program.c

#include <windows.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <stdlib.h>

struct StudentInfo
{
    char ID[10];
    char Name[20];
    char Email[30];
    char Phone[20];
    int  NumberOfCourse;
};

struct CourseInfo
{
    char StudentID[10];
    char Code[10];
    char Name[20];
};

struct StudentInfo Students[100];
struct CourseInfo Courses[500];

// some global variables
int i,j;
int TotalStudents = 0;
int TotalCourse = 0;
char StudentID[10];
FILE *AllStudents;
FILE *AllCourses;
FILE *ExistingAllStudents;
FILE *TempAllStudents;
FILE *ExistingAllCourses;
FILE *TempAllCourses;
// end

bool IsRunning = true;
void Menu();
void AddNewStudent();
void ShowAllStudents();
int  SearchStudent(char StudentID[10]);
void EditStudent(int StudentFoundIndex);
void DeleteStudent(int StudentIndex);
void DeleteAllStudents();
int  IsAlreadyExists(char GivenLine[30],char InfoType, char StudentID[300]);
void ErrorAndRestart(char *Error[100]);
void DeleteCourseByIndex(int CourseIndex);
void DeleteStudentByIndex(int CourseIndex);
void UserGuideline();
void AboutUs();
void GoBackOrExit();
void ExitProject();
void DataSeed();

int main()
{
    DataSeed(); // you can comment this line if not want dummy data

    while(IsRunning)
    {
        Menu();
        int Option;
        scanf("%d",&Option);
        switch(Option)
        {
        case 0:
            IsRunning = false;
            ExitProject();
            break;
        case 1:
            system("cls");
            printf("\n\t\t **** Add A New Student ****\n\n");
            AddNewStudent();
            GoBackOrExit();
            break;
        case 2:
            system("cls");
            printf("\n\t\t **** All Students ****\n\n");
            ShowAllStudents();
            GoBackOrExit();
            break;
        case 3:
        {
            system("cls");
            printf("\n\t\t **** Search Students ****\n\n");
            printf(" Enter The Student ID: ");
            scanf("%s",StudentID);
            int IsFound = SearchStudent(StudentID);
            if(IsFound<0)
            {
                printf(" No Student Found\n\n");
            }
            printf("\n");
            GoBackOrExit();
            break;
        }
        case 4:
            system("cls");
            printf("\n\t\t **** Edit a Student ****\n\n");
            printf(" Enter The Student ID: ");
            scanf("%s",StudentID);
            int StudentFoundIndex = SearchStudent(StudentID);

            if(StudentFoundIndex>=0)
            {
                EditStudent(StudentFoundIndex);
            }
            else
            {
                printf(" No Student Found\n\n");
            }
            GoBackOrExit();
            break;
        case 5:
            system("cls");
            printf("\n\t\t **** Delete a Student ****\n\n");
            printf(" Enter The Student ID: ");
            scanf("%s",StudentID);

            int DeleteStudentFoundIndex = SearchStudent(StudentID);

            if(DeleteStudentFoundIndex>=0)
            {
                char Sure = 'N';
                getchar();
                printf("\n\n");
                printf(" Are you sure want to delete this student? (Y/N): ");
                scanf("%c",&Sure);

                if(Sure == 'Y' || Sure == 'y')
                {
                    DeleteStudent(DeleteStudentFoundIndex);
                }
                else
                {
                    printf(" Your Data is Safe.\n\n");
                    GoBackOrExit();
                }

            }
            else
            {
                printf(" No Student Found\n\n");
                GoBackOrExit();
            }

            break;
        case 6:
        {
            char Sure = 'N';
            getchar();
            system("cls");
            printf("\n\t\t **** Delete ALL Students ****\n\n");

            printf(" Are you sure want to delete all the students? (Y/N): ");
            scanf("%c",&Sure);
            if(Sure == 'Y' || Sure == 'y')
            {
                DeleteAllStudents();
            }
            else
            {
                printf(" Your Data is Safe.\n\n");
                GoBackOrExit();
            }
            break;
        }

        case 7:
            system("cls");
            break;
        case 8:
            system("cls");
            UserGuideline();
            GoBackOrExit();
            break;
        case 9:
            system("cls");
            AboutUs();
            GoBackOrExit();
            break;
        default:
            ExitProject();
            break;
        }
    }

