Re: Reversing a linked list

From	James Kuyper <jameskuyper@verizon.net>
Newsgroups	comp.lang.c
Subject	Re: Reversing a linked list
Date	2011-09-18 21:34 -0400
Organization	A noiseless patient Spider
Message-ID	<j5667s$426$1@dont-email.me> (permalink)
References	(6 earlier) <f5628460-c702-43ac-b946-7f8a274d1b0e@bi2g2000vbb.googlegroups.com> <lnhb4a6yqm.fsf@nuthaus.mib.org> <d648e169-8c24-43a5-9700-c15128ac5235@b28g2000yqa.googlegroups.com> <ln4o0974s6.fsf@nuthaus.mib.org> <2694599f-274b-4006-8371-74a1c05c7414@c22g2000yqa.googlegroups.com>

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On 09/18/2011 08:51 PM, henry eshbaugh wrote:
> On Sep 18, 8:30�pm, Keith Thompson <ks...@mib.org> wrote:
...
>> I never said it wouldn't work with whatever implementation you
>> happen to be using. �I didn't even say it would fail under *any*
>> implementation. �I said that the behavior is undefined.
> 
> Technically, the entire compilation process is undefined. :P.

Not as far as the C standard is concerned. The C standard says that
"undefined behavior" is behavior "for which this international standard
imposes no requirements". That standard imposes LOTs of requirements on
the translation process as a whole (which corresponds to the combination
of compilation of linking).

> I can't afford any compilers that aren't free, but be my guest to test
> it out and let me know if there are compilers that do that.

There's no need for testing; read and understand the reservations
established by the C standard - make sure to never violate them, and you
code will (if it contains no other problems) work as specified by that
standard when translated and executed by a standard-conforming
implementation of C.

Ignore those reservations, and your code might or might not mysteriously
malfunction. If you want to take that risk, feel free to do so, but why
would you want to? What benefit do you gain? Do you get a thrill from
breaking the rules?

> I don't see why; it would break a lot of code and be overall pretty
> pointless.

The point is to give implementations of C a set of identifiers that they
are free to use without breaking your code, and to give you a set of
identifiers that you are free to use without breaking the
implementation. It serves essentially the same purpose as the dividers
on the highway that prevent traffic heading south from running into
traffic heading north; if you cross those dividers, you might be
perfectly safe, or you might cause a high-speed front-end collision.
Your chances of survival are a lot higher using reserved words in C than
crossing to the wrong side of a highway - but the risks are nonetheless
perfectly real.
-- 
James Kuyper

