Writing to file using the APPEND mode

 THIS IS THE CODE USED TO EXPLAIN:

• HOW TO USE APPEND MODE, WHEN STORING TO FILE
• HOW TO STORE THE TO A FILE, THE NUMBER OF RECORDS STORED.

_________________________________________________________________

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

char name[100][50], address[100][75];
int count;

FILE *countptr; //pointer to the file that holds the next available position
FILE *dataptr; //pointer to the file that hold the records

void fill(); // fill the arrays with data
void retrievecount(); //stores the next available position in count
void view (); //allow the user to view what is in the file

int main()
{
   
    fill();
    view();
    getch();
    return 0;
}

void retrievecount()
{
     //open the file to read the integer value in the file and store it in count.
     if((countptr = fopen("CountFile.txt","r")) == NULL)
     {
         printf("File cannot open");
     }
     else
     {
         fscanf(countptr, "%d", &count);
     }
     fclose(countptr);
}

void fill()
{
     char choice;
     retrievecount(); //putting a value in count
    
     do
     {
         printf("\nEnter name:\t" );
         fflush(stdin);
         gets(name[count]);
        
         printf("\nEnter address:\t" );
         fflush(stdin);
         gets(address[count]);
       
         //each time a record is entered, it stored to the file in append mode
         if((dataptr = fopen("DataFile.txt", "a"))== NULL)
         {
            printf("FILE CANNOT OPEN");
         }
         else
         {
            fprintf(dataptr, "%s\n%s\n", name[count], address[count]);
         }  
         fclose(dataptr);
        
         count++;
         printf("\nWould you like to continue:\t" );
         scanf("%c", &choice);
     }while((count <100) && ((choice == 'Y') || (choice == 'y')));
    
     //save updated count to file
     if((countptr = fopen("CountFile.txt","w")) == NULL)
     {
         printf("File cannot open");
     }
     else
     {
         fprintf(countptr, "%d", count);
     }
     fclose(countptr);
       
}

void view()
{
    retrievecount();
       
    if((dataptr = fopen("DataFile.txt","r")) == NULL)
     {
         printf("File cannot open");
     }
     else
     {
         //allow count to determine how many times you loop.
         for (int c=0; c < count; c++)
         {        
            fgets(name[c],50,dataptr);
            fgets(address[c],75,dataptr);
           
            printf("Name is %sAddress is %s\n\n", name[c],address[c]);
         }
     }
     fclose(dataptr);
}