How to organize files to write include?

[Kevin Handy]

Hi all

look at the organize tree

Sounds like a troll already.
Bad engrish, lack of caps, etc.

main.c
------
#include lib_adapter.c
main()
{
foo();
}


lib_adapter.c
-------------
#include "foo_liba.c"
#include "foo_libb.c"

void foo(){
#ifdef USING_LIBA
foo_liba()
#endif
#ifdef USING_LIBB
foo_libb()
#endif
}

void need();


lib_a.c
=======
void foo_liba()
{
need();
}

lib_b.c
-------
void foo_libb()
{
need()
}


gcc -o main main.c lib_adapter.c lib_a.c lib_b.c

some of the problems:

1. main should return an int.
2. Include files should not contain executable code.
You want to end up with one copy of each function,
and putting code in include files causes the function
to be expressed every time you include the file,
causing the linker to be upset about multiple definitions.
3. Include files should end in a '.h' extension.
It's a convention, and most C programmers expect it.
This allows for a 'cc *.c -o xxx' at the command line
to compile most simple programs.
4. Since lib_adapter.c, lib_a.c, and lib_b.c are all
included in main.c, why are you compiling them a
second time?
5. main should return a value.
6. need() is not implementated anywhere.
7. Neither "USING_LIBA" nor "USING_LIBB" are defined,
thus foo() is a null function.
8. need() is prototyped after use, instead of before.
....

the code can not be complained , what I want to know is

Why can't it be complained. I see lots of things to complain about.
What errors do you get? Are we supposed to guess?

I can not put need() out side of the lib_adapter.c

What happens when you try? What error do you get?

1.how to write include structure
2.need I have to write .h file instead of include c file?

You don't seem to really understand the purpose of
include files.

 

[key9]

Hi all

look at the organize tree

main.c
------
#include lib_adapter.c
main()
{
foo();
}


lib_adapter.c
-------------
#include "foo_liba.c"
#include "foo_libb.c"

void foo(){
#ifdef USING_LIBA
foo_liba()
#endif
#ifdef USING_LIBB
foo_libb()
#endif
}

void need();


lib_a.c
=======
void foo_liba()
{
need();
}

lib_b.c
-------
void foo_libb()
{
need()
}


gcc -o main main.c lib_adapter.c lib_a.c lib_b.c
the code can not be complained , what I want to know is

I can not put need() out side of the lib_adapter.c


1.how to write include structure
2.need I have to write .h file instead of include c file?

best regards


your key9

 

[Thad Smith]

Hi all

look at the organize tree

main.c

main()
{
foo();
}


lib_adapter.c
-------------
#include "foo_liba.c"
#include "foo_libb.c"

void foo(){
#ifdef USING_LIBA
foo_liba()
#endif
#ifdef USING_LIBB
foo_libb()
#endif
}

void need();


lib_a.c
=======
void foo_liba()
{
need();
}

lib_b.c
-------
void foo_libb()
{
need()
}


gcc -o main main.c lib_adapter.c lib_a.c lib_b.c
the code can not be complained , what I want to know is

I can not put need() out side of the lib_adapter.c

Do you mean that gcc does not give error messages or warnings? If not,
I can't interpret your comment.

1.how to write include structure

Questions should have a subject, verb, and end in a question mark, as
well as ask a question: "How can I include a structure in my program?"
That might not be the question you intended to ask. I think you are
asking about how to use #include statements in a program.

By convention, C programs are separated into code files and declaration
files. The code files contain function definitions and normally have an
extension of .c. The declaration files have declarations normally used
by multiple code files and have an extension of .h. These naming and
organizational conventions are not requirements of the language, though,
and compilers don't care what extensions are used on the files.

Normally .c files are each compiled into a separate object file, then
the object file are linked into a single executable file. In contrast,
I have used a C dialect compiler (for small microprocessors) that
requires all code files to be compiled together -- it cannot compile to
object files and link. For that compiler, it is typical to have a main
file include other code files. This is not recommended for normal use,
though.

2.need I have to write .h file instead of include c file?

No. In general you should compile code files separately and link them.
I recommend writing a header file for each code and placing the
prototypes (and other definitions required to use the code module) in
the associated header file. Then include the header file in both the
code file defining the functions and code files using the defined functions.

I suggest finding a good text book on C.