Thread: C Program Help Please (File Handling)

Hello Everyone,

I hope you are all doing well and thanks in advance for any help you can offer.

I have the below code which need to open a .txt file with addresses in the below format, then it need to take those and sort them by zip code and output the sorted addresses to a new .txt file.

Address Format (There is no limit to amount of addresses file can have, minimum is 2):
FirstName, LastName
12345 Street Name Ave.
City Name, ST
12345

It needs to do this using fopen, fgets, fputs, fclose and FILE pointers but i cant get my head around this, i know its rather simple but im having trouble.

Any help is greatly appreciated.

here is the code that needs to be changed

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct storeaddress
{
   char fandlname[50];
   char street[50];
   char cityandstate[25];
   int zip;
};
struct storeaddress*createaddress();
void printaddr(int ptrct, struct storeaddress*ptr[]);
void sortingzip(int ptrct, struct storeaddress*ptr[]);
int main()
{
   struct storeaddress *ptr[50];
   int ptrct = 0;
   char buf[50];
   fflush(stdin);
   do
   {
       ptr[ptrct] = createaddress();
       ptrct++;
   } while (((fgets(buf, 50, stdin) != NULL)));
   fflush(stdin);
   sortingzip(ptrct, ptr);
   printaddr(ptrct, ptr);
   return 0;
   free(ptr);
}
struct storeaddress*createaddress()
{
   fflush(stdin);
   struct storeaddress *newaddress = (struct storeaddress*)malloc(sizeof(struct storeaddress));
   fgets(newaddress->fandlname, 50, stdin);
   fgets(newaddress->street, 50, stdin);
   fgets(newaddress->cityandstate, 50, stdin);
   fflush(stdin);
   scanf("%d", &newaddress->zip);
   return newaddress;
}
void printaddr(int ptrct, struct storeaddress *ptr[50])
{
   int j;
   fflush(stdin);
   for (j = 0; j < ptrct; j++)
   {
       printf("\n%s%s%s%d", ptr[j]->fandlname, ptr[j]->street, ptr[j]->cityandstate, ptr[j]->zip);
   }
};
void sortingzip(int ptrct, struct storeaddress *ptr[])
{
   int i, k;
   for (i = 0; i < ptrct; i++)
   {
       for (k = 0; k < ptrct; k++)
       {
           if (ptr[k]->zip > ptr[i]->zip)
           {
               struct storeaddress *temp = ptr[i];
               ptr[i] = ptr[k];
               ptr[k] = temp;
           }
       }
   }
}

Hello Salem,

Thank you for your comments and for your help, i see what you are saying regarding my issues. I've changed them based on your comments and the program does seem to be running better.

Do you have any ideas on how i can implement file handling in this using fopen, fgets, fputs, fclose and FILE pointers? Im really stuck there and cant figure it out.

Any help is appreciated.

Hi Salem,

Thanks again for your tips i really appreciate it, let me try to work and and implement this in my code to see if i can wrap my head around it and get it functioning.

Quick question, maybe it will answer itself when i get there but how does the program know where the file is located that im trying to open? do i have to specify its location on the drive somewhere?

Hello All,

So i've revised my code quite a bit, trying to make it more efficient. I think i'm on the right track. One issue i'm having is on line 33, i'm getting an error saying too few arguments. any ideas how to fix this as i'm not sure.

Code:

do //reading file
    {
        fscanf(fp, "%s %s %s %d", fandlname, street, cityandstate, zip);
        ptr[ptrct] = createaddress(fandlname, street, cityandstate, zip);
        ptrct++;
    } while (((fgets(fp)) != EOF)); /*ERROR IS HERE for "FP"*/

Here's all of my revised code. Any help, tips or pointers would be appreciated. One issue i'm wondering is how my code knows where my input.txt file is and also where to put my output.txt file. Errors have prevented me from running it successfully but i'm wondering.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct storeaddress
{
    char fandlname[50];
    char street[50];
    char cityandstate[25];
    int zip;
};
struct storeaddress*createaddress();
void printaddr(int ptrct, struct storeaddress*ptr[]);
void sortingzip(int ptrct, struct storeaddress*ptr[]);
int main()
{
    struct storeaddress *ptr[50];
    int ptrct = 0;
    char buf[50];
    FILE *fp;
    char fandlname[50];
    char street[50];
    char cityandstate[25];
    int zip;
    fflush(stdin);
    fp = fopen("input.txt", "r");


    do //reading file
    {
        fscanf(fp, "%s %s %s %d", fandlname, street, cityandstate, zip);
        ptr[ptrct] = createaddress(fandlname, street, cityandstate, zip);
        ptrct++;
    } while (((fgets(fp)) != EOF));
    fflush(stdin);
    sortingzip(ptrct, ptr);
    printaddr(ptrct, ptr);
    return 0;
    free(ptr);
}
struct storeaddress*createaddress(char fandlname[50], char street[50], char cityandstate[50], int zip)
{
    fflush(stdin);
    struct storeaddress *newaddress = (struct storeaddress*)malloc(sizeof(struct storeaddress));
    //creating struct with parametres sent while file reading
    strcpy(newaddress->fandlname, fandlname);
    strcpy(newaddress->street, street);
    strcpy(newaddress->cityandstate, cityandstate);
    newaddress->zip = zip;
    return newaddress;
}
void printaddr(int ptrct, struct storeaddress *ptr[50])
{
    int j;
    fflush(stdin);
    FILE *outputFile = fopen("output.txt", "w");
    for (j = 0; j < ptrct; j++)
    {
        printf("\n%s%s%s%d", ptr[j]->fandlname, ptr[j]->street, ptr[j]->cityandstate, ptr[j]->zip);
        //writing to a file
        fprintf(outputFile, "\n%s%s%s%d", ptr[j]->fandlname, ptr[j]->street, ptr[j]->cityandstate, ptr[j]->zip);
    }
};
void sortingzip(int ptrct, struct storeaddress *ptr[])
{
    int i, k;
    for (i = 0; i < ptrct; i++)
    {
        for (k = 0; k < ptrct; k++)
        {
            if (ptr[k]->zip > ptr[i]->zip)
            {
                struct storeaddress *temp = ptr[i];
                ptr[i] = ptr[k];
                ptr[k] = temp;
            }
        }
    }
}