حذف أسطر من ملف موظفين بحسب العمر في ++C

ازاي احذف موظفين اللي بين عمر كذا وكذا في كود زي دا

*/

#include <iostream>

#include <iomanip>



using namespace std;

int main()

{

    FILE *fp, *ft;

    char another, choice;



    struct employee

    {

        char first_name[50], last_name[50];

        int Age;

        long Salary;

    };



    struct employee e;

    int xAge;

    long int recsize;



    fp=fopen("users.txt","rb+");



    if (fp == NULL)

    {

        fp = fopen("users.txt","wb+");



        if (fp==NULL)

        {

            puts("Cannot open file");

            return 0;

        }

    }







    recsize = sizeof(e);



    while(1)

    {

        system("cls");



        cout << "\t\t====== Employee DATABASE MANAGEMENT SYSTEM ======";

        cout <<"\n\n                                          ";

        cout << "\n\n";

        cout << "\n \t\t\t 1. Add New Employee ";

        cout << "\n \t\t\t 2. List Employees  ";

        cout << "\n \t\t\t 3. Modify Employee's Salary ";

        cout << "\n \t\t\t 4. Delete Employee ";

        cout << "\n \t\t\t 5. Exit  ";

        cout << "\n\n";

        cout << "\t\t\t Select Your Choice :=> ";

        fflush(stdin);

        choice = getchar();

        switch(choice)

        {

        case '1' :

            fseek(fp,0,SEEK_END);

            another ='Y';

            while(another == 'Y' || another == 'y')

            {

                system("cls");

                cout << "Enter the First Name : ";

                cin >> e.first_name;

                cout << "Enter the Last Name : ";

                cin >> e.last_name;

                cout << "Enter the Employee Age : ";

                cin >> e.Age;

                cout << "Enter the Employee Salary : ";

                cin >> e.Salary;

                fwrite(&e,recsize,1,fp);

                cout << "\n Add Another Record (Y/N) ";

                fflush(stdin);

                another = getchar();

            }

            break;

        case '2':

            system("cls");

            rewind(fp);

            cout << "=== View the Records in the Database ===";

            cout << "\n";

            while (fread(&e,recsize,1,fp) == 1)

            {

                cout << "\n";

                cout <<"\n" << e.first_name << setw(10)  << e.last_name;

                cout << "\n";

                cout <<"\n" <<e.Age <<  setw(8)  << e.Salary;

            }

            cout << "\n\n";

            system("pause");

            break;



        case '3' :

            system("cls");

            another = 'Y';

            while (another == 'Y'|| another == 'y')

            {

                cout << "\n Enter the Age of the Employee : ";

                cin >> xAge;



                rewind(fp);

                while (fread(&e,recsize,1,fp) == 1)

                {

                    if (e.Age=xAge)

                    {

                        cout << "Enter New Employee Salary   : ";

                        cin >> e.Salary;

                        fseek(fp, - recsize, SEEK_CUR);

                        fwrite(&e,recsize,1,fp);

                        break;

                    }

                    else

                        cout<<"record not found";

                }

                cout << "\n Modify Another Record (Y/N) ";

                fflush(stdin);

                another = getchar();

            }

            break;





        case '4':

            system("cls");

            another = 'Y';

            while (another == 'Y'|| another == 'y')

            {

                cout << "\n Enter the Age of the Employee to delete : ";

                cin >> xAge;



                ft = fopen("temp.dat", "wb");



                rewind(fp);

                while (fread (&e, recsize,1,fp) == 1)



                    if (e.Age!=xAge)

                    {

                        fwrite(&e,recsize,1,ft);

                    }

                fclose(fp);

                fclose(ft);

                remove("users.txt");

                rename("temp.dat","users.txt");



                fp=fopen("users.txt","rb+");



                cout << "\n Delete Another Record (Y/N) ";

                fflush(stdin);

                another = getchar();

            }



            break;



        case '5':

            fclose(fp);

            cout << "\n\n";

            cout << "\t\t     THANK YOU";

            cout << "\n\n";

            exit(0);

        }

    }





    system("pause");

    return 0;

}