#include <stdio.h>
#include <stdlib.h>
#include <pcap.h>
#include <sys/socket.h>

int main(int argc, char *argv[]){
char errbuf[PCAP_ERRBUF_SIZE+1];
pcap_if_t * j;
  pcap_findalldevs(&j, errbuf);
  printf("Accessible interfaces are:\n");
  for(; j; j = j->next) {printf("network device name: %s, description: %s, \n",
        j->name, j->description);
    pcap_t* dev = pcap_open_live(j->name, 20, 0, 150, errbuf);
    if(dev){int j=20; printf("pcap_t: ");
        while(j--) printf("%02x ", *(j+(char*)dev)); printf("\n");
      {int typ = pcap_datalink(dev); printf("link layer type: %d %s: %s\n",
        typ, pcap_datalink_val_to_name(typ), 
        pcap_datalink_val_to_description(typ));
        pcap_close(dev);}}
    else {perror("wont open! "); errbuf[PCAP_ERRBUF_SIZE]=0; printf("%s\n", errbuf);}
    pcap_addr_t * adrs = j-> addresses;
    for(; adrs; adrs = adrs -> next) printf("sa_family=%d ", (adrs -> addr) -> sa_family);
    printf("\n");}
return(0);}

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


/* 2009, Jan, Mac OS 10.5.6
Accessible interfaces are:
network device name: en0, description: (null), 
pcap_t: 00 00 00 01 00 00 00 14 00 00 00 00 00 00 00 03 00 00 00 03 
link layer type: 1 EN10MB: Ethernet
sa_family=18 
network device name: fw0, description: (null), 
pcap_t: 00 00 00 ffffff8a 00 00 00 14 00 00 00 00 00 00 00 03 00 00 00 03 
link layer type: 138 APPLE_IP_OVER_IEEE1394: Apple IP-over-IEEE 1394
sa_family=18 
network device name: en1, description: (null), 
pcap_t: 00 00 00 01 00 00 00 14 00 00 00 00 00 00 00 03 00 00 00 03 
link layer type: 1 EN10MB: Ethernet
sa_family=18 sa_family=30 sa_family=2 
network device name: lo0, description: (null), 
pcap_t: 00 00 00 00 00 00 00 14 00 00 00 00 00 00 00 03 00 00 00 03 
link layer type: 0 NULL: BSD loopback
sa_family=18 sa_family=30 sa_family=2 sa_family=30 
*/