尝试创建命名管道失败并显示ERROR_IS_SUBSTED



我从msdn博客中获得了以下代码:

#include <windows.h> 
#include <stdio.h>
#include <conio.h>
#include <tchar.h>
#define BUFSIZE 512
int _tmain(int argc, TCHAR *argv[]) 
{ 
   HANDLE hPipe; 
   LPTSTR lpvMessage=TEXT("Default message from client."); 
   TCHAR  chBuf[BUFSIZE]; 
   BOOL   fSuccess = FALSE; 
   DWORD  cbRead, cbToWrite, cbWritten, dwMode; 
   LPTSTR lpszPipename = TEXT("H:\Users\uname\Documents\fff.txt"); 
   if( argc > 1 )
      lpvMessage = argv[1];
// Try to open a named pipe; wait for it, if necessary. 
   while (1) 
   { 
      hPipe = CreateFile( 
         lpszPipename,   // pipe name 
         GENERIC_READ |  // read and write access 
         GENERIC_WRITE, 
         0,              // no sharing 
         NULL,           // default security attributes
         OPEN_ALWAYS,  // opens existing pipe 
         0,              // default attributes 
         NULL);          // no template file 
   // Break if the pipe handle is valid. 
      if (hPipe != INVALID_HANDLE_VALUE) 
         break; 
      // Exit if an error other than ERROR_PIPE_BUSY occurs. 
      if (GetLastError() != ERROR_PIPE_BUSY) 
      {
         _tprintf( TEXT("Could not open pipe. GLE=%dn"), GetLastError() ); 
         return -1;
      }
      // All pipe instances are busy, so wait for 20 seconds. 
      if ( ! WaitNamedPipe(lpszPipename, 20000)) 
      { 
         printf("Could not open pipe: 20 second wait timed out."); 
         return -1;
      } 
   } 
// The pipe connected; change to message-read mode. 
   dwMode = PIPE_READMODE_MESSAGE; 
   fSuccess = SetNamedPipeHandleState( 
      hPipe,    // pipe handle 
      &dwMode,  // new pipe mode 
      NULL,     // don't set maximum bytes 
      NULL);    // don't set maximum time 
   if ( ! fSuccess) 
   {
      _tprintf( TEXT("SetNamedPipeHandleState failed. GLE=%dn"), GetLastError() ); 
      return -1;
   }
// Send a message to the pipe server. 
   cbToWrite = (lstrlen(lpvMessage)+1)*sizeof(TCHAR);
   _tprintf( TEXT("Sending %d byte message: "%s"n"), cbToWrite, lpvMessage); 
   fSuccess = WriteFile( 
      hPipe,                  // pipe handle 
      lpvMessage,             // message 
      cbToWrite,              // message length 
      &cbWritten,             // bytes written 
      NULL);                  // not overlapped 
   if ( ! fSuccess) 
   {
      _tprintf( TEXT("WriteFile to pipe failed. GLE=%dn"), GetLastError() ); 
      return -1;
   }
   printf("nMessage sent to server, receiving reply as follows:n");
   do 
   { 
   // Read from the pipe. 
      fSuccess = ReadFile( 
         hPipe,    // pipe handle 
         chBuf,    // buffer to receive reply 
         BUFSIZE*sizeof(TCHAR),  // size of buffer 
         &cbRead,  // number of bytes read 
         NULL);    // not overlapped 
      if ( ! fSuccess && GetLastError() != ERROR_MORE_DATA )
         break; 
      _tprintf( TEXT(""%s"n"), chBuf ); 
   } while ( ! fSuccess);  // repeat loop if ERROR_MORE_DATA 
   if ( ! fSuccess)
   {
      _tprintf( TEXT("ReadFile from pipe failed. GLE=%dn"), GetLastError() );
      return -1;
   }
   printf("n<End of message, press ENTER to terminate connection and exit>");
   _getch();
   CloseHandle(hPipe); 
   return 0; 
}

我浏览了代码中使用的大多数函数的文档。我没有发现任何可能引起麻烦的操作。显然,在循环中打开文件是不应该存在的东西。但是我在编译代码(VS 2010 Ultimate)并运行它时,它失败了,并显示
ERROR_IS_SUBSTED错误。GetLastError 返回此错误的点在这里:

while (1) 
       { 
          hPipe = CreateFile( 
             lpszPipename,   // pipe name 
             GENERIC_READ |  // read and write access 
             GENERIC_WRITE, 
             0,              // no sharing 
             NULL,           // default security attributes
             OPEN_ALWAYS,  // opens existing pipe 
             0,              // default attributes 
             NULL);          // no template file 

我仍然是Windows编程的新手,这些错误代码让我感到困惑。此错误的 msdn 文档指出An attempt was made to use a JOIN or SUBST command on a drive that has already been substituted.所以社区的人可以请

1.明确什么是ERROR_IS_SUBSTD?msdn给出的描述对我来说太神秘了。:(

2.为什么我会收到此错误?

3.(有点跑题了)我错过了strace实用程序,它在我的编程生涯中一直是我的救星,可以跟踪/纠正此类错误。我们在窗口中有类似的东西吗?

错误消息看起来像是随机废话,除非您的 H 驱动器是网络共享。 但是,即使错误消息看起来像随机废话,您的管道名称也是如此。

若要创建命名管道,请参阅此处的 MSDN:创建命名管道

管道名称必须类似于

"\\.\pipe\pipename"

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