Thread

Reversing a linked list jacob navia <jacob@spamsink.net> - 2011-09-16 08:30 +0200
  Re: Reversing a linked list jacob navia <jacob@spamsink.net> - 2011-09-16 08:33 +0200
  Re: Reversing a linked list Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-16 12:51 +0100
    Re: Reversing a linked list jacob navia <jacob@spamsink.net> - 2011-09-16 14:18 +0200
      Re: Reversing a linked list jacob navia <jacob@spamsink.net> - 2011-09-16 14:26 +0200
        Re: Reversing a linked list Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-16 07:09 -0700
          Re: Reversing a linked list ImpalerCore <jadill33@gmail.com> - 2011-09-16 08:28 -0700
            Re: Reversing a linked list falk@rahul.net (Edward A. Falk) - 2011-09-16 16:34 +0000
            Re: Reversing a linked list Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-16 09:28 -0700
              Re: Reversing a linked list ImpalerCore <jadill33@gmail.com> - 2011-09-16 11:12 -0700
                Re: Reversing a linked list "Tony" <nospamme@ever.net> - 2011-09-16 20:01 -0500
      Re: Reversing a linked list Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-16 21:56 +0100
        Re: Reversing a linked list "Tony" <nospamme@ever.net> - 2011-09-16 20:16 -0500
          Re: Reversing a linked list Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-17 02:48 +0100
            Re: Reversing a linked list "Tony" <nospamme@ever.net> - 2011-09-16 22:15 -0500
              Re: Reversing a linked list jacob navia <jacob@spamsink.net> - 2011-09-17 07:40 +0200
                Re: Reversing a linked list "Tony" <nospamme@ever.net> - 2011-09-17 01:24 -0500
                Re: Reversing a linked list cri@tiac.net (Richard Harter) - 2011-09-17 15:07 +0000
                Re: Reversing a linked list jacob navia <jacob@spamsink.net> - 2011-09-17 17:47 +0200
                Re: Reversing a linked list jacob navia <jacob@spamsink.net> - 2011-09-17 17:54 +0200
                Re: Reversing a linked list Michael Press <rubrum@pacbell.net> - 2011-09-27 19:21 -0700
              Re: Reversing a linked list Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-17 12:00 +0100
                Re: Reversing a linked list "Tony" <nospamme@ever.net> - 2011-09-17 23:53 -0500
    Re: Reversing a linked list ImpalerCore <jadill33@gmail.com> - 2011-09-16 07:21 -0700
      Re: Reversing a linked list jacob navia <jacob@spamsink.net> - 2011-09-16 16:47 +0200
        Re: Reversing a linked list Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-16 08:20 -0700
        Re: Reversing a linked list "Tony" <nospamme@ever.net> - 2011-09-16 20:25 -0500
      Re: Reversing a linked list Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-16 22:32 +0100
      Re: Reversing a linked list pete <pfiland@mindspring.com> - 2011-09-16 17:53 -0400
    Re: Reversing a linked list "Tony" <nospamme@ever.net> - 2011-09-16 19:48 -0500
      Re: Reversing a linked list Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-17 02:41 +0100
        Re: Reversing a linked list "Tony" <nospamme@ever.net> - 2011-09-16 22:57 -0500
          Re: Reversing a linked list "BartC" <bc@freeuk.com> - 2011-09-17 12:48 +0100
            Re: Reversing a linked list jacob navia <jacob@spamsink.net> - 2011-09-17 13:55 +0200
            Re: Reversing a linked list "Tony" <nospamme@ever.net> - 2011-09-17 23:39 -0500
  Re: Reversing a linked list HENRY Eshbaugh <henryeshbaugh@gmail.com> - 2011-09-16 16:56 -0700
    Re: Reversing a linked list Ian Collins <ian-news@hotmail.com> - 2011-09-17 12:09 +1200
      Re: Reversing a linked list HENRY Eshbaugh <henryeshbaugh@gmail.com> - 2011-09-16 19:53 -0700
        Re: Reversing a linked list "Tony" <nospamme@ever.net> - 2011-09-16 23:00 -0500
          Re: Reversing a linked list Jonathan Leffler <jleffler@earthlink.net> - 2011-09-16 23:20 -0700
          Re: Reversing a linked list Keith Thompson <kst-u@mib.org> - 2011-09-17 13:46 -0700
            Re: Reversing a linked list henry eshbaugh <henryeshbaugh@gmail.com> - 2011-09-17 19:51 -0700
              Re: Reversing a linked list Keith Thompson <kst-u@mib.org> - 2011-09-18 01:28 -0700
                Re: Reversing a linked list henry eshbaugh <henryeshbaugh@gmail.com> - 2011-09-18 15:39 -0700
