我有应用服务器（server.py）和C ++作为客户端（client.exe）。 Client.exe通过“命名管道”将变量发送到server.py。
问题是当我从server.py中的client.exe发送例如“来自客户端的默认消息”时，只生成“D”（仅发送第一个字符）。
任何人都可以帮助我吗？
C ++
server.py
from ctypes import *
PIPE_ACCESS_DUPLEX = 0x3
PIPE_TYPE_MESSAGE = 0x4
PIPE_READMODE_MESSAGE = 0x2
PIPE_WAIT = 0
PIPE_UNLIMITED_INSTANCES = 255
BUFSIZE = 4096
NMPWAIT_USE_DEFAULT_WAIT = 0
INVALID_HANDLE_VALUE = -1
ERROR_PIPE_CONNECTED = 535
MESSAGE = "Default answer from server\0"
szPipename = "\\\\.\\pipe\\mynamedpipe"
def ReadWrite_ClientPipe_Thread(hPipe):
chBuf = create_string_buffer(BUFSIZE)
cbRead = c_ulong(0)
while 1:
fSuccess = windll.kernel32.ReadFile(hPipe, chBuf, BUFSIZE,
byref(cbRead), None)
if ((fSuccess ==1) or (cbRead.value != 0)):
print chBuf.value
cbWritten = c_ulong(0)
fSuccess = windll.kernel32.WriteFile(hPipe,c_char_pc_char_p(MESSAGE),len(MESSAGE),byref(cbWritten),None)
else:
break
if ( (not fSuccess) or (len(MESSAGE) != cbWritten.value)):
print "Could not reply to the client's request from the pipe"
break
else:
print "Number of bytes written:", cbWritten.value
windll.kernel32.FlushFileBuffers(hPipe)
windll.kernel32.DisconnectNamedPipe(hPipe)
windll.kernel32.CloseHandle(hPipe)
return 0
def main():
THREADFUNC = CFUNCTYPE(c_int, c_int)
thread_func = THREADFUNC(ReadWrite_ClientPipe_Thread)
while 1:
hPipe = windll.kernel32.CreateNamedPipeA(szPipename,PIPE_ACCESS_DUPLEX,PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT, PIPE_UNLIMITED_INSTANCES, BUFSIZE, BUFSIZE, NMPWAIT_USE_DEFAULT_WAIT,None)
if (hPipe == INVALID_HANDLE_VALUE):
print "Error in creating Named Pipe"
return 0
fConnected = windll.kernel32.ConnectNamedPipe(hPipe, None)
if ((fConnected == 0) and (windll.kernel32.GetLastError() == ERROR_PIPE_CONNECTED)):
fConnected = 1
if (fConnected == 1):
dwThreadId = c_ulong(0)
hThread = windll.kernel32.CreateThread(None, 0, thread_func, hPipe, 0, byref(dwThreadId))
if (hThread == -1):
print "Create Thread failed"
return 0
else:
windll.kernel32.CloseHandle(hThread)
else:
print "Could not connect to the Named Pipe"
windll.kernel32.CloseHandle(hPipe)
return 0
if __name__ == "__main__":
main()
Client.cpp
#include "stdafx.h"
#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("\\\\.\\pipe\\mynamedpipe");
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_EXISTING, // 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;
}
CloseHandle(hPipe);
return 0;
}
答案 0 :(得分：3)
如果您打印出服务器收到的缓冲区的.raw，您可以看到它实际上收到了整条消息：
> print repr(chBuf.raw)
'D\x00e\x00f\x00a\x00u\x00l\x00t\x00 \x00m\x00e\x00s\x00s\x00a\x00g\x00e\x00 \x00f\x00r\x00o\x00m\x00\x00c\x00l\x00i\x00e\x00n\x00t\x00.\x00\x00\x00\x00\x00 ... \x00\x00'
问题是在合法字符之间散布着空值（\ x00），当您尝试打印chBuf.value时，这些值看起来像空终止符。那么为什么所有的零呢？这是因为您的C ++客户端正在发送wchar_t *消息（使用LPTSTR），但Python服务器需要char *字符串。
更改此行：
chBuf = create_string_buffer(BUFSIZE)
到此：
chBuf = create_unicode_buffer(BUFSIZE)
这应解决问题。
哦，看起来你在这里有一个复制粘贴错误：
fSuccess = windll.kernel32.WriteFile(hPipe,c_char_pc_char_p(MESSAGE),len(MESSAGE),byref(cbWritten),None)
它应该是：
fSuccess = windll.kernel32.WriteFile(hPipe, c_char_p(MESSAGE),len(MESSAGE),byref(cbWritten),None)
我在Python代码中出现了名称错误，直到我改变了它。
答案 1 :(得分：-1)
也许服务器应该尝试从循环中读取管道，直到达到预期到达的所有数据（根据您与客户端的协议，例如，直到读取空终结符）。