    return 0;
} // end main function

void Menu()
{
    printf("\n\n\t***Student Management System Using C***\n\n");
    printf("\t\t\tMAIN MENU\n");
    printf("\t\t=======================\n");
    printf("\t\t[1] Add A New student.\n");
    printf("\t\t[2] Show All students.\n");
    printf("\t\t[3] Search A student.\n");
    printf("\t\t[4] Edit A student.\n");
    printf("\t\t[5] Delete A student.\n");
    printf("\t\t[6] Delete All students.\n");
    printf("\t\t[7] Clear The window.\n");
    printf("\t\t[8] User Guideline.\n");
    printf("\t\t[9] About Us.\n");
    printf("\t\t[0] Exit the Program.\n");
    printf("\t\t=======================\n");
    printf("\t\tEnter The Choice: ");
} // end menu

void AddNewStudent()
{
    char StudentID[300];
    char Name[300];
    char Phone[300];
    char Email[300];
    int NumberOfCourses;
    char CourseCode[300];
    char CourseName[300];

    int IsValidID = 0;
    while(!IsValidID)
    {
        printf(" Enter The ID: ");
        scanf("%s",&StudentID);
        if(IsAlreadyExists(StudentID,'i',StudentID) > 0)
        {
            printf(" Error: This ID is already exists.\n\n");
            IsValidID = 0;
        }
        else if(strlen(StudentID) > 10)
        {
            printf(" Error: ID can not be more than 10 characters.\n\n");
            IsValidID = 0;
        }
        else if(strlen(StudentID) <= 0)
        {
            printf(" Error: ID can not be empty.\n\n");
            IsValidID = 0;
        }
        else
        {
            IsValidID = 1;
        }
    }

    int IsValidName = 0;
    while(!IsValidName)
    {
        printf(" Enter The Name: ");
        scanf(" %[^\n]s",&Name);
        if(strlen(Name) > 20)
        {
            printf(" Error: Name can not be more than 20 characters.\n\n");
            IsValidName = 0;
        }
        if(strlen(Name) <= 0)
        {
            printf(" Error: Name can not be empty.\n\n");
            IsValidName = 0;
        }
        else
        {
            IsValidName = 1;
        }
    }

    int IsValidEmail = 0;
    while(!IsValidEmail)
    {
        printf(" Enter The Email: ");
        scanf("%s",&Email);
        if(IsAlreadyExists(Email,'e',StudentID) > 0)
        {
            printf(" This Email is Already Exists.\n");
            IsValidEmail = 0;
        }
        else if(strlen(Email) > 30)
        {
            printf(" Error: Email can not be more than 30 characters.\n\n");
            IsValidEmail = 0;
        }
        else if(strlen(Email) <= 0)
        {
            printf(" Error: Email can not be empty.\n\n");
            IsValidEmail = 0;
        }
        else
        {
            IsValidEmail = 1;
        }
    }

    int IsValidPhone = 0;
    while(!IsValidPhone)
    {
        printf(" Enter The Phone: ");
        scanf("%s",&Phone);
        if(IsAlreadyExists(Phone,'p',StudentID) > 0)
        {
            printf(" This Phone Number is Already Exists\n");
            IsValidPhone = 0;
        }
        else if(strlen(Phone) > 20)
        {
            printf(" Error: Phone can not be more than 20 characters.\n\n");
            IsValidPhone = 0;
        }
        else if(strlen(Phone) <= 0)
        {
            printf(" Error: Phone can not be empty.\n\n");
            IsValidPhone = 0;
        }
        else
        {
            IsValidPhone = 1;
        }
    }

    int IsValidNumberOfCourse = 0;
    while(!IsValidNumberOfCourse)
    {
        printf(" Number of courses: ");
        scanf("%d",&NumberOfCourses);
        if(NumberOfCourses <= 0 || NumberOfCourses > 4)
        {
            printf(" Error: Number of courses can not be more than 4 and lees than 1.\n\n");
            IsValidNumberOfCourse = 0;
        }
        else
        {
            IsValidNumberOfCourse = 1;
        }
    }

    strcpy(Students[TotalStudents].ID,StudentID);
    strcpy(Students[TotalStudents].Name,Name);
    strcpy(Students[TotalStudents].Phone,Phone);
    strcpy(Students[TotalStudents].Email,Email);
    Students[TotalStudents].NumberOfCourse = NumberOfCourses;
    TotalStudents++;

    for(i=0; i<NumberOfCourses; i++)
    {

        printf(" Enter Course %d Code: ",i+1);
        scanf("%s",&CourseCode);

        printf(" Enter Course %d Name: ",i+1);
        scanf(" %[^\n]s",&CourseName);

        strcpy(Courses[TotalCourse].StudentID,StudentID);
        strcpy(Courses[TotalCourse].Code,CourseCode);
        strcpy(Courses[TotalCourse].Name,CourseName);
        TotalCourse++;
    }

