Re: Small challenge: sort names

From	cross@spitfire.i.gajendra.net (Dan Cross)
Newsgroups	comp.lang.c
Subject	Re: Small challenge: sort names
Date	2026-04-27 20:43 +0000
Organization	PANIX Public Access Internet and UNIX, NYC
Message-ID	<10sohpc$444$1@reader1.panix.com> (permalink)
References	<10r4h6o$396qn$1@dont-email.me> <10soe78$2kmgo$1@dont-email.me> <10soe9m$2l223$1@dont-email.me> <10sof6k$2l43i$1@kst.eternal-september.org>

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In article <10sof6k$2l43i$1@kst.eternal-september.org>,
Keith Thompson  <Keith.S.Thompson+u@gmail.com> wrote:
>"Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> writes:
>> On 4/27/2026 12:42 PM, Chris M. Thomasson wrote:
>[...]
>>> Fwiw, I only use '\0' for the null terminator in strings, not for
>>> pointers...
>
>I'm not sure why that's worth mentioning.  The only reason I can
>think of to use '\0' for pointers is deliberate obfuscation, or
>*maybe* testing how a compiler handles it.

Some time ago, a rather famous production outage at Google was
the result of something very similar.  The author wrote,

	ptr->some_bool = false;

where what was meant was,

	*ptr->some_bool = false;

Here, `some_bool` was `bool *some_bool`.  Perfectly legal, of
course: `false` was just a macro expanding to the integer
constant 0, which in pointer context is a null pointer constant,
thus setting `some_bool` to the null pointer.  But clearly what
was meant was to assign false to the actual boolean.  Oops.

At the time, the compiler (gcc) did not emit a diagnostic for
this, but `clang` did.  The build system was quickly changed to
invoke both; showing combined diagnostics from both compilers,
but keeping only the object file emitted by gcc (as I understand
it, Google has since switched to using `clang` as the default
compiler in its monorepo).

This, and similar incidents, are one reason I greatly prefer
domain-specific constructs (e.g, '\0' for character data instead
of plain ol' 0) and explicit comparisons (`if (ptr != NULL)` vs
`if (ptr)`).  Over time and at large enough scale, these things
really do start to matter.

>> Or NUL for strings?
>
>NUL is a name for the null character, but there's no such identifier
>in the C standard language or library.

FWIW, observation over some time makes me think that the person
to whom you are responding is driving with an engine that is not
quite firing on all cylinders.  His posts are usually non
sequiturs, and he tends to reply to himself often.  He's not
offensive or anything, so I haven't plonked him, but I try to
refrain from engaging with him.

	- 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> - 2026-04-26 04:13 +0200
                Re: Small challenge: sort names Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-04-25 19:50 -0700
                Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-26 05:28 +0200
                Re: Small challenge: sort names David Brown <david.brown@hesbynett.no> - 2026-04-26 12:08 +0200
                Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-26 18:16 +0200
                Re: Small challenge: sort names David Brown <david.brown@hesbynett.no> - 2026-04-26 19:37 +0200
                Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-27 02:17 +0200
                Re: Small challenge: sort names David Brown <david.brown@hesbynett.no> - 2026-04-27 09:19 +0200
                Re: Small challenge: sort names scott@slp53.sl.home (Scott Lurndal) - 2026-04-26 17:47 +0000
                Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-27 02:33 +0200
                Re: Small challenge: sort names David Brown <david.brown@hesbynett.no> - 2026-04-27 09:34 +0200
                Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-27 12:35 +0200
                Re: Small challenge: sort names Bart <bc@freeuk.com> - 2026-04-27 13:28 +0100
                Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-27 17:02 +0200
                Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-27 17:36 +0200
                Re: Small challenge: sort names scott@slp53.sl.home (Scott Lurndal) - 2026-04-27 16:18 +0000
                Re: Small challenge: sort names Michael S <already5chosen@yahoo.com> - 2026-04-27 11:42 +0300
                Re: Small challenge: sort names scott@slp53.sl.home (Scott Lurndal) - 2026-04-27 16:27 +0000
                Assembler verb choice (Was: Small challenge: sort names) gazelle@shell.xmission.com (Kenny McCormack) - 2026-04-28 12:59 +0000
                Re: Assembler verb choice (Was: Small challenge: sort names) Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-28 16:26 +0200
                Re: Small challenge: sort names "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-04-27 12:45 -0700
                Re: Small challenge: sort names "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-04-27 12:42 -0700
                Re: Small challenge: sort names "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-04-27 12:43 -0700
                Re: Small challenge: sort names Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-04-27 12:59 -0700
                Re: Small challenge: sort names "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-04-27 13:26 -0700
                Re: Small challenge: sort names cross@spitfire.i.gajendra.net (Dan Cross) - 2026-04-27 20:43 +0000
                Re: Small challenge: sort names "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-04-27 17:30 -0700
                Re: Small challenge: sort names Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-04-27 19:15 -0700
                Re: Small challenge: sort names gazelle@shell.xmission.com (Kenny McCormack) - 2026-04-28 12:01 +0000
                Re: Small challenge: sort names David Brown <david.brown@hesbynett.no> - 2026-04-28 08:35 +0200
                Re: Small challenge: sort names cross@spitfire.i.gajendra.net (Dan Cross) - 2026-04-28 13:27 +0000
                Re: Small challenge: sort names David Brown <david.brown@hesbynett.no> - 2026-04-28 15:59 +0200
                Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-28 16:49 +0200
                Re: Small challenge: sort names David Brown <david.brown@hesbynett.no> - 2026-04-28 17:25 +0200
                Re: Small challenge: sort names Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-04-28 23:46 +0200
                Re: Small challenge: sort names cross@spitfire.i.gajendra.net (Dan Cross) - 2026-04-28 18:12 +0000
                Re: Small challenge: sort names David Brown <david.brown@hesbynett.no> - 2026-04-28 20:28 +0200
                Re: Small challenge: sort names vallor <vallor@vallor.earth> - 2026-04-28 13:45 +0000
          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 vallor <vallor@vallor.earth> - 2026-04-28 14:19 +0000
    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 Bonita Montero <Bonita.Montero@gmail.com> - 2026-04-26 13:01 +0200
  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
  Re: Small challenge: sort names Bonita Montero <Bonita.Montero@gmail.com> - 2026-04-28 06:53 +0200
    Re: Small challenge: sort names gazelle@shell.xmission.com (Kenny McCormack) - 2026-04-28 13:01 +0000

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