What does scanf() returns in c language?

Question

Write your own rand function which returns random numbers in a given range(input) so that the numbers in the given range is equally likely to appear.

Answer 1

Number of successful read.
For example
int i;
char ch[100];
scanf("%d"%s", i, ch);

If scanf reads successfully both the variables then it returns 2.

Answer 2

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.