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Re: Small challenge: sort names

From cross@spitfire.i.gajendra.net (Dan Cross)
Newsgroups comp.lang.c
Subject Re: Small challenge: sort names
Date 2026-04-09 15:15 +0000
Organization PANIX Public Access Internet and UNIX, NYC
Message-ID <10r8fr5$37g$1@reader1.panix.com> (permalink)
References <10r4h6o$396qn$1@dont-email.me> <20260409001030.000006c9@yahoo.com> <bDBBR.139$Np7d.78@fx15.iad> <20260409025901.00002bc6@yahoo.com>

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In article <20260409025901.00002bc6@yahoo.com>,
Michael S  <already5chosen@yahoo.com> wrote:
>On Wed, 08 Apr 2026 23:35:35 GMT
>scott@slp53.sl.home (Scott Lurndal) wrote:
>
>> Michael S <already5chosen@yahoo.com> writes:
>> >On Wed, 08 Apr 2026 21:04:56 GMT
>> >scott@slp53.sl.home (Scott Lurndal) wrote:
>> >  
>> >> > [snip]
>> >> 
>> >> Idiomatically, I might have written
>> >> 
>> >>    size_t
>> >>    countchar(const char *str, char match)
>> >>    {
>> >>        size_t count = 0u;
>> >>        for(; *str != '\0'; str++) count += (*str == match);
>> >>        return count;
>> >>    }
>> >> 
>> >> 
>> >>      
>> >
>> >I'd change it to 
>> >
>> >   size_t
>> >   countchar(const char *str, char match)
>> >   {
>> >       size_t count = 0;
>> >       for(; *str != 0; str++) count += (*str == match);
>> >       return count;
>> >   }  
>> 
>> Personally, I prefer to properly identify integer constants
>> with the appropriate type annotation.  I always explicitly
>> check against NULL rather than using !ptr, for example. I
>> never use an unadorned integer for a character constant,
>> rather using either 'c' for printables, the legal escapes
>> (e.g. \n) and for any non-printable, the appropriate
>> octal escape.
>> 
>> Perhaps some of this is pedantic.   I worked with a system 
>> where the null pointer constant was not the value zero, so
>> I'm aware that !ptr may not actually do the right thing in
>> such cases.
>
>Which is irrelevant in this specific case.
>BTW, I think that (ptr != 0) is guaranteed to work even on systems with
>null pointers not being numerically zero. But I am not certain about it.
>What I am certain is that on the right side of assignment to pointer 0
>always acts the same as NULL.
>But that's too irrelevant for our case.

It's easy enough to verify looking at a canonical source.
Section 6.3.2.3 coupled with 6.5.9 of C18 suggest this is
guaranteed to work.

>As to being pedantic w.r.t. '\0', may be you acquired this habit
>because of C++? If I am not mistaken, in C++ '\0' has type char and due
>to that (or because of, which is IMHO, more appropriate wording) can in
>some contexts lead to results different from 0, with differences as huge
>as call to completely different procedure. It does not happen in C where
>we have no misfeature of type based static polymorphism.

'\0' is indeed a `char` in C++.  But I don't think that really
changes the point, which is more about semantics.  Why NOT use a
relevant character constant instead of `0`?  It's not whether
one can or not, or whether it's semantically equivalent, or
whether C's `char` type is really an integer in a trenchcoat:
it's using the appropriate constant to match the domain: in this
case, matching character data.

	- Dan C.

