How to call another C program?

[rpk2006]

Hi,

I have one MAIN C program in which I have to call other C program
files. How to call them?
Suppose the main program is MAIN.C and I have to call a function
called "Add" located in another C program called "Second.C".
How to call?

Secondly, calling another C program is good, or should I copy the
MAIN function of "Second.C" and make an independent function of
my main program.


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Securing a computer system has traditionally been a battle of wits: the penetrator tries to find the holes, and the designer tries to close them. � M.Gosser

 

[chipperMDW]

What are you asking? How to execute another program from a C program, or how to call a function from another source file?

I'm guessing you mean the latter. Make sure you know the difference between program and function; they're not interchangable.

Compile main.c and second.c separately, then link them together.

I can't understand your last paragraph, but I think the answer you want is: in general, it's definitely better to compile code separately and have a modular application than to have everything in one file and have a monolithic one. If everything's in one file and you make a change, you have to recompile the entire thing. If code is spread out among different files, you only have to recompile the part you changed.

 

[naraic]

Try using header files. Put the function declaration of add in second.h, for example

//second.h

int add(int, int);

Then in second.c have the function definition

//second.c
#include "second.h"

int add(int a, int b) {
.....
}

And in main.c

//main.c
# include "second.h"

void main(void) {
  in a, b, c;
  ....

  b = add(a, c);
  ....
}