MESSAGE
| DATE | 2008-06-29 |
| FROM | Ruben Safir
|
| SUBJECT | Re: [NYLXS - HANGOUT] C Programing Workshop
|
On Sun, Jun 29, 2008 at 02:47:24PM -0400, Ronny Abraham wrote:
> If you're going to teach a class, I think it's important to also go
> into makefiles. Personally, I hate makefiles and prefer to use scons
> (it's python based and a hell of a lot simpler). Nevertheless, you
> need to know how makefiles work if you want to do anything usefull
> with the majority of projects out there. I would sign up for a class
> if you intend to explore that aspect.
>
Yeah, I agree. We should conver autoconf and make at some point.
> Also, if you are going to go into C++, it's better to stick with Bruce
> Eckels book Thinking
> in C++ It's downloadable and free (as in beer), so there is no
> reason not to use it. It's also the best book you are ever going to
> find on the language.
>
We can use any book that you desire, but I'm going to stick with my text and
will refer to it. I'm not extremely happy with the text, but I have a head
start with it. I really was thinking of using the Strousberg tet.
> He has a second volume covering the Standard Template Library, but
> unfortunately I never found the time to go through it.
>
> The thing that makes Eckel stand out is that he explains why things
> are done in a certain way.
For what it is worth, I believe the paragin for OO languages is sommewhat
contrite, and I'm intersted in why things are done in a certain way
only to the degree that things are made easier to debug and read...period.
I go over much of this conceptually in the advanced Perl class, but frankly
the OO guys are whacked. Squeezing out all proceduale code from a launguage
defies the basic logic of how computers work and makes for a lot of bad
code which is tough on y carpul tunnel syndrome.
> And since he was on the standards board
> for 10 years, he also has no problem being open about what is wrong
> with the language.
>
A lot is wrong with C++ and nearly every other language. C++ is famous for
making people unhappy, and so is c and LISP and Perl and any language that
has been around and used enough to bread contempt ;)
Ruben
> -ron
>
> On Sat, Jun 28, 2008 at 10:04 PM, Ruben Safir wrote:
> > The C programming language was invented side by side with Unix. The King text goes through
> > much of the history of the language. Here I'd like to make a few points both in the general
> > and specific to GNU/Linux as a platform for C development.
> >
> > Oxymoronic as it sounds C language is a bare bones specification without anything useful.
> > All it requires is the keyword main, which defines the root function that everything else
> > is piled into. Everything that C does is imported from external libraries. These libraries
> > are defined, in the simplist case, on top of your program.
> >
> > For example, on page 10 of the King book is the following program:
> >
> > #include
> >
> > main(){
> > printf("To C, or not to C: that is the question \n");
> > }
> >
> > which was inherited from the K&R text. The first line defines the
> > library stdio.h which c is to import. The main keyword is present
> > (which defines the required function main() to be explained later,
> > and the function printf which is defined in the library stdio.h.
> >
> > Unlike programming languages such as Perl, Python and Rudy, C is a compiled
> > programming language. It needs a compiler to make a binary program that
> > can then be executed. The binary has machine like instructions which your
> > computer can directly understand. Unfortunately, your computer doesn't speak
> > English (or Spanish, Russian, Japanese, Manderin, Hebrew, or Udo). It speaks
> > binary. C is the interface between human language and machine code. The binaries
> > are very low level and C as a language, today, is considered to be very close to
> > the machine. You'd have to write programs in Assembly to get much close to your CPU.
> >
> > Therefor, you need a C compiler to translate your C Programming text into machine code.
> > At one time suc compilers were expensive and hard to get. Thanks to Richard Stallman and
> > friends, today we have compilers on almost every GNU based system. That compiler is called
> > gcc. Compilers do three things: Parse, compile and link.
> >
> > When you call:
> >
> > gcc file.c
> >
> > It loads file.c into the compiler. It then parses the programming you created and checks
> > for errors. It then analysis the symbols in your program and looks for their programming
> > definitions in the libraries that you call with #include. It then the different code
> > machine code peices it finds into a single binary.
> >
> > The gcc compiler is very complex and learning C includes learning much about the compiler
> > and also the debugger, called gdb. Both are documented with man pages, and have full books
> > which are available from the Free Software Foundation and worthy additions to your library.
