C코드 : 네트워크 Interface 트래픽 구하기

#include <stdio.h>
#include <string.h>

// 네트워크 인터페이스 정보를 저장한 proc(:12) 파일
const char *ProcDev = "/proc/net/dev";
const char *Format = "%s %s %s %s %s %s %s %s %s %s";

// 트래픽 정보를 저장하기 위한 구조체
struct traffic
{
  char bytes[16];
  char packets[16];
  char errs[16];
};

int GetTraffic(struct traffic *in, struct traffic *out, char *ifname);

int main(int argc, char **argv)
{
  struct traffic in, out;
  int rtv;
  rtv = GetTraffic(&in, &out, "eth0");
  if (rtv == 1)
    printf("Traffic eth0 OK | inbps=%s inpps=%s outbps=%s outpps=%s\n",
            in.bytes, in.packets, out.bytes, out.packets);
}

int GetTraffic(struct traffic *in, struct traffic *out, char *ifname)
{
  FILE *fp;
  char *hp;
  char buf[256];
  char ifheader[16];
  sprintf(ifheader, "%s:", ifname);
  fp = fopen(ProcDev,"r");
  int noused[16];
  char tell[12];

  if (fp == NULL)
    return -1;

  while(fgets(buf, 255, fp)!=NULL)
  {
    if ((hp  = strstr(buf, ifheader)) != NULL)
    {
      hp = hp + strlen(ifheader);
      sscanf(hp, Format, in->bytes, in->packets, in->errs,
                         noused, noused, noused, noused, noused,
                         out->bytes, out->packets, out->errs);
      break;
    }
  }
  fclose(fp);
  return 1;
}