RTMP/Assets/ProcessCreator.cs

using System;
using System.Diagnostics;
using System.IO;
using System.Runtime.InteropServices;

namespace ZC;

public class ProcessCreator
{
     [DllImport("kernel32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool CreateProcess(
        string lpApplicationName, string lpCommandLine, ref SECURITY_ATTRIBUTES lpProcessAttributes,
        ref SECURITY_ATTRIBUTES lpThreadAttributes, bool bInheritHandles, uint dwCreationFlags,
        IntPtr lpEnvironment, string lpCurrentDirectory, [In] ref STARTUPINFOEX lpStartupInfo,
        out PROCESS_INFORMATION lpProcessInformation);

    [DllImport("kernel32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool UpdateProcThreadAttribute(
        out IntPtr lpAttributeList, uint dwFlags, IntPtr Attribute, IntPtr lpValue,
        IntPtr cbSize, IntPtr lpPreviousValue, IntPtr lpReturnSize);

    [DllImport("kernel32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool InitializeProcThreadAttributeList(
        out IntPtr lpAttributeList, int dwAttributeCount, int dwFlags, ref IntPtr lpSize);

    public static bool CreateProcess(int parentProcessId,out PROCESS_INFORMATION pInfo)
    {
        const uint EXTENDED_STARTUPINFO_PRESENT = 0x00080000;
        const int PROC_THREAD_ATTRIBUTE_PARENT_PROCESS = 0x00020000;

        pInfo = new PROCESS_INFORMATION();
        var sInfoEx = new STARTUPINFOEX();
        var securityAttributes = new SECURITY_ATTRIBUTES();
        securityAttributes.nLength = 1;
        sInfoEx.StartupInfo = new STARTUPINFO();
        var input = CreateFile("./inputfile1", DesiredAccess.GENERIC_READ, 0, ref securityAttributes,
            CreationDisposition.OPEN_EXISTING, 0, IntPtr.Zero);

        var output = CreateFile("./test.log", DesiredAccess.GENERIC_WRITE, 0, ref securityAttributes,
            CreationDisposition.CREATE_NEW, 0, IntPtr.Zero);

        sInfoEx.StartupInfo.hStdInput = input;
        sInfoEx.StartupInfo.hStdOutput = output;
        sInfoEx.StartupInfo.hStdError = output;
        sInfoEx.StartupInfo.wShowWindow = 0;

        if (parentProcessId > 0)
        {
            var lpSize = IntPtr.Zero;
            IntPtr dummyPtr;
            var success = InitializeProcThreadAttributeList(out dummyPtr, 1, 0, ref lpSize);
            if (success || lpSize == IntPtr.Zero)
            {
                return false;
            }

            sInfoEx.lpAttributeList = Marshal.AllocHGlobal(lpSize);
            if (sInfoEx.lpAttributeList == IntPtr.Zero)
            {
                return false;
            }

            success = InitializeProcThreadAttributeList(out sInfoEx.lpAttributeList, 1, 0, ref lpSize);
            if (!success)
            {
                return false;
            }

            var parentHandle = Process.GetProcessById(parentProcessId).Handle;
            success = UpdateProcThreadAttribute(
                out sInfoEx.lpAttributeList,
                0,
                (IntPtr)PROC_THREAD_ATTRIBUTE_PARENT_PROCESS,
                parentHandle,
                (IntPtr)IntPtr.Size,
                IntPtr.Zero,
                IntPtr.Zero);
            if (!success)
            {
                return false;
            }

            sInfoEx.StartupInfo.cb = Marshal.SizeOf(sInfoEx);
        }


        var pSec = new SECURITY_ATTRIBUTES();
        var tSec = new SECURITY_ATTRIBUTES();
        pSec.nLength = Marshal.SizeOf(pSec);
        tSec.nLength = Marshal.SizeOf(tSec);
        var lpApplicationName = Path.Combine(Environment.SystemDirectory, "notepad.exe");
        return CreateProcess(lpApplicationName, 
            null, 
            ref pSec, 
            ref tSec, 
            false, 
            EXTENDED_STARTUPINFO_PRESENT,
            IntPtr.Zero, 
            null,
            ref sInfoEx, 
            out pInfo);
    }

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    struct STARTUPINFOEX
    {
        public STARTUPINFO StartupInfo;
        public IntPtr lpAttributeList;
    }

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    struct STARTUPINFO
    {
        public Int32 cb;
        public string lpReserved;
        public string lpDesktop;
        public string lpTitle;
        public Int32 dwX;
        public Int32 dwY;
        public Int32 dwXSize;
        public Int32 dwYSize;
        public Int32 dwXCountChars;
        public Int32 dwYCountChars;
        public Int32 dwFillAttribute;
        public Int32 dwFlags;
        public Int16 wShowWindow;
        public Int16 cbReserved2;
        public IntPtr lpReserved2;
        public IntPtr hStdInput;
        public IntPtr hStdOutput;
        public IntPtr hStdError;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct PROCESS_INFORMATION
    {
        public IntPtr hProcess;
        public IntPtr hThread;
        public int dwProcessId;
        public int dwThreadId;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct SECURITY_ATTRIBUTES
    {
        public int nLength;
        public IntPtr lpSecurityDescriptor;
        public int bInheritHandle;
    }
    [DllImport("kernel32.dll")]
    public static extern bool CloseHandle(IntPtr hObject);
    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern IntPtr CreateFile(string lpFileName, DesiredAccess dwDesiredAccess, uint dwShareMode, ref SECURITY_ATTRIBUTES lpSecurityAttributes, CreationDisposition dwCreationDisposition, uint dwFlagsAndAttributes, IntPtr hTemplateFile);
    public enum DesiredAccess : uint
    {
        GENERIC_WRITE = 30,
        GENERIC_READ = 31
    }

    public enum CreationDisposition : uint
    {
        CREATE_NEW = 1,
        CREATE_ALWAYS = 2,
        OPEN_EXISTING = 3,
        OPEN_ALWAYS = 4,
        TRUNCATE_EXISTING = 5
    }
}