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Small challenge: sort names DFS <nospam@dfs.com> - 2026-04-07 23:14 -0400
  Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-08 10:22 +0200
    Re: Small challenge: sort names DFS <nospam@dfs.com> - 2026-04-08 12:25 -0400
      Re: Small challenge: sort names Bart <bc@freeuk.com> - 2026-04-08 18:57 +0100
        Re: Small challenge: sort names scott@slp53.sl.home (Scott Lurndal) - 2026-04-08 21:04 +0000
          Re: Small challenge: sort names Michael S <already5chosen@yahoo.com> - 2026-04-09 00:10 +0300
            Re: Small challenge: sort names scott@slp53.sl.home (Scott Lurndal) - 2026-04-08 23:35 +0000
              Re: Small challenge: sort names Michael S <already5chosen@yahoo.com> - 2026-04-09 02:59 +0300
                Re: Small challenge: sort names James Kuyper <jameskuyper@alumni.caltech.edu> - 2026-04-09 06:29 -0400
                Re: Small challenge: sort names cross@spitfire.i.gajendra.net (Dan Cross) - 2026-04-09 15:15 +0000
                Re: Small challenge: sort names Tim Rentsch <tr.17687@z991.linuxsc.com> - 2026-04-11 08:49 -0700
                Re: Small challenge: sort names cross@spitfire.i.gajendra.net (Dan Cross) - 2026-04-11 19:59 +0000
                Re: Small challenge: sort names Bonita Montero <Bonita.Montero@gmail.com> - 2026-04-16 18:50 +0200
                Re: Small challenge: sort names cross@spitfire.i.gajendra.net (Dan Cross) - 2026-04-16 19:54 +0000
                Re: Small challenge: sort names Bonita Montero <Bonita.Montero@gmail.com> - 2026-04-17 16:22 +0200
              Re: Small challenge: sort names Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-04-08 17:27 -0700
              Re: Small challenge: sort names Tim Rentsch <tr.17687@z991.linuxsc.com> - 2026-04-08 22:14 -0700
                Re: Small challenge: sort names Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-04-09 02:19 -0700
                Re: Small challenge: sort names scott@slp53.sl.home (Scott Lurndal) - 2026-04-09 15:06 +0000
                Re: Small challenge: sort names Tim Rentsch <tr.17687@z991.linuxsc.com> - 2026-04-12 06:35 -0700
                Re: Small challenge: sort names scott@slp53.sl.home (Scott Lurndal) - 2026-04-12 14:51 +0000
                Re: Small challenge: sort names Tim Rentsch <tr.17687@z991.linuxsc.com> - 2026-04-13 06:31 -0700
                Re: Small challenge: sort names Tim Rentsch <tr.17687@z991.linuxsc.com> - 2026-04-12 06:48 -0700
                Re: Small challenge: sort names Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-04-12 16:15 -0700
                Re: Small challenge: sort names Tim Rentsch <tr.17687@z991.linuxsc.com> - 2026-04-25 13:31 -0700
                Re: Small challenge: sort names Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-04-25 15:12 -0700
          Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-11 08:44 +0200
        Re: Small challenge: sort names DFS <nospam@dfs.com> - 2026-04-08 17:13 -0400
          Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-11 08:59 +0200
            Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-11 09:34 +0200
      Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-11 08:31 +0200
    Re: Small challenge: sort names BGB <cr88192@gmail.com> - 2026-04-12 13:08 -0500
    What is the point of anything? (Was: Small challenge: sort names) gazelle@shell.xmission.com (Kenny McCormack) - 2026-04-17 20:44 +0000
  Re: Small challenge: sort names Tim Rentsch <tr.17687@z991.linuxsc.com> - 2026-04-08 18:46 -0700
  Re: Small challenge: sort names Sort <Sort@invalid.invalid> - 2026-04-11 19:15 +0100
  Re: Small challenge: sort names Bonita Montero <Bonita.Montero@gmail.com> - 2026-04-16 18:24 +0200
    Re: Small challenge: sort names Bart <bc@freeuk.com> - 2026-04-16 18:38 +0100
      Re: Small challenge: sort names Bonita Montero <Bonita.Montero@gmail.com> - 2026-04-16 19:43 +0200
    Re: Small challenge: sort names Bart <bc@freeuk.com> - 2026-04-18 11:22 +0100
      Re: Small challenge: sort names Bonita Montero <Bonita.Montero@gmail.com> - 2026-04-18 17:48 +0200
        Re: Small challenge: sort names Bonita Montero <Bonita.Montero@gmail.com> - 2026-04-19 08:44 +0200
    Re: Small challenge: sort names DFS <nospam@dfs.com> - 2026-04-22 05:33 -0400
      Re: Small challenge: sort names Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-04-22 03:16 -0700
        Re: Small challenge: sort names DFS <nospam@dfs.com> - 2026-04-22 07:35 -0400
          Re: Small challenge: sort names Tim Rentsch <tr.17687@z991.linuxsc.com> - 2026-04-23 08:11 -0700
            Re: Small challenge: sort names Bonita Montero <Bonita.Montero@gmail.com> - 2026-04-23 20:14 +0200
              Re: Small challenge: sort names gazelle@shell.xmission.com (Kenny McCormack) - 2026-04-23 18:30 +0000
        Re: Small challenge: sort names gazelle@shell.xmission.com (Kenny McCormack) - 2026-04-23 17:19 +0000
      Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-22 14:11 +0200
        Re: Small challenge: sort names James Kuyper <jameskuyper@alumni.caltech.edu> - 2026-04-22 21:27 -0400
          [OT][meta] Gender (was Re: Small challenge: sort names) Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-23 15:51 +0200
            Re: [OT][meta] Gender (was Re: Small challenge: sort names) scott@slp53.sl.home (Scott Lurndal) - 2026-04-23 14:45 +0000
