Re: C Programming

From: Wade Chandler (wchandler_at_redesetgrow.com)
Date: 05/11/04

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    Date: Mon, 10 May 2004 18:47:52 -0400
To: For users of Fedora Core releases <fedora-list@redhat.com>

    fredex wrote:

    > On Sun, May 09, 2004 at 10:48:03PM -0500, Jeff Vian wrote:
    >
    >>
    >>fredex wrote:
    >>
    >>
    >>>On Sun, May 09, 2004 at 08:34:28AM -0500, Jeff Vian wrote:
    >>>
    >>>
    >>>
    >>>>fredex wrote:
    >>>>
    >>>>
    >>>>
    >>>>>On Sat, May 08, 2004 at 10:46:37PM -0400, Wade Chandler wrote:
    >>>>>
    >>>>>
    >>>>>
    >>>>>>Gene Heskett wrote:
    >>>>>>
    >>>>>>
    >>>>>>
    >>>>>>>On Saturday 08 May 2004 06:27, Trevor McNamara wrote:
    >>>>>>>
    >>>>>>>
    >>>>>>>
    >>>>>>>>Hello,
    >>>>>>>>
    >>>>>>>>
    >>
    >><snip>
    >>
    >>>>>Not to be a negative-sounding force here, but I would urge you to NOT
    >>>>>ever use any of Herbert Schildt's books.
    >>>>>
    >>>>>Mr. Schildt is a skillful writer, his writing is clear and lucid. He
    >>>>>writes books on C and C++ that very easily and clearly lead you down
    >>>>>the path to writing programs that are WRONG. he teaches bad practice in
    >>>>>C and C++ in clear and easily understood ways, such that if you follow
    >>>>>his advice you will learn his bad habits. one minor example is that he
    >>>>>is one of the many people who incorrectly teach that it is permissible
    >>>>>to declare main() as being of type void:
    >>>>> void main (void)
    >>>>> {
    >>>>> ...
    >>>>> }
    >>>>>A little web searching, or spending a little time on groups.google.com
    >>>>>reading comp.lang.c will find you plenty of examples of why his books
    >>>>>are not a good way to learn C or C++. You can learn, in the same way,
    >>>>>of many other books that do teach the language(s) correctly.
    >>>>>
    >>>>>
    >>>>>
    >>>>>
    >>>>
    >>>>Please explain why main cannot be of type void.
    >>>>
    >>>>
    >>>
    >>>1. Because the ANSI/ISO standard for the C language requires that main
    >>>returns int.
    >>>
    >>>2. And if that isn't good enough for you, if you don't care about
    >>>standards, look at the practical implications. When you write a function:
    >>>
    >>>
    >>>
    >>
    >>I expected a reasoned discussion, not flaming.
    >
    >
    > I didn't (and don't) view this as flaming. I merely state it that way
    > because I've seen discussion on this for years from people who aren't
    > interested in what the standard says (they say "Well, it works for me
    > on my compiler, so why shouldn't I use it???). So, I gave a practical
    > reason for why it matters.
    >
    >
    >><snip>
    >>
    >>>>While I agree main is most often typed to int for the purpose of
    >>>>returning a value designating completion with no errors or an error,
    >>>>there is no *requirement* for that.
    >>>>
    >>>>
    >>>
    >>>ah, but there is. Again, the language standard requires that main return
    >>>an integer.
    >>>
    >>>
    >>>So "why", you ask, "does the standard require main to return int?".
    >>>The original C standard was written to "codify existing practice". In many
    >>>environments (Unix, MS-DOS, probably other platforms) the return value of
    >>>main is (or can be) used by the invoking program as a success or fail
    >>>status indicator. If the program doesn't return such a value the calling
    >>>program has no way to find out if hte program ran successfully or not.
    >>>
    >>>
    >>
    >>true
    >>
    >>
    >>>True, you CAN write a broken program that doesn't return anything from
    >>>main, but it's still going to hand back SOME value to the invoking program
    >>>as its status. if you don't provide a value, the code that calls main is
    >>>going to return something anyway, most likely some garbage/arbitrary
    >>>value it picked up from the place main's return should have been, but
    >>>wasn't (since main is expected to return something but didn't).
    >>>
    >>>Understand, main() is NOT the first code to execute when a C program is
    >>>invoked. There's a chunk of "startup code", that is provided by the
    >>>compiler vendor or a linkable library (invisible to the user) that
    >>>actually is invoked first, before main(). This code may do little in some
    >>>environments, or in other environments it may do a great deal of
    >>>stuff. But whatever it does, it (among other things) hands main its two
    >>>arguments, and receives an integer back from main. Changing the type of
    >>>main in your program does not change this code.
    >>>
    >>>
    >>>
    >>>
    >>>
    >>>>If you can provide *definitive documentation* of your statement that his
    >>>>teaching is wrong in the requirements for function main() I would like
    >>>>to see it.
    >>>>
    >>>>
    >>>
    >>>See the language standard document.
    >>>
    >>>
    >>
    >>I did look at that, all 550 pages of it.
    >>
    >
    > OK, then, you surely saw the place(s) where it discusses main().
    >
    >
    >>>Or go ask this question in the newsgroup comp.lang.c where you'll either
    >>>be ignored as a troll, or else will get flamed, depending on the mood
    >>>this week.
    >>>
    >>>Mr. Schildt, for all his skill as a writer (and he is good, no denying
    >>>that!), is one (of many) people who perpetuate the myth that it's OK
    >>>to play fast and loose with the language standard. The result is that
    >>>so many people think that it IS OK to do so. But some day, somewhere in
    >>>the future, doing one of these things he teaches will nail your program
    >>>to the wall and you won't have a clue why it went wrong.
    >>>
    >>>
    >>
    >>This as certainly not the first author of programming books to violate
    >>the standards in his methods. I first learned C in the days of
    >
    >
    > Did I say he was the first/only? No, I did not.
    >
    >
    >>Borland's Turbo C compiler, (taught at Drexel University in
    >>Philadelphia), and the text book used in that class also ignored the
    >>return type of main(). ( yes, I still have the text and verified this )
    >>
    >>Are you planning to be this hostile about ALL books that you don't
    >>happen to like.?
    >
    >
    > Again, it's not intended as hostility. It is intended as a warning to
    > people who will take a book and learn from it, especially those books
    > that teach incorrect programming. It's not the reader's fault that the
    > book teaches them wrongly. However someone who does not already know C
    > will not be able to discern those areas where the book teaches wrong
    > practice. There are books around that carefully do not teach bad practice,
    > many of them are recommended whenever this discussion comes up.
    >
    > Again, the reason why I warn people about the books of Mr. Schildt is
    > that they too often teach bad practice, book after book. (no I haven't
    > read them all, but I have read some of them, and have seen plenty of
    > disucssion from those who both know C and have read his books).
    >
    >
    > I've said all I want to say on this. Please do not continue to
    > misinterpret what I'm trying to say (which is intended as a service to
    > those who might be lead astray by books that teach incorrect practice).
    >
    >
    >>Your point would be much better made without hostility, but reasoned
    >>agrument instead. I noted where the standards define main and I am
    >>satisfied with that. All I originally asked for was the location where
    >>it was defined that way, not a hostile diatribe.
    >
    >
    > And you got a pointer to the standard (I don't happen to have a copy
    > of it HERE right now to which I can refer so I could have given you
    > a more detailed reference). What you also got was a lengthy discussion
    > of why it matters, it was NOT a diatribe. sorry if you misinterpreted it.
    >
    > Goodbye.
    >
    >
    >
    Basically this thread has went nuts. I followed up on a post and I
    mentioned the wrong name of a book of Herberts I like, and I still do by
    the way. It isn't C++ Bible, but "The Complete Reference: C++". One,
    this book doesn't use void main(void). The only mention of void in main
    is int main(void) or int main() (perfectly legal and logical). int
    main() directly from "The C++ Programming Language" Stroustrap and int
    main(void) and even int main()...in "The C Programming Language"
    Kernighan/Ritchie.

