Path: utzoo!attcan!uunet!convex!killer!ames!pasteur!ucbvax!decwrl!hplabs!hpl-opus!hpccc!hp-sde!hpfcdc!rml From: rml@hpfcdc.HP.COM (Bob Lenk) Newsgroups: comp.unix.wizards Subject: Re: RESULTS from adding unix groups Message-ID: <5980028@hpfcdc.HP.COM> Date: 12 Sep 88 23:51:57 GMT References: <13456@mimsy.UUCP> Organization: HP Ft. Collins, Co. Lines: 13 > This confirms that `dd bs=N' and `dd ibs=N obs=N' do different things. When you think about it, this really has to be the case. If "bs=N" is to avoid internal copying, it has little choice about how to handle reads shorter than of K ( < N ) bytes. It could write K bytes, or it could attempt to read N-K bytes before doing a write. Neither is equivalent to "ibs=N obs=N". Arguably the latter behavior would be preferable, since it is clear that the input block size is not an absolute. The manual page should point this out. Bob Lenk hplabs!hpfcla!rml rml%hpfcla@hplabs.hp.com