    printf("\n Student Added Successfully.\n\n");
}

void ShowAllStudents()
{
    printf("|==========|====================|==============================|====================|=============|\n");
    printf("|    ID    |        Name        |            Email             |       Phone        |  NO.Course  |\n");
    printf("|==========|====================|==============================|====================|=============|\n");

    for(i=0; i<TotalStudents; i++)
    {
        printf("|");
        printf("%s",Students[i].ID);
        for(j=0; j < (10-strlen(Students[i].ID)); j++)
        {
            printf(" ");
        }
        printf("|");
        printf("%s",Students[i].Name);
        for(j=0; j < (20-strlen(Students[i].Name)); j++)
        {
            printf(" ");
        }
        printf("|");
        printf("%s",Students[i].Email);
        for(j=0; j < (30-strlen(Students[i].Email)); j++)
        {
            printf(" ");
        }
        printf("|");
        printf("%s",Students[i].Phone);
        for(j=0; j < (20-strlen(Students[i].Phone)); j++)
        {
            printf(" ");
        }
        printf("|");
        printf("%d",Students[i].NumberOfCourse);
        for(j=0; j < 12; j++)
        {
            printf(" ");
        }
        printf("|\n");
        printf("|----------|--------------------|------------------------------|--------------------|-------------|\n");

    }
    printf("\n");
}

int SearchStudent(char StudentID[10])
{
    system("cls");
    int StudentFoundIndex = -1;

    int i;
    for(i=0; i<TotalStudents; i++)
    {
        if(strcmp(StudentID,Students[i].ID) == 0)
        {
            StudentFoundIndex = i;
            printf("\n One Student Found for ID: %s\n\n",StudentID);
            printf(" Student Informations\n");
            printf("-------------------------\n");

            printf(" ID:    %s\n",Students[i].ID);
            printf(" Name:  %s\n",Students[i].Name);
            printf(" Email: %s\n",Students[i].Email);
            printf(" Phone: %s\n",Students[i].Phone);
            printf("\n Total Number of Courses: %d\n",Students[i].NumberOfCourse);
        }
    }
    int CourseCount = 0;
    int j;
    for(j=0; j<TotalCourse; j++)
    {
        if(strcmp(StudentID,Courses[j].StudentID) == 0)
        {
            CourseCount++;
            printf(" Course %d Code: %s\n",CourseCount,Courses[j].Code);
            printf(" Course %d Name: %s\n",CourseCount,Courses[j].Name);
        }
    }

    return StudentFoundIndex;
}

void EditStudent(int StudentFoundIndex)
{
    printf("\n\t\t **** Update The New Student ****\n\n");

    char NewName[300];
    char NewPhone[300];
    char NewEmail[300];
    int NewNumberOfCourses;
    char StudentID[300];
    strcpy(StudentID, Students[StudentFoundIndex].ID);
    int OldTotalNumberOfCourse = Students[StudentFoundIndex].NumberOfCourse;

    int IsValidName = 0;
    while(!IsValidName)
    {
        printf(" Enter The New Name(0 for skip): ");
        scanf(" %[^\n]s",&NewName);
        if(strlen(NewName) > 20)
        {
            printf(" Error: Name can not be more than 20 characters.\n\n");
            IsValidName = 0;
        }
        else if(strlen(NewName) <= 0)
        {
            printf(" Error: Name can not be empty.\n\n");
            IsValidName = 0;
        }
        else
        {
            IsValidName = 1;
        }
    }

    int IsValidEmail = 0;
    while(!IsValidEmail)
    {
        printf(" Enter The New Email(0 for skip): ");
        scanf("%s",&NewEmail);

        if(strlen(NewEmail) > 30)
        {
            printf(" Error: Email can not be more than 30 characters.\n\n");
            IsValidEmail = 0;
        }
        else if(strlen(NewEmail) <= 0)
        {
            printf(" Error: Email can not be empty.\n\n");
            IsValidEmail = 0;
        }
        else if(IsAlreadyExists(NewEmail,'e',StudentID) > 0)
        {
            printf(" Error: This Email Already Exists.\n\n");
            IsValidEmail = 0;
        }
        else
        {
            IsValidEmail = 1;
        }
    }

    int IsValidPhone = 0;
    while(!IsValidPhone)
    {
        printf(" Enter The New Phone(0 for skip): ");
        scanf("%s",&NewPhone);

        if(strlen(NewPhone) > 20)
        {
            printf(" Error: Phone can not be more than 20 characters.\n\n");
            IsValidPhone = 0;
        }
        else if(strlen(NewPhone) <= 0)
        {
            printf(" Error: Phone can not be empty.\n\n");
            IsValidPhone = 0;
        }
        else if(IsAlreadyExists(NewPhone,'p',StudentID) > 0)
        {
            printf(" Error: This Phone Number is Already Exists.\n\n");
            IsValidPhone = 0;
        }
        else
        {
            IsValidPhone = 1;
        }
    }

