From: utzoo!decvax!cca!Michael.Young@CMU-CS-A@sri-unix
Newsgroups: net.unix-wizards
Title: Re: useful view extension
Article-I.D.: sri-unix.4253
Posted: Sat Nov 20 01:58:25 1982
Received: Sun Nov 21 02:21:41 1982

From: Michael Wayne Young <Michael.Young@CMU-CS-A>
Date: 16 November 1982 1853-EST (Tuesday)
"don't extend vi, do it yourself with a shell script:" -- that's
sick.  I cannot believe that anyone with any talent at using
a Unix system would write a shell script for something that
they (or anyone else they give it to) will use often.  Parsing
arguments, handling interrupts, etc. are best done in a program,
not a shell script.  I draw an analogy to the difference between
a compiler or an interpreter -- you don't run your BASIC interpreter
on anything that's gonna get used much; you don't compile things
(well, you shouldn't have to, but I usually do anyway) that you'll
just run once.

I think "vi" is large and complex, but it is clearly the place to
put the additions.  How do you suspect "vi" reads in its input
file into its buffer in the first place?  Would it be too much
trouble to alter the mechanism which does that to accept
standard input rather than opening a file?  I think not.

Another point you bring up is the use of /tmp files.  Ugh again.
What you end up doing is wasting more space in /tmp for a file
that you will throw away.  In fact, I also find that people use
/tmp (and /usr/tmp) an awful lot when they can easily avoid it --
it's a matter of convenience (until you run out of space, or
other disaster strikes).  I'd in fact be in favour of allowing
you to specify an "unnamed" file to be created, for just these
types of appplications; for example, rather than doing something
like:
	f = creat ("/tmp/foo", 0666); /* Make my file, with name */
	f2 = open ("/tmp/foo", 0);    /* Get a readable fd too */
	unlink ("/tmp/foo");	      /* Throw away the filename */
 ... you'd instead do something like
	f = creat_unnamed ("/tmp/foo");

[With 4.2BSD, this'd just be another mode bit, not a whole new
call -- save the flaming here.]  Why the filename?  Just so
the kernel doesn't make the decision where to put the file
(which filesystem); also note that no mode is necessary if you
don't want a filename to ever appear in a directory.

I may sound a bit too efficiency-oriented, but I think that keeping
in mind what resources you're using is important.  Abusing "sh"
and "/tmp/" are just personal dislikes.

Then of course is the multi-pass nature of your approach: one pass
to copy to /tmp/, one to read into "vi", and if you wanted to alter
it, you'd also make another to copy from /tmp/ to standard output.
Yuch again.

			Michael