\n",
          cpu_stat.cpu_sysinfo.syscall-statlast.cpu_sysinfo.syscall);
     }
     statlast=cpu_stat;
   }
   first=0;
   sleep(1);
   kstat_chain_update(kc);
 }
 kstat_close(kc);
 exit(0);
}