Wireshark-dev: Re: [Wireshark-dev] 90GB pcap file get last frame time stamp

From: Timmy Brolin <tib@xxxxxx>
Date: Fri, 26 Feb 2021 17:50:14 +0000
The pcapng file format supports "backwards" reading.


-----Original Message-----
From: Wireshark-dev <wireshark-dev-bounces@xxxxxxxxxxxxx> On Behalf Of Richard Sharpe
Sent: den 26 februari 2021 18:39
To: Developer support list for Wireshark <wireshark-dev@xxxxxxxxxxxxx>
Subject: Re: [Wireshark-dev] 90GB pcap file get last frame time stamp

On Fri, Feb 26, 2021 at 9:10 AM Raj sekar <mrajsekar@xxxxxxxxx> wrote:
>
> Hi Everyone!
>
> Need a help. Is there any library or method to get large pcap file's( offline ) last timestamp.
>
> I know capinfos can get this. But i want faster than capinfos.
>
> Any suggestion?

Because each captured frame can be a different length, normally you would have to skip all the preceding frames to get the timestamp of the last record.

However, a heuristic approach might be to read the header to get the capture-length, and then read that much from the end of the file and look for an appropriate record header ...

On the other hand, I am unaware of any code that does that.

--
Regards,
Richard Sharpe
(何以解憂?唯有杜康。--曹操)(传说杜康是酒的发明者)
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