Update Files

[nuddy]

Is this syntax C++?
If it is how can i make it do the same thing in the C Language

void studentClass::updateIndex(int id, long int pos)
{
    indexType INDEX;
    ofstream indexFile( INDEXFILE, ios::binary | ios::app);

    INDEX.id = id;
    INDEX.pos = pos;
    if(!indexFile)
    {
        cerr << "File could not be opened." << endl;
        exit( 1 );
    }

    indexFile.write( (const char *)(&INDEX), sizeof(indexType) );
    indexFile.close();

}//updateIndex 

[hk_mp5kpdw]

Yes, it's C++. Use fopen/fclose and a FILE* object instead of the ofstream object and fwrite instead of the ofstream object's write member function. Instead of output with cerr you'd use fprintf with stderr. The function itself won't be a member function of any class/namespace so it will instead be a freestanding function. Other than that, it's the same, the basic structure will remain the same.

[nuddy]

Could u show me how can i upate this record from this function i have created?

#include <stdio.h>
#include <ctype.h>

struct Student
{
  int ID;
  char LastName[32]; 
  char FirstName[32];
  int DateOfBirth; // This could be of the form YYYYMMDD. For example someone born on December 21st, 1990 would have a value of 19901221
  char Address[32];
  char TelephoneNumber[11]; // a 10-digit string
  char ProgramPursued[32];   
};

struct Student students[10]={
{234,"Spencer", "Sochelle", 220587, "29_Decent_Village", "528-5214", "Business"},         
{345,"Dobson", "Dwayne", 890583, "263_Far Park Blvd", "457-2014", "Computer"},
{456,"Clarke", "Dave", 110181, "87_Rasta_Village", "354-5874", "Law"},
{567,"Currie", "Nickeisha", 230491, "26_Waterground_rd", "898-6578", "Nurse"},
{678,"Blackwood", "Mariann", 10490, "3_St_Johns_road", "256-1458", "Art"},
{789,"Hall", "Wesley", 101086, "3_Bayfarm_road", "236-1028", "Science"},
{891,"Hall", "Bouki", 251285, "67_pimpim_drive", "887-9910", "Engineer"},
{912,"Paul", "Shawn", 231180, "25_glasco_Close", "567-1996", "Law"},
{101,"Able", "Frank", 100591, "1_Camp_road", "528-1235", "Business"},
};

char GetUserOption();
int GetIDFromUser();
void LetUserSearchForStudent();
void UpdateStudents(Student students[]);
void PrintStudents(Student students[]);
void LoadStudents(Student students[]);
void SaveStudents(Student students[]);


char GetUserOption()
{
  char option = 'I'; // 'I' for Invalid

  while(option == 'I')
  {
    // Print the menu items
    printf("\n");
    printf("Choose one of the following options:\n[u]pdate   [P]rint   [S]earch   [E]xit\n");
    scanf("%c", &option);

    switch(toupper(option))
    {
      case 'U':
      case 'P':
      case 'S':
      case 'E':
        break;
      default:
        option = 'I';
        break;
    }
  }

  return option;
}

int GetIDFromUser()
{
  int id = 0;
  printf("Enter the ID: ");
  scanf("%d", &id);
  return id;
}

void LetUserSearchForStudent()
{
  // Getting the ID from the user to search for
  int id = GetIDFromUser();
  
}





// students must hold 10 students
void UpdateStudents(Student students[])
{
    

} 



// students must hold 10 students
void PrintStudents(Student students[])
{

FILE *fp ;
char ch ;

fp = fopen ( "records.txt", "r" ) ;

while ( 1 )
{
ch = fgetc ( fp) ;

if ( ch == EOF )
break ;

printf ( "%c", ch ) ;
}

}


// students must hold 10 students
void LoadStudents(Student students[])
{
  int i;
  FILE *fp;
  fp=fopen("records.txt","a+");
    
  for(i = 0; i < 10; ++i)
  {
    // Write the student to the file....here we will use comma-separated values
    fprintf(fp, "%d,%s,%s,%d,%s,%s,%s\r\n", 
            students[i].ID,
            students[i].LastName,
            students[i].FirstName,
            students[i].DateOfBirth,
            students[i].Address,
            students[i].TelephoneNumber,
            students[i].ProgramPursued
    );    
  }
}



// students must hold 10 students
void SaveStudents(Student students[])
{
  int i;

  // Open the file for writing
  FILE *fp = fopen("records.txt", "wb");
  if(fp == NULL) return; 

  // Loop through each student
  for(i = 0; i < 10; ++i)
  {
    // Write the student to the file....here we will use comma-separated values
    fprintf(fp, "%d,%s,%s,%d,%s,%s,%s\r\n", 
            students[i].ID,
            students[i].LastName,
            students[i].FirstName,
            students[i].DateOfBirth,
            students[i].Address,
            students[i].TelephoneNumber,
            students[i].ProgramPursued
    );    
  }

  // Close the file
  fclose(fp);  
}


int main()
{
  
  int looping = 1;

  // Load the students from the file
  LoadStudents(students);

  // Loop until exit
  while(looping)
  {
    char option = GetUserOption();
    switch(option)
    {
      case 'U':
        UpdateStudents(students);
        break;

      case 'P':
        PrintStudents(students);
        break;

      case 'S':
        LetUserSearchForStudent();
        break;

      case 'E':
        looping = 0; // exit the loop
        break;
    }
  } 

  // Save the students to the file
  SaveStudents(students);

  return 0;
}