Родительский и дочерний процесс: почему запуск начинается сразу с дочернего процесса?

#include <windows.h> 
#include <tchar.h>
#include <stdio.h> 
#include <strsafe.h>
 
#define BUFSIZE 4096 
 
HANDLE g_hChildStd_IN_Rd = NULL;
HANDLE g_hChildStd_IN_Wr = NULL;
HANDLE g_hChildStd_OUT_Rd = NULL;
HANDLE g_hChildStd_OUT_Wr = NULL;
 
HANDLE g_hInputFile = NULL;
 
void CreateChildProcess(void);
void WriteToPipe(void);
void ReadFromPipe(void);
void ErrorExit(PTSTR);
 
int _tmain(int argc, TCHAR *argv[])
{
    SECURITY_ATTRIBUTES saAttr;
 
    printf("\n->Start of parent execution.\n");
 
    // Установить флаг bInheritHandle, чтобы pipe наследовался. 
 
    saAttr.nLength = sizeof(SECURITY_ATTRIBUTES);
    saAttr.bInheritHandle = TRUE;
    saAttr.lpSecurityDescriptor = NULL;
 
    // Создать pipe для дочернего процесса в stdout. 
 
    if (!CreatePipe(&g_hChildStd_OUT_Rd, &g_hChildStd_OUT_Wr, &saAttr, 0))
        ErrorExit(TEXT("StdoutRd CreatePipe"));
 
    // Убедитесь, что для чтение к pipe для STDOUT не передается по наследству.
 
    if (!SetHandleInformation(g_hChildStd_OUT_Rd, HANDLE_FLAG_INHERIT, 0))
        ErrorExit(TEXT("Stdout SetHandleInformation"));
 
    // Создать pipe для дочернего процесса STDIN. 
 
    if (!CreatePipe(&g_hChildStd_IN_Rd, &g_hChildStd_IN_Wr, &saAttr, 0))
        ErrorExit(TEXT("Stdin CreatePipe"));
 
    // Убедитесь, что для чтение к pipe для STDIN не передается по наследству. 
 
    if (!SetHandleInformation(g_hChildStd_IN_Wr, HANDLE_FLAG_INHERIT, 0))
        ErrorExit(TEXT("Stdin SetHandleInformation"));
 
    // Создаём дочерний. 
 
    CreateChildProcess();
 
    //Получаем дескриптор входного файла для родителей.
    // Этот пример предполагает, что обычный текстовый файлиспользует выходную строку для проверки потока данных. 
 
    if (argc == 1)
        ErrorExit(TEXT("Please specify an input file.\n"));
 
    g_hInputFile = CreateFile(
        argv[1],
        GENERIC_READ,
        0,
        NULL,
        OPEN_EXISTING,
        FILE_ATTRIBUTE_READONLY,
        NULL);
 
    if (g_hInputFile == INVALID_HANDLE_VALUE)
        ErrorExit(TEXT("CreateFile"));
 
    // Write to the pipe that is the standard input for a child process. 
    // Data is written to the pipe's buffers, so it is not necessary to wait
    // until the child process is running before writing data.
 
    WriteToPipe();
    printf("\n->Contents of %s written to child STDIN pipe.\n", argv[1]);
 
    // Read from pipe that is the standard output for child process. 
 
    printf("\n->Contents of child process STDOUT:\n\n", argv[1]);
    ReadFromPipe();
 
    printf("\n->End of parent execution.\n");
 
    // The remaining open handles are cleaned up when this process terminates. 
    // To avoid resource leaks in a larger application, close handles explicitly. 
 
    return 0;
}
 
void CreateChildProcess()
// Create a child process that uses the previously created pipes for STDIN and STDOUT.
{
    TCHAR szCmdline[] = TEXT("child");
    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. 
    // This structure specifies the STDIN and STDOUT handles for redirection.
 
    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;
 
    // Create the child process. 
 
    bSuccess = CreateProcess(NULL,
        szCmdline,     // 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)
        ErrorExit(TEXT("CreateProcess"));
    else
    {
        // Close handles to the child process and its primary thread.
        // Some applications might keep these handles to monitor the status
        // of the child process, for example. 
 
        CloseHandle(piProcInfo.hProcess);
        CloseHandle(piProcInfo.hThread);
    }
}
 
void WriteToPipe(void)
 
// Read from a file and write its contents to the pipe for the child's STDIN.
// Stop when there is no more data. 
{
    DWORD dwRead, dwWritten;
    CHAR chBuf[BUFSIZE];
    BOOL bSuccess = FALSE;
 
    for (;;)
    {
        bSuccess = ReadFile(g_hInputFile, chBuf, BUFSIZE, &dwRead, NULL);
        if (!bSuccess || dwRead == 0) break;
 
        bSuccess = WriteFile(g_hChildStd_IN_Wr, chBuf, dwRead, &dwWritten, NULL);
        if (!bSuccess) break;
    }
 
    // Close the pipe handle so the child process stops reading. 
 
    if (!CloseHandle(g_hChildStd_IN_Wr))
        ErrorExit(TEXT("StdInWr CloseHandle"));
}
 
void ReadFromPipe(void)
 
// Read output from the child process's pipe for STDOUT
// and write to the parent process's pipe for STDOUT. 
// Stop when there is no more data. 
{
    DWORD dwRead, dwWritten;
    CHAR chBuf[BUFSIZE];
    BOOL bSuccess = FALSE;
    HANDLE hParentStdOut = GetStdHandle(STD_OUTPUT_HANDLE);
 
    for (;;)
    {
        bSuccess = ReadFile(g_hChildStd_OUT_Rd, chBuf, BUFSIZE, &dwRead, NULL);
        if (!bSuccess || dwRead == 0) break;
 
        bSuccess = WriteFile(hParentStdOut, chBuf,
            dwRead, &dwWritten, NULL);
        if (!bSuccess) break;
    }
}
 
void ErrorExit(PTSTR lpszFunction)
 
// Format a readable error message, display a message box, 
// and exit from the application.
{
    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);
}

#include <windows.h>
#include <stdio.h>
 
#define BUFSIZE 4096 
 
int main(void)
{
    CHAR chBuf[BUFSIZE];
    DWORD dwRead, dwWritten;
    HANDLE hStdin, hStdout;
    BOOL bSuccess;
 
    hStdout = GetStdHandle(STD_OUTPUT_HANDLE);
    hStdin = GetStdHandle(STD_INPUT_HANDLE);
    if (
        (hStdout == INVALID_HANDLE_VALUE) ||
        (hStdin == INVALID_HANDLE_VALUE)
        )
        ExitProcess(1);
 
    // Send something to this process's stdout using printf.
    printf("\n ** This is a message from the child process. ** \n");
    
    // This simple algorithm uses the existence of the pipes to control execution.
    // It relies on the pipe buffers to ensure that no data is lost.
    // Larger applications would use more advanced process control.
 
    for (int i = 0; i < 2; ++i)
    {
        // Read from standard input and stop on error or no data.
        bSuccess = ReadFile(hStdin, chBuf, BUFSIZE, &dwRead, NULL);
 
        if (!bSuccess || dwRead == 0)
            break;
 
        // Write to standard output and stop on error.
        bSuccess = WriteFile(hStdout, chBuf, dwRead, &dwWritten, NULL);
 
        if (!bSuccess)
            break;
    }
    return 0;
}