Subject: Re: dd and pipe question
To: None <current-users@NetBSD.ORG>
From: Michael van Elst <>
List: current-users
Date: 04/13/1996 17:55:51
der Mouse <mouse@Collatz.McRCIM.McGill.EDU> writes:

>I can't see how.  I'd expect dd ibs=10240 obs=10240, or dd bs=10240, to
>behave this way:

>- read(input,ibuffer,10240) -> get N
>- copy N from ibuffer to obuffer
>- write(output,obuffer,N) (or 10240 instead of N if conv=sync)

Hmm. Ultrix and SunOS4.1.1 behave differently. If you specify obs
then dd will always write records that large which are filled completely
with the input data. With bs it copies block sizes up to the buffer size
and larger blocks are truncated (or the driver reports an error).

                                Michael van Elst

                                "A potential Snark may lurk in every tree."