Create a file using structures

Question

I wrote this code, but it gives a segmentation fault. The loop works only till the printf statement. Please help me rectify the problem.

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


FILE *fp;
int n,i;

typedef struct transactions
{

 char bank_name;                    
 int amount;           
 int time; //to be given in the form:1320
 char location;
 int acc_no;      

}transaction;//structure

transaction t;

void main()
{
   printf("\nHow many records you would like to insert ? : ");
    scanf("%d",&n);
    fp=fopen("input.txt","r+");
    for(i=0;i<n;i++)
    {
        printf("\nEnter the transaction details");
        scanf("%s%d%d%s%d",t.bank_name,&t.amount,&t.time,t.location,&t.acc_no);
        fwrite(&t,sizeof(t),1,fp);
    }
    fclose(fp);
}

Answer 1

bank_name and location are not strings but single characters. But you attempt to store a string inside them with %s. Therefore the program will crash and burn.

Answer 2

You should activate the warnings when you compile...

Using clang:

 % clang testt.c -Wall
testt.c:22:1: warning: return type of 'main' is not 'int' [-Wmain-return-type]
void main()
^
testt.c:30:28: warning: format specifies type 'char *' but the argument has type 'int' [-Wformat]
        scanf("%s%d%d%s%d",t.bank_name,&t.amount,&t.time,t.location,&t.acc_no);
               ~~          ^~~~~~~~~~~
testt.c:30:58: warning: format specifies type 'char *' but the argument has type 'int' [-Wformat]
        scanf("%s%d%d%s%d",t.bank_name,&t.amount,&t.time,t.location,&t.acc_no);
                     ~~                                  ^~~~~~~~~~
3 warnings generated.

Using gcc:

 % gcc testt.c -Wall
testt.c:22:6: warning: return type of ‘main’ is not ‘int’ [-Wmain]
 void main()
      ^
testt.c: In function ‘main’:
testt.c:30:9: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘int’ [-Wformat=]
         scanf("%s%d%d%s%d",t.bank_name,&t.amount,&t.time,t.location,&t.acc_no);
         ^
testt.c:30:9: warning: format ‘%s’ expects argument of type ‘char *’, but argument 5 has type ‘int’ [-Wformat=]

I'm sure you can solve the issue by yourself (wrong type).