program output?

[bnp]

Hi,

I took a test on C.
there was an objective question for program output type.
following is the program:

main()
{
char ch;
int i =2;
for (ch=0;ch<128;ch++)
i+=2;
printf("%d",i);
}
i wrote the answer 256 will be printed.
But our instructor told me that it will be infinite loop.
Is that right, I am not sure of the answer.

Regards,

Bhavik

[Dan Pop]

In <40***************@yahoo.com> CBFalconer <cb********@yahoo.com> writes:

Joe Wright wrote:

... snip ...

Well, even if the requirement for trailing new-line is documented
by the implementation, who exactly is the requirement binding
upon? The programmer or the implementation? For example:

FILE *t = fopen("text.txt", "w");
fprintf(t, "Hello world");
fclose(t);

I suppose I have written eleven characters to text.txt and
nothing else. And so it would not be a line because the required
'\n' is not there. And perhaps not even a stream for the same
reason. Again, who is this requirement incumbent upon?

Now precede the fclose(t); line with:

fflush(t);

and I believe the line needs to be written without the \n.

Considering that fclose(t) will flush the stream, it is downright foolish
to believe that preceding it with a fflush(t) is going to make any
difference.

The only reason for calling fflush on a stream before fclose is to be
able to check its return value and take whatever actions are appropriate
in case of failure.

Dan
--
Dan Pop
DESY Zeuthen, RZ group
Email: Da*****@ifh.de

[Joe Wright]

CBFalconer wrote:

Joe Wright wrote:

... snip ...

Well, even if the requirement for trailing new-line is documented
by the implementation, who exactly is the requirement binding
upon? The programmer or the implementation? For example:

FILE *t = fopen("text.txt", "w");
fprintf(t, "Hello world");
fclose(t);

I suppose I have written eleven characters to text.txt and
nothing else. And so it would not be a line because the required
'\n' is not there. And perhaps not even a stream for the same
reason. Again, who is this requirement incumbent upon?

Now precede the fclose(t); line with:

fflush(t);

and I believe the line needs to be written without the \n.

In actual practice I think the standards provision allows for the
fact that, without a final \n (or fflush), the final data may be
left in an internal buffer, and may simply get discarded.

From N869..

[#2] The fclose function causes the stream pointed to by
stream to be flushed and the associated file to be closed.
Any unwritten buffered data for the stream are delivered to
the host environment to be written to the file; any unread
buffered data are discarded. The stream is disassociated
from the file. If the associated buffer was automatically
allocated, it is deallocated.

No need for fflush() before fclose().
--
Joe Wright mailto:jo********@comcast.net
"Everything should be made as simple as possible, but not simpler."
--- Albert Einstein ---

[Dan Pop]

In <hi********************************@4ax.com> Leor Zolman <le**@bdsoft.com> writes:

On 26 May 2004 15:48:32 GMT, Da*****@cern.ch (Dan Pop) wrote:

In <to********************************@4ax.com> Leor Zolman <le**@bdsoft.com> writes:

On 26 May 2004 12:40:05 GMT, Da*****@cern.ch (Dan Pop) wrote:

I thought it was supposed to be a question about a C program, not about
an unspecified implementation...

If it's a question about a C program, your answer is downright wrong,
period.

The OP asked about "program output type". What does the Standard have to
say about /that/? ;-)
Few things are lamer on Usenet than invoking someone's poor command of the
English language...

It never even occurred to me that he had poor command of the English
language.

OK, let's have a look again:

I took a test on C.
there was an objective question for program output type.
following is the program:
<snip>
i wrote the answer 256 will be printed.
But our instructor told me that it will be infinite loop.
Is that right, I am not sure of the answer.

If this reflects a good command of the English language, then I don't
even want to see one that, in your opinion, doesn't. In particular, the
sentence:

there was an objective question for program output type.

doesn't make any sense alone. It the rest of the post that clarifies that
the OP wanted to know what is the intended output of a certain program.
And, since he posted the question in c.l.c, it is more than reasonable to
assume that he wanted the answer from the language point of view;
otherwise a newsgroup dedicated to programming on his platform
(whatever that was) was the natural choice.
His post looks better in that regard than some...
I agree that I have seen worse, yet this doesn't make this one look good.
So here's where I think we stand. I'm saying I cannot tell whether the OP
was asking "What does the Standard say about what the output should be", as
you interpret the question (and it is certainly a reasonable
interpretation, especially since that's the core flavor of question this
group deals with day-to-day), or if he's really asking, "How was I
supposed to predict what the output of this program would be on our class
platform?" which, given the quality of the question, strikes me as more
likely to reflect actual intent of the instructor. But of course, I don't
know.

How do you explain the fact that all the other regulars interpreted it in
the context of the newsgroup and only you managed to find a different
interpretation?

Dan
--
Dan Pop
DESY Zeuthen, RZ group
Email: Da*****@ifh.de

[CBFalconer]

Dan Pop wrote:

Leor Zolman <le**@bdsoft.com> writes:
... snip various ...
How do you explain the fact that all the other regulars
interpreted it in the context of the newsgroup and only you
managed to find a different interpretation?

Obviously he is a free spirit, thinking "outside the box" :-)

--
Chuck F (cb********@yahoo.com) (cb********@worldnet.att.net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net> USE worldnet address!

[Eric Sosman]

Douglas A. Gwyn wrote:

Eric Sosman wrote:

Arthur J. O'Dwyer wrote:

On Wed, 26 May 2004, Douglas A. Gwyn wrote:

As I understand the Standard's intent: An implementation must document
the behavior of a program whose output does not end in a newline, in
one of two ways: either that the output is printed, or that the behavior
is undefined. [...]

...

I didn't say that, and in fact I disagree with it.
Please be more careful in your attributions.

Actually, my error was one of incomplete snippage
rather than of misattribution (count the >'s). Sorry
for the confusion.

--
Er*********@sun.com