#include <io.h>
#include <string.h>
#include <stdio.h>
#include <iostream>
#include <assert.h>

int 
_tmain(int argc, _TCHAR* argv[]) 
{

    for (size_t i = 0; i < 5000; ++ i) {
        std::cout << "i = " << i << std::endl;

    FILE *pFile  = fopen("C:/Test.txt", "w+");
        assert(NULL != pFile);

        int   iFile = fileno(pFile);      
        assert(- 1 != iFile);
        
        errno = 0;
        FILE *pFile2 = fdopen(iFile, "w+");
        if (NULL == pFile2) {
                std::cout << strerror(errno) << std::endl;
            std::cout << "NULL == pFile2 (" << strerror(errno) << ")" << std::endl;
                assert(false);
        }

        fclose(pFile);
    }

    return 0;
}

---------------------------
Microsoft Visual C++ Debug Library
---------------------------
Debug Error!

Program: C:\TempFile 2\Debug\TempFile.exe

R6010

- abort() has been called



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---------------------------
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---------------------------

i = 0
i = 1
...
i = 506
i = 507
i = 508
Too many open files
NULL == pFile2 (Too many open files)

        fclose(pFile2); //?
        fclose(pFile);

V>        fclose(pFile2); //?
V>        fclose(pFile);
V>

        fclose(pFile);
        fclose(pFile2);

---------------------------
Microsoft Visual C++ Debug Library
---------------------------
Debug Assertion Failed!

Program: C:\TempFile 2\Debug\TempFile.exe
File: f:\dd\vctools\crt_bld\self_x86\crt\src\close.c
Line: 47

Expression: (_osfile(fh) & FOPEN)

For information on how your program can cause an assertion
failure, see the Visual C++ documentation on asserts.

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---------------------------

fclose(pFile2)

#include <windows.h>
#include <io.h>
#include <string.h>
#include <stdio.h>
#include <iostream>
#include <assert.h>
#include <xiosbase>
#include <fcntl.h>

int main(int argc, char* argv[]) 
{
  HANDLE hStdHandle = GetStdHandle(STD_OUTPUT_HANDLE);
  HANDLE hStdHandleCopy = 0;
  if(!DuplicateHandle(GetCurrentProcess(), hStdHandle, GetCurrentProcess(), &hStdHandleCopy, 0, FALSE, DUPLICATE_SAME_ACCESS))
  {
    assert(false);
  }
  int hConHandle = _open_osfhandle((intptr_t)hStdHandleCopy, _O_TEXT);
  FILE* stdinCopy = _fdopen(hConHandle, "w");

  printf("111\n");

  errno = 0;
  FILE* pFile = _wfreopen(L"C:/Test.txt", L"w+", stdout);
  if (NULL == pFile) {
    std::cout << strerror(errno) << std::endl;
    std::cout << "NULL == pFile2 (" << strerror(errno) << ")" << std::endl;
    assert(false);
    return 1;
  }

  for (size_t i = 0; i < 5000; ++ i) {
    std::cout << "i = " << i << std::endl;
  }

  fclose(pFile);

  // redirect unbuffered STDOUT to the console

  *stdout = *stdinCopy;

  setvbuf( stdout, NULL, _IONBF, 0 ); // no buffering

  //std::ios::sync_with_stdio();

  printf("222\n");
  std::cout << "333" << std::endl;

  if(!CloseHandle(hStdHandleCopy))
  {
    assert(false);
  }

  return 0;
}

#include <windows.h>
#include <io.h>
#include <string.h>
#include <stdio.h>
#include <iostream>
#include <assert.h>
#include <xiosbase>
#include <fcntl.h>

int 
main(int argc, char* argv[]) 
{
    for (size_t i = 0; i < 5000; ++ i) {
        HANDLE hStdHandle = GetStdHandle(STD_OUTPUT_HANDLE);
        HANDLE hStdHandleCopy = 0;
        if (!DuplicateHandle(GetCurrentProcess(), hStdHandle, GetCurrentProcess(), &hStdHandleCopy, 0, FALSE, DUPLICATE_SAME_ACCESS)) {
            assert(false);
        }
        int hConHandle = _open_osfhandle((intptr_t)hStdHandleCopy, _O_TEXT);
        FILE* stdinCopy = _fdopen(hConHandle, "w");

        printf("111\n");

        errno = 0;
        FILE* pFile = _wfreopen(L"C:/Test.txt", L"w+", stdout);
        if (NULL == pFile) {
            std::cout << strerror(errno) << std::endl;
            std::cout << "NULL == pFile2 (" << strerror(errno) << ")" << std::endl;
            assert(false);

            return 1;
        }
      
        std::cout << "i = " << i << std::endl;

        fclose(pFile);

        // redirect unbuffered STDOUT to the console
        *stdout = *stdinCopy;

        setvbuf( stdout, NULL, _IONBF, 0 ); // no buffering

        //std::ios::sync_with_stdio();

        printf("222\n");
        std::cout << "333" << std::endl;

        if (!CloseHandle(hStdHandleCopy)) {
            assert(false);
        }
    }

    return 0;
}

111                                                                                                                                                                                                     
222                                                                                                                                                                                                     
333                                                                                                                                                                                                     
Assertion failed: false, file c:\tempfile 3\tempfile.cpp, line 17

---------------------------
Microsoft Visual C++ Debug Library
---------------------------
Debug Error!

Program: C:\TempFile 3\Debug\TempFile.exe

R6010

- abort() has been called



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---------------------------
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---------------------------