Untitled

// Kamberly Training Courses V 0.1

#include <stdio.h>
#include <string.h>

typedef struct
{
        int number;
        char cName[20];
        char courseCode[6];
} Course;

/* After Execution - Course details are fetched from file and the last index
                                         that was used it loaded (if the file exsist). If the file
                                         does not exist return -1 */
int populateCourse(char filename[], Course courses[]);

/* After Execution - Menu option is obtained from the user */
int mainMenu();

/* Before Execution - lastIndex is the total number of courses */
void printCourses(Course courses[], int lastIndex);

/*  */
int findCourse(Course courses[], int lastIndex, int cName);

/*  */
void getNumber(int *number);

/* */
void getString(char s[], int size);

/* */
void removeNewline(char s[]);

/* */
void saveAll(char fileName[], Course courses[], int lastIndex);


int main()
{
        int numOfCourses = 5;
        Course courses[numOfCourses]; //A structure to hold 5 courses' details
        int lastIndex = -1; // Used to store the last index of the courses structure
                            // that was used

        char fileName[] = "course.dat"; // Filename to be used to save and load data

        lastIndex = populateCourses(fileName, courses);

        int option; /* used to store the menu option
                                   and returns until the user enters the
                                   exit option */

        do
        {
                option = mainMenu();
                /* Used if the user enters the option for adding a new course */
                if (option == 1)
                {
                        system("cls");
                        printf("Add new course\n");
                        /* Check that the structure is full */
                        if (lastIndex == numOfCourses -1)
                        {
                                printf("Unable to add any more students\n");
                                system("pause");
                        }
                        /* If array is not full */
                        else
                        {
                                lastIndex++; /* Adds 1 to the contents of lastIndex */
                                getNumber(&courses[lastIndex].number);

                                printf("Enter course name: ");
                                getString(courses[lastIndex].cName,
                                        sizeof(courses[lastIndex].cName));

                                printf("Enter course code: ");
                                getString(courses[lastIndex].courseCode,
                                        sizeof(courses[lastIndex].courseCode));

                        }
                }

                /* Used if the user enters the option for displaying courses' details */
                else if (option == 3)
                {
                        /*prompts the user to enter a course code */
                        printCourses(courses, lastIndex);
                        printf("Enter course code to change the cost: ");
                        int cCode; // Used to store the course code
                        scanf("%i", &cCode);
                        _flushall();

                        /* Checks Course Code exsists */
                        int found = findCourse(courses, lastIndex, cCode);
                        /* Performed if the course code doesn't exsist */
                        if (found == -1)
                        {
                                printf("Course was not found\n");
                                system("pause");
                        }

                        /* Performed if the course was found */
                        else
                        {
                                printf("Course found\n");

                                /* Display option choices for update */
                                printf("1 - Course Name\n 2- Course Code\n");
                                int updateOption; /* Used to store the option
                                                                         the user selected */
                                scanf("%i", &updateOption);
                                _flushall();
                                /* Performed if the user wants to update the name of the
                                course */
                                if (updateOption == 1)
                                {
                                        /* Get new Course name */
                                        printf("Enter new course name: ");
                                        getString(courses[found].cName,
                                                sizeof(courses[found].cName));
                                }

                                /* Performed if the user wants to modify the course code
                                for the course */
                                else if (updateOption == 2)
                                {
                                        /* Get new course code */
                                        printf("Enter new course code: ");
                                        getString(courses[found].courseCode,
                                                sizeof (courses[found].courseCode));
                                }
                        }
                }

                /* Perfomed if the user enters the option for exiting the program */
                else if (option == 4)
                {
                        saveAll(fileName, courses, lastIndex);
                }
        } while (option != 4);

        system("pause");
        return 0;
}

int mainMenu()
{
        int option;
        system("cls");
        printf("Kambury IT Training\n\n");
        printf("1: Add new course\n");
        printf("2: Display courses' details\n");
        printf("3: Edit course code\n");
        printf("4: Exit\n");
        printf("Enter options; ");
        scanf("%i", &option);
        _flushall();
        return option;
}

int populateCourses(char fileName[], Course courses[])
{
   FILE *courseFile;
   // try to open the file in read binary mode
   courseFile = fopen(fileName, "rb"); // open the file in read binary file

   int lastIndex = -1;
   // checks if the file exists or not.
   // if the file exists, retrieve the information from the file
   if (courseFile != NULL)
   {
      int i = -1;
      // obtain the information relating to the number of students' details
      // that have been saved
      fread(&lastIndex, sizeof(int), 1, courseFile);
      // retrieve each student's details
      while (i < lastIndex)
      {
         i = i + 1;
         fread(&courses[i], sizeof(Course), 1, courseFile);
      }
      fclose(courseFile);
   }
   return lastIndex;
}

// displays all the courses' details on the screen
void printCourses(Course courses[], int lastIndex)
{
   int i;
   system("cls");
   printf("Courses' details\n\n");
   // performed if the course structure contains at least one record
   if (lastIndex >= 0)
   {
      printf("ID\tName\t\tCourse Code\n");
      // repeats until all of the courses' details have been displayed
      for (i = 0; i <= lastIndex; i++)
      {
         printf("%i\t%s\t\t%s\n", courses[i].number, courses[i].cName,
                           courses[i].courseCode);
      }
   }
}

// searches through the structure until a match for the course code is found, or
// until the end of the structure has been reached
// returns the index where the course code was found, otherwise returns -1
int findCourse(Course courses[], int lastIndex, int cCode)
{  int i;
   // repeats while the contents of i is less than or equal to the contents of
   // lastIndex
   for (i = 0; i <= lastIndex; i++)
   {
      // checks if the contents of cCode is the same as the student's id.  A match
      // has been made
      if (cCode == courses[i].number)
      {
         return i; // returns the position where the student id as found
      }
   }
   system("pause");
   return -1; // returns a non-index value, the id was not found in the structure
}

void saveAll(char fileName[], Course courses[], int lastIndex)
{
   // checks that the structure has at least one record to save
   if (lastIndex >= 0)
   {
      FILE *courseFile = fopen(fileName, "wb"); // open the file in write
                                                 // binary mode
      int i;

      // save the contents of lastIndex so the program will know how many
      // records need to be read back from the file
      fwrite(&lastIndex, sizeof(int), 1, courseFile);
      // repeat until all the students' details have been saved to file
      for (i = 0; i <= lastIndex; i++)
      {
         fwrite(&courses[i], sizeof(Course), 1, courseFile);
      }
      fclose(courseFile); // close the file
   }
}

void getNumber(int *number)
{
     printf("Enter student number ");
     scanf("%i", number);
     _flushall();
}

void getString(char s[], int size)
{
     fgets(s, size, stdin);
     removeNewline(s);
}

// function to remove \n for the end of the string, if \n exists
void removeNewline(char s[])
{
    // find the length of the string (this will include \n if
    // it exists) and then subtract 1 from the length
    int i = strlen(s) - 1;
    // check if the character at position 1 is \n
    if (s[i] == '\n')
    {
        // replace \n with \0
        s[i] = '\0';
    }
}