Slip 1 - B) Create a C++ class MyFile with data membersfile pointer and filename. Write necessary member functions to accept and display File. Overload the following operators: Operator Example Purpose + F3=F1+F2 Concatenate the contents of file F1 and F2 in F3. ! !F3 Changesthe case of alternate characters of file F3.

Solution: 

#include <stdio.h>

#include <stdlib.h>

#include <istream>

#include <conio.h>

#include <ctype.h>

#include <fstream>

#include <iostream>

using namespace std;

#include <string.h>

#define MAXSIZE (10)

class myfile

{

    FILE *fp;

    char fn[MAXSIZE];

public:

    myfile(const char *fname)

    {

        strcpy(fn, fname);

    }

    myfile operator+(myfile);

    void operator!();

    void display();

};

void myfile::display()

{

    fp = fopen(fn, "r");

    char ch;

    while ((ch = fgetc(fp)) != EOF)

    {

        cout << ch;

    }

    fclose(fp);

}

void myfile::operator!()

{

    myfile f4("sy.txt");

    char ch;

    fp = fopen(fn, "r");

    f4.fp = fopen(f4.fn, "w");

    while ((ch = fgetc(fp)) != EOF)

    {

        if (isupper(ch))

            fputc(tolower(ch), f4.fp);

        else if (islower(ch))

            fputc(toupper(ch), f4.fp);

        else

            fputc(ch, f4.fp);

    }

    fclose(fp);

    fclose(f4.fp);

    remove("abc.txt");

    rename("sy.txt", "abc.txt");

}

myfile myfile::operator+(myfile f2)

{

    myfile f3("abc.txt");

    fp = fopen(fn, "r");

    f2.fp = fopen(f2.fn, "r");

    f3.fp = fopen(f3.fn, "w");

    char ch;

    while ((ch = fgetc(fp)) != EOF)

    {

        fputc(ch, f3.fp);

    }

    fclose(fp);

    while ((ch = fgetc(f2.fp)) != EOF)

    {

        fputc(ch, f3.fp);

    }

    _fcloseall();

    return f3;

}

int main()

{

    myfile f1("xyz.txt");

    myfile f2("lmn.txt");

    myfile f3("abc.txt");

    cout << "first file \n";

    f1.display();

    cout << "\nsecond file \n";

    f2.display();

    f3 = f1 + f2;

    cout << "\nAfter concatnation file is ";

    f3.display();

    cout << "\nAfter changes case \n";

    !f3;

    f3.display();

    return 0;

}