basic c i/o and EOF

[Dave]

Below is the code ive written just to count the characters typed in. I
assumed EOF is -1, so if i type -1 and then press enter shouldnt the
program end? It orks if i put something like 'q' in the while loop to
end the loop.

what is up?

<code>

#include <stdio.h>

void main() {

long nc;

nc = 0;
while (getchar() != 'EOF') {
++nc;
}
printf("%ld\n", nc);

}

</code>

thanks
Dave

[The Real OS/2 Guy]

On Thu, 11 Sep 2003 21:00:07 UTC, dj******@csclub .uwaterloo.ca (Dave
Vandervies) wrote:

In article <wmzsGguTDN6N-pn2-1wd4V82b3Onx@mo on>,
The Real OS/2 Guy <os****@pc-rosenau.de> wrote:

On Thu, 11 Sep 2003 16:27:04 UTC, Johan Aurér <au***@axis.com > wrote:

It's not "illegal," just implementation-defined. In fact, 'EOF' might
even equal EOF if you're lucky. :-)

ITYM "not lucky".

No, 'abc' or 'EOF' or 'BAD' is NOT a character. A character is a
single char, not a sequence of chars. A sequence of chars is known a
string, but a string must be in double quotes. So the compiler will
throw a diagnistic.

Quoth n869 (6.4.4.4):
--------
Description

[#2] An integer character constant is a sequence of one or
^^^^^^
more multibyte characters enclosed in single-quotes, as in
^^^^
'x' or 'ab'. A wide character constant is the same, except
prefixed by the letter L. With a few exceptions detailed
later, the elements of the sequence are any members of the
source character set; they are mapped in an implementation-
defined manner to members of the execution character set.
--------

So 'abc' is no less a character constant than 'a'. It may or may not
correspond to an acceptable char value, but it's perfectly acceptable as a
source code construct. (And, just for if you're going to try to nitpick
on the 'may not correspond to an acceptable value', I'll point out that
'a' isn't a "character" either, only a character constant whose value
(of integer type) corresponds to the appropriate character.)

I don't think that the OP uses a multibyte character sert. When he has
an single byte character set then the paragraph above is meaningless.

--
Tschau/Bye
Herbert

eComStation 1.1 Deutsch Beta ist verügbar

[The Real OS/2 Guy]

On Fri, 12 Sep 2003 02:15:04 UTC, ne*****@tokyo.c om (Mantorok
Redgormor) wrote:

Irrwahn Grausewitz <ir*****@freene t.de> wrote in message news:<f3******* *************** **********@4ax. com>...

"The Real OS/2 Guy" <os****@pc-rosenau.de> wrote:

On Thu, 11 Sep 2003 16:27:04 UTC, Johan Aurér <au***@axis.com > wrote:

> On Thu, 11 Sep 2003, Irrwahn Grausewitz wrote:
>
> > Dave <no*****@noemai l.com> wrote:
> >
> > >
> > > long nc;
> > >
> > > nc = 0;
> > > while (getchar() != 'EOF') {
> > ^^^^^
> > illegal character constant, just write EOF (it is defined in stdio.h)
>
> It's not "illegal," just implementation-defined. In fact, 'EOF' might
> even equal EOF if you're lucky. :-)
>
No, 'abc' or 'EOF' or 'BAD' is NOT a character.

It's not a character, it's a (integer) character constant with
implementation-defined value.

From WG14/N843, section 6.4.4.4:

When I use:

printf("%c\n", 'EOF');

It prints 'F', is it suppose to print that or am I invoking undefined behavior?

I'm happy to have a compiler that will give a diagnostic when the
locale is not set to a multibyte character set, but uses a single byte
one.

--
Tschau/Bye
Herbert

eComStation 1.1 Deutsch Beta ist verügbar

[The Real OS/2 Guy]

On Thu, 11 Sep 2003 21:19:53 UTC, Richard Heathfield
<do******@addre ss.co.uk.invali d> wrote:

The Real OS/2 Guy wrote:

On Thu, 11 Sep 2003 16:27:04 UTC, Johan Aurer <au***@axis.com > wrote:

It's not "illegal," just implementation-defined. In fact, 'EOF' might
even equal EOF if you're lucky. :-)
No, 'abc' or 'EOF' or 'BAD' is NOT a character.

It is, however, a character constant.

The Standard says: "An integer character constant is a sequence of one or
more multibyte characters enclosed in single-quotes, as in 'x' or 'ab'."

Does you know the difference between multibyte and single byte
chararer sets?

A character is a
single char,

So 'a' is not a character, then?

It is.
(Hint: 'a' is of type int, not char.)

It gets converted implicity to an int but it is none, else it were
impossible to assign it to an char without diagnostic.

--
Tschau/Bye
Herbert

eComStation 1.1 Deutsch Beta ist verügbar

[The Real OS/2 Guy]

On Thu, 11 Sep 2003 22:03:53 UTC, Default User
<fi********@com pany.com> wrote:

The Real OS/2 Guy wrote:

No, 'abc' or 'EOF' or 'BAD' is NOT a character. A character is a
single char, not a sequence of chars. A sequence of chars is known a
string, but a string must be in double quotes. So the compiler will
throw a diagnistic.

That must come as a shock to the guys who wrote the Standard:
[#2] An integer character constant is a sequence of one or
more multibyte characters enclosed in single-quotes, as in
'x' or 'ab'. A wide character constant is the same, except
prefixed by the letter L. With a few exceptions detailed
later, the elements of the sequence are any members of the
source character set; they are mapped in an implementation-
defined manner to members of the execution character set.

