pcap使用之pcap_looupdev

1.得到当前可用设备pcap_lookupdev 
代码举例：

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

int main()
{
        char *buf=NULL;
        char errbuf[PCAP_ERRBUF_SIZE];
        buf=pcap_lookupdev(errbuf);
        printf("%s\n",buf);

}

2.使用方法
NAME
       pcap_lookupdev - find the default device on which to capture


SYNOPSIS
       #include


       char errbuf[PCAP_ERRBUF_SIZE];


       char *pcap_lookupdev(char *errbuf);


DESCRIPTION
       pcap_lookupdev()  returns  a  pointer  to a string giving the name of a
       network device suitable for use with pcap_create() and pcap_activate(),
       or  with  pcap_open_live(),  and with pcap_lookupnet().  If there is an
       error, NULL is returned and errbuf is filled  in  with  an  appropriate
       error  message.   errbuf  is  assumed  to  be  able  to  hold  at least
       PCAP_ERRBUF_SIZE chars.

3.pcap_lookupnet :得到设备的网络标示与掩码这个不举例了，很简单，看帮助文档

SYNOPSIS
       #include


       char errbuf[PCAP_ERRBUF_SIZE];


       int pcap_lookupnet(const char *device, bpf_u_int32 *netp,
               bpf_u_int32 *maskp, char *errbuf);


DESCRIPTION
       pcap_lookupnet()  is used to determine the IPv4 network number and mask
       associated with the network device device.  Both  netp  and  maskp  are
       bpf_u_int32 pointers.


RETURN VALUE
       pcap_lookupnet()  returns  0  on  success  and -1 on failure.  If -1 is
       returned, errbuf is  filled  in  with  an  appropriate  error  message.
       errbuf is assumed to be able to hold at least PCAP_ERRBUF_SIZE chars.