我从一个 msdn 博客中获取了这段代码：
#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=%d\n"), 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=%d\n"), 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=%d\n"), 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=%d\n"), 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部分函数的文档。我没有发现任何可能导致麻烦的操作。显然，在循环中打开文件是不应该存在的。但是当我编译代码（VS 2010 Ultimate）并运行它时，它失败并出现
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
我还是 Windows 编程新手，这些错误代码让我感到困惑。此错误的 msdn文档说，An attempt was made to use a JOIN or SUBST command on a drive that has already been substituted.
请来自社区的人
1.明确什么是ERROR_IS_SUBSTD？msdn给出的描述对我来说太神秘了。:(
2.为什么我会收到这个错误？
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跟踪/纠正此类错误的救星。我们在Windows中有类似的东西吗？