In C file handling equivalent to scanf("%d",&val); is:

Question

Accepted Answer

The correct option is (1):
The fundamental difference between the standard console I/O functions and the file I/O functions in C is that the file functions require an explicit stream pointer. The `scanf()` function is, in fact, a specialized version of the file input function `fscanf()`. While `scanf("%d",&val);` is used to read formatted input from the console, its true equivalent in the file-handling family is `fscanf(stdin, "%d",&val);`. Here, `stdin` is a predefined file pointer that points to the *standard input stream*, which is typically the keyboard. By explicitly specifying `stdin` as the stream argument, `fscanf()` performs the exact same operation as `scanf()`, thus proving its conceptual equivalence.

The incorrect option is (2):
The function `fprintf()` is a standard I/O function used for *output*, not input. It is designed to write formatted data to a specified output stream. When used with `stdout` (the standard output stream, which is the console screen), `fprintf(stdout, "value=%d
", val)` will print a formatted string to the user's screen. This operation is the inverse of `scanf()`'s job, which is to read and store data *from* the input stream into a variable. Therefore, it is entirely inappropriate as an equivalent input function.

The incorrect option is (3):
The function call `scanf(value)` is syntactically flawed and incorrect. The `scanf()` function requires a format string (a C string literal, like `"%d"`) as its first argument to define the data type it must read from the input stream. A simple variable name like `value` cannot serve as this format control string, as it does not reliably contain the type information needed for the function. Moreover, to store the input, the address-of operator (`&`) must be used for the variable, making the correct structure `scanf("format", &variable)`.

The incorrect option is (4):
The call `scanf()` is fundamentally incomplete and syntactically invalid in C programming. The `scanf()` function is a variadic function that requires at least one argument: the format control string. This format string is essential because it informs the function what type of data (`%d` for integer, `%c` for character, etc.) to look for and read from the input buffer. Without this necessary format specification, the compiler cannot generate the correct code to handle the input, leading to a compile-time error or a serious run-time failure.