                Re: Reversing a linked list Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-18 22:43 +0000
                Re: Reversing a linked list henry eshbaugh <henryeshbaugh@gmail.com> - 2011-09-18 17:54 -0700
                Re: Reversing a linked list James Kuyper <jameskuyper@verizon.net> - 2011-09-18 21:20 -0400
                Re: Reversing a linked list Keith Thompson <kst-u@mib.org> - 2011-09-18 17:30 -0700
                Re: Reversing a linked list henry eshbaugh <henryeshbaugh@gmail.com> - 2011-09-18 17:51 -0700
                Re: Reversing a linked list James Kuyper <jameskuyper@verizon.net> - 2011-09-18 21:34 -0400
                Re: Reversing a linked list Robert Wessel <robertwessel2@yahoo.com> - 2011-09-18 21:25 -0500
                Re: Reversing a linked list Keith Thompson <kst-u@mib.org> - 2011-09-19 09:56 -0700
                Re: Reversing a linked list gazelle@shell.xmission.com (Kenny McCormack) - 2011-09-19 17:16 +0000
                Re: Reversing a linked list Willem <willem@toad.stack.nl> - 2011-09-19 17:25 +0000
                Re: Reversing a linked list Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-19 23:40 -0700
                Re: Reversing a linked list henry eshbaugh <henryeshbaugh@gmail.com> - 2011-09-20 17:55 -0700
                Re: Reversing a linked list henry eshbaugh <henryeshbaugh@gmail.com> - 2011-09-20 17:48 -0700
                Re: Reversing a linked list Geoff <geoff@invalid.invalid> - 2011-09-20 19:12 -0700
                Re: Reversing a linked list henry eshbaugh <henryeshbaugh@gmail.com> - 2011-09-21 10:15 -0700
                Re: Reversing a linked list David Resnick <lndresnick@gmail.com> - 2011-09-22 08:43 -0700
                Re: Reversing a linked list Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-23 02:45 -0700
                Re: Reversing a linked list David Resnick <lndresnick@gmail.com> - 2011-09-23 05:38 -0700
                Re: Reversing a linked list Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-23 07:58 -0700
                Re: Reversing a linked list David Resnick <lndresnick@gmail.com> - 2011-09-23 08:15 -0700
                Re: Reversing a linked list Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-23 18:00 +0100
                Re: Reversing a linked list David Resnick <lndresnick@gmail.com> - 2011-09-23 10:49 -0700
                Re: Reversing a linked list Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-23 20:05 +0100
                Re: Reversing a linked list pete <pfiland@mindspring.com> - 2011-09-23 18:05 -0400
                Re: Reversing a linked list Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-24 00:19 +0100
                Re: Reversing a linked list ImpalerCore <jadill33@gmail.com> - 2011-09-23 09:25 -0700
                Re: Reversing a linked list Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-22 22:49 +0300
                Re: Reversing a linked list Keith Thompson <kst-u@mib.org> - 2011-09-20 19:51 -0700
                Re: Reversing a linked list henry eshbaugh <henryeshbaugh@gmail.com> - 2011-09-21 09:51 -0700
                Re: Reversing a linked list Keith Thompson <kst-u@mib.org> - 2011-09-21 11:21 -0700
                Re: Reversing a linked list James Kuyper <jameskuyper@verizon.net> - 2011-09-20 23:00 -0400
                Re: Reversing a linked list henry eshbaugh <henryeshbaugh@gmail.com> - 2011-09-21 09:47 -0700
                Re: Reversing a linked list Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-23 11:22 +0300
                Re: Reversing a linked list Keith Thompson <kst-u@mib.org> - 2011-09-23 08:20 -0700
                Re: Reversing a linked list Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-23 18:12 +0100
                Re: Reversing a linked list Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-24 13:13 -0800
                Re: Reversing a linked list Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-23 23:49 +0300
                Re: Reversing a linked list James Kuyper <jameskuyper@verizon.net> - 2011-09-24 08:15 -0400
                Re: Reversing a linked list Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-24 20:15 +0300
                Re: Reversing a linked list Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-24 13:28 -0800
