Make file and including external file

Now in this section, we will create a folder to contain some extra files.
1- How to compile those files.
2- We will create a separate folder to contain the obj files.
3- We will create a separate folder to the output executable as well.

Will create a folder called "api" inside the source folder:
this folder will contain:

mmath.h

#ifndef _MMATH_H_
#define _MMATH_H_

double Add(int a, int b);

#endif

mmath.c

#include "mmath.h"

double Add(int a, int b)
{
    return a+b;
}

Let's update out main as well...

main.c

#include <stdio.h>
#include "api/mmath.h"

int main(int argc,char *argv[])
{
    double res = Add(23,26);
    printf("You see, u see this... I'm running\r\n");
    printf("%f\r\n", res);
    printf("Externals Executed\r\n");
    return 0;
}

Now How to compile this?

We need to include our custom header file as well while compiling and we also need to out put the results to bin folder....

So, we include a directory where source code is, using -I<DirectoryName>

So, here we go...

$ gcc -c -Iapi  ./api/mmath.c -o ./obj/mmath.obj

for now this is good...

Let's compile main.

$ gcc -c -Iapi main.c -o./obj/main.obj

Let's link objs and form .exe now ...

$ gcc ./obj/main.obj ./obj/mmath.obj -o ./bin/mobi.exe

 So, crossponding make file look like this:

mobi.mk

CC=gcc
OUT=mobi.exe
TARGET=main
OBJ=./obj
BIN=./bin
INCLUDE=./api
IPATH=-I$(INCLUDE)


all: clean compile build

build:
    $(CC)  $(OBJ)/$(TARGET).obj $(OBJ)/mmath.obj  -o $(BIN)/$(OUT)

compile:
    $(CC) -c $(IPATH)  $(INCLUDE)/mmath.c -o $(OBJ)/mmath.obj
    $(CC) -c $(IPATH)  $(TARGET).c -o $(OBJ)/$(TARGET).obj

clean:
    rm -f $(BIN)/* $(OBJ)/*

Looks a bit scary by now :(


Let's try it now ...

$ make -f ./mobi.mk
rm -f ./bin/* ./obj/*
gcc -c -I./api  ./api/mmath.c -o ./obj/mmath.obj
gcc -c -I./api  main.c -o ./obj/main.obj
gcc ./obj/main.obj ./obj/mmath.obj -o ./bin/mobi.exe

 Let's execute it...

$ ./bin/mobi.exe
You see, u see this... I'm running
49.000000
Externals Executed

 yupiii... let's do more make file ...