    int IsValidNumberOfCourse = 0;
    while(!IsValidNumberOfCourse)
    {
        printf(" Number of New courses(0 for skip): ");
        scanf("%d",&NewNumberOfCourses);

        if(NewNumberOfCourses > 4 || NewNumberOfCourses < 0)
        {
            printf(" Error: A Student can have maximum 4 and Minimum 0 number of courses.\n\n");
            IsValidNumberOfCourse = 0;
        }
        else
        {
            IsValidNumberOfCourse = 1;
        }
    }

    if(strcmp(NewName,"0") != 0)
    {
        strcpy(Students[StudentFoundIndex].Name,NewName);
    }

    if(strcmp(NewEmail,"0") != 0)
    {
        strcpy(Students[StudentFoundIndex].Email,NewEmail);
    }

    if(strcmp(NewPhone,"0") != 0)
    {
        strcpy(Students[StudentFoundIndex].Phone,NewPhone);
    }

    if(NewNumberOfCourses != 0)
    {
        int OldTotalCourse = Students[StudentFoundIndex].NumberOfCourse;
        Students[StudentFoundIndex].NumberOfCourse = NewNumberOfCourses;


        int FirstCourseIndex;
        int dc;
        for(dc=0; dc<TotalCourse; dc++)
        {
            if(strcmp(StudentID,Courses[dc].StudentID) == 0)
            {
                FirstCourseIndex = dc; // store the index for delete
                break;
            }
        }
        // after every delete array index will update (decrease by one)
        // we store the courses sequential
        // so if we know the first course index and total number of course we can delete all
        for(dc=1; dc<=OldTotalCourse; dc++)
        {
            DeleteCourseByIndex(FirstCourseIndex);
        }

        char CourseCode[300];
        char CourseName[300];
        for(i=1; i<=NewNumberOfCourses; i++)
        {
            printf(" Enter New Course %d Code: ",i);
            scanf("%s",&CourseCode);

            printf(" Enter New Course %d Name: ",i);
            scanf(" %[^\n]s",&CourseName);

            strcpy(Courses[TotalCourse].StudentID,StudentID);
            strcpy(Courses[TotalCourse].Code,CourseCode);
            strcpy(Courses[TotalCourse].Name,CourseName);
            TotalCourse++;
        }
    }

    printf(" Student Updated Successfully.\n\n");

}

void DeleteStudent(int StudentIndex)
{
    int d;
    int FirstCourseIndexs;
    struct StudentInfo ThisStudents;
    ThisStudents = Students[StudentIndex];
    for(d=0; d<TotalCourse; d++)
    {
        if(strcmp(ThisStudents.ID,Courses[d].StudentID) == 0)
        {
            FirstCourseIndexs = d;
            break;
        }
    }
    for(d=1; d<=ThisStudents.NumberOfCourse; d++)
    {
        DeleteCourseByIndex(FirstCourseIndexs);
    }
    DeleteStudentByIndex(StudentIndex);
    printf(" Student Deleted Successfully.\n\n");
    GoBackOrExit();
}

void DeleteAllStudents()
{
    TotalStudents = 0;
    TotalCourse = 0;
    printf(" All Students Deleted Successfully.\n\n");
    GoBackOrExit();
}


void DeleteCourseByIndex(int CourseIndex)
{
    int c;
    for(c=0; c<TotalCourse-1; c++)
    {
        if(c>=CourseIndex)
        {
            Courses[c] = Courses[c+1];
        }
    }
    TotalCourse--;

}

void DeleteStudentByIndex(int CourseIndex)
{
    int s;
    for(s=0; s<TotalStudents-1; s++)
    {
        if(s>=CourseIndex)
        {
            Students[s] = Students[s+1];
        }
    }
    TotalStudents--;
}


int IsAlreadyExists(char GivenLine[300],char InfoType, char StudentID[300])
{
    int EmailExists = 0;
    int PhoneExists = 0;
    int IDExists = 0;
    int ep;

    for(ep=0; ep<TotalStudents; ep++)
    {
        if(strcmp(GivenLine,Students[ep].ID) == 0)
        {
            IDExists++;
        }
        if(strcmp(GivenLine,Students[ep].Email) == 0 && strcmp(StudentID,Students[ep].ID) != 0 )
        {
            EmailExists++;
        }
        if(strcmp(GivenLine,Students[ep].Phone) == 0 && strcmp(StudentID,Students[ep].ID) != 0)
        {
            PhoneExists++;
        }

