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From: Vir Campestris <vir.campestris@invalid.invalid>
Newsgroups: comp.lang.c
Subject: Re: relearning C: why does an in-place change to a char* segfault?
Date: Tue, 13 Aug 2024 15:34:19 +0100
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On 12/08/2024 22:11, Tim Rentsch wrote:
> Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:
> 
> [...]
> 
>> A string literal creates an array object with static storage
>> duration.  [...]
> 
> A small quibble.  Every string literal does sit in an array,
> but it might not be a _new_ array, because different string
> literals are allowed to overlap as long as the bytes in the
> overlapping arrays have the right values.

And this is exactly why string literals should always have been const.

A compiler is entitled to share memory between strings. so

	puts("lap");
	puts("overlap");

it's entitled to make them overlap. Then add

	char * p = "lap";
	*p='X';

and it can overwrite the shared string. I think. which would mean that 
writing "lap" again would have a different result.

But that ship has sailed. I'm not even sure const had been invented that 
far back!

Andy