Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!henry From: henry@utzoo.UUCP (Henry Spencer) Newsgroups: net.unix Subject: Re: tar .vs. cpio -- flame! Message-ID: <4207@utzoo.UUCP> Date: Sun, 12-Aug-84 17:41:01 EDT Article-I.D.: utzoo.4207 Posted: Sun Aug 12 17:41:01 1984 Date-Received: Sun, 12-Aug-84 17:41:01 EDT References: <198@ucbopal.CC.Berkeley.ARPA>, <1108@sdcsvax.UUCP> Organization: U of Toronto Zoology Lines: 43 > ...................................................... Tar comes from > Berkeley and cpio from Bell (now AT&T)... Wrong, tar comes from the authors of Unix (the Murray Hill research lab), while cpio comes from the wonderful people who brought you PWB (retch). > ..............They grew up to solve different problems. Tar is a "tape > archiver" and its major function is to produce backups of filesystems. > (This was in the days when a filesystem would fit on a single tape.) Wrong again, both tar and the older tp were for exchanging data on tapes. Dump and restor are the backup utilities. > ..... cpio was designed from the ground up to solve a very different > problem -- selectivly copying lists of files (actually, filesystem elements). > Thus, it is useful for distributions, or for copying recently-changed files > for backup, or for copying a selected part of a directory tree somewhere > else, or ..... These are among the things tar is used for, albeit not as easily as cpio for some of them. > Tar takes its list of files from the command line, effectivly > limiting the number of arguments, while cpio takes them from the standard > input, giving no such limitation... Quite true, but it's not hard to add such a facility to tar. It would have been very easy to do this, instead of going with an incompatible format. (I know that cpio pre-dates tar; that's no excuse for perpetuating it, though.) > ....Philosophy. Cpio is more in keeping with the Unix (tm) philosophy, > since it seperates the job of SELECTING the files from the job of COPYING > the files... See previous comment on the ease of adding this facility to tar. Actually, cpio is quite in keeping with the philosophy of the PWB/SysIII/SysV folks, which is never to adopt an existing program if they can write something else (incompatible, of course) themselves. Unix philosophy? They've never heard of it! -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry