CODEWITHSUNDEEP
cfile-io
user3676752
user3676752

Reputation: 19

Cannot update record in a sequential access file

I'm having some problem with modifying records in a sequential access file. When I have 2 records in the file, and I update the 2nd one, it shows:

enter model code to update
RECORD UPDATED

But when I opened the file, it just shows the first record.

void edit(void){

    char mcode[20]; //model code for car
    char mname[20]; //name of car
    int quantity; //how many of cars are in stock
    float cost; //cost to make the car
    float sellingprice; //price of the car

    char code[20];

    FILE *fp;
    FILE *temp;
    printf("enter model code to update:");
    scanf("%s",code);

        fp=fopen("stock.txt","r");
        temp=fopen("temp.txt","w");
        rewind(fp);

         while(fscanf(fp,"%s %s %f %f %d\n",mcode,mname,&cost,&sellingprice,&quantity)==5){

         fprintf(temp,"%s %s %.2f %.2f %d\n",mcode,mname,cost,sellingprice,quantity);

             if (strcmp(code,mcode) == 0) {
             printf("Enter quantity : ");
             scanf("%d",&quantity);                   
             fprintf(temp,"%s %s %.2f %.2f %d\n",mcode,mname,cost,sellingprice,quantity);       
             }

         fclose(fp);
         fclose(temp);
         }
         remove("stock.txt");
         rename("temp.txt", "stock.txt");

Upvotes: 0

Views: 182

Answers (1)

001
001

Reputation: 13533

The fclose statements should be outside of the while loop.

Also when code = mcode, both fprintf commands will get executed. Try this

while(fscanf(fp,"%s %s %f %f %d\n",mcode,mname,&cost,&sellingprice,&quantity)==5){

    if (strcmp(code,mcode) == 0) {
        printf("Enter quantity : ");
        scanf("%d",&quantity);                   
    }

    fprintf(temp,"%s %s %.2f %.2f %d\n",mcode,mname,cost,sellingprice,quantity);  
 }
 fclose(fp);
 fclose(temp);

Upvotes: 2

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