CreatePipe 创建管道的问题，急，解决马上结贴

Question

功能很简单，创建管道执行dir c:,然后messagebox出来。 代码能编译了，但命令写入管道时不成功，不知为什么，高手指点一下啊！！
void CCmdpipeDlg::OnCmd()
{   
int ret;
SECURITY_ATTRIBUTES    sa1,sa2;
HANDLE hReadPipe2,hWritePipe2,hReadPipe1,hWritePipe1; CreatePipe( &hReadPipe1, &hWritePipe1, &sa1, 0 ); 
         CreatePipe( &hReadPipe2, &hWritePipe2, &sa2, 0 );  STARTUPINFO si;
::ZeroMemory(&si,sizeof(si));
si.dwFlags=STARTF_USESHOWWINDOW|STARTF_USESTDHANDLES;
si.hStdInput=hReadPipe2;
si.hStdOutput=si.hStdError=hWritePipe1;

PROCESS_INFORMATION    processInfo; 
         char    cmdLine[] = "cmd.exe"; 
         ZeroMemory( &processInfo , sizeof(PROCESS_INFORMATION) ); 
         ret=CreateProcess(NULL, cmdLine, NULL,NULL,1,0,NULL,NULL,&si,&processInfo); 
        if( !ret ) return;

unsigned long bytesRead=0;
char *buff="dir c:";
bytesRead=strlen(buff);
   

ret = WriteFile( hWritePipe2, buff, bytesRead, &bytesRead, 0 ); //把命令写入管道
         if( !ret ) return;         ret = ReadFile( hReadPipe1, buff, bytesRead, &bytesRead, 0 ); //把执行的结果读出来
         if( !ret ) return; AfxMessageBox(buff);
TerminateProcess( processInfo.hProcess, 0 ); 
    CloseHandle( hReadPipe1 ); 
    CloseHandle( hReadPipe2 ); 
    CloseHandle( hWritePipe1 ); 
    CloseHandle( hWritePipe2 ); }

Answer 1

int ret;
SECURITY_ATTRIBUTES    sa1,sa2;
sa1.nLength = sizeof(SECURITY_ATTRIBUTES);
sa1.lpSecurityDescriptor = NULL;
sa1.bInheritHandle = TRUE;
sa2.nLength = sizeof(SECURITY_ATTRIBUTES);
sa2.lpSecurityDescriptor = NULL;
sa2.bInheritHandle = TRUE;
HANDLE hReadPipe2,hWritePipe2,hReadPipe1,hWritePipe1; CreatePipe( &hReadPipe1, &hWritePipe1, &sa1, 0 ); 
        CreatePipe( &hReadPipe2, &hWritePipe2, &sa2, 0 );  STARTUPINFO si;
::ZeroMemory(&si,sizeof(si));
si.dwFlags=STARTF_USESHOWWINDOW|STARTF_USESTDHANDLES;
si.hStdInput=hReadPipe2;
si.hStdOutput=si.hStdError=hWritePipe1;
si.cb=sizeof(si); 
PROCESS_INFORMATION    processInfo; 
    char    cmdLine[] = "cmd.exe /k dir c:"; 
    ZeroMemory( &processInfo , sizeof(PROCESS_INFORMATION) ); 
    ret=CreateProcess(NULL, cmdLine, NULL,NULL,1,0,NULL,NULL,&si,&processInfo); 
    if( !ret ) return;
char buff[1024]={'\0'};
strcpy(buff,"dir c:");
DWORD  bytesRead=1024; Sleep(1000);
ret = WriteFile( hWritePipe2, buff, bytesRead, &bytesRead, 0 ); 
    if( !ret ) return; 
ret = ReadFile( hReadPipe1, buff, 1024, &bytesRead, 0 ); 
    if( !ret ) return; AfxMessageBox(buff);
   TerminateProcess( processInfo.hProcess, 0 ); 
    CloseHandle( hReadPipe1 ); 
    CloseHandle( hReadPipe2 ); 
    CloseHandle( hWritePipe1 ); 
    CloseHandle( hWritePipe2 );