c++ - 如何从附加的控制台执行命令

Question

我正在编写一个 WinAPI GUI 程序，该程序需要调用ftp和可能的其他控制台程序，同时让它们的控制台输出相应地采取行动，即。在读取所有输出之前等待 ftp 完成执行是不行的。

我目前的方法是调用CreateProcess()创建一个可能隐藏丑陋控制台窗口的cmd.exeAttachConsole()进程，使其成为我自己的，GetStdHandle()获取输入和输出句柄，SetConsoleCursorPosition()到控制台缓冲区的末尾，并WriteConsole()使用诸如ftp\n或dir之类的命令\n。然而，这个命令被写入但没有被执行。但是，我可以手动使用相同的控制台（使用CreateProcess()with CREATE_NEW_CONSOLEflag）输入ftp press enter 并执行它。

以前的方法涉及：

1. 直接使用并重定向输入/输出 调用ftp 。CreateProcess()

   在进程结束之前无法获得ftp输出。CreateProcess()

2. 使用system().

   在获得任何输出之前被建议不要使用它。

我当前的精简代码：

// Next two structures might be a bit misleading, they were used for the 1. previous
// approach
PROCESS_INFORMATION piProcInfo;
ZeroMemory( &piProcInfo, sizeof(PROCESS_INFORMATION)); 
STARTUPINFO siStartInfo;
ZeroMemory( &siStartInfo, sizeof(STARTUPINFO) );
siStartInfo.cb = sizeof(STARTUPINFO); 
siStartInfo.hStdError = g_hChildStd_OUT_Wr;
siStartInfo.hStdOutput = g_hChildStd_OUT_Wr;
siStartInfo.hStdInput = g_hChildStd_IN_Rd;
siStartInfo.dwFlags |= STARTF_USESTDHANDLES;
SECURITY_ATTRIBUTES security;
security.nLength = sizeof(SECURITY_ATTRIBUTES); 
security.lpSecurityDescriptor = NULL;
security.bInheritHandle = FALSE;
CreateProcess( NULL, "cmd", &security, &security, FALSE, NORMAL_PRIORITY_CLASS |
 CREATE_NEW_CONSOLE, NULL, NULL, &siStartInfo, &piProcInfo); 
uint32_t pidConsole = piProcInfo.dwProcessId;
while ( ! AttachConsole(pidConsole) ){};
HANDLE myConsoleIn, myConsoleOut;
myConsoleIn = GetStdHandle(STD_INPUT_HANDLE);
myConsoleOut = GetStdHandle(STD_OUTPUT_HANDLE);
Sleep(100);
CONSOLE_SCREEN_BUFFER_INFO myConsoleCursorInformation = {};
GetConsoleScreenBufferInfo(myConsoleOut,&myConsoleCursorInformation);
SetConsoleCursorPosition(myConsoleOut,myConsoleCursorInformation.dwSize);
CHAR myConsoleBuffer[200]="dir\n";
DWORD myConsoleProcessed;
WriteConsole( myConsoleOut, myConsoleBuffer, 4, &myConsoleProcessed, NULL);

如何让写在控制台中的命令执行？\n 我尝试用尾随ie 结束命令是否有替代方法。与 dir\n 或 ftp\n 参数一起使用。WriteConsole()

我考虑在输入所需命令后向相关进程发送按键。然而，创建的控制台不仅需要手动按下回车键，还需要手动输入dir、ftp或任何命令。

请随时指出任何缺失的信息！

标签： c++winapic++17windows-console

Answer 1

如何让写在控制台中的命令执行？我尝试用尾随 \n 结束命令是否有替代方法，即。使用带有 dir\n 或 ftp\n 参数的 WriteConsole()。

试试下面的代码看看它是否有效：

STARTUPINFO si;
PROCESS_INFORMATION pi;

ZeroMemory(&si, sizeof(si));
si.cb = sizeof(si);
ZeroMemory(&pi, sizeof(pi));

const wchar_t *cmdPath = L"C:\\Windows\\System32\\cmd.exe";
wchar_t *cmdArgs = (wchar_t *)L"C:\\Windows\\System32\\cmd.exe /k dir";

BOOL result = CreateProcess(cmdPath, cmdArgs, NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi);
DWORD errCode = GetLastError();
if (!result)
{
    std::cout << "Create Process failed: " << GetLastError() << std::endl;
}

/K 运行命令，然后返回到 CMD 提示符。这对于测试很有用，可以检查变量

如果要“运行命令然后终止”，请使用 /C。

更新： 使用管道与子进程（cmd.exe）进行通信的完整代码。

HANDLE g_hChildStd_IN_Rd = NULL;
HANDLE g_hChildStd_IN_Wr = NULL;
HANDLE g_hChildStd_OUT_Rd = NULL;
HANDLE g_hChildStd_OUT_Wr = NULL;

