控制台下输出DLL的调试信息_dll 输出调试消息console-优快云博客

问：

在cmd.exe下运行rundll32.exe mydll.dll,MyFunc ,本想直接在当前cmd窗口输出调试信息.
可因rundll32是Win32 GUI程序而非Win32 console,所以cmd.exe标准输入输出句柄无法被mydll.dll继承用来向父进程cmd.exe输出数据.
这时, 如果用强行用GetStdHandle获得句柄,然后用WriteConsole来进行输出,则会发生无效句柄错误.
但是如果在这之前先AllocConsole,则可正常WriteConsole,但是会新建个控制台窗口来输出数据,很不爽 :-P

有没有什么办法向当前cmd.exe窗口输出数据呢?

我想通过给进程拍照和遍历,
可以获得rundll32的父进程cmd.exe的PID和Handle,但如何进一步下去(建立管道, 写数据)就没辙了?

不知道有没有描述清楚还是太罗嗦了,麻烦大家看看,谢谢~

答：

如果只是要输出数据的话可以向父窗口发送键盘消息 WM_CHAR 输出你的数据

代码

Code:


BOOL APIENTRY DllMain( HANDLE hModule, 
                       DWORD  ul_reason_for_call, 
                       LPVOID lpReserved ) 
{ 
    switch (ul_reason_for_call) 
    { 
        case DLL_PROCESS_ATTACH: 
            ShowMe(); 
             
        case DLL_THREAD_ATTACH: 
        case DLL_THREAD_DETACH: 
        case DLL_PROCESS_DETACH: 
            break; 

    } 
    return TRUE; 
} 


void ShowMe() 
{ 
    DWORD    dwProcID; 
    HWND    hWnd; 
    dwProcID = FindParentProcID(GetCurrentProcessId()); 
        sprintf(buf, "dwProcID:%d/nProcessId:%d ",  dwProcID, GetCurrentProcessId()); 
        MessageBox (NULL, buf, "提示", MB_ICONERROR); 
    if(dwProcID == -1) 
        return; 

    hWnd = GetProcessMainWnd(dwProcID); 
    if(hWnd ==NULL) 
        return; 

    SendMessage(hWnd, WM_CHAR, WPARAM('Z'), NULL); 
}

Code:


DWORD FindParentProcID(DWORD dwChildProcID)        //找到返回父进程PID, 找不到返回-1 
{ 
    PROCESSENTRY32     pr32 = {0}; 
    pr32.dwSize = sizeof(PROCESSENTRY32);   // 不要漏了这句 

    // 提权先 
    DebugPrivilege(SE_DEBUG_NAME, TRUE);     
    // 给进程照相 
    HANDLE hSnap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS,0); 
    // 拍照失败, 返回-1 
    if (hSnap == (HANDLE)-1) return (DWORD)-1; 
     
    // 开始枚举... 
    if (Process32First(hSnap,&pr32) == FALSE)   
    { 
        CloseHandle( hSnap ); 
        return (DWORD)-1; 
    } 

    do 
    { 
        if( pr32.th32ProcessID == dwChildProcID)   
        {            // 如果被枚举到的进程ID等于所给的ID, 则返回父进程ID 
            CloseHandle( hSnap ); 
            return pr32.th32ParentProcessID; 
        } 
    } 
    while( Process32Next(hSnap, &pr32)); 

    // 找不到父进程ID, 返回-1 
    CloseHandle(hSnap); 
    return -1; 
}

Code:


typedef struct tagWNDINFO 
{ 
    DWORD dwProcessId; 
    HWND hWnd; 
} WNDINFO, *LPWNDINFO; 

BOOL CALLBACK YourEnumProc(HWND hWnd,LPARAM lParam) 
{ 
    DWORD dwProcessId; 
    GetWindowThreadProcessId(hWnd, &dwProcessId); 
    LPWNDINFO pInfo = (LPWNDINFO)lParam; 
    if(dwProcessId == pInfo->dwProcessId) 
    { 
        pInfo->hWnd = hWnd; 
        return FALSE; 
    } 
    return TRUE; 
} 

HWND GetProcessMainWnd(DWORD dwProcessId)        // 找到返回进程主窗口的hWnd, 如果没有,返回NULL 
{ 
    WNDINFO wi; 
    wi.dwProcessId = dwProcessId; 
    wi.hWnd = NULL; 
    EnumWindows(YourEnumProc,(LPARAM)&wi); 
    return wi.hWnd; 
}