libpcap error.

error1:

include<pcap.h>     no such file

sudo apt-get install libpcap-dev

error2:

sniffer.c:(.text+0x43): undefined reference to `pcap_findalldevs'
sniffer.c:(.text+0x142): undefined reference to `pcap_open_live'
sniffer.c:(.text+0x1df): undefined reference to `pcap_loop'

gcc sniffer.c -o sniffer -lpcap