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| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Reading beyond the end of file |
| Date | 2015-08-17 18:44 -0700 |
| Organization | None to speak of |
| Message-ID | <lnk2st4bg0.fsf@kst-u.example.com> (permalink) |
| References | <b62ba036-de31-4f37-aaad-3d1372d40d3f@googlegroups.com> <mqts2p$js0$1@dont-email.me> |
Bartc <bc@freeuk.com> writes:
> On 18/08/2015 00:24, janus wrote:
>> I am not getting the expected result from the below code whenever I
>> change '\0' to EOF. I noticed that the below will read pass the end
>> of file. What is it that I am doing wrong? Could someone help me out?
>
> What's the input format? Is it a string terminated with \0, or with EOF?
>
> Note that EOF, normally set to -1, might not be properly representable
> when the 'char' type is unsigned (it will be 255). It might work, but I
> think 0 is a better terminator if it's going to be a char value.
EOF is the value returned by getchar() and related functions when they
encounter an end-of-file condition.
(Strictly speaking, it's a macro that expands to a constant expression
whose value is as I described.)
It never makes sense to store the value EOF in a char, signed char, or
unsigned char object. It's intended as an in-band signal, distinct from
any valid input character. getchar(), for example, returns an input
character interpreted as an unsigned char (and therefore >= 0) *or* the
value EOF (guaranteed to be negative). If the input happens to have a
value of -1 when interpreted as a signed char, getchar() will return 255
(assuming CHAR_BIT==8).
[...]
C strings are by definition terminated by a `'\0'` character.
--
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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Reading beyond the end of file janus <emekamicro@gmail.com> - 2015-08-17 16:24 -0700
Re: Reading beyond the end of file Bartc <bc@freeuk.com> - 2015-08-18 00:53 +0100
Re: Reading beyond the end of file Keith Thompson <kst-u@mib.org> - 2015-08-17 18:44 -0700
Re: Reading beyond the end of file Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-06 14:41 -0700
Re: Reading beyond the end of file Keith Thompson <kst-u@mib.org> - 2015-09-06 17:09 -0700
Re: Reading beyond the end of file James Kuyper <jameskuyper@verizon.net> - 2015-08-17 20:10 -0400
Re: Reading beyond the end of file janus <emekamicro@gmail.com> - 2015-08-18 00:54 -0700
Re: Reading beyond the end of file janus <emekamicro@gmail.com> - 2015-08-18 01:43 -0700
Re: Reading beyond the end of file James Kuyper <jameskuyper@verizon.net> - 2015-08-18 10:18 -0400
Re: Reading beyond the end of file Barry Schwarz <schwarzb@dqel.com> - 2015-08-18 09:18 -0700
Re: Reading beyond the end of file Keith Thompson <kst-u@mib.org> - 2015-08-18 11:17 -0700
Re: Reading beyond the end of file Barry Schwarz <schwarzb@dqel.com> - 2015-08-18 13:24 -0700
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