Date: Wed, 19 Jun 1996 10:18:16 GMT From: James Raynard <fcurrent@jraynard.demon.co.uk> To: wosch@cs.tu-berlin.de Cc: freebsd-current@freebsd.org Subject: Re: ktrace [Was: 2.2-960612-SNAP resolver problems] Message-ID: <199606191018.KAA12951@jraynard.demon.co.uk> In-Reply-To: <199606190007.CAA01478@campa.panke.de> (message from Wolfram Schneider on Wed, 19 Jun 1996 02:07:42 %2B0200)
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> >Indeed. Apart from volume of output, is there any particular reason > >why ktrace writes to a file which kdump reads in, as opposed to using > >a pipe? Particularly as the first thing kdump does is > >freopen(tracefile, "r", stdin)! > > Hm, try `ktrace -f /dev/stdout | kdump -f /dev/stdin' $ ktrace -f /dev/stdout -p 12922 | kdump -f /dev/stdin ktrace: /dev/stdout: Operation not supported by device. I did actually try this before I posted, although with /dev/fd/[01]. The problem is that ktrace doesn't actually write to the file itself, it passes the name of the file to a system call that does kernel writes to the vnode, and this only seems to work for regular files. -- James Raynard, Edinburgh, Scotland james@jraynard.demon.co.uk
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