sacnf_s () function Small note

I've been wondering why the scanf () function of the C program always gets an error on visual Stdio2013, but it is correct to copy the program to other compilers. So when using the VS programming program, always mechanically follow the scanf_s () to replace the scanf () function as it reminds me, although I don't know why, but there is no problem. Know today, when I want to read into a string, as follows:

#include <stdio.h><string.h>int main (void) {     char str [+];     scanf_s ("%s", str);     printf ("%d%s", strlen (str), str);      return 0 ;}

Result output: 0

My first reaction is that the scanf_s () function and scanf () do not seem to be exactly equal (this is not nonsense, at least before the problem, I have been directly using the scanf () grammar directly on the scanf_s (), so I searched for a bit, the result is as follows: this function is specific to Microsoft compilers.  It is the same as scanf, except it does not cause buffer overload. It takes the input in a, text based console program, and places it into a variable. –from here

Originally it is Microsoft's compiler dedicated, such as Vc++,vs (vs after 2013), because the scanf () function input does not check the subscript, if the input string length is greater than the length of the declaration, may be written to other memory, resulting in an unknown error, and scanf_s () The function is improved based on scanf (), and the input string is incremented with a length parameter, as the code above can be changed to:scanf_s ("%s", str, 100), This allows the program to read only the first 99 characters and then add a ' 0 ' if the input is overrun.

Say to yourself: out of the mix, always have to, avoid better take away

sacnf_s () function Small note