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.

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).

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 ----------

Wrong case. s, not S.