Why? Read it carefully! Get be informed on the difference between
multibyte and single byte character sets.
A multibyte character set uses multiple bytes to show a single char. A
singe byte character set only one.

--
Tschau/Bye
Herbert

eComStation 1.1 Deutsch Beta ist verügbar

[Irrwahn Grausewitz]

"The Real OS/2 Guy" <os****@pc-rosenau.de> wrote:

<SNIP>

I don't think that the OP uses a multibyte character sert. When he has
an single byte character set then the paragraph above is meaningless.

Which part of

[...] With a few exceptions detailed
later, the elements of the sequence are any members of the
source character set; they are mapped in an implementation-
defined manner to members of the execution character set.

do you consider meaningless???
--
do not write: void main(...)
do not use gets()
do not cast the return value of malloc()
do not fflush( stdin )
read the c.l.c-faq: http://www.eskimo.com/~scs/C-faq/top.html

[Irrwahn Grausewitz]

"The Real OS/2 Guy" <os****@pc-rosenau.de> wrote:

On Thu, 11 Sep 2003 21:19:53 UTC, Richard Heathfield
<do******@addr ess.co.uk.inval id> wrote:

The Real OS/2 Guy wrote:

> On Thu, 11 Sep 2003 16:27:04 UTC, Johan Aurer <au***@axis.com > wrote:
>
>> It's not "illegal," just implementation-defined. In fact, 'EOF' might
>> even equal EOF if you're lucky. :-)
>>
> No, 'abc' or 'EOF' or 'BAD' is NOT a character.

It is, however, a character constant.

The Standard says: "An integer character constant is a sequence of one or
more multibyte characters enclosed in single-quotes, as in 'x' or 'ab'."

Does you know the difference between multibyte and single byte
chararer sets?

Do you know?

<SNIP>

--
do not write: void main(...)
do not use gets()
do not cast the return value of malloc()
do not fflush( stdin )
read the c.l.c-faq: http://www.eskimo.com/~scs/C-faq/top.html

[Irrwahn Grausewitz]

"The Real OS/2 Guy" <os****@pc-rosenau.de> wrote:

On Thu, 11 Sep 2003 21:19:53 UTC, Richard Heathfield wrote:

(Hint: 'a' is of type int, not char.)

It gets converted implicity to an int but it is none, else it were
impossible to assign it to an char without diagnostic.

This is simply wrong. Character constants in C are of type integer.
Lookup the standard on 'character constants'.
--
do not write: void main(...)
do not use gets()
do not cast the return value of malloc()
do not fflush( stdin )
read the c.l.c-faq: http://www.eskimo.com/~scs/C-faq/top.html

[Richard Heathfield]

The Real OS/2 Guy wrote:

On Thu, 11 Sep 2003 21:19:53 UTC, Richard Heathfield
<do******@addre ss.co.uk.invali d> wrote:

The Real OS/2 Guy wrote:

> On Thu, 11 Sep 2003 16:27:04 UTC, Johan Aurer <au***@axis.com > wrote:
>
>> It's not "illegal," just implementation-defined. In fact, 'EOF' might
>> even equal EOF if you're lucky. :-)
>>
> No, 'abc' or 'EOF' or 'BAD' is NOT a character.
It is, however, a character constant.

The Standard says: "An integer character constant is a sequence of one or
more multibyte characters enclosed in single-quotes, as in 'x' or 'ab'."

Does you know the difference between multibyte and single byte
chararer sets?

Yes.

> A character is a
> single char,

So 'a' is not a character, then?

It is.

Right, 'a' is a character, and 'a' is an int. Therefore, a character is not
a single char.

(Hint: 'a' is of type int, not char.)

It gets converted implicity to an int

No, it really really doesn't. It /is/ an int. AS USUAL, you sound very
confident but in fact you are utterly, utterly wrong. PLEASE understand
that you don't know as much about C as you thought you did. This is
something most of us go through when we start using this group; I know I
did, and lots of others here did too. But you seem to be slow to grasp
this. It's about time that you got a clue, and started to check your
opinions against an authoritative source before posting them.
but it is none, else it were
impossible to assign it to an char without diagnostic.

Nonsense.

--
Richard Heathfield : bi****@eton.pow ernet.co.uk
"Usenet is a strange place." - Dennis M Ritchie, 29 July 1999.
C FAQ: http://www.eskimo.com/~scs/C-faq/top.html
K&R answers, C books, etc: http://users.powernet.co.uk/eton

[Mark McIntyre]

On Sat, 13 Sep 2003 05:39:23 +0000 (UTC), in comp.lang.c , "The Real
OS/2 Guy" <os****@pc-rosenau.de> wrote:

On Thu, 11 Sep 2003 21:19:53 UTC, Richard Heathfield
<do******@addr ess.co.uk.inval id> wrote:

So 'a' is not a character, then?
It is.

(Hint: 'a' is of type int, not char.)

It gets converted implicity to an int but it is none,

Er, no, a single character is of type int. The standard says so in
6.4.4.4.
else it were
impossible to assign it to an char without diagnostic.

Balderdash.

--
Mark McIntyre
CLC FAQ <http://www.eskimo.com/~scs/C-faq/top.html>
CLC readme: <http://www.angelfire.c om/ms3/bchambless0/welcome_to_clc. html>