Date: Mon, 4 Mar 2013 11:29:00 +0000 From: Steve O'Hara-Smith <steve@sohara.org> To: freebsd-questions@freebsd.org Cc: Polytropon <freebsd@edvax.de> Subject: Re: Grepping though a disk Message-ID: <20130304112900.660b3e29dbec8f2f60fffa9b@sohara.org> In-Reply-To: <20130304121524.63685108.freebsd@edvax.de> References: <20130304013608.7981e8a9.freebsd@edvax.de> <51347454.5060605@gmail.com> <20130304121524.63685108.freebsd@edvax.de>
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On Mon, 4 Mar 2013 12:15:24 +0100 Polytropon <freebsd@edvax.de> wrote: > But I don't know how to do this. From reading "man dd" > my impression (consistent with my experience) is that > the option skip= operates in units of bs= size, so I'm > not sure how to compose a command that reads units of > 1 MB, but skips in units of 950 kB. Maybe some parts of > my memory have also been marked "unused" by fsck. :-) Not too hard (you'll kick yourself when you read down) - translation to valid shell script is left as an exercise for the reader :) bs=50k count=(n*20) skip=(n*20 - 1) Probably nicer to use powers of 2 bs=64k count=(n*16) skip=(n*16 - 1) -- Steve O'Hara-Smith <steve@sohara.org>
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