text: #include <stdio.h>
  
  #include <util/strlen-s.h>
  
  #define SOURCE "1234567890"
  
  int main () {
  
      int len;
  
      len = strlen_s(SOURCE, 100); 
  
      printf("%d\n", len); // prints: 10
  
      len = strlen_s(SOURCE, 5);
  
      printf("%d\n", len); // prints: 5
  
      len = strlen_s(SOURCE, -1);
  
      printf("%d\n", len); // prints: 10
  
      return 0;
  }