#include <stdio.h>  // Needed for FILE, fopen, etc.
#include <stdlib.h> // Needed for calloc, free, etc.

// A simple 3-byte structure. Only for testing
typedef struct {
    char NumA;
    char NumB;
    char NumC;
} TestStruct;

void main() {
    // Remember that MSVC++ likes C variables declared at top
    char *Buffer;             // In-memory buffer pointer
    TestStruct *TestArray;    // In-buffer array pointer
    FILE *FilePtr;            // File I/O stream pointer

    // Essentially the same as:
    //    Dim Buffer(0 to 63) As Byte
    Buffer = calloc(64, 1);
    // calloc() sets memory to 0. malloc() only allocates
    // ReDim: void *realloc(void *ptr, size_t size);

    // Uses a pointer as an array at location Buffer + 1
    // Buffer + 1 starts at the second byte, not the first
    TestArray = (TestStruct*) (Buffer + 1);

    // Sets a couple of elements
    TestArray[0].NumA = 16;
    TestArray[0].NumB = 32;
    TestArray[0].NumC = 48;

    TestArray[1].NumA = 1;
    TestArray[1].NumB = 5;
    TestArray[1].NumC = 10;

    // Essentially the same as:
    //    Open "C:\Test.dat" For Binary Access Write As FilePtr
    //    Put FilePtr, 1, Buffer
    //    Close FilePtr
    FilePtr = fopen("C:\\Test.dat", "wb");
    fwrite(Buffer, 64, 1, FilePtr); // The 1 here is element size
    // fread() works with the same arguments
    fclose(FilePtr);

    // IMPORTANT: Deallocate the buffer. Not required in BASIC
    free(Buffer);

    // Not required, but good habit
    return;
}