#define BUFSIZE 1024

void ErrorExit(LPCTSTR lpszFunction)
{
    LPVOID lpMsgBuf;
    LPVOID lpDisplayBuf;
    DWORD dw = GetLastError();

    FormatMessage(
        FORMAT_MESSAGE_ALLOCATE_BUFFER |
        FORMAT_MESSAGE_FROM_SYSTEM |
        FORMAT_MESSAGE_IGNORE_INSERTS,
        NULL,
        dw,
        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
        (LPTSTR)&lpMsgBuf,
        0, NULL);

    lpDisplayBuf = (LPVOID)LocalAlloc(LMEM_ZEROINIT,
        (lstrlen((LPCTSTR)lpMsgBuf) + lstrlen((LPCTSTR)lpszFunction) + 40) * sizeof(TCHAR));
    StringCchPrintf((LPTSTR)lpDisplayBuf,
        LocalSize(lpDisplayBuf) / sizeof(TCHAR),
        TEXT("%s failed with error %d: %s"),
        lpszFunction, dw, lpMsgBuf);
    MessageBox(NULL, (LPCTSTR)lpDisplayBuf, TEXT("Error"), MB_OK);

    LocalFree(lpMsgBuf);
    LocalFree(lpDisplayBuf);
    ExitProcess(1);
}

void ReadFromPipe(void)
{
    DWORD dwRead, dwWritten;
    CHAR chBuf[BUFSIZE];
    BOOL bSuccess = FALSE;
    HANDLE hParentStdOut = GetStdHandle(STD_OUTPUT_HANDLE);

    for (;;)
    {
        DWORD bytesAvail = 0;
        if (!PeekNamedPipe(g_hChildStd_OUT_Rd, NULL, 0, NULL, &bytesAvail, NULL)) {
            std::cout << "Failed to call PeekNamedPipe" << std::endl;
        }
        if (bytesAvail) {
            DWORD n;
            BOOL success = ReadFile(g_hChildStd_OUT_Rd, chBuf, BUFSIZE, &n, NULL);
            if (!success || n == 0) {
            }
            bSuccess = WriteFile(hParentStdOut, chBuf,n, &dwWritten, NULL);
        }
        else
        {
            break;
        }
    }

}

void WriteToPipe(void)
{
    DWORD dwWritten;
    BOOL bSuccess = FALSE;
    CHAR buf[] = "dir\n";

    bSuccess = WriteFile(g_hChildStd_IN_Wr, buf, sizeof(buf)-1, &dwWritten, NULL);
}

int main()
{
    STARTUPINFO si;
    PROCESS_INFORMATION pi;

    SECURITY_ATTRIBUTES saAttr;

    printf("\n->Start of parent execution.\n");

    // Set the bInheritHandle flag so pipe handles are inherited. 

    saAttr.nLength = sizeof(SECURITY_ATTRIBUTES);
    saAttr.bInheritHandle = TRUE;
    saAttr.lpSecurityDescriptor = NULL;

    // Create a pipe for the child process's STDOUT. 

    if (!CreatePipe(&g_hChildStd_OUT_Rd, &g_hChildStd_OUT_Wr, &saAttr, 0))
        ErrorExit(TEXT("StdoutRd CreatePipe"));

    // Ensure the read handle to the pipe for STDOUT is not inherited.

    if (!SetHandleInformation(g_hChildStd_OUT_Rd, HANDLE_FLAG_INHERIT, 0))
        ErrorExit(TEXT("Stdout SetHandleInformation"));

    // Create a pipe for the child process's STDIN. 

    if (!CreatePipe(&g_hChildStd_IN_Rd, &g_hChildStd_IN_Wr, &saAttr, 0))
        ErrorExit(TEXT("Stdin CreatePipe"));

    // Ensure the write handle to the pipe for STDIN is not inherited. 

    if (!SetHandleInformation(g_hChildStd_IN_Wr, HANDLE_FLAG_INHERIT, 0))
        ErrorExit(TEXT("Stdin SetHandleInformation"));

    ZeroMemory(&si, sizeof(si));
    si.cb = sizeof(si);
    ZeroMemory(&pi, sizeof(pi));


    si.cb = sizeof(STARTUPINFO);
    si.hStdError = g_hChildStd_OUT_Wr;
    si.hStdOutput = g_hChildStd_OUT_Wr;
    si.hStdInput = g_hChildStd_IN_Rd;
    si.dwFlags |= STARTF_USESTDHANDLES;

    TCHAR cmdPath[] = TEXT("C:\\Windows\\System32\\cmd.exe");

    BOOL result = CreateProcess(cmdPath, NULL, NULL, NULL, TRUE, 0, NULL, NULL, &si, &pi);
    DWORD errCode = GetLastError();
    if (!result)
    {
        std::cout << "Create Process failed: " << GetLastError() << std::endl;
    }

    for (;;)
    {
        ReadFromPipe();

        WriteToPipe();
    }
}