Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!tank!uxc!uxc.cso.uiuc.edu!m.cs.uiuc.edu!gillies
From: gillies@m.cs.uiuc.edu
Newsgroups: comp.arch
Subject: Re: Endian wars
Message-ID: <3300050@m.cs.uiuc.edu>
Date: 7 Feb 89 03:19:00 GMT
References: <6133@columbia.edu>
Lines: 31
Nf-ID: #R:columbia.edu:6133:m.cs.uiuc.edu:3300050:000:1218
Nf-From: m.cs.uiuc.edu!gillies    Feb  6 21:19:00 1989


/* Written 12:25 am  Feb  5, 1989 by PLS@cup.portal.com in m.cs.uiuc.edu:comp.arch */
This deserves a new subject.

Since it was mentioned in the Endian Wars, does anyone know why C uses the
null terminated string rather than an explicit length?
...
  - It removes a character from the character set, a source of many C bugs
  - All machines I know of that have character string instructions want
    the length of the string. This forces the string primitives to first
    scan for null, a time wasting operation.
/* End of text from m.cs.uiuc.edu:comp.arch */

First, let me say that string type is a religious issue.  I once
worked for a workstation vendor whose main workstation had THREE
different types of strings.  Each development group claimed THEIR
strings ran the fastest on the hardware platform.  Every package had
about 25 string subroutines, including 5-10 for "converting"
"inferior" formats into "ours".

Second, I was once told that the following C code compiles into 1
instruction (or something amazingly short) on the PDP-11, C's mother
machine:

while (*p++ = *q++);

This is perhaps part of the reason why strings were designed with
null-termination


Don Gillies {uiucdcs!gillies} U of Illinois