问题描述

关于Windows下管道通信的问题

我想要通过管道通信控制CMD，能从父进程读数据就是写不了，WriteFile后没反应，szCOMMAND改成随便一个DOS命令，就是没反应，没辙了，请问代码什么地方出了问题呢？
SECURITY_ATTRIBUTES sa;
SECURITY_ATTRIBUTES sa1;
HANDLE hRead_A, hWrite_A;
HANDLE hRead_B, hWrite_B;
sa.nLength = sizeof(SECURITY_ATTRIBUTES);
sa.lpSecurityDescriptor = NULL;
sa.bInheritHandle = TRUE;
sa1.bInheritHandle = TRUE;
sa1.lpSecurityDescriptor = NULL;
sa1.nLength = sizeof(sa1);
if (!CreatePipe(&hRead_A, &hWrite_A, &sa, 0)) {
printf("ERROR,createpipe_1");
}
if (!CreatePipe(&hRead_B, &hWrite_B, &sa1, 0)){
printf("ERROR,createpipe_2");

}
STARTUPINFO si;
PROCESS_INFORMATION pi;
si.cb = sizeof(STARTUPINFO);
GetStartupInfo(&si);
si.hStdInput = hRead_A;
si.hStdError = hWrite_B;
si.hStdOutput = hWrite_B;
si.wShowWindow = SW_HIDE;
si.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
if (!CreateProcess(NULL, TEXT("cmd")
    , NULL, NULL, TRUE, NULL, NULL, NULL, &si, &pi)) {
    printf("createprocess %d",GetLastError());
}

char buffer[4096] = { 0 };
DWORD bytesRead;
while (true) {
    DWORD dwdw;
    WriteFile(hWrite_A,szCOMMAND , sizeof(szCOMMAND), &dwdw, NULL);
    if (ReadFile(hRead_B, buffer, 4095, &bytesRead, NULL) == NULL)
        break;
    printf(buffer);
}
![图片说明](http://img.ask.csdn.net/upload/201503/18/1426675258_757052.jpg)
这个是把szCOMMAND改成ping命令的，运行后没反应
![图片说明](http://img.ask.csdn.net/upload/201503/18/1426675388_229721.jpg)