On Thursday 06 January 2005 16:18, donald.ritchey AT exeloncorp DOT com 
wrote:
>Gene:
>
>My experience with 'dd' on many UNIX platforms is that it generally
> tries not
>to make assumptions about block size ,and unless specified, will
> generally take
>whatever is the device default.  The value of the default will often
>surprise you.

Which is why it makes a relatively painless tool to determine the 
current working block size of a tape system.

>That being said, I have had my hands bitten by 'dd' enough in the
> past that I ALWAYS specify a block size on any transfer using the
> tool.  Because of the
>need for 'dd' to get down and dirty with the tape hardware and the
>undeniable
>fact that many UNIX implementations handle the subtleties of device
> I/O differently, it is almost always a good idea to make sure your
> commands know
>
>exactly what you want done.  Block size is a prime example.
>
>'dd' is one of the original, old-school UNIX commands and make a
> good illustration of why UNIX is like an experienced craftsman's
> tool:
>
> A consumer-grade tool is like a ShopSmith (a 1950's era hobbyist
>tool),
> with lots of bells and whistles, and lots of shields and guards to
>keep
> the casual user's fingers out of the dangerous areas and away from
>sharp
> edges (and keep the plaintiff's lawyers out of the vendors
> pockets).
>
I don't have any of those to speak of, and have a slightly odd shaped 
finger because of their not being enough guarding on my jointer & 
managed to take about 1/16" worth of skin off.  Lucky, really...

> A UNIX system is like a blacksmith's shop.  The tools ALL have
> sharp
>
> edges and are dangerous for the inexperienced user to be around. 
> An
>
> apprentice is expected to be supervised by a master until the
> master
>
> is sure that the apprentice will not cut off something vital.
> The master is expected to know what works and what does not and
> where to safely make short-cuts.  The master generally has several
>old
> scars that demonstrate gaining that knowledge.
>
> UNIX has gotten somewhat away from its original roots, where the
> standard failure response from a command was to print '?' on the
> command line.
>
>There is still room for improvement.
>
>Donald L. (Don) Ritchey
>Information Technology
>Exelon Corporation

Point taken Donald, Thanks.

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
99.31% setiathome rank, not too shabby for a WV hillbilly
Yahoo.com attorneys please note, additions to this message
by Gene Heskett are:
Copyright 2004 by Maurice Eugene Heskett, all rights reserved.