Question

Complete these steps to write a simple calculator program:

1. Create a calc project directory

2. Create a mcalc.c source file containing five functions; add, sub, mul, div, and mod; that implement integer addition, subtraction, multiplication, division, and modulo (remainder of division) respectively. Each function should take two integer arguments and return an integer result.

3. Create a mcalc.h header file that contains function prototypes for each of the five functions implemented in mcalc.c.

4. Create a calc.c source file with a single main function that implements a simple calculator program with the following behavior:

-> Accepts a line of input on stdin of the form ”number operator number” where number is a signed decimal integer, and operator is one of the characters ”+”, ”-”, ”*”, ”/”, or ”%” that corresponds to the integer addition, subtraction, multiplication, division, and modulo operation respectively.

-> Performs the corresponding operation on the two input numbers using the five mcalc.c functions.

-> Displays the signed decimal integer result on a separate line and loops to accept another line of input.

-> Or, for any invalid input, immediately terminates the program with exit status 0.

5. Create a Makefile using the following Makefile below as a starting point. Modify the Makefile so that it builds the executable calc as the default target. The Makefile should also properly represent the dependencies of calc.o and mcalc.o.

CC = gcc
CFLAGS = -g -O2 -Wall -Werror
ASFLAGS = -g

objects = calc.o mcalc.o

default: calc

.PHONY: default clean clobber

calc: $(objects)
   $(CC) -g -o $@ $^

calc.o: calc.c mcalc.h

%.o: %.c
   $(CC) -c $(CFLAGS) -o $@ $<

%.o: %.s
   $(CC) -c $(ASFLAGS) -o $@ $<

clean:
   rm -f $(objects)

clobber: clean
   rm -f calc

6. Compile the calc program by executing ”make” and verify that the output is proper. For example:

# ./calc

3 + 5

8

6 * 7

42

Answer 1

If you have any doubts, please give me comment...

mcalc.h

int add(int n1, int n2);

int sub(int n1, int n2);

int mul(int n1, int n2);

int div(int n1, int n2);

int mod(int n1, int n2);

mcalc.c

#include "mcalc.h"

int add(int n1, int n2){

    return n1+n2;

}

int sub(int n1, int n2){

    return n1-n2;

}

int mul(int n1, int n2){

    return n1*n2;

}

int div(int n1, int n2){

    return n1/n2;

}

int mod(int n1, int n2){

    return n1%n2;

}

calc.c

#include<stdio.h>

#include "mcalc.h"

int main(){

    int n1, n2;

    char op;

    while(scanf("%d %c %d", &n1, &op, &n2)==3){

            if(op=='+')

                printf("%d\n", add(n1, n2));

            else if(op=='-')

                printf("%d\n", sub(n1, n2));

            else if(op=='*')

                printf("%d\n", mul(n1, n2));

            else if(op=='/')

                printf("%d\n", div(n1, n2));

            else if(op=='%')

                printf("%d\n", mod(n1, n2));

            else{

                printf("Invalid operator");

                break;

            }

    }

    return 0;

}