How to test input is sane

Question

Consider the following simple C program.

//C test

#include

int main()
{
   int a, b, c;

   printf(\"Enter two numbers to add\\n\");
   scan         


        

Answer 1

Also you can do this to prevent anything after second number

int a,b;
char c;
if( scanf("%d%d%c", &a, &b, &c) == 3) {
    if (c == '\n') {
        puts("good");
    }
} else {
    puts("bad");
}
    return 0;
}