Error Handling in C? How to deal with scanf and illegal characters? [closed]

Answer 1

scanf() returns the number of successful arguments. If you do:

int ivar, return_val;
return_val = scanf("%i", &ivar);

return_val should be 1, cause of 1 parameter (ivar). Check the user input:

if (return_val == 1) {
    // right input
} else {
    // wrong input
}