GCC编译出现undefined reference to `pcap_lex'
代码如下
#include <stdio.h>
#include <stdlib.h>
#include <pcap.h> /* GIMME a libpcap plz! */
#include <errno.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

int main(int argc, char **argv)
{
char *dev; /* name of the device to use */
char *net; /* dot notation of the network address */
char *mask;/* dot notation of the network mask */
int ret; /* return code */
char errbuf[PCAP_ERRBUF_SIZE];
bpf_u_int32 netp; /* ip */
bpf_u_int32 maskp;/* subnet mask */
struct in_addr addr;

/* ask pcap to find a valid device for use to sniff on */
dev = pcap_lookupdev(errbuf);

/* error checking */
if(dev == NULL)
{
printf("%s\n",errbuf);
exit(1);
}

/* print out device name */
printf("DEV: %s\n",dev);

/* ask pcap for the network address and mask of the device */
ret = pcap_lookupnet(dev,&netp,&maskp,errbuf);

if(ret == -1)
{
printf("%s\n",errbuf);
exit(1);
}

/* get the network address in a human readable form */
addr.s_addr = netp;
net = inet_ntoa(addr);

if(net == NULL)/* thanks Scott :-P */
{
perror("inet_ntoa");
exit(1);
}

printf("NET: %s\n",net);

/* do the same as above for the device's mask */
addr.s_addr = maskp;
mask = inet_ntoa(addr);

if(mask == NULL)
{
perror("inet_ntoa");
exit(1);
}

printf("MASK: %s\n",mask);

return 0;
}


[解决办法]
很有可能是ls说的
[解决办法]
sudo apt-get install libpcap-dev