[Guy Harris <gharris@xxxxxxxxxxxx>]

> Neither Ethereal nor Tethereal currently support command-line arguments
> other than flag arguments.  For invocations that start out doing a
> capture (Ethereal with the "-k" flag, Tethereal without the "-r" flag),
> perhaps if there's no "-f" flag, the command-line arguments should be
> treated as tokens in a packet filter expression, just as happens with
> tcpdump and snoop.

I've just checked in a change to Tethereal to support that; capture or
read filters can either be specified with "-f" and "-R" flags,
respectively, or as additional non-flag command line arguments, as is
the case with tcpdump or snoop, so you can, for example, do

	tethereal host www.sun.com

to do a capture that sees only packets going to or from "www.sun.com",
or do

	tethereal -r my_capture.pcap ip.addr == 128.1.2.3

to read the capture file "my_capture.pcap" and see only packets going to
or from the IP address 128.1.2.3.

(Note that if any of the tokens in the capture or display filter contain
shell meta-characters, they'll still have to be put in quotes.)