From owner-freebsd-net@freebsd.org  Wed Aug 26 22:23:11 2015
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Date: Wed, 26 Aug 2015 23:23:08 +0100
From: Gary Palmer <gpalmer@freebsd.org>
To: Chris Stankevitz <chris@stankevitz.com>
Cc: John-Mark Gurney <jmg@funkthat.com>, freebsd-net@freebsd.org
Subject: Re: ssh over WAN: TCP window too small
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On Wed, Aug 26, 2015 at 02:30:07PM -0700, Chris Stankevitz wrote:
> > ktrace -i ssh <params>...
> 
> Thank you, this is awesome.  Is there a way for me to ktrace 'b' in this 
> example: `a | b | c`?  I tried `ktrace a | b | c` and `ktrace test.sh` 
> (which included a|b|c) but neither seemed to work.  I'm using stream 
> redirection now but it doesn't afford me the bs control of dd.  Perhaps 
> named pipes is the solution.


a | ktrace b | c

or

ktrace -di test.sh

(I suspect only -i is needed, but I've gotten so used to using both flags)

You can also start ktrace on an existing process if you know its PID

ktrace -p <pid>

To stop all ongoing tracing:

ktrace -C 

Regards,

Gary