Dear C group,
I'm very interested in writing portable C, but I only have GNU, Sparc
and Cygwin to compile on.
What I find is the biggest problem to writing portable C is what headers
to include. What sites do people know about that are comprehensive in
their differences?
For example, MacOSX complained about <string.h>. With Solaris I needed
to include another header file other than <fcntrl.h> to get definitions
for changing the nonblocking status of reading/writing files.
If there is a definitive guide between "modern" systems, this would be
very helpful.
TIA.
Jason. 10 2161
Jason Curl wrote: Dear C group,
I'm very interested in writing portable C, but I only have GNU, Sparc and Cygwin to compile on.
What I find is the biggest problem to writing portable C is what headers to include. What sites do people know about that are comprehensive in their differences?
For example, MacOSX complained about <string.h>. With Solaris I needed to include another header file other than <fcntrl.h> to get definitions for changing the nonblocking status of reading/writing files.
If there is a definitive guide between "modern" systems, this would be very helpful.
TIA. Jason.
The simplest answer is to adhere to some standard and perhaps the best
choice is one of the ANSI standards. With gcc you can use the
-std=standard option to define which standard to use.
IAn
--
Ian Bell
Jason Curl <j_********@motorola.com> wrote: I'm very interested in writing portable C, but I only have GNU, Sparc and Cygwin to compile on.
What I find is the biggest problem to writing portable C is what headers to include. What sites do people know about that are comprehensive in their differences?
The C standard(s) list all include files that you can protably use. For
C89 these are
<assert.h> <locale.h> <stddef.h>
<ctype.h> <math.h> <stdio.h>
<errno.h> <setjmp.h> <stdlib.h>
<float.h> <signal.h> <string.h>
<limits.h> <stdarg.h> <time.h>
and C99 adds the following
<complex.h> <iso646.h> <tgmath.h>
<fenv.h> <stdbool.h> <wchar.h>
<inttypes.h> <stdint.h> <wctype.h>
For example, MacOSX complained about <string.h>.
Then the compiler isn't standard compliant and you have no chance
to write anything portably.
With Solaris I needed to include another header file other than <fcntrl.h> to get definitions for changing the nonblocking status of reading/writing files.
Standard C doesn't allow you to set a "non-blocking" status - you
must already be using some non-standard functions (like open() or
fcntl() etc.) to be able to do that.
If there is a definitive guide between "modern" systems, this would be very helpful.
It's not a question which system you're using but you must restrict
yourself to what the C standard specifies. If you don't mean portable
in a C sense, there are also other standards, so you can write portable
programs e.g. as far as the POSIX standard goes, but then you should
ask in e.g. comp.unix.programmer.
Regards, Jens
--
\ Jens Thoms Toerring ___ Je***********@physik.fu-berlin.de
\__________________________ http://www.toerring.de
On Mon, 14 Mar 2005 15:30:33 +0100, Jason Curl
<j_********@motorola.com> wrote: I'm very interested in writing portable C, but I only have GNU, Sparc and Cygwin to compile on.
What I find is the biggest problem to writing portable C is what headers to include. What sites do people know about that are comprehensive in their differences?
It's a little OT, but I've found GNU Autoconf and Automake invaluable
for this sort of thing. It doesn't solve the problem, but it does
make handling the problem much easier.
You're right that finding which header files to include is one of the
big problems, but it's not the only one. You'll probably find that
some OSes don't have all the functions that you need, so you need to
write replacements (e.g. Linux has getopt_long_only, but FreeBSD
doesn't).
Roy
In article <39*************@uni-berlin.de>,
<Je***********@physik.fu-berlin.de> wrote: For example, MacOSX complained about <string.h>.
Then the compiler isn't standard compliant and you have no chance to write anything portably.
Thousands, probably millions, of programs are compiled using
<string.h> every day. The OP's real problem must be something else.
-- Richard
Richard Tobin <ri*****@cogsci.ed.ac.uk> wrote: In article <39*************@uni-berlin.de>, <Je***********@physik.fu-berlin.de> wrote:
For example, MacOSX complained about <string.h>.
Then the compiler isn't standard compliant and you have no chance to write anything portably.
Thousands, probably millions, of programs are compiled using <string.h> every day. The OP's real problem must be something else.
I heard that there are some systems tha have a <strings.h> instead
of the correct <string.h> - perhaps MacOSX is one of them, I can't
tell since I never used it. It would be good if the OP would cite
the full error message was, otherwise it's all guesswork.