> > Both are included in the NYLXS library as references.
> >
> > Any editor can be used to make C programs, but I strongly recommend learning either EMACS
> > or VI. EMACS has a GNU version, and VI has a version called VIM which can be downloaded and
> > used. I perfer the VIM editor and will use in in example and demonstrations. No editor
> > wars are needed here. I will say, however, if your using EMACS, then LEARN it. It is not
> > Microsoft Notepad.
> >
> > After editing this first program run the following command on the command line:
> > For this workshop, the "$" or "ruben-at-www2:~/cprog>" is the shell prompt. Your prompt
> > on the NYLXS server will look like the second example.
> >
> >
> > $ gcc -Wall file1.c -o file1
> >
> > the output will look like this:
> > ruben-at-www2:~/cprog> gcc -Wall file1.c -o file1
> > file1.c:3: warning: return type defaults to `int'
> > file1.c: In function `main':
> > file1.c:5: warning: control reaches end of non-void function
> > ruben-at-www2:~/cprog>
> >
> >
> > The compiler gives you 3 warning messages. I won't go into them currently, but in a few
> > weeks it should make sense to you. We will, however, fix the warnings later. For now, if
> > you look at your directory
> >
> > ruben-at-www2:~/cprog> ls -l
> > total 12
> > -rwxr-xr-x 1 ruben staff 7041 2008-06-28 21:45 file1
> > -rw-r--r-- 1 ruben staff 86 2008-06-28 21:35 file1.c
> >
> > file1.c is the file we are editing. You see it has no permisions to be executed.
> > file1 is the new executable we created. In addition. you see that it is executable.
> > gcc makes it executable permisions for us in most systems. We run our new program
> > on the command line like this:
> >
> > ruben-at-www2:~/cprog> ./file1
> > To C, or not to C: that is the question
> >
> > The C language defines the function main() and not much else. However, it is defined
> > as a function that returns an integer. We didn't return anything. We can fix this with
> > a "return function".
> >
> > We return a 0 by convention unless we are trying to indicate an error or other message. We also
> > put the keyword 'int' infront of main which explicitly defines that main returns integers.
> >
> > Our program not looks like this:
> >
> > #include
> >
> > int main(){
> > printf("To C, or not to C: that is the question \n");
> > return 0;
> > }
> >
> > and when we compile:
> >
> > ruben-at-www2:~/cprog> gcc -Wall file2.c -o file2
> > ruben-at-www2:~/cprog>
> >
> > No warnings.
> >
> > and when we run it, it looks like this:
> >
> > ruben-at-www2:~/cprog> ./file2
> > To C, or not to C: that is the question
> > ruben-at-www2:~/cprog>
> >
> >
> >
> > Next - Comments and C varriable basics.
> >
> >
> >
> > --
> > http://www.mrbrklyn.com - Interesting Stuff
> > http://www.nylxs.com - Leadership Development in Free Software
> >
> > So many immigrant groups have swept through our town that Brooklyn, like Atlantis, reaches mythological proportions in the mind of the world - RI Safir 1998
> >
> > http://fairuse.nylxs.com DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
> >
> > "Yeah - I write Free Software...so SUE ME"
> >
> > "The tremendous problem we face is that we are becoming sharecroppers to our own cultural heritage -- we need the ability to participate in our own society."
> >
> > "> I'm an engineer. I choose the best tool for the job, politics be damned.<
> > You must be a stupid engineer then, because politcs and technology have been attached at the hip since the 1st dynasty in Ancient Egypt. I guess you missed that one."
> >
> > (c) Copyright for the Digital Millennium
> >
--
http://www.mrbrklyn.com - Interesting Stuff
http://www.nylxs.com - Leadership Development in Free Software
So many immigrant groups have swept through our town that Brooklyn, like Atlantis, reaches mythological proportions in the mind of the world - RI Safir 1998
http://fairuse.nylxs.com DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
"Yeah - I write Free Software...so SUE ME"
"The tremendous problem we face is that we are becoming sharecroppers to our own cultural heritage -- we need the ability to participate in our own society."
"> I'm an engineer. I choose the best tool for the job, politics be damned.<
You must be a stupid engineer then, because politcs and technology have been attached at the hip since the 1st dynasty in Ancient Egypt. I guess you missed that one."
© Copyright for the Digital Millennium
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