从运行进程重定向输出(Visual C#)

Question

我有一个正在运行的控制台,我需要获得输出.我不能用它startprocess来启动控制台,因为它是单独生成的.我无法访问源代码,我只是尝试在控制台运行时重定向控制台.

Answer 1

事实证明,使用托管框架附加到已经运行的单独进程是不可能的.

但是,使用Console Api Functionsunder 可以实现这一点kernel32.dll.

编辑:代码已改进,以提高可用性

为了实现这一点,我们需要使用FreeConsole,AttachConsole,ReadConsoleOutputCharacter,GetConsoleScreenBufferInfo和AttachConsole从WinApi

静态外部库的声明:

[DllImport("kernel32.dll")]
private extern static IntPtr GetStdHandle(int nStdHandle);

[DllImport("kernel32.dll")]
static extern bool ReadConsoleOutputCharacter(IntPtr hConsoleOutput,
  [Out] StringBuilder lpCharacter, uint nLength, COORD dwReadCoord,
  out uint lpNumberOfCharsRead);

[DllImport("kernel32.dll")]
static extern bool FreeConsole();
[DllImport("kernel32.dll")]
static extern bool AttachConsole(int dwProcessId);

[DllImport("kernel32.dll")]
static extern bool GetConsoleScreenBufferInfo(
    IntPtr hConsoleOutput,
    out CONSOLE_SCREEN_BUFFER_INFO lpConsoleScreenBufferInfo
);

[StructLayout(LayoutKind.Sequential)]
struct COORD
{
    public short X;
    public short Y;
}

[StructLayout(LayoutKind.Sequential)]
struct CONSOLE_SCREEN_BUFFER_INFO
{

    public COORD dwSize;
    public COORD dwCursorPosition;
    public short wAttributes;
    public SMALL_RECT srWindow;
    public COORD dwMaximumWindowSize;

}

[StructLayout(LayoutKind.Sequential)]
struct SMALL_RECT
{

    public short Left;
    public short Top;
    public short Right;
    public short Bottom;

}

const int STD_OUTPUT_HANDLE = -11;
const Int64 INVALID_HANDLE_VALUE = -1;

我们首先需要释放当前的控制台句柄,因为我们只能连接到一个控制台

private static string ReadALineOfConsoleOutput(IntPtr stdout, ref short currentPosition)
{

    if (stdout.ToInt32() == INVALID_HANDLE_VALUE)
        throw new Win32Exception();

    //Get Console Info
    if (!GetConsoleScreenBufferInfo(stdout, out CONSOLE_SCREEN_BUFFER_INFO outInfo))
        throw new Win32Exception();

    //Gets Console Output Line Size
    short lineSize = outInfo.dwSize.X;

    //Calculates Number of Lines to be read
    uint numberofLinesToRead = (uint)(outInfo.dwCursorPosition.Y - currentPosition);

    if (numberofLinesToRead < 1) return null;

    // read from the first character of the first line (0, 0).
    COORD dwReadCoord;
    dwReadCoord.X = 0;
    dwReadCoord.Y = currentPosition;

    //total characters to be read
    uint nLength = (uint)lineSize * numberofLinesToRead + 2*numberofLinesToRead;

    StringBuilder result = new StringBuilder((int)nLength);
    StringBuilder lpCharacter = new StringBuilder(lineSize);
    for (int i = 0; i < numberofLinesToRead; i++)
    {
        if (!ReadConsoleOutputCharacter(stdout, lpCharacter, (uint) lineSize, dwReadCoord, out uint lpNumberOfCharsRead))
            throw new Win32Exception();
        result.AppendLine(lpCharacter.ToString(0, (int)lpNumberOfCharsRead-1));
        dwReadCoord.Y++;
    }

    currentPosition = outInfo.dwCursorPosition.Y;
    return result.ToString();
}

public static async Task Main()
{
    var processId = 8560;
    if (!FreeConsole()) return ;
    if (!AttachConsole(processId)) return;

    IntPtr stdout = GetStdHandle(STD_OUTPUT_HANDLE);
    short currentPosition = 0;

    while (true)
    {
        var r1 = ReadALineOfConsoleOutput(stdout, ref currentPosition);
        if (r1 != null)
            //write to file or somewhere => //Debug.WriteLine(r1);
    }
}

改进

• ref short currentPosition添加到ReadALineOfConsoleOutput用于同步标准输出的currentPosition的功能
• GetConsoleScreenBufferInfo用于获取lineSize控制台
  • short lineSize = outInfo.dwSize.X 为lineSize添加
• uint numberofLinesToRead = (uint) (outInfo.dwCursorPosition.Y - currentPosition) 用于使用控制台的实际位置和光标的当前位置之间的差异来计算要读取的行数.
• 考虑lpNumberOfCharsRead避免垃圾线结束