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

#define ps 160
#define macc 10 // How many MAC addresses we will remember
u_char mac[macc][6]; // Array of seen MAC addresses
int mcc = 0; // How many we have seen
u_char * frmpp = (u_char*) "frmp";
int min(int a, int b){return a<b?a:b;}
int maccv(const u_char * xx){int k=mcc; while(k--) if(!memcmp(mac[k], xx, 6)) {return k;}
  if(mcc==macc) exit(printf("Crowd\n")); memmove(mac[mcc], xx, 6); return mcc++;}
void hndl(u_char * id, const struct pcap_pkthdr * ph, const u_char * data){
   if (id != frmpp) exit(printf("Foo\n"));
   printf("%d->%d ", maccv(data), maccv(data+6));
   printf("mch11=%d, when: %d sec + %d μsec\n",
      ph->len, (int)ph->ts.tv_sec, (int)ph->ts.tv_usec);
   if(0){int j=min(ps,ph->caplen); while(j--) {
     printf("%02x", *(data+j)); if(!((j+2)&3)) putchar(' ');} printf("\n");}
   else {int j, l=min(ps,ph->caplen); for(j=14; j<l; ++j) {
      if(!((j+2)&3)) putchar(' '); printf("%02x", *(data+j));} printf("\n");}}

int main(int argc, char *argv[]){
char errbuf[PCAP_ERRBUF_SIZE];
  pcap_t* dev = pcap_open_live("en1", ps, 1, 150, errbuf);
  printf("pcap_t at 0x%x\n", dev);
  if(dev){int j=20; while(j--) printf("%02x ", *(j+(char*)dev)); printf("\n");}
  else {perror("Bah!");
    int j; for(j=0; j<PCAP_ERRBUF_SIZE; ++j)
     if(errbuf[j]) putchar(errbuf[j]); else {putchar('\n'); return 0;}}
  {int typ = pcap_datalink(dev);
     if(typ != 1) exit(printf("Type not Ethernet! %d\n", typ));}
  pcap_loop(dev, 10, hndl, frmpp);
  printf("Back from pcap_loop\n");
return(0);}

// gcc ac.c -lpcap
// sudo ./a.out