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Re: string literals vs char*

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glen herrmannsfeldt <gah@ugcs.caltech.edu> writes:

> Keith Thompson <kst-u@mib.org> wrote:
>
> (snip)
>
>> All this applies to C90, C99, and C11.
>  
>> Yes, there's a difference between constant and const, but you haven't
>> stated it correctly.
>  
>> A *constant expression* is one that can be (and in some cases must be)
>> evaluated at compile time.  (And a "constant", used as a noun, is a
>> token in source code, referred to in some languages as a "literal".)
>  
> (snip)
>
>> Some pre-ANSI C compilers, IIRC, actually allowed you to modify string
>> literals, so that this:
>  
>>    char *s = "hello";
>>    s[0] = 'H';
>>    puts(s);
>
> I don't have my K&R1 nearby, but I thought I remember that it
> specifically allowed for this. 

I can't find any explicit text either way, but that suggests, to me,
that the arrays denoted by string literals are just like any other (K&R)
C arrays and may be modified.

Further evidence comes form that fact the K&R1 does say that all
strings, even when written identically, are distinct.  That's not
conclusive, but sharing between similar strings is one reason to make
writing to them undefined.

<snip>
-- 
Ben.

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Thread

string literals vs char* arnuld <sunrise@invalid.address> - 2014-12-27 05:37 +0000
  Re: string literals vs char* Kaz Kylheku <kaz@kylheku.com> - 2014-12-27 06:36 +0000
  Re: string literals vs char* Barry Schwarz <schwarzb@dqel.com> - 2014-12-27 00:58 -0800
    Re: string literals vs char* Ian Collins <ian-news@hotmail.com> - 2014-12-27 22:03 +1300
    Re: string literals vs char* Keith Thompson <kst-u@mib.org> - 2014-12-27 11:55 -0800
      Re: string literals vs char* glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-12-28 07:55 +0000
        Re: string literals vs char* Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-12-28 11:39 +0000
          Re: string literals vs char* Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-24 08:55 -0700
            Re: string literals vs char* Keith Thompson <kst-u@mib.org> - 2015-03-24 12:17 -0700
  Re: string literals vs char* James Kuyper <jameskuyper@verizon.net> - 2014-12-27 11:36 -0500
    Re: string literals vs char* Vincenzo Mercuri <nomail@yahoo.it> - 2014-12-27 18:20 +0100
      Re: string literals vs char* Vincenzo Mercuri <nomail@yahoo.it> - 2014-12-27 18:55 +0100
    Re: string literals vs char* Kaz Kylheku <kaz@kylheku.com> - 2014-12-27 17:25 +0000
    Re: string literals vs char* Keith Thompson <kst-u@mib.org> - 2014-12-27 12:08 -0800
    Re: string literals vs char* James Kuyper <jameskuyper@verizon.net> - 2014-12-28 07:01 -0500
  Re: string literals vs char* John Bode <jfbode1029@gmail.com> - 2014-12-30 10:52 -0800

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