Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

[...]

For example, this program:

#include <stdio.h>
int main(void) {
const int result = printf("%ld\n", 0.3);
printf("printf returned %d\n", result);
}

on my system prints:

140732048673560
printf returned 16

gcc and clang warn about the format string. tcc doesn't.

The (first) printf call was apparently successful because printf
has no way to know that the argument was of an incorrect type
(types don't really exist at run time).

printf() could know if an argument were of an incorrect type, if
an implementation chose to do so.

Sure. I did write "on my system", where printf has no way to know
that the argument was of an incorrect type.

The "on my system" applies to what the program prints.

The paragraph that says "printf has no way to know" is a general
statement, for any implementation of printf(). If you had meant it
to apply only to your system, you should have said something like
"because that printf had no way to know". Without any qualifying
adjective or other indicator the statement is generic, not
specific.

--- PyGate Linux v1.5.19
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

[...]

For example, this program:

#include <stdio.h>
int main(void) {
const int result = printf("%ld\n", 0.3);
printf("printf returned %d\n", result);
}

on my system prints:

140732048673560
printf returned 16

gcc and clang warn about the format string. tcc doesn't.

The (first) printf call was apparently successful because printf
has no way to know that the argument was of an incorrect type
(types don't really exist at run time).

printf() could know if an argument were of an incorrect type, if
an implementation chose to do so.

Sure. I did write "on my system", where printf has no way to know
that the argument was of an incorrect type.

The "on my system" applies to what the program prints.

The paragraph that says "printf has no way to know" is a general
statement, for any implementation of printf(). If you had meant it
to apply only to your system, you should have said something like
"because that printf had no way to know". Without any qualifying
adjective or other indicator the statement is generic, not
specific.

You're quibbling about something I wrote nearly two months ago.

Certainly printf has no way defined by the language to know whether
its arguments are of the correct types. An implementation could
provide that information via some system-specific method, but I know
of no implementations that do so, and I'd be surprised if any such implementations exist. What I wrote was true on my system and is
very likely true on all real-world systems.

If you have something to say about whether any such implementations
exist, I invite you, but do not expect you, to share it. That might
actually be interesting.

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */

--- PyGate Linux v1.5.19
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

[...]

For example, this program:

#include <stdio.h>
int main(void) {
const int result = printf("%ld\n", 0.3);
printf("printf returned %d\n", result);
}

on my system prints:

140732048673560
printf returned 16

gcc and clang warn about the format string. tcc doesn't.

The (first) printf call was apparently successful because printf
has no way to know that the argument was of an incorrect type
(types don't really exist at run time).

printf() could know if an argument were of an incorrect type, if
an implementation chose to do so.

Sure. I did write "on my system", where printf has no way to know
that the argument was of an incorrect type.

The "on my system" applies to what the program prints.

The paragraph that says "printf has no way to know" is a general
statement, for any implementation of printf(). If you had meant it
to apply only to your system, you should have said something like
"because that printf had no way to know". Without any qualifying
adjective or other indicator the statement is generic, not
specific.

[...] Certainly printf has no way defined by the language to know
whether its arguments are of the correct types. An implementation
could provide that information via some system-specific method,
[...]

I'm glad to know we are in agreement.

--- PyGate Linux v1.5.19
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
[...]

I'm glad to know we are in agreement.

We're not.

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */

--- PyGate Linux v1.5.19
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
[...]

I'm glad to know we are in agreement.

We're not.

I don't know why you say this. I said this:

printf() could know if an argument were of an incorrect type,
if an implementation chose to do so.

You said this:

Certainly printf has no way defined by the language to know
whether its arguments are of the correct types. An
implementation could provide that information via some
system-specific method,

To me that statement implies that an implementation could provide a
printf() function that took advantage of the argument types you say
an implementation could provide, and thus could know if an argument
were of an incorrect type. What part of what you think I am saying
do you not agree with?

--- PyGate Linux v1.5.19
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On 23/08/2026 9:18 PM, Tim Rentsch wrote:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
[...]

I'm glad to know we are in agreement.

We're not.

I don't know why you say this. I said this:

printf() could know if an argument were of an incorrect type,
if an implementation chose to do so.

