Path: utzoo!attcan!uunet!pyrdc!pyrnj!rutgers!cmcl2!phri!roy
From: roy@phri.UUCP (Roy Smith)
Newsgroups: comp.unix.wizards
Subject: Re: Accessing a VAX tape drive from a S
Summary: dd man page is confusing, at best.
Message-ID: <3464@phri.UUCP>
Date: 7 Sep 88 12:18:09 GMT
References: <711@auvax.UUCP> <43200035@uicsrd.csrd.uiuc.edu> <13412@mimsy.UUCP>
Reply-To: roy@phri.UUCP (Roy Smith)
Organization: Public Health Research Inst. (NY, NY)
Lines: 25

In article <13412@mimsy.UUCP> chris@mimsy.UUCP (Chris Torek) writes:
> Note that, as I mentioned above,
> 	dd bs=N
> and
> 	dd ibs=N obs=N
> have different meanings.

	This may be true, but you wouldn't guess it from the 4.3BSD dd man
page:

     ibs=n          input block size n bytes (default 512)
     obs=n          output block size (default 512)
     bs=n           set both input and output block size,
                    superseding ibs and obs; also, if no conver-
                    sion is specified, it is particularly effi-
                    cient since no copy need be done

	If I didn't know better, and I was reading the man page for the
first time, I would sure assume that "bs=N" and "ibs=N obs=N" would have
exactly the same effect, modulo efficiency considerations.
-- 
Roy Smith, System Administrator
Public Health Research Institute
{allegra,philabs,cmcl2,rutgers}!phri!roy -or- phri!roy@uunet.uu.net
"The connector is the network"