Regards, Jens
--
\ Jens Thoms Toerring ___ Je***********@physik.fu-berlin.de
\__________________________ http://www.toerring.de
In article <39*************@uni-berlin.de>,
<Je***********@physik.fu-berlin.de> wrote: I heard that there are some systems tha have a <strings.h> instead of the correct <string.h> - perhaps MacOSX is one of them
No, MacOS X has a perfectly good string.h (it also has strings.h which
was the traditional BSD name, but that just #includes <string.h>).
It would be good if the OP would cite the full error message was, otherwise it's all guesswork.
Yes!
-- Richard
Jason Curl wrote: Dear C group,
I'm very interested in writing portable C, but I only have GNU, Sparc and Cygwin to compile on.
Good, because portable C is what we specialise in here.
What I find is the biggest problem to writing portable C is what headers to include. What sites do people know about that are comprehensive in their differences?
It depends on how portable you want to be. Portability here generally
means sticking to ISO standard C and, due to the lack of C99 compilers,
sticking to the old C90 standard. I would suggest the FAQ for
comp.lang.c and buying a copy of K&R2 would be a good start. Note that
ONE chapter of K&R2 is not portable because it is talking about Unix,
but the rest is portable.
If you want to go beyond what ISO C requires, then you need to decide
what systems you want to be portable to and whether they follow any
common standard such as POSIX, but any such standard are off topic here.
For example, MacOSX complained about <string.h>.
It should not complain about string.h since that is an ISO standard
header. Query that on a MacOSX group.
With Solaris I needed to include another header file other than <fcntrl.h> to get definitions for changing the nonblocking status of reading/writing files.
That is beyond what ISO C provides, so you will have to decide what
systems you want to be portable to and see if there is a common standard.
If there is a definitive guide between "modern" systems, this would be very helpful.
There is probably no definitive guide for things outside ISO C that I am
aware of since Windows and *nix are rather different. However, there are
libraries ported to a number of systems that can help with portability.
--
Flash Gordon
Living in interesting times.
Although my email address says spam, it is real and I read it.
Jason Curl <j_********@motorola.com> wrote: Dear C group,
I'm very interested in writing portable C, but I only have GNU, Sparc and Cygwin to compile on.
What I find is the biggest problem to writing portable C is what headers to include. What sites do people know about that are comprehensive in their differences?
http://oakroadsystems.com/tech/c-predef.htm
For example, MacOSX complained about <string.h>. With Solaris I needed to include another header file other than <fcntrl.h> to get definitions for changing the nonblocking status of reading/writing files.
These are Unix'ish systems. Interfaces exposing things like "changing the
nonblock status of reading/writing files" is not portable C, though is
generally portable among Unix systems (and most definitely not portable
between Unix and Windows). Most Unices generally expose their common
interfaces according to the Standard Unix Specification. http://www.opengroup.org/onlinepubs/009695399/toc.htm.
You're supposed to first fill out this harmless form before viewing the
specification. http://www.opengroup.org/online-pubs...9775&FORM=HTML
If there is a definitive guide between "modern" systems, this would be very helpful.
None other than the C standards. For the "fun" stuff you have to become
platform specific, and the Unix platform is about as general as you can get
without being forced to delve into platform specific stuff. (I suppose that
follows from my definition of general.)
A good Unix group is comp.unix.programmer.
Flash Gordon wrote: Jason Curl wrote:
Dear C group,
I'm very interested in writing portable C, but I only have GNU, Sparc and Cygwin to compile on.
Good, because portable C is what we specialise in here.
What I find is the biggest problem to writing portable C is what headers to include. What sites do people know about that are comprehensive in their differences?
It depends on how portable you want to be. Portability here generally means sticking to ISO standard C and, due to the lack of C99 compilers, sticking to the old C90 standard. I would suggest the FAQ for comp.lang.c and buying a copy of K&R2 would be a good start. Note that ONE chapter of K&R2 is not portable because it is talking about Unix, but the rest is portable.
I've read K&R 2 a long time ago and staying to the C90 standard I agree
is the best. If you want to go beyond what ISO C requires, then you need to decide what systems you want to be portable to and whether they follow any common standard such as POSIX, but any such standard are off topic here.
For example, MacOSX complained about <string.h>.
It should not complain about string.h since that is an ISO standard header. Query that on a MacOSX group.
Sorry - I don't have MacOSX, a friend of mine has and he compiled
something for me. The solution to the problem was including another
header file, don't remember exactly what - strings.h or string.h. > With Solaris I needed to include another header file other than <fcntrl.h> to get definitions for changing the nonblocking status of reading/writing files.
That is beyond what ISO C provides, so you will have to decide what systems you want to be portable to and see if there is a common standard.
