Re: very important

First, learn to ask intelligent questions:

http://www.catb.org/~esr/faqs/smart-questions.html

Your subject is worse than useless.


ali awan wrote:
> 
> I m facing a problem in using libpcap in a C program on linux 7.2. I 
> have libpcap-0.7.2 installed in the root directory.

Installed by hand?  You probably could save yourself a lot of effort by 
using the libpcap package provided by Red Hat.

> and have copied the 
> folder in the include directory.

Remove it, that's not where it belongs.

> but when I compile my program it gives 
> the following error:
> 
> /tmp/ccSuKW14.o(.text+0x1ab):undefined reference to "pcap_lookupdev"

You need to tell the build scripts where to find libpcap.  That may be:

LDFLAGS="-lpcap -L/root/libpcap-0.7.2" ./configure ; make

Hard to say without any information about what you're trying to build. 
In any case, the -L argument is missing from the build you're 
attempting, and it needs to be added.

Or just install Red Hat's package, and everything should work without 
additional effort on your part.

> the same error comes on all the libpcap functions. I have also tried to 
> install libpcap in the include folder and then include the file but it 
> doesnt work even then.
> What should i do.

Remove the pcap library from any extra places in the filesystem you've 
put it, and follow the instructions above.