#include <stdio.h> 
#include <string.h> 
 
// 네트워크 인터페이스 정보를 저장한 proc 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; 
}