LinuxQuestions.org

LinuxQuestions.org (/questions/)
-   Linux - Networking (https://www.linuxquestions.org/questions/linux-networking-3/)
-   -   file -vv -s 0 -w /location/name of file (https://www.linuxquestions.org/questions/linux-networking-3/file-vv-s-0-w-location-name-of-file-4175500375/)

eddie9681 04-02-2014 07:28 PM

file -vv -s 0 -w /location/name of file
 
Hi, completely new, sorry if im not doing it right but can any one please explain to me whats going on in the subject header?

I am running a command line emulator on my android device and have allowed tcpdump read/writable permission(chmod 77)

I am capturing packets on my android device and am keen to know what -vv -s 0 -w actually does

here is the exact commands i have:

root@m0: /system/xbin # chmod 777 tcpdump

root@m0: /system/xbin # tcpdump -vv -s 0 -w /storage/extSdCard/tcp.cap

thanks.

Habitual 04-03-2014 01:44 PM

Code:

-vv
    Even more verbose output. For example, additional fields are printed from NFS reply packets, and SMB packets are fully decoded.
-S
    Print absolute, rather than relative, TCP sequence numbers.

from man tcpdump or http://www.tcpdump.org/manpages/tcpdump.1.html

I don't know what 'other' options there are for -s as I've always used 0 from the examples I have found.

-vv is pretty common for additional verbosity (vs -v, I suppose).

acid_kewpie 04-03-2014 01:45 PM

chmod 777 tcpdump? Really? that's a really really bad idea, why did you do that? That means that anyone on the system can edit or delete that program. Don't do that. If you're running this as someone wrote in in your internal documentation or such like, go find who wrote it and poke them in the eye.

If you run "man tcpdump" you'll get the manpage and you'll see what the options do. But -v means "verbose", -vv means "more verbose" -s0 means capture all the packet, not just the first chunk of tcp/ip headers and -w <filename> writes it to a file. Given that you're writing tpo a file, -vv doesn't actually do anything useful, but it's harmless.

---------- Post added 03-04-14 at 07:46 PM ----------

Quote:

I don't know what 'other' options there are for -S as I've always used 0 from the examples I have found.
Wrong case. s, not S.


All times are GMT -5. The time now is 09:35 AM.