如何使用CreateProcess()和CreatePipe()从cmd.exe读取输出

#include <windows.h>
#include <iostream>

int main() {
    HANDLE hChildStdOutRead, hChildStdOutWrite;
    SECURITY_ATTRIBUTES saAttr;

    // 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(&hChildStdOutRead, &hChildStdOutWrite, &saAttr, 0)) {
        std::cerr << "CreatePipe Error: " << GetLastError() << std::endl;
        return 1;
    }

    // Ensure the read handle to the pipe for STDOUT is not inherited.
    if (!SetHandleInformation(hChildStdOutRead, HANDLE_FLAG_INHERIT, 0)) {
        std::cerr << "SetHandleInformation Error: " << GetLastError() << std::endl;
        return 1;
    }

    // Create the child process.
    PROCESS_INFORMATION piProcInfo;
    STARTUPINFO siStartInfo;
    BOOL bSuccess = FALSE;

    // Set up members of the PROCESS_INFORMATION structure.
    ZeroMemory(&piProcInfo, sizeof(PROCESS_INFORMATION));

    // Set up members of the STARTUPINFO structure.
    ZeroMemory(&siStartInfo, sizeof(STARTUPINFO));
    siStartInfo.cb = sizeof(STARTUPINFO);
    siStartInfo.hStdOutput = hChildStdOutWrite;
    siStartInfo.hStdError = hChildStdOutWrite;
    siStartInfo.dwFlags |= STARTF_USESTDHANDLES;

    // Create the child process.
    bSuccess = CreateProcess(NULL,
                             "cmd.exe /c dir",     // command line 
                             NULL,                   // process security attributes 
                             NULL,                   // primary thread security attributes 
                             TRUE,                   // handles are inherited 
                             0,                      // creation flags 
                             NULL,                   // use parent's environment 
                             NULL,                   // use parent's current directory 
                             &siStartInfo,           // STARTUPINFO pointer 
                             &piProcInfo);           // receives PROCESS_INFORMATION 

    // If an error occurs, exit the application. 
    if (!bSuccess) {
        std::cerr << "CreateProcess Error: " << GetLastError() << std::endl;
        return 1;
    }

    // Close the write end of the pipe before reading from the read end of the pipe.
    CloseHandle(hChildStdOutWrite);

    // Read output from the child process's pipe for STDOUT.
    CHAR chBuf[4096];
    DWORD dwRead;
    std::string strOutput;

    while (ReadFile(hChildStdOutRead, chBuf, sizeof(chBuf), &dwRead, NULL) && dwRead != 0) {
        strOutput.append(chBuf, dwRead);
    }

    // Close the read handle.
    CloseHandle(hChildStdOutRead);

    // Wait until child process exits.
    WaitForSingleObject(piProcInfo.hProcess, INFINITE);

    // Close process and thread handles.
    CloseHandle(piProcInfo.hProcess);
    CloseHandle(piProc::hThread);

    // Output the result.
    std::cout << "Output from cmd.exe:\n" << strOutput << std::endl;

    return 0;
}