Nothing is getting written to file - c

Question

Code:
struct subscriber
{
char phonenumber[20];
char name[50];
float amount;
}s;
void addrecords()
{
FILE *f;
char test;
f=fopen("file.txt","ab+");
//if(f==0)
//{ f=fopen("file.txt","wb+");
//system("clear");
//printf("please wait while we configure your computer");
//printf("/npress any key to continue");
//getchar();
//getch();
//}
while(1)
{
//system("clear");
printf("\n Enter phone number:");
scanf("%s",s.phonenumber);
printf("\n Enter name:");
fflush(stdin);
//scanf("%[^\n]",s.name);
scanf("%s",s.name);
printf("\n Enter amount:");
scanf("%f",&s.amount);
printf("check 1");
fwrite(&s,sizeof(s),1,f);
fflush(stdin);
printf("check 2");
//system("clear");
printf("1 record successfully added");
printf("\n Press esc key to exit, any other key to add other record:");
test=getchar();
//test=getche();
if(test==27)
break;
}
fclose(f);
}
I am facing two problems here:
Nothing is getting written to file although file is being created.
After I enter the amount it outputs all the print statements and goes to the initial of the while loop that is it does not wait at getchar.

Answer 1

The last scanf() doesn't read the newline at the end of the input, that's why getchar() returns immediately and doesn't wait and that's also the cause of the first problem, why the file isn't written, because you have to terminate the program to exit and the file isn't flushed. so you need to consume the newline char at the end of the last input you can do that with scanf()
scanf("%f%*[^\n]%*c",&s.amount);
Or using fgets() to read the whole line and using scanf() on that. Finally, note that you shouldn't use fflush() to clear an input stream, it's undefined:
7.19.5.2.2 If stream points to an output stream or an update stream in which the most recent operation was not input, the fflush function
causes any unwritten data for that stream to be delivered to the host
environment to be written to the file; otherwise, the behavior is
undefined.

Answer 2

fflush is never necessary if you have fclose.
But in your case, you have while(1) and fclose outside, that means fclose never get called so the file content never gets updated by fclose function.
You might want to use fflush inside the loop, e.g. right after fwrite, then it will flush the buffer to actual file.

Answer 3

You have named your file file.txt, so I assume you intend the file to be a text file? But then you open it with the b flag, which indicates binary format, and you write to it using fwrite, which doesn't convert the data to text, but just dumps the internal format to the file.
If you look at the created file in some sort of binary editor, you will see that it contains the data.