[paranoia] splitting sound files?

[Douglas Gilbert]

Wolfgang Weisselberg wrote:
> 
> Hi, Ralph!
> 
> Trying to kill the keyboard, Ralph Corderoy
> (ralph at inputplus.demon.co.uk) produced 0,9K in 29 lines:
> 
> > If your head and tail prefer text files then use dd(1).
> 
> >     dd if=big.raw of=part0.raw bs=1024k skip=0 count=1
> >     dd if=big.raw of=part1.raw bs=1024k skip=1 count=1
> >     dd if=big.raw of=part2.raw bs=1024k skip=2 count=1
> >     ...
> 
> This can get SLOW for large values of skip, since (at least
> some versions of) dd read through the whole 'skip' part instead
> of skipping to the part that matters.

Recent versions of dd use lseek() to implement 'skip'
(and 'seek'). That system command accepts a signed
long for its 'offset' argument so on the i386 architecture
that limits a single lseek() command to moving the byte
pointer by 2 GB. To get around this limitation, dd
does some calculations and potentially calls multiple
lseek() calls.
 
> But then there's always 'man split'.

I wonder how split is any better.

Doug Gilbert

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