                Re: Reversing a linked list Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-02-12 01:41 +0200
                Re: Reversing a linked list Tim Rentsch <txr@alumni.caltech.edu> - 2012-03-08 09:08 -0800
                Re: Reversing a linked list Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-03-13 17:21 +0200
                Re: Reversing a linked list Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-24 13:04 -0800
                Re: Reversing a linked list Seebs <usenet-nospam@seebs.net> - 2011-09-23 01:46 +0000
                Re: Reversing a linked list James Kuyper <jameskuyper@verizon.net> - 2011-09-18 21:17 -0400
            Re: Reversing a linked list "Tony" <nospamme@ever.net> - 2011-09-17 23:50 -0500
              Re: Reversing a linked list Keith Thompson <kst-u@mib.org> - 2011-09-18 01:29 -0700
        Re: Reversing a linked list Seebs <usenet-nospam@seebs.net> - 2011-09-18 07:03 +0000
    Re: Reversing a linked list Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-17 02:13 +0100
      Re: Reversing a linked list HENRY Eshbaugh <henryeshbaugh@gmail.com> - 2011-09-16 19:52 -0700
        Re: Reversing a linked list Willem <willem@toad.stack.nl> - 2011-09-17 08:58 +0000
          Re: Reversing a linked list henry eshbaugh <henryeshbaugh@gmail.com> - 2011-09-18 15:32 -0700
            Re: Reversing a linked list James Kuyper <jameskuyper@verizon.net> - 2011-09-18 21:36 -0400
              Re: Reversing a linked list cri@tiac.net (Richard Harter) - 2011-09-19 05:24 +0000
                Re: Reversing a linked list James Kuyper <jameskuyper@verizon.net> - 2011-09-19 08:21 -0400
                Re: Reversing a linked list cri@tiac.net (Richard Harter) - 2011-09-19 14:28 +0000
                Re: Reversing a linked list Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-19 17:01 +0100
                Re: Reversing a linked list cri@tiac.net (Richard Harter) - 2011-09-19 16:25 +0000
                Re: Reversing a linked list henry eshbaugh <henryeshbaugh@gmail.com> - 2011-09-21 10:41 -0700
                Re: Reversing a linked list Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-21 17:58 +0000
                Re: Reversing a linked list James Kuyper <jameskuyper@verizon.net> - 2011-09-21 14:07 -0400
                Re: Reversing a linked list Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-21 11:15 -0700
                Re: Reversing a linked list Keith Thompson <kst-u@mib.org> - 2011-09-21 11:37 -0700
                Re: Reversing a linked list Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-23 11:50 +0300
                Re: Reversing a linked list Seebs <usenet-nospam@seebs.net> - 2011-09-23 01:46 +0000
    Re: Reversing a linked list Geoff <geoff@invalid.invalid> - 2011-09-18 18:22 -0700
  Re: Reversing a linked list "Tony" <nospamme@ever.net> - 2011-09-16 19:37 -0500
    Re: Reversing a linked list jacob navia <jacob@spamsink.net> - 2011-09-17 07:52 +0200
      Re: Reversing a linked list "Tony" <nospamme@ever.net> - 2011-09-17 02:09 -0500
        Re: Reversing a linked list Ian Collins <ian-news@hotmail.com> - 2011-09-17 19:35 +1200
          Re: Reversing a linked list "Tony" <nospamme@ever.net> - 2011-09-17 03:35 -0500
        Programming languages jacob navia <jacob@spamsink.net> - 2011-09-17 22:14 +0200
          Re: Programming languages "Tony" <nospamme@ever.net> - 2011-09-18 00:11 -0500
            Re: Programming languages jacob navia <jacob@spamsink.net> - 2011-09-18 08:37 +0200
            Re: Programming languages Seebs <usenet-nospam@seebs.net> - 2011-09-18 07:03 +0000
              Re: Programming languages jacob navia <jacob@spamsink.net> - 2011-09-18 09:50 +0200
              Re: Programming languages Keith Thompson <kst-u@mib.org> - 2011-09-18 01:31 -0700
                Re: Programming languages James Kuyper <jameskuyper@verizon.net> - 2011-09-18 06:43 -0400
                Re: Programming languages Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-09-18 07:42 -0700
                Re: Programming languages "Tony" <nospamme@ever.net> - 2011-09-18 04:05 -0500
            Re: Programming languages Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-09-18 07:40 -0700
  Re: Reversing a linked list Gene <gene.ressler@gmail.com> - 2011-09-22 06:59 -0700

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