abhisheksikka

hi .. im having trouble writing a simple snippet using pcap.h

even when i try to compile a simple code like :

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

int main(int argc, char *argv[])
{
char *dev, errbuf[PCAP_ERRBUF_SIZE];
dev = pcap_lookupdev(errbuf);

if (dev == NULL) {
fprintf(stderr, "Couldn't find default device: %s\n", errbuf);
return(2);
}
printf("Device: %s\n", dev);
return(0);
}

.. i get an error saying undefined reference to "pcap_lookupdev".

Even if i try a longer code .. i get the same error for each of the pcaps functionalities i have used (pcap_open_live, pcap_loop, etc).

I downloaded the pcap folder from tcpdump.org and pasted it in my usr/include. All include files are in order as far as i know.

I have 2 days left to my project deadline .. someone please help .. thanks alot .. cheers

bluehive

This error seems to be coming because linker is unable to find the library. After downloading and unzippping, you should have got a libpcap.so file in the same folder.

I'd suggest you two things to do:
1. export LD_LIBRARY_PATH=absolute_path_of_pcap_lib:$LD_LIBR ARY_PATH

OR

2. In the compilation command, add "-lpcap" at the end of command.

HTH,
Bluehive