How to handle exception when scanf of integer gets a character

Question

The following simple program would give an endless loop when the input is a character, though it meant to tell a character from a digit. How to test if scanf gets a

Answer 1

You should really use TheDubleM's suggestion and check if buffer is numeric and if so use atoi on it. In what I put below you will not detect 8f8 as bad input but just read the 8.

#include 

int main() {
  int n;
  int return_value = 0;
  char buffer[1024];

  while (!return_value) {
    printf("Input a digit:");
    scanf("%1024s", buffer);
    return_value = sscanf(buffer, "%d", &n);
  }

  printf("Your input is %d\n", n);

  return 0;
}