You said this:

Certainly printf has no way defined by the language to know
whether its arguments are of the correct types. An
implementation could provide that information via some
system-specific method,

To me that statement implies that an implementation could provide a
printf() function that took advantage of the argument types you say
an implementation could provide, and thus could know if an argument
were of an incorrect type. What part of what you think I am saying
do you not agree with?

Dear Tim,

I believe you are correct. If there is a disagreement, it's probable
that Keith does not have enough reading comprehension. He is probably killfiling me, so you can do with this knowledge what you want.


Best wishes, and happy C coding!
--
Johann | email: invalid -> com | http://www.myrkraverk.com/blog/
I'm not from the Internet, I just work there. | via Easynews.com https://bsky.app/profile/myrkraverk.bsky.social | for ( ;; ) _:;

--- PyGate Linux v1.5.19
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
[...]

I'm glad to know we are in agreement.

We're not.

I don't know why you say this.

And I'm ok with that. Your reactions when I've asked you to clarify
things in the past do not incline me to do the same for you.

[...]

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */

--- PyGate Linux v1.5.19
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
[...]

I'm glad to know we are in agreement.

We're not.

I don't know why you say this.

And I'm ok with that. Your reactions when I've asked you to clarify
things in the past do not incline me to do the same for you.

The difference here is that I didn't just ask a question, but
gave a detailed explanation for my statement. So your response
gives the impression of you simply not wanting to admit that
you're wrong.

--- PyGate Linux v1.5.19
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

In article <86fqzzxzof.fsf@linuxsc.com>,
Tim Rentsch <tr.17687@z991.linuxsc.com> wrote:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
[...]

I'm glad to know we are in agreement.

We're not.

I don't know why you say this.

And I'm ok with that. Your reactions when I've asked you

to clarify

things in the past do not incline me to do the same for you.

The difference here is that I didn't just ask a question, but
gave a detailed explanation for my statement.

Your error here is that you seem to believe that Keith owes you
some kind of response. In fact, he owes you nothing.

So your response
gives the impression of you simply not wanting to admit that
you're wrong.

That's rich. You make a number of incorrect statements that
make clear that, frequently, you do not know what you are
talking about. Yet despite your obvious ignorance on a number
of technical subjects, I do not believe I have ever once seen
you admit a mistake. Furthermore, you frequently present
opinion as fact, despite contradictory evidence.

Perhaps you should reflect on your own inability to admit when
you are wrong (or just saying something for imagined cachet,
like your frequent allusions to Knuth) before criticizing
others.

- Dan C.


--- PyGate Linux v1.5.19
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
[...]

I'm glad to know we are in agreement.

We're not.

I don't know why you say this.

And I'm ok with that. Your reactions when I've asked you to clarify
things in the past do not incline me to do the same for you.

The difference here is that I didn't just ask a question, but
gave a detailed explanation for my statement. So your response
gives the impression of you simply not wanting to admit that
you're wrong.

Then let me be clear. Your impression is incorrect. I simply
don't want to discuss it *with you*.

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */

--- PyGate Linux v1.5.19
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On 27/08/2026 19:04, Tim Rentsch wrote:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
[...]

I'm glad to know we are in agreement.

We're not.

I don't know why you say this.

And I'm ok with that. Your reactions when I've asked you to clarify
things in the past do not incline me to do the same for you.

The difference here is that I didn't just ask a question, but
gave a detailed explanation for my statement. So your response
gives the impression of you simply not wanting to admit that
you're wrong.

Given that you have done exactly this on more than one (though not many
more) occasion, but I have never noticed Keith doing so, I find that
answer ironic. My experience is that Keith is happy to accept when he
is wrong - happier, no doubt, when he has learned something new rather
than just made a mistake.

I won't try to speak for anyone else, but Keith's response does not give
/me/ the impression that he does not want to admit to being wrong. It
gives the impression that he feels it is a waste of time trying to
discuss more with you on the topic. Given how often you leave detailed
posts from others unanswered, only to follow up with a meaningless and pointless comment several months later, I fully understand if that is
Keith's reasoning.

If Keith believe he had been wrong here, or suspected that he might have
been, I think he would have said so - despite not wanting to continue
another pointless thread with you.

(I am not claiming to know that this is Keith's reasoning, merely saying
the impression his post gives me.)



--- PyGate Linux v1.5.19
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)