Path: utzoo!mnetor!uunet!husc6!think!barmar
From: barmar@think.COM (Barry Margolin)
Newsgroups: comp.arch
Subject: Re: Null-terminated C strings
Message-ID: <14116@think.UUCP>
Date: 21 Dec 87 16:38:35 GMT
References: <261@ivory.SanDiego.NCR.COM> <164@sdeggo.UUCP> <174@quick.COM>
Sender: usenet@think.UUCP
Reply-To: barmar@sauron.think.com.UUCP (Barry Margolin)
Organization: Thinking Machines Corporation, Cambridge, MA
Lines: 24

In article <174@quick.COM> srg@quick.COM (Spencer Garrett) writes:
>2) Having a CHARACTER to mark the end of a string is ever so much
>more convenient and efficient than having to compare lengths all the
>time

The problem with this is that you must reserve a character.  I've had
trouble with terminal emulators on machines whose keyboard-reading
system call returns 0 to indicate that no data is available, but 0 is
also the code for Control-@.  This type of problem occurs in file
reading, too.  If you are reading a binary file, or perhaps a file of
keyboard operations (perhaps you recorded an Emacs session), as
characters the NULL character can no longer be used as a string
terminator; such files can contain any 8-bit code, so NO 8-bit
character can be used as a termination indicator.

Strings with lengths ALWAYS work.


---
Barry Margolin
Thinking Machines Corp.

barmar@think.com
seismo!think!barmar