c语言安全输入字符数组

#include <stdio.h>

int main()
{
    const int max_name = 20;  //  字符数组最大长度
    char name[max_name];

    char fmt[10];
    sprintf(fmt,"%%%ds",max_name - 1 );
    scanf(fmt,name);
    printf("%s\n",name);
    return 0;
}