I don't know how to include my own header files in my source file.
I declare addition in my header file(myhead.h):
int addition(int a, int b);
In the source file I define it(myhead.c):
int addition(int a, int b){
return a+b;
}
In the third source file I include the header file and use addition(processSimulator.c):
#include "myhead.h"
#include <stdio.h>
int main(){
printf("Compiled %d\n", addition(3,5));
}
It gives me this error
You need to add myhead.c file to gcc arguments gcc processSimulator.c my head.c
Related
I need to compile a static library which inherits functions with the same name and these functions are furthermore calling each other.
Is there a way to solve my problem?
Here is the minimal example:
add_outer.c
#include "bridge.h"
int add(int a, int b){
return add_bridge(a,b);
}
bridge.c
#include "add_inner.h"
int add_bridge(int a, int b){
return add(a,b);
}
add_inner.c
int add(int a, int b){
return a+b;
}
Now my problems:
I can't change the structure
I can't modify the code at all
It needs to be compiled to a static library
so i can't cheat using a version-script (->shared library)
Instead of compiling them together, write a .c file that will
#define add something_else
then #include the add_bridge.c and add_inner.c
I have 3 directories, src, lib, and include. In include I have header file header3.h. Its code is as follows:
// header3.h
extern void change(int *a);
In lib I have file change4.c, which contains:
// change4.c
#include <stdlib.h>
#include "header3.h"
void change(int *a){
int y=100;
a=y;
}
In src I have file manipulate5.c, which contains:
// manipulate5.c
#include <stdio.h>
#include "header3.h"
int main(void){
int x=10;
printf("x is %d\n", x );
change(&x);
printf("x is now %d\n", x );
}
When I attempt to compile manipulate5.c with following command:
gcc -I ../include manipulate5.c`
when in directory src, I get the following error:
In function main:
manipulate5.c:(.text+0x2b): undefined reference to change
So how do I get manipulate5.c to properly work?
I try to make program in C and I cant use functions from .h without including .c file too. If I include .c after including .h it works. I get "undefined reference to ..." error on every function defined in .h.
main.c:
#include "mp.h"
//#include "mp.c"
int main()
{
int n;
printf("Unesite broj clanova niza: ");
scanf("%d",&n);
int *a=(int *)malloc(n*sizeof(int));
if (a==NULL) exit(0);
unos(a,n);
sortiranje(a,n,rastuci);
stampanje(a,n);
sortiranje(a,n,opadajuci);
stampanje(a,n);
return 0;
}
mp.h:
#ifndef MP_H_INCLUDED
#define MP_H_INCLUDED
#include <stdio.h>
#include <stdlib.h>
enum tip_sort {opadajuci,rastuci};
void unos(int *, int);
void sortiranje(int *, int, enum tip_sort);
void stampanje(int *, int);
#endif // MP_H_INCLUDED
mp.c:
#include "mp.h"
void unos(int *a, int n){
...
}
void sortiranje(int *a, int n, enum tip_sort t){
...
}
void stampanje(int *a, int n){
...
}
What you're seeing is a linker error. I guess, you're trying to compile main.c all alone.
You compilation statement should look like
gcc main.c mp.c -o output
and yes, do not #include .c (source) files. Source files are meant to be compiled and linked together to form the binary.
Note: Also, please do not cast the return value of malloc().
My files are
// main.c
#include <ClasseAusiliaria.c>
int main(void) {
int result = add(5,6);
printf("%d\n", result);
}
and
// add.c
int add(int a, int b) {
return a + b;
}
Use double quotes #include "ClasseAusiliaria.c" [Don't use angle brackets (< >) ]
And I prefer to save the file with .h extension In the same directory/folder.
TLDR:
Replace #include <ClasseAusiliaria.c> with
#include "ClasseAusiliaria.c"
Change your Main.c like so
#include <stdlib.h>
#include <stdio.h>
#include "ClasseAusiliaria.h"
int main(void)
{
int risultato;
risultato = addizione(5,6);
printf("%d\n",risultato);
}
Create ClasseAusiliaria.h like so
extern int addizione(int a, int b);
I then compiled and ran your code, I got an output of
11
You must declare
int add(int a, int b); (note to the semicolon)
in a header file and include the file into both files.
Including it into Main.c will tell compiler how the function should be called.
Including into the second file will allow you to check that declaration is valid (compiler would complain if declaration and implementation were not matched).
Then you must compile both *.c files into one project. Details are compiler-dependent.
make a file classAusiliaria.h and in there provide your method signatures.
Now instead of including the .c file include this .h file.
There are many great contributions here, but let me add mine non the less.
First thing i noticed is, you did not make any promises in the main file that you were going to create a function known as add(). This count have been done like this in the main file:
int add(int a, int b);
before your main function, that way your main function would recognize the add function and try to look for its executable code.
So essentially your files should be
Main.c
int add(int a, int b);
int main(void) {
int result = add(5,6);
printf("%d\n", result);
}
and
// add.c
int add(int a, int b) {
return a + b;
}
You can include the .c files, no problem with it logically, but according to the standard to hide the implementation of the function but to provide the binaries, headers and source files techniques are used, where the headers are used to define the function signatures where as the source files have the implementation. When you sell your project to outside you just ship the headers and binaries(libs and dlls) so that you hide the main logic behind your function implementation.
Here the problem is you have to use "" instead of <> as you are including a file which is located inside the same directory to the file where the inclusion happens. It is common to both .c and .h files
you shouldn't include c-files in other c-files. Instead create a header file where the function is declared that you want to call.
Like so:
file ClasseAusiliaria.h:
int addizione(int a, int b); // this tells the compiler that there is a function defined and the linker will sort the right adress to call out.
In your Main.c file you can then include the newly created header file:
#include <stdlib.h>
#include <stdio.h>
#include <ClasseAusiliaria.h>
int main(void)
{
int risultato;
risultato = addizione(5,6);
printf("%d\n",risultato);
}
write main.c like this -
caution : while linking both main.0 and ClasseAusiliaria.o should be
available to linker.
#include <stdlib.h>
#include <stdio.h>
extern int addizione(int a, int b)
int main(void)
{
int risultato;
risultato = addizione(5,6);
printf("%d\n",risultato);
}
I am not familiar to Eclipse IDE. I want to know how can O call various functions from a single source file that contains a main() function.
For Example
Project name - TestProject
Source File name - EntryPoint.c
Now I want to make various method like add(), Sub(), mul() etc.
Please tell me these method should be in another source file or a file.
If you want to call a function that is defined in another source file, you still need to declare the function in the source file you are calling it from. This is commonly done through the use of header files which are included at the top of each source file that refers to the function.
Here is an example.
methods.c
#include "header.h"
int add(int a, int b){
return a+b;
}
int sub(int a, int b){
return a-b;
}
int mult(int a, int b){
return a*b;
}
EntryPoint.c
#include "header.h"
int main(){
return sub(add(2, 3), mult(2,5));
}
header.h
#ifndef _HEADER_H
#define _HEADER_H
int add(int, int);
int sub(int, int);
int mult(int, int);
#endif
See setup guide http://tylorsherman.com/hello-world-eclipse.
You can call add and other function as you call in c++ , so nothing special is required.