// Code 1: dùng C RTL File IO functions
#include <stdio.h>
#include <errno.h>

#define BUF_SIZE 256

int main (int argc, char *argv [])
{
   FILE *in_file, *out_file;
   char rec [BUF_SIZE];
   size_t bytes_in, bytes_out;

   if (argc != 3) {
      printf ("Usage: cpC file1 file2\n");
      return 1;
   }

   in_file = fopen (argv [1], "rb");
   if (in_file == NULL) {
      perror (argv [1]);
      return 2;
   }

   out_file = fopen (argv [2], "wb");
   if (out_file == NULL) {
      perror (argv [2]);
      return 3;
   }

   /*   Process the input file a record at a time. */
   while ((bytes_in = fread (rec, 1, BUF_SIZE, in_file)) > 0) {
      bytes_out = fwrite (rec, 1, bytes_in, out_file);
      if (bytes_out != bytes_in) {
         perror ("Fatal write error.");
         return 4;
      }
   }

   fclose (in_file);
   fclose (out_file);

   return 0;
}

// Code 2: dùng Windows File IO API functions
#include <windows.h>
#include <stdio.h>

#define BUF_SIZE 256

int main (int argc, LPTSTR argv [])
{
   HANDLE hIn, hOut;
   DWORD nIn, nOut;
   CHAR Buffer [BUF_SIZE];

   if (argc != 3) {
      printf ("Usage: cpW file1 file2\n");
      return 1;
   }

   hIn = CreateFile (argv [1], GENERIC_READ, 0, NULL,
         OPEN_EXISTING, 0, NULL);
   if (hIn == INVALID_HANDLE_VALUE) {
      printf ("Cannot open input file. Error: %x\n",
             GetLastError ());
      return 2;
   }

   hOut = CreateFile (argv [2], GENERIC_WRITE, 0, NULL,
          CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
   if (hOut == INVALID_HANDLE_VALUE) {
      printf ("Cannot open output file. Error: %x\n",
             GetLastError ());
      return 3;
   }

   while (ReadFile (hIn, Buffer, BUF_SIZE, &nIn, NULL) && nIn > 0) {
      WriteFile (hOut, Buffer, nIn, &nOut, NULL);
      if (nIn != nOut) {
         printf ("Fatal write error: %x\n", GetLastError ());
         return 4;
      }
   }

   CloseHandle (hIn);
   CloseHandle (hOut);

   return 0;
}

// Code 3: Dùng Windows CopyFile API function
#include <windows.h>
#include <stdio.h>

int main (int argc, LPTSTR argv [])
{
   if (argc != 3) {
      printf ("Usage: cpCF file1 file2\n");
      return 1;
   }

   if (!CopyFile (argv [1], argv [2], FALSE)) {
      printf ("CopyFile Error: %x\n", GetLastError ());
      return 2;
   }

   return 0;
}