Path: utzoo!mnetor!uunet!portal!cup.portal.com!Isaac_K_Rabinovitch
From: Isaac_K_Rabinovitch@cup.portal.com
Newsgroups: comp.sys.ibm.pc
Subject: Re: MKS: multi-volume backups.
Message-ID: <2962@cup.portal.com>
Date: 5 Feb 88 03:17:56 GMT
References: <195@tijc02.UUCP>
Organization: The Portal System (TM)
Lines: 48
XPortal-User-Id: 1.1001.1472


rdo031@tijc02.UUCP (Rick Odle           ) writes:
->I have been trying to creat a combination of MKS tools to do effectively
->the job of dos's backup and pkarc combined together.  
->
->MKS gives an example in their manual of doing something like this:
->
->	find /dir -type f | cpio -oc | dd of=a:
->
->which finds all of the files starting at root dir, creates an archive
->with ASCII headers ( -oc ), and pipes it to dd, which writes it to the a:
->diskette in a sequential record format( not dos compatable).  I have
->modified this in the following manner:
->
->	find /dir -name * | cpio -oa | dd of=a:
->
->The find command as shown will also get directory entries, even those that
->are empty.  The -oc is not needed for dos-to-dos backups and restores, and
->the -oa keeps the modification time of the original file.  The real problem
->lies in the fact that dd will not write a large archive to a multi-diskette
->volume.  Also there is no compression of the files involved.  
->
->So there you have it.  Any suggestions would be welcome.

The above examples remind me of the sort of shell script I was always writing
when I was administering unix boxes. (I was never very good at it, so
no guru requests, please.)  Every since I became a DOSier, I've been wondering
if I should buy the MKS toolkit -- will it really get me some Unix
functionality, or is MS-DOS just not up to dealing with that sort of thing?
Your examples express my worries.  The pipeline works efficiently under
Unix, because the three programs are all executing "at once" (working in
lock-step, taking advantage of each others' pauses), with the pipeline
keeping the three processes in sync.  By contrast, MS-DOS implements
this pipeline as three sequential program loads, with nothing happening
when the program waits on I/O, and two humungous temp files being created.
Time consuming, and prodigal of disk space.

It's worth noting that, except for people like MKS who port Unix filters to
DOS, nobody seems to be interested in writing programs that utilize the
DOS pipe mechanism.  Which is why you can't find any DOS filters to do
the manipulations you need.

If my understanding of the problem deserves flames, I certainly want to
see them -- I'd rather be wrong about this!

Isaac Rabinovitch
Disclaimer:  Just because I think you're wrong, doesn't
             mean I don't think you're a fun person!
:-)