473,320 Members | 1,612 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,320 software developers and data experts.

E*

7.26.3 Errors <errno.h>
Macros that begin with E and a digit or E and an uppercase letter
may be added to the declarations in the <errno.hheader.

May an implementation define an error macro EOF with a value different
from the EOF in <stdio.h>?

-- Richard
--
:wq
Jun 27 '08 #1
5 1129
On 10 May 2008 21:12:28 GMT, ri*****@cogsci.ed.ac.uk (Richard Tobin)
wrote in comp.lang.c:
7.26.3 Errors <errno.h>
Macros that begin with E and a digit or E and an uppercase letter
may be added to the declarations in the <errno.hheader.

May an implementation define an error macro EOF with a value different
from the EOF in <stdio.h>?
Perhaps in a non-standard extra include file, or guarded by some
conditional compilation guard in <errno.h>.

It could not unconditionally include such a definition in <errno.h>
when the compiler is invoked in conforming mode because it would break
conforming programs that included both <stdio.hand <errno.h>.

--
Jack Klein
Home: http://JK-Technology.Com
FAQs for
comp.lang.c http://c-faq.com/
comp.lang.c++ http://www.parashift.com/c++-faq-lite/
alt.comp.lang.learn.c-c++
http://www.club.cc.cmu.edu/~ajo/docs/FAQ-acllc.html
Jun 27 '08 #2
Richard Tobin <ri*****@cogsci.ed.ac.ukwrote:
7.26.3 Errors <errno.h>
Macros that begin with E and a digit or E and an uppercase letter
may be added to the declarations in the <errno.hheader.

May an implementation define an error macro EOF with a value different
from the EOF in <stdio.h>?
No. A strictly conforming program is allowed to include both headers
and the conflicting definitions of EOF would violate the constraint in
6.10.3p2. Since a conforming implementation is not allowed to have
entensions that invalidate strictly conforming programs, such a
definition is not allowed.

Conformance questions like this really belong in comp.std.c where
there's less traffic, much less heat, and far more light than there is
here.

-- Larry Jones

I think we need to change the rules. -- Calvin
Jun 27 '08 #3
Richard Tobin wrote:
7.26.3 Errors <errno.h>
Macros that begin with E and a digit or E and an uppercase letter
may be added to the declarations in the <errno.hheader.

May an implementation define an error macro EOF with a value different
from the EOF in <stdio.h>?
No, because a conforming program can include both <stdio.h>
and <errno.h>. Note that the freedom to add more EXXX macros
in <errno.hdoes not imply that every EXXX macro everywhere
must be an error number.

The paragraph can be read as a warning and as an implied
promise. First, it warns you not to use EEYORE for your own
purposes, because a future <errno.hmight define it. And
second, it implies that future <errno.hversions will *not*
define E12MANY or EiEiO or E_IS_FOR_ELEPHANT, so you can use
those identifiers as you wish. However, implications are not
actual promises: Witness C99's encroachment on names reserved
to the programmer in C90.

--
Eric Sosman
es*****@ieee-dot-org.invalid
Jun 27 '08 #4
On Sun, 11 May 2008 09:01:36 -0400, Eric Sosman wrote:
Richard Tobin wrote:
> 7.26.3 Errors <errno.h>
Macros that begin with E and a digit or E and an uppercase letter
may be added to the declarations in the <errno.hheader.

The paragraph can be read as a warning and as an implied
promise. First, it warns you not to use EEYORE for your own purposes,
because a future <errno.hmight define it. And second, it implies that
future <errno.hversions will *not* define E12MANY or EiEiO or
E_IS_FOR_ELEPHANT, so you can use those identifiers as you wish.
Why can't E12MANY be defined? It's a macro that begins with E and a digit,
which is allowed, right? I'm asking because E2BIG is a fairly common real-
world macro provided by <errno.h>.
Jun 27 '08 #5
Harald van Dijk wrote:
On Sun, 11 May 2008 09:01:36 -0400, Eric Sosman wrote:
>Richard Tobin wrote:
>> 7.26.3 Errors <errno.h>
Macros that begin with E and a digit or E and an uppercase letter
may be added to the declarations in the <errno.hheader.
The paragraph can be read as a warning and as an implied
promise. First, it warns you not to use EEYORE for your own purposes,
because a future <errno.hmight define it. And second, it implies that
future <errno.hversions will *not* define E12MANY or EiEiO or
E_IS_FOR_ELEPHANT, so you can use those identifiers as you wish.

