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| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Fgets question |
| Date | 2015-07-11 14:04 -0700 |
| Organization | None to speak of |
| Message-ID | <lnr3oepfri.fsf@kst-u.example.com> (permalink) |
| References | <0b5d570e-eed5-4162-b5f9-44b2058639ee@googlegroups.com> <lnpp44c1bq.fsf@kst-u.example.com> <kfnfv4u28k0.fsf@x-alumni2.alumni.caltech.edu> |
Tim Rentsch <txr@alumni.caltech.edu> writes:
> Keith Thompson <kst-u@mib.org> writes:
[...]
>> *However* the description of text streams in 7.21.2 says that a trailing
>> new-line may be required. (By implication, if there is no new-line at
>> the very end of the file, the behavior is undefined.) [snip]
>
> FWIW I think you may be reading that wrongly. The requirement is not
> on the program but on the line. ("Whether the last line requires a
> terminating new-line character is implementation-defined.") It's
> not obvious that leaving off a final new-line was meant to be (or
> was meant not to be) undefined behavior.
Can you clarify what a requirement *on the line* means?
Implementations have behavior; lines don't. I think it's just
slightly odd wording. In any case, it's the implementation that
has to specify whether it's required or not.
If, for a given implementation, the last line doesn't require a
terminating new-line, writing a text file with no newline and then
reading it has well defined behavior. If the last line *does*
require it, then the standard doesn't say what the behavior of a
program that omits it is -- thus, undefined behavior.
--
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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Fgets question Paul N <gw7rib@aol.com> - 2015-07-06 14:06 -0700
Re: Fgets question Barry Schwarz <schwarzb@dqel.com> - 2015-07-06 15:09 -0700
Re: Fgets question Keith Thompson <kst-u@mib.org> - 2015-07-06 16:41 -0700
Re: Fgets question Paul N <gw7rib@aol.com> - 2015-07-07 15:16 -0700
Re: Fgets question Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-07-06 23:13 +0100
Re: Fgets question Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-07-07 00:57 +0100
Re: Fgets question Keith Thompson <kst-u@mib.org> - 2015-07-06 16:29 -0700
Re: Fgets question Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-11 05:16 -0700
Re: Fgets question Keith Thompson <kst-u@mib.org> - 2015-07-11 14:04 -0700
Re: Fgets question Richard Damon <Richard@Damon-Family.org> - 2015-07-11 19:56 -0400
Re: Fgets question Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-15 09:26 -0700
Re: Fgets question Keith Thompson <kst-u@mib.org> - 2015-07-15 10:42 -0700
Re: Fgets question Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-20 10:53 -0700
Re: Fgets question Keith Thompson <kst-u@mib.org> - 2015-07-20 12:51 -0700
Re: Fgets question Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-24 10:10 -0700
Re: Fgets question Keith Thompson <kst-u@mib.org> - 2015-07-24 12:15 -0700
Re: Fgets question Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-26 16:41 -0700
Re: Fgets question Keith Thompson <kst-u@mib.org> - 2015-07-27 11:42 -0700
Re: Fgets question Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-30 15:42 -0700
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