    Anyways, void main(void) is a bad example to use to make a point against
    an author without giving a book and page number. I have not seen where
    Schildt says to use or uses void main(void) in any book I've seen. In
    the complete reference I can turn to the index page 1003 look in M and
    find a reference to page 153 (main, return value from) (in the complete
    reference). Now, if I turn to page 153 I'll find (as I should):
    "
    What Does main() Return?
    The main() function returns an integer to the calling process, which is
    generally the operating system. Returning a value from main() is the
    equivalent of calling exit() with the same value. If main() does not
    explicitly return a value, the value passed to the calling process is
    technically undefined. In practice, most C/C++ compilers automatically
    return 0, but do not rely on this if portability is a concern.
    "

    I guess he could have said one should always use return values, which
    would have been more correct according to many standards, however, I
    don't think this warrants an example of void main(void) in his name.
    Maybe you saw some typo or something that passed the editors, but I have
    never seen void main(void) in the book I'm speaking of nor any others of
    his...that I have personally seen.

    I personally find "The Complete Reference: C++" to be a well written
    book, and it gets into details that plenty of books I have read do not.
       I know plenty of convert C to C++ programmers who use static instead
    of an empty namespace for hiding from the global scope because they
    don't know you can...apparently. So instead of typing a few characters
    they have to type static multiple times.

    Contrast this book to "The C++ Programming Language". I happen to like
    Stroustrap's book, but it is a little hard to read at times. It isn't
    because the subject is very complicated either. It is just laid out a
    little strange (in my opinion), and isn't as nice to read as "The
    Complete Reference: C++". It just doesn't seem to flow as well is what
    I'm saying. This in no way means that Stroustrap's book isn't useful or
    doesn't have a lot of good info. I happen to like them both, but I
    don't believe Schildts writing is bad nor incorrect either.

    Remember that I'm talking about "The Complete Reference: C++" as the
    example here.

    Wade 

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