Why can't E12MANY be defined? It's a macro that begins with E and a digit,
which is allowed, right? I'm asking because E2BIG is a fairly common real-
world macro provided by <errno.h>.
Oops! My blunder; sorry.

--
Eric Sosman
es*****@ieee-dot-org.invalid
Jun 27 '08 #6

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

3
by: William C. White | last post by:
Does anyone know of a way to use PHP /w Authorize.net AIM without using cURL? Our website is hosted on a shared drive and the webhost company doesn't installed additional software (such as cURL)...
2
by: Albert Ahtenberg | last post by:
Hello, I don't know if it is only me but I was sure that header("Location:url") redirects the browser instantly to URL, or at least stops the execution of the code. But appearantely it continues...
3
by: James | last post by:
Hi, I have a form with 2 fields. 'A' 'B' The user completes one of the fields and the form is submitted. On the results page I want to run a query, but this will change subject to which...
0
by: Ollivier Robert | last post by:
Hello, I'm trying to link PHP with Oracle 9.2.0/OCI8 with gcc 3.2.3 on a Solaris9 system. The link succeeds but everytime I try to run php, I get a SEGV from inside the libcnltsh.so library. ...
1
by: Richard Galli | last post by:
I want viewers to compare state laws on a single subject. Imagine a three-column table with a drop-down box on the top. A viewer selects a state from the list, and that state's text fills the...
4
by: Albert Ahtenberg | last post by:
Hello, I have two questions. 1. When the user presses the back button and returns to a form he filled the form is reseted. How do I leave there the values he inserted? 2. When the...
1
by: inderjit S Gabrie | last post by:
Hi all Here is the scenerio ...is it possibly to do this... i am getting valid course dates output on to a web which i have designed ....all is okay so far , look at the following web url ...
2
by: Jack | last post by:
Hi All, What is the PHP equivilent of Oracle bind variables in a SQL statement, e.g. select x from y where z=:parameter Which in asp/jsp would be followed by some statements to bind a value...
3
by: Sandwick | last post by:
I am trying to change the size of a drawing so they are all 3x3. the script below is what i was trying to use to cut it in half ... I get errors. I can display the normal picture but not the...
0
by: DolphinDB | last post by:
Tired of spending countless mintues downsampling your data? Look no further! In this article, you’ll learn how to efficiently downsample 6.48 billion high-frequency records to 61 million...
0
by: ryjfgjl | last post by:
ExcelToDatabase: batch import excel into database automatically...
0
by: Vimpel783 | last post by:
Hello! Guys, I found this code on the Internet, but I need to modify it a little. It works well, the problem is this: Data is sent from only one cell, in this case B5, but it is necessary that data...
0
by: ArrayDB | last post by:
The error message I've encountered is; ERROR:root:Error generating model response: exception: access violation writing 0x0000000000005140, which seems to be indicative of an access violation...
1
by: PapaRatzi | last post by:
Hello, I am teaching myself MS Access forms design and Visual Basic. I've created a table to capture a list of Top 30 singles and forms to capture new entries. The final step is a form (unbound)...
1
by: CloudSolutions | last post by:
Introduction: For many beginners and individual users, requiring a credit card and email registration may pose a barrier when starting to use cloud servers. However, some cloud server providers now...
1
by: Defcon1945 | last post by:
I'm trying to learn Python using Pycharm but import shutil doesn't work
1
by: Shællîpôpï 09 | last post by:
If u are using a keypad phone, how do u turn on JavaScript, to access features like WhatsApp, Facebook, Instagram....
0
by: Faith0G | last post by:
I am starting a new it consulting business and it's been a while since I setup a new website. Is wordpress still the best web based software for hosting a 5 page website? The webpages will be...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.