problem with flushing input stream C

Answer 1

fflush(stdin) is undefined behavior. Instead, make scanf "eat" the newline:

scanf("%s %d %f\n", e.name, &e.age, &e.bs);

Everyone else makes a good point about scanf being a bad choice. Instead, you should use fgets and sscanf:

const unsigned int BUF_SIZE = 1024;
char buf[BUF_SIZE];
fgets(buf, BUF_SIZE, stdin);
sscanf(buf, "%s %d %f", e.name, &e.age, &e.bs);

Answer 2

It's not a good practice to use fflush( stdin ) as it has undefined behavior. Generally, functions like scanf() leaves trailing newlines in stdin. So, it is better to use functions that are "cleaner" than scanf(). You can replace your scanf() with a combination of fgets() and sscanf() and you can do away with fflush( stdin ).

Answer 3

Update: You need to add another getchar() at the end of your loop to consume the '\n' that follows the Y/N. I don't think this is the best way to go, but it will make your code work as it stands now.

while(another=='y') {
    printf("\nEnter name,age and basic salary : ");
    fgets(buf, BUF_SIZE, stdin);
    sscanf(buf, "%s %d %f", e.name, &e.age, &e.bs);
    fwrite(&e,sizeof(e),1,fp);
    printf("Add another record (Y/N)");
    another=getchar();
    getchar();
}

I would suggest reading the data you want to parse (up to and including the '\n') into a buffer and then parse it out using sscanf(). This way you consume the newline and you can perform other sanity checks on the data.

Answer 4

Use this instead of getchar():

   char another[BUF_SIZE] = "y";
   while( 'y' == another[0] )
   {
        printf( "\nEnter name,age and basic salary : " );
        fgets( buf, BUF_SIZE, stdin );
        sscanf( buf, "%s %d %f", e.name, &e.age, &e.bs );
        fwrite( &e, sizeof(e) , 1, fp );
        printf( "Add another record (Y/N)" );
        fgets( another, BUF_SIZE, stdin );
    }

Answer 5

I would recommend the fgets()+sscanf() approach that a lot of other people have suggested. You could also use scanf("%*c"); before the call to getchar(). That will essentially eat a character.