cutting mail spool

[Craig White]

On Fri, 2005-07-29 at 11:27 -0700, Lynn David Newton wrote:
> Using dd to cut a large mail spool file blindly cuts it
> at some random place. It would be better to split it at
> the beginning of messages. An email message begins with
> the string "^From ".
> 
> I played a couple of minutes with csplit(1) (context
> split), which looks like a possibility, and used to
> understand, but it's been 10-15 years since I've used
> it for anything, and couldn't quite make it work. But
> I'll bet with a little experimentation you could use
> that to divide the file into multiple spool files.
----
random was OK - I'll not elaborate but the cost is one of 11,210 emails.
Seems a fair price to pay.

Thanks for the fish - I was too panicked to research. My mind went to dd
but I didn't know skip option.

FTR...

dd if=big.mailbox of=new.file bs=1048576 count=1000
OK

dd if=big.mailbox of=other.part bs=1048576 seek=1000
Not OK (gave me 2.9G file)

but
dd if=big.mailbox of=other.part bs=1048576 skip=1000

was the winner - thanks all (actually my number was 1073737, which was
1/2 rounded upwards)

Craig