How to know how much RAM/Flash i am using

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I’ve been wanting to do this, so thanks for the push! Read the comments near the bottom… seem legit?

Adapted from:
http://playground.arduino.cc/Code/AvailableMemory

    unsigned int __heap_start;
    void *__brkval;
    
    /*
     * The free list structure as maintained by the 
     * avr-libc memory allocation routines.
     */
    struct __freelist {
      size_t sz;
      struct __freelist *nx;
    };
    
    /* The head of the free list structure */
    struct __freelist *__flp;
    
    // MemoryFree library based on code posted here:
    // http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1213583720/15
    // 
    // Extended by Matthew Murdoch to include walking of the free list.
    
    //#ifdef __cplusplus
        //extern "C" {
    //#endif
    
    int freeMemory();
    
    //#ifdef __cplusplus
        //}
    //#endif
    
    /* Calculates the size of the free list */
    int freeListSize() {
      struct __freelist* current;
      int total = 0;
    
      for (current = __flp; current; current = current->nx) {
        total += 2; /* Add two bytes for the memory block's header  */
        total += (int) current->sz;
      }
    
      return total;
    }
    
    int freeMemory() {
      int free_memory;
    
      if ((int)__brkval == 0) {
        free_memory = ((int)&free_memory) - ((int)&__heap_start);
      } else {
        free_memory = ((int)&free_memory) - ((int)__brkval);
        free_memory += freeListSize();
      }
      return free_memory;
    }
    
    // On Spark Core
    //
    // Reported free memory with str commented out:
    // 17584 bytes RAM
    //
    // Reported free memory with str and Serial.println(str) uncommented:
    // 17552 bytes RAM
    //
    // Difference: 32 bytes (31 ascii chars + null terminator)
    
    // 14-bytes string
    //char str[] = "Hello, Spark!!! Hello, Spark!!!";
    
    void setup() {
        Serial1.begin(115200);
    }
    
    
    void loop() {
        //Serial1.println(str);
    
        Serial1.print("freeMemory()=");
        Serial1.println(freeMemory());
    
        delay(1000);
    }
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