struct sysinfo {

    long uptime;             /* Seconds since boot */

    unsigned long loads[3];  /* 1, 5, and 15 minute load averages */

    unsigned long totalram;  /* Total usable main memory size */

    unsigned long freeram;   /* Available memory size */

    unsigned long sharedram; /* Amount of shared memory */

    unsigned long bufferram; /* Memory used by buffers */

    unsigned long totalswap; /* Total swap space size */

    unsigned long freeswap;  /* swap space still available */

    unsigned short procs;    /* Number of current processes */

    unsigned long totalhigh; /* Total high memory size */

    unsigned long freehigh;  /* Available high memory size */

    unsigned int mem_unit;   /* Memory unit size in bytes */

    char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding for libc5 */

};

#include <stdio.h>

#include <time.h>

#include <stdio.h>

#include <errno.h>

#include <linux/unistd.h>       /* for _syscallX macros/related stuff */

#include <linux/kernel.h>       /* for struct sysinfo */

#include <sys/sysinfo.h>

long get_uptime()

{

    struct sysinfo s_info;

    int error;

    error = sysinfo(&s_info);

    if(error != 0)

    {

        printf("code error = %d\n", error);

    }

    return s_info.uptime;

}

long out_sys(){

	  /* Conversion constants. */

	  const long minute = 60;

	  const long hour = minute * 60;

	  const long day = hour * 24;

	  const double megabyte = 1024 * 1024;

	  /* Obtain system statistics. */

	  struct sysinfo si;

	  sysinfo (&si);

	  /* Summarize interesting values. */

	  printf ("system uptime : %ld days, %ld:%02ld:%02ld\n",

	          si.uptime / day, (si.uptime % day) / hour,

	          (si.uptime % hour) / minute, si.uptime % minute);

	  printf ("total RAM     : %5.1f MB\n", si.totalram / megabyte);

	  printf ("free RAM      : %5.1f MB\n", si.freeram / megabyte);

	  printf ("process count : %d\n", si.procs);

}

int main(int argc, char* argv[]) {

  struct timespec t;

  clock_gettime(CLOCK_MONOTONIC, &t);

  printf("tv_sec=%llu tv_nsec=%llu\n uptime time:%llu\n",

    (unsigned long long)t.tv_sec,

    (unsigned long long)t.tv_nsec,

    get_uptime());

  out_sys();

  return 0;

}