Bug #26937 for Net-Pcap: Bug report for Net-Pcap

Thanks for your quick response. Sorry if I did not explain the problem clearly enough for you. Let me try again... In the PCAP file, each packet has a timestamp which, if viewed with a tool like ethereal, would be displayed as hh:mm:ss.yyyyyy. In order to get at this timestamp information when using Net::Pcap, I would have to do the following: $tv_sec = $hdr->{tv_sec}; # seconds since the beginning of the epoch $tv_usec = $hdr->{tv_usec}; # fractional part of timestamp And yes, I agree that tv_usec is an integer (which is why I use %06d in my sprintf format string and not %06f). However, I think the confusion came from the fact that it represents the fractional part of the timestamp value (i.e. the part after the decimal point). The problem that I found is that if the yyyyyy part contains a zero at the beginning (e.g. hh:mm:ss.012345 as shown by a tool like ethereal), when I use $tv_usec to create a floating point number, i.e. $fp_tv = "$tv_sec.$tv_usec"; I get <epoch seconds>.12345 and not <epoch seconds>.012345, i.e. the leading 0 is missing from the fractional part of the number. In order to rectify this problem, I used: $tv_usec = sprintf "%06d", $hdr->{tv_usec}; so that it is padded with the necessary zeros at the beginning. Hope that helps. Regards, Nick This transmission may contain information that is privileged, confidential and/or exempt from disclosure under applicable law. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the information contained herein (including any reliance thereon) is STRICTLY PROHIBITED. If you received this transmission in error, please immediately contact the sender and destroy the material in its entirety, whether in electronic or hard copy format. "Sébastien Aperghis-Tramoni via RT" To <bug-Net-Pcap@rt. Nick Smith/CanWest/IBM@IBMCA cpan.org> cc 05/04/2007 01:44 Subject PM Re: [rt.cpan.org #26937] Bug report for Net-Pcap Please respond to bug-Net-Pcap@rt.c pan.org <URL: http://rt.cpan.org/Ticket/Display.html?id=26937 > Hello, Show quoted text
Sorry but I do not understand the problem: tv_usec is a long integer, so it clearly cannot get floating point values. Can you show an example of code which exposes your problem? -- Sébastien Aperghis-Tramoni Close the world, txEn eht nepO.

Actually, you can call me dense. Although I read the documentation for Net::Pcap, I obviously did not understand what it was telling me with respect to the tv_usec header field. You are right, this is a formatting issue and the bug is in my head not in Net::Pcap. However, I am not the only one who has fallen into the trap of thinking that I can do something as silly as $timestamp = "$hdr->{tv_sec}.$hdr->{tv_usec}"; I guess that I have fallen into the trap of thinking that everything should be handed to me on a plate because Perl makes it so easy when it comes to handling numbers (I can take a string and use it like a number). Perhaps when / if the Net::Pcap module is updated in the future you could add a brief note to the documentation to make it clear that tv_usec is not a string representation of the fractional part of the timestamp. Thanks for your time and sorry to bother you with this. Regards, Nick This transmission may contain information that is privileged, confidential and/or exempt from disclosure under applicable law. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the information contained herein (including any reliance thereon) is STRICTLY PROHIBITED. If you received this transmission in error, please immediately contact the sender and destroy the material in its entirety, whether in electronic or hard copy format.