What does the scanf function return?

Question

What is the value returned by scanf when:

int g; int p = scanf("%d", &g);      // Originally: int p = scanf("%d", g); 

I know that the signature of the scanf function is:

int scanf(const char *format, ...) 

What is the int value returned from this function?

Answer 1

From the man page:

NAME        scanf,  fscanf, sscanf, vscanf, vsscanf, vfscanf          ...  RETURN VALUE        These functions return the number of input items  successfully  matched        and assigned, which can be fewer than provided for, or even zero in the        event of an early matching failure.         The value EOF is returned if the end of input is reached before  either        the  first  successful conversion or a matching failure occurs.  EOF is        also returned if a read error occurs, in which case the error indicator        for  the  stream  (see ferror(3)) is set, and errno is set indicate the        error. 

In your case, scanf() can return 0, 1 or EOF.