Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!olivea!mintaka!spdcc!ima!haddock!karl
From: karl@haddock.ima.isc.com (Karl Heuer)
Newsgroups: comp.lang.c
Subject: Re: Literal Strings in C ( was Re: example of how toupper() works )
Message-ID: <18577@haddock.ima.isc.com>
Date: 18 Oct 90 22:04:49 GMT
References: <2466@ux.acs.umn.edu> <256@dcsun21.dataco.UUCP>
Reply-To: karl@ima.isc.com (Karl Heuer)
Organization: Interactive Systems, Cambridge, MA 02138-5302
Lines: 17

In article <256@dcsun21.dataco.UUCP> amodeo@dcsun03.UUCP (Roy Amodeo,DC ) writes:
>>	char *duh = "Hello"; ... *duh = ...
>
>In the above segment of code, the literal string pointed to by 'duh' is
>being modified in place. Is this portable according to the ANSI standard?

No.  String literals may be shared and read-only.  (K&R 1 explicitly said
otherwise, which was a botch; I choose to interpret it as having described a
particular implementation rather than the language itself.)

>What does current practice dictate on this?

Some compilers make them writable and separate; others make them read-only and
shared.  The latter compilers usually have an option to yield the former
behavior, since some existing code depends on it.

Karl W. Z. Heuer (karl@ima.isc.com or uunet!ima!karl), The Walking Lint