将cout重定向到Windows中的控制台 [英] Redirecting cout to a console in windows

问题描述

我有一个比较老的应用程序。通过一些小的改动，它几乎完美地与Visual C ++ 2008构建。我注意到的一个事情是，我的调试控制台不是很好的工作。基本上在过去，我使用 AllocConsole（）创建一个控制台，让我的调试输出去。然后，我将使用 freopen 将 stdout 重定向到它。这与C和C ++风格的IO完美兼容。

I have an application which is a relatively old. Through some minor changes, it builds nearly perfectly with Visual C++ 2008. One thing that I've noticed is that my "debug console" isn't quite working right. Basically in the past, I've use AllocConsole() to create a console for my debug output to go to. Then I would use freopen to redirect stdout to it. This worked perfectly with both C and C++ style IO.

现在，它似乎只适用于C风格的IO。将 cout 重定向到分配有 AllocConsole（）？

Now, it seems that it will only work with C style IO. What is the proper way to redirect things like cout to a console allocated with AllocConsole()?

这里是以前工作的代码：

Here's the code which used to work:

if(AllocConsole()) {
    freopen("CONOUT$", "wt", stdout);
    SetConsoleTitle("Debug Console");
    SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_GREEN | FOREGROUND_BLUE | FOREGROUND_RED);
}

EDIT ：我可以做一个自定义的streambuf，其溢出方法写使用C风格的IO和替换 std :: cout 的默认流缓冲区。但这似乎是一个失败。在2008年有正确的方法吗？或者，这可能是MS忽略了？

EDIT: one thing which occurred to me is that I could make a custom streambuf whose overflow method writes using C style IO and replace std::cout's default stream buffer with it. But that seems like a cop-out. Is there a proper way to do this in 2008? Or is this perhaps something that MS overlooked?

EDIT2 ：好的，所以我已经实现了我上面阐述的想法。基本上看起来像这样：

EDIT2: OK, so I've made an implementaiton of the idea I spelled out above. Basically it looks like this:

class outbuf : public std::streambuf {
public:
    outbuf() {
        setp(0, 0);
    }

    virtual int_type overflow(int_type c = traits_type::eof()) {
        return fputc(c, stdout) == EOF ? traits_type::eof() : c;
    }
};

int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow) {
    // create the console
    if(AllocConsole()) {
        freopen("CONOUT$", "w", stdout);
        SetConsoleTitle("Debug Console");
        SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_GREEN | FOREGROUND_BLUE | FOREGROUND_RED);  
    }

    // set std::cout to use my custom streambuf
    outbuf ob;
    std::streambuf *sb = std::cout.rdbuf(&ob);

    // do some work here

    // make sure to restore the original so we don't get a crash on close!
    std::cout.rdbuf(sb);
    return 0;
}

任何人都有一个比只是强制 std :: cout 是一个荣耀 fputc ？

Anyone have a better/cleaner solution than just forcing std::cout to be a glorified fputc?

推荐答案

我发布一个便携式解决方案，以回答形式，所以它可以接受。基本上，我使用c文件I / O替换 cout 的 streambuf 。感谢所有人的输入。

I'm posting a portable solution in answer form so it can be accepted. Basically I replaced cout's streambuf with one that is implemented using c file I/O which does end up being redirected. Thanks to everyone for your input.

class outbuf : public std::streambuf {
public:
    outbuf() {
        setp(0, 0);
    }

    virtual int_type overflow(int_type c = traits_type::eof()) {
        return fputc(c, stdout) == EOF ? traits_type::eof() : c;
    }
};

int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow) {
    // create the console
    if(AllocConsole()) {
        freopen("CONOUT$", "w", stdout);
        SetConsoleTitle("Debug Console");
        SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_GREEN | FOREGROUND_BLUE | FOREGROUND_RED);  
    }

    // set std::cout to use my custom streambuf
    outbuf ob;
    std::streambuf *sb = std::cout.rdbuf(&