per...@pluto.rain.com wrote:
Greg Larkin <glar...@freebsd.org> wrote:
> ...
> > truncate -4 myfile should get rid of the last four bytes. Maybe
> > there's a similar efficient way to truncate the start of a file.
>
> This should do it:
>
> dd if=oldfile of=newfile bs=1 skip=4
Or, perhaps marginally more efficient:
dd if=oldfile of=newfile bs=4 skip=1
It would be nice to avoid the file copy, but maybe there's no way to do
that. The small buffer size for dd will probably make copies of
multi-gig files slow. This might be faster:
tail -c +5 myfile > outfile
truncate -4 outfile
(Has anyone mentioned that you can edit binary files interactively with
vi yet? No? Well, it's horrific and surely has interesting failure
modes. And there are probably disadvantages also.)
-Warren Block * Rapid City, South Dakota USA
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