    }

    if(InfoType == 'i')
    {
        return IDExists;
    }
    else if(InfoType == 'e')
    {
        return EmailExists;
    }
    else if(InfoType == 'p')
    {
        return PhoneExists;
    }
    else
    {
        return 0;
    }
}

void ErrorAndRestart(char *error[100])
{
    printf("%s\n",error);
    int i = 0;
    printf("Restarting the program: ");
    for(i=0; i<10; i++)
    {
        printf(".");
        Sleep(500);
    }
    system("cls");
    main();
}

void UserGuideline()
{
    printf("\n\t\t **** How it Works? ****\n\n");
    printf(" -> You will only able to store the Student's ID, Name, Email, Phone, Number of Courses.\n");
    printf(" -> A student can have maximum 4 courses and minimum 1 course.\n");
    printf(" -> Student ID can be maximum 10 characters long and unique for every students.\n");
    printf(" -> Student Name can be maximum 20 characters long.\n");
    printf(" -> Student Email can be maximum 30 characters long and unique for every students.\n");
    printf(" -> Student Phone can be maximum 20 characters long and unique for every students.\n");
    printf(" -> Course code can be maximum 10 characters long.\n");
    printf(" -> Course Name can be maximum 20 characters long.\n\n");

    printf(" ->> visit www.insideTheDiv.com for more project like this. <<-\n\n");
}

void AboutUs()
{
    printf("\n\t\t **** About US? ****\n\n");

    printf(" Some important note we should remember.\n");
    printf(" -> This is a simple student management system project.\n");
    printf(" -> You can modify the source code.\n");
    printf(" -> You can use this project only for personal purpose not for business.\n\n");

    printf(" ->> visit www.insideTheDiv.com for more project like this. <<-\n\n");
}

void GoBackOrExit()
{
    getchar();
    char Option;
    printf(" Go back(b)? or Exit(0)?: ");
    scanf("%c",&Option);
    if(Option == '0')
    {
        ExitProject();
    }
    else
    {
        system("cls");
    }
}

void ExitProject()
{
    system("cls");
    int i;
    char ThankYou[100]     = " ========= Thank You =========\n";
    char SeeYouSoon[100]   = " ========= See You Soon ======\n";
    for(i=0; i<strlen(ThankYou); i++)
    {
        printf("%c",ThankYou[i]);
        Sleep(40);
    }
    for(i=0; i<strlen(SeeYouSoon); i++)
    {
        printf("%c",SeeYouSoon[i]);
        Sleep(40);
    }
    exit(0);
}

void DataSeed()
{

    //-- store some dummy data
    //-- student 1
    strcpy(Students[0].ID,"S-1");
    strcpy(Students[0].Name,"Student 1");
    strcpy(Students[0].Phone,"016111111111");
    strcpy(Students[0].Email,"student-1@gmail.com");
    Students[0].NumberOfCourse=1;

    strcpy(Courses[0].StudentID,"S-1");
    strcpy(Courses[0].Code,"CSE-1");
    strcpy(Courses[0].Name,"Course - 1");

    //-- student 2
    strcpy(Students[1].ID,"S-2");
    strcpy(Students[1].Name,"Student 2");
    strcpy(Students[1].Phone,"016111111112");
    strcpy(Students[1].Email,"student-2@gmail.com");
    Students[1].NumberOfCourse=2;

    strcpy(Courses[1].StudentID,"S-2");
    strcpy(Courses[1].Code,"CSE-1");
    strcpy(Courses[1].Name,"Course - 1");

    strcpy(Courses[2].StudentID,"S-2");
    strcpy(Courses[2].Code,"CSE-2");
    strcpy(Courses[2].Name,"Course - 2");


    //-- student 3
    strcpy(Students[2].ID,"S-3");
    strcpy(Students[2].Name,"Student 3");
    strcpy(Students[2].Phone,"016111111113");
    strcpy(Students[2].Email,"student-3@gmail.com");
    Students[2].NumberOfCourse=3;

    strcpy(Courses[3].StudentID,"S-3");
    strcpy(Courses[3].Code,"CSE-1");
    strcpy(Courses[3].Name,"Course - 1");

    strcpy(Courses[4].StudentID,"S-3");
    strcpy(Courses[4].Code,"CSE-2");
    strcpy(Courses[4].Name,"Course - 2");

    strcpy(Courses[5].StudentID,"S-3");
    strcpy(Courses[5].Code,"CSE-3");
    strcpy(Courses[5].Name,"Course - 3");

    TotalStudents = 3;
    TotalCourse = 6;
}