Any suggestions of other newsgroups I could ask? I guess specific
newsgroups would only give me information specific to a compiler or
platform, but what is really needed is some kind of comparison list.
I've seen that GNU AutoConf tools documentation contains a small list. If there is a definitive guide between "modern" systems, this would be very helpful.
There is probably no definitive guide for things outside ISO C that I am aware of since Windows and *nix are rather different. However, there are libraries ported to a number of systems that can help with portability.
Narrowing down the search, if we remove "Windows" and go for POSIX-like
systems (e.g. QNX, BSD, GNU, Cygwin, MacOSX).
But most of all, thanks for the help so far.
Jason Curl wrote: Flash Gordon wrote:
Jason Curl wrote:
Dear C group,
I'm very interested in writing portable C, but I only have GNU, Sparc and Cygwin to compile on.
<snip> I've read K&R 2 a long time ago and staying to the C90 standard I agree is the best.
Well, you should keep a copy handy as a reference. Mine is sat on my
desk at work.
<snip>
For example, MacOSX complained about <string.h>.
It should not complain about string.h since that is an ISO standard header. Query that on a MacOSX group.
Sorry - I don't have MacOSX, a friend of mine has and he compiled something for me. The solution to the problem was including another header file, don't remember exactly what - strings.h or string.h.
Well, either you were using a non-standard function or your friends
install was broken. With Solaris I needed to include another header file other than <fcntrl.h> to get definitions for changing the nonblocking status of reading/writing files.
That is beyond what ISO C provides, so you will have to decide what systems you want to be portable to and see if there is a common standard.
Any suggestions of other newsgroups I could ask? I guess specific newsgroups would only give me information specific to a compiler or platform, but what is really needed is some kind of comparison list. I've seen that GNU AutoConf tools documentation contains a small list.
I would suggest that comp.programming would be a good start. If there is a definitive guide between "modern" systems, this would be very helpful.
There is probably no definitive guide for things outside ISO C that I am aware of since Windows and *nix are rather different. However, there are libraries ported to a number of systems that can help with portability.
Narrowing down the search, if we remove "Windows" and go for POSIX-like systems (e.g. QNX, BSD, GNU, Cygwin, MacOSX).
If you stick to POSIX like systems, comp.unix.programmer would be a good
place to start.
You *may* find that Windows groups can help with the differences between
Windows and POSIX, failing that comp.programming. It *is* possible to
write SW that goes beyond the C standard that runs on Windows and *nix,
but depending on what you want to do it can take a bit of work.
But most of all, thanks for the help so far.
OK, but now you have a better group to ask in for the bits beyond the C
standard.
--
Flash Gordon
Living in interesting times.
Although my email address says spam, it is real and I read it. This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
by: aaronfude |
last post by:
Hi,
Perhaps this is slightly offtopic.
Coming into the Windows world from Unix.
Is there a reference on writing C++ libraries in a portable way.
For example, right now I'm sticking...
|
by: Xah Lee |
last post by:
Jargons of Info Tech industry
(A Love of Jargons)
Xah Lee, 2002 Feb
People in the computing field like to spur the use of spurious jargons.
The less educated they are, the more they like...
|
by: Richard Giuly |
last post by:
Hello,
I would like to write "portable" C++ code that could theoretically run
on linux, windows, and other platforms, and I'd like to use VS as the
editor/compiler/linker.
The simplest thing...
|
by: Skybuck Flying |
last post by:
Hello,
This morning I had an idea how to write Scalable Software in general.
Unfortunately with Delphi 2007 it can't be done because it does not support
operating overloading for classes, or...
|
by: jacob navia |
last post by:
There are some people here (let's call them "regulars" for short)
that are always giving lessons to people about how easy is to
write portable code, etc. They always point fingers at you telling...
| |
by: Hystou |
last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can...
|
by: Oralloy |
last post by:
Hello folks,
I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>".
The problem is that using the GNU compilers,...
|
by: jinu1996 |
last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven...
|
by: Hystou |
last post by:
Overview:
Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows...
|
by: tracyyun |
last post by:
Dear forum friends,
With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each...
|
by: agi2029 |
last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing,...
| |
by: isladogs |
last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM).
In this session, we are pleased to welcome a new...
|
by: TSSRALBI |
last post by:
Hello
I'm a network technician in training and I need your help.
I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs.
The...
|
by: 6302768590 |
last post by:
Hai team
i want code for transfer the data from one system to another through IP address by using C# our system has to for every 5mins then we have to update the data what the data is updated ...
| |