What is the difference between stdin with fscanf and scanf

Question

I want to get a integer from to user. But I wonder what is the difference between fscanf(stdin, "%d", &x); and scanf("%d", &x); ?

Answer 1

What is the difference between stdin with fscanf and scanf?

The scanf function is equivalent to fscanf with the argument stdin interposed before the arguments to scanf . C11 §7.21.6.4 2

So aside from a different amount of typing the code, they are the same.

Answer 2

Unless you #defined fscanf , scanf or stdin , both calls will do the same thing. Note that such redefinitions would invoke undefined behavior.

Some standard input output functions have shorter versions for dealing with stdin or stdout :

• fscanf(stdin, ...) is equivalent to scanf(...
• getc(stdin) is the same as getchar()
• putc(c, stdout) can be written putchar(c)
• fprintf(stdout, "Hello world\\n"); is usually shortened to printf("Hello world\\n");