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Groups > comp.lang.c > #124072
| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: NULL as the empty string |
| Date | 2017-12-09 12:22 -0800 |
| Organization | None to speak of |
| Message-ID | <lny3mbr6rv.fsf@kst-u.example.com> (permalink) |
| References | <ov2an8$7sq$1@dont-email.me> <f92tlaFp91dU8@mid.individual.net> |
Ian Collins <ian-news@hotmail.com> writes:
> On 11/22/2017 11:52 AM, jacobnavia wrote:
>> Whaat would happen if we decide to give meaning to NULL?
>>
>> Assume that in all places of the string library (strlen, strcmp, etc) a
>> NULL was the equivalent of the string "\0"
>>
>> strlen would return zero, etc. This way, we would save terabytes of "\0"
>> strings since an empty string would not require any storage, since it is
>> empty of course!
>
> How would you distinguish between an error condition, returning null and
> a normal return of an empty string?
Well, you could still compare the result for equality to NULL.
But if the standard were changed to treat a null pointer as if it
were a pointer to an empty string, then non-standard functions
would likely return a null pointer to denote an empty string.
For example, strdup() (which is POSIX, not ISO C) might return
a null pointer given a null pointer argument -- or even given a
non-null pointer to an empty string.
A related problem with this change is that new code would be written
with the assumption that strlen(NULL)==0. Such code would break
when compiled with many existing implementations that conform to
C11 or earlier. It might be worthwhile *if* there were enough
advantages to the change, but IMHO there are not.
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
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NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-21 23:52 +0100
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-11-21 15:16 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-22 00:38 +0100
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-11-21 16:02 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-22 01:13 +0100
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-11-21 16:52 -0800
Re: NULL as the empty string Robert Wessel <robertwessel2@yahoo.com> - 2017-11-21 18:09 -0600
Re: NULL as the empty string Siri Cruise <chine.bleu@yahoo.com> - 2017-11-21 16:34 -0800
Re: NULL as the empty string David Brown <david.brown@hesbynett.no> - 2017-11-22 12:12 +0100
Re: NULL as the empty string supercat@casperkitty.com - 2017-11-21 15:57 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-22 01:06 +0100
Re: NULL as the empty string supercat@casperkitty.com - 2017-11-22 15:42 -0800
Re: NULL as the empty string Melzzzzz <Melzzzzz@zzzzz.com> - 2017-11-22 23:49 +0000
Re: NULL as the empty string supercat@casperkitty.com - 2017-11-22 15:56 -0800
Re: NULL as the empty string Melzzzzz <Melzzzzz@zzzzz.com> - 2017-11-23 00:06 +0000
Re: NULL as the empty string supercat@casperkitty.com - 2017-11-23 17:31 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-24 09:42 +0100
Re: NULL as the empty string supercat@casperkitty.com - 2017-11-24 13:47 -0800
Re: NULL as the empty string Jorgen Grahn <grahn+nntp@snipabacken.se> - 2017-11-22 06:46 +0000
Re: NULL as the empty string John Bode <jfbode1029@gmail.com> - 2017-12-08 10:27 -0800
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-12-08 11:11 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-12-08 21:39 +0100
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-12-08 13:03 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-12-08 22:50 +0100
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-12-08 15:19 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-12-09 00:35 +0100
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-12-08 16:05 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-12-09 01:22 +0100
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-12-08 17:39 -0800
Re: NULL as the empty string John Bode <jfbode1029@gmail.com> - 2017-12-11 12:22 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-12-09 01:29 +0100
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-12-08 17:47 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-12-09 07:05 +0100
Re: NULL as the empty string David Brown <david.brown@hesbynett.no> - 2017-12-09 18:37 +0100
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-12-09 11:53 -0800
Re: NULL as the empty string supercat@casperkitty.com - 2017-12-12 10:49 -0800
Re: NULL as the empty string Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2017-12-12 13:39 -0800
