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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.lang.c
Subject: Re: C String terminator
Date: Sat, 22 Feb 2020 08:13:26 -0800
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Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

> Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
>
>> Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:
>
> [...]
>
>>> A pointer to a string *is* required for a "%s" directive, but the
>>> standard says so only indirectly.
>>
>> I have some quibbles about the wording here, but more importantly I
>> think this is a bad way to take in what the Standard does say.  What
>> the Standard does say is that an 's' specifier takes a pointer to an
>> array of character type, which in some situations much include a
>> null character within the array (and a %s specification is one of
>> those).
>
> As you know, and as long as we're being precise, it doesn't take a
> pointer to an array of character type.  It takes a pointer to char (and
> the char in question is treated as an element of an array).  [...]

Yes, I glossed over the distinction between pointing to an array
and pointing to the first element of an array.  I thought the
meaning would be clear from context.

I need to add though that 'char' is not really accurate.  The Standard
says "character type" and I think it means that, not just 'char'.
Furthermore if an 'l' length modifier is present then the array
elements are assumed to be of type 'wchar_t'.  Both the regular
character types and wchar_t fall under the common umbrella of
"character type".

>>          It can be convenient to think of a %s directive as needing
>> a string argument, but the Standard doesn't say anything about
>> strings in its description of 's' specifiers, only arrays of
>> character type.  In some cases an array argument needs to contain a
>> string, but the argument is still the array, not the string.
>
> The argument is a pointer to the initial element of the array.  Other
> than that, I agree, and that was pretty much my point.  The requirements
> for the argument corresponding to a "%s" are equivalent to requiring a
> pointer to a string, though they're not stated that way (and it would
> not be particularly useful to state them that way).

I'm glad we are essentially in agreement.