tcpdump mailing list archives
Re: about packet capture
From: Tao Peng <taop () ee mu oz au>
Date: Wed, 4 Feb 2004 11:01:23 +1100 (EST)
Hi, Erik, Thanks a lot! It works now. Best regards Tao ------------------------------- Tao Peng CUBIN Research Centre,EEE Dept. Melbourne Uni., Australia Phone: + 61 3 8344 3822 Fax: + 61 3 8344 3821 Mobile: 0402 947 026 ------------------------------- On Tue, 3 Feb 2004, Erik de Castro Lopo wrote:
On Tue, 3 Feb 2004 15:44:41 +1100 (EST) Tao Peng <taop () ee mu oz au> wrote:Dear All, I am a rookie to network programming, and I am having troubles of compling a single code. The code is as follows: ****************************************************** #include <stdio.h> #include <pcap.h> int main() { char *dev, errbuf[PCAP_ERRBUF_SIZE]; dev = pcap_lookupdev(errbuf); printf("Device: %s\n", dev); return(0); } ****************************************************** when I complie it using gcc, it gives me an error as follows: /var/tmp//cc95eETb.o: In function `main': /var/tmp//cc95eETb.o(.text+0x1e): undefined reference to `pcap_lookupdev'This is a linker message not a compiler message (you can tell from the /var/tmp//*.o). That means that the compiler had no problem with the C code, but that the linker was not able to find the object file that defined 'pcap_lookupdev'.But I had my pcap.h included, and I don't know why. Can anyone help me about this?You were probably doing something like: gcc program.c -o program What you need is: gcc program.c -lpcap -o program The "-lpcap" tells gcc to tell the linker to link to libpcap. If libpcap is installed in a non-standard location you might need to do something like this: gcc procgram.c -L/some/path -lpcap -o program HTH, Erik -- ------------------------------------------------------ [N] Erik de Castro Lopo, Senior Computer Engineer [E] erik.de.castro.lopo () sensorynetworks com [W] http://www.sensorynetworks.com [T] +61 2 83022726 [F] +61 2 94750316 [A] L4/140 William St, East Sydney NSW 2011, Australia ------------------------------------------------------ - This is the TCPDUMP workers list. It is archived at http://www.tcpdump.org/lists/workers/index.html To unsubscribe use mailto:tcpdump-workers-request () tcpdump org?body=unsubscribe
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Current thread:
- about packet capture Tao Peng (Feb 02)
- Re: about packet capture Erik de Castro Lopo (Feb 02)
- Re: about packet capture Tao Peng (Feb 03)
- Re: about packet capture Erik de Castro Lopo (Feb 02)