Re: NULL as the empty string supercat@casperkitty.com - 2017-12-12 16:05 -0800
Re: NULL as the empty string Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2017-12-13 03:43 -0800
Re: NULL as the empty string supercat@casperkitty.com - 2017-12-13 08:45 -0800
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-12-13 09:12 -0800
Re: NULL as the empty string Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2017-12-13 13:27 -0800
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-12-13 14:02 -0800
Re: NULL as the empty string asetofsymbols@gmail.com - 2017-12-13 14:58 -0800
Re: NULL as the empty string asetofsymbols@gmail.com - 2017-12-13 15:11 -0800
Re: NULL as the empty string Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2017-12-14 03:49 -0800
Re: NULL as the empty string mark.bluemel@gmail.com - 2017-12-14 04:05 -0800
Re: NULL as the empty string David Brown <david.brown@hesbynett.no> - 2017-12-14 13:09 +0100
Re: NULL as the empty string Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2017-12-14 05:02 -0800
Re: NULL as the empty string David Brown <david.brown@hesbynett.no> - 2017-12-14 14:54 +0100
Re: NULL as the empty string supercat@casperkitty.com - 2017-12-14 07:38 -0800
Re: NULL as the empty string Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2017-12-14 09:50 -0800
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-12-14 09:20 -0800
Re: NULL as the empty string supercat@casperkitty.com - 2017-12-14 09:53 -0800
Re: NULL as the empty string Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2017-12-14 12:57 -0800
Re: NULL as the empty string herrmannsfeldt@gmail.com - 2017-12-14 17:22 -0800
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-12-14 17:26 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-12-08 21:23 +0100
Re: NULL as the empty string Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2017-12-08 13:41 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-12-08 22:54 +0100
Re: NULL as the empty string supercat@casperkitty.com - 2017-11-21 15:17 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-22 00:26 +0100
Re: NULL as the empty string supercat@casperkitty.com - 2017-11-21 16:03 -0800
Re: NULL as the empty string "Pascal J. Bourguignon" <pjb@informatimago.com> - 2017-11-22 00:27 +0100
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-22 00:42 +0100
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-11-21 16:05 -0800
Re: NULL as the empty string herrmannsfeldt@gmail.com - 2017-12-06 22:33 -0800
Re: NULL as the empty string supercat@casperkitty.com - 2017-12-07 12:04 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-12-07 23:20 +0100
Re: NULL as the empty string supercat@casperkitty.com - 2017-12-07 15:04 -0800
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-11-21 15:28 -0800
Re: NULL as the empty string Thiago Adams <thiago.adams@gmail.com> - 2017-11-21 16:04 -0800
Re: NULL as the empty string Siri Cruise <chine.bleu@yahoo.com> - 2017-11-21 16:25 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-11-22 01:34 +0100
Re: NULL as the empty string bartc <bc@freeuk.com> - 2017-11-22 00:36 +0000
Re: NULL as the empty string Öö Tiib <ootiib@hot.ee> - 2017-11-21 23:07 -0800
NULL as the empty string asetofsymbols@gmail.com - 2017-11-23 22:23 -0800
Re: NULL as the empty string Geoff <geoff@invalid.invalid> - 2017-12-09 09:05 -0800
Re: NULL as the empty string Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2017-12-09 12:40 -0500
Re: NULL as the empty string gordonb.yj0bc@burditt.org (Gordon Burditt) - 2017-12-09 13:50 -0600
Re: NULL as the empty string Ian Collins <ian-news@hotmail.com> - 2017-12-10 08:59 +1300
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-12-09 12:22 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-12-11 01:42 +0100
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-12-10 19:20 -0800
Re: NULL as the empty string jacobnavia <jacob@jacob.remcomp.fr> - 2017-12-11 18:56 +0100
Re: NULL as the empty string Keith Thompson <kst-u@mib.org> - 2017-12-11 11:19 -0800
Re: NULL as the empty string supercat@casperkitty.com - 2017-12-15 09:29 -0800
Re: NULL as the empty string Thiago Adams <thiago.adams@gmail.com> - 2018-01-05 08:28 -0800
Re: NULL as the empty string supercat@casperkitty.com - 2018-01-05 09:37 -0800
Re: NULL as the empty string Thiago Adams <thiago.adams@gmail.com> - 2018-01-05 17:08 -0800
Re: NULL as the empty string supercat@casperkitty.com - 2017-12-15 09:18 -0800
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