[SOLVED] *** stack smashing detected ***: terminated even when i enter much less chars

Issue

#include<stdio.h>

int main()

{

    char x[6];
    scanf("%S",x);
    printf("%S",x);
return 0;

}

The code is so simple and the output:

*** stack smashing detected ***: terminated

Even when I enter just one character, I know about the canary protection variable.

But does the compiler add that variable to my array or there is something else?

Solution

Use %s format specifier, not %S. And notice that a correct prototype for main is int main(void). Your code should be:

#include <stdio.h>

int main(void)
{
  char x[6];
  scanf("%s",x);
  printf("%s\n",x);
  return 0;
}

Use:

$ ./main
abc
abc

Answered By - Arkadiusz Drabczyk