              Re: [OT][meta] Gender (was Re: Small challenge: sort names) Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-23 17:03 +0200
              Re: [OT][meta] Gender (was Re: Small challenge: sort names) DFS <nospam@dfs.com> - 2026-04-23 20:31 -0400
                Re: [OT][meta] Gender (was Re: Small challenge: sort names) Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-04-23 18:43 -0700
                Re: [OT][meta] Gender (was Re: Small challenge: sort names) gazelle@shell.xmission.com (Kenny McCormack) - 2026-04-24 16:58 +0000
                Re: [OT][meta] Gender (was Re: Small challenge: sort names) Jan van den Broek <balglaas@dds.nl> - 2026-04-24 06:57 +0000
                Re: [OT][meta] Gender (was Re: Small challenge: sort names) Bonita Montero <Bonita.Montero@gmail.com> - 2026-04-24 10:10 +0200
                Re: [OT][meta] Gender (was Re: Small challenge: sort names) David Brown <david.brown@hesbynett.no> - 2026-04-24 12:52 +0200
            Re: [OT][meta] Gender (was Re: Small challenge: sort names) Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-04-23 16:36 -0700
              Re: [OT][meta] Gender (was Re: Small challenge: sort names) Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-24 03:01 +0200
                Re: [OT][meta] Gender (was Re: Small challenge: sort names) Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-04-23 18:50 -0700
                Re: [OT][meta] Gender (was Re: Small challenge: sort names) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-04-24 20:35 -0700
            Re: [OT][meta] Gender (was Re: Small challenge: sort names) Michael S <already5chosen@yahoo.com> - 2026-04-24 14:20 +0300
              Re: [OT][meta] Gender (was Re: Small challenge: sort names) Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-24 14:32 +0200
      Re: Small challenge: sort names Bonita Montero <Bonita.Montero@gmail.com> - 2026-04-23 20:10 +0200
        Re: Small challenge: sort names DFS <nospam@dfs.com> - 2026-04-25 10:26 -0400
  Re: Small challenge: sort names Rosario19 <Ros@invalid.invalid> - 2026-04-18 11:16 +0200
    Re: Small challenge: sort names DFS <nospam@dfs.com> - 2026-04-18 08:11 -0400
      Re: Small challenge: sort names Bart <bc@freeuk.com> - 2026-04-18 14:03 +0100
    Re: Small challenge: sort names Rosario19 <Ros@invalid.invalid> - 2026-04-20 21:20 +0200
      Re: Small challenge: sort names DFS <nospam@dfs.com> - 2026-04-20 16:43 -0400
        Re: Small challenge: sort names Rosario19 <Ros@invalid.invalid> - 2026-04-21 05:09 +0200
          Re: Small challenge: sort names DFS <nospam@dfs.com> - 2026-04-21 08:46 -0400
            Re: Small challenge: sort names Bart <bc@freeuk.com> - 2026-04-21 16:08 +0100
              Re: Small challenge: sort names DFS <nospam@dfs.com> - 2026-04-21 11:33 -0400
                Re: Small challenge: sort names Bart <bc@freeuk.com> - 2026-04-21 18:25 +0100
                Re: Small challenge: sort names scott@slp53.sl.home (Scott Lurndal) - 2026-04-21 17:38 +0000
                Re: Small challenge: sort names Michael S <already5chosen@yahoo.com> - 2026-04-21 20:50 +0300
                Re: Small challenge: sort names scott@slp53.sl.home (Scott Lurndal) - 2026-04-21 18:22 +0000
                Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-22 03:48 +0200
                Re: Small challenge: sort names David Brown <david.brown@hesbynett.no> - 2026-04-22 09:18 +0200
                Re: Small challenge: sort names Michael S <already5chosen@yahoo.com> - 2026-04-22 13:22 +0300
                Re: Small challenge: sort names David Brown <david.brown@hesbynett.no> - 2026-04-22 12:38 +0200
                Re: Small challenge: sort names Michael S <already5chosen@yahoo.com> - 2026-04-22 13:58 +0300
                Re: Small challenge: sort names David Brown <david.brown@hesbynett.no> - 2026-04-22 13:13 +0200
                Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-22 14:53 +0200
                Re: Small challenge: sort names DFS <nospam@dfs.com> - 2026-04-21 16:31 -0400
                Re: Small challenge: sort names Bart <bc@freeuk.com> - 2026-04-21 23:04 +0100
      Re: Small challenge: sort names Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-04-20 14:16 -0700
        An audience of one (Was: Small challenge: sort names) gazelle@shell.xmission.com (Kenny McCormack) - 2026-04-21 13:00 +0000
          Re: An audience of one (Was: Small challenge: sort names) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-04-21 12:21 -0700
    Re: Small challenge: sort names Rosario19 <Ros@invalid.invalid> - 2026-04-21 05:00 +0200
      Re: Small challenge: sort names Rosario19 <Ros@invalid.invalid> - 2026-04-21 05:06 +0200
  Re: Small challenge: sort names gggggggggggunit <gunitinug@50cent.com> - 2026-04-18 10:19 +0000
    [OT] Shell approach to Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-19 09:35 +0200
      Re: [OT] Shell approach to Re: Small challenge: sort names gazelle@shell.xmission.com (Kenny McCormack) - 2026-04-19 14:18 +0000
        Re: [OT] Shell approach to Re: Small challenge: sort names cross@spitfire.i.gajendra.net (Dan Cross) - 2026-04-19 19:32 +0000
          Re: [OT] Shell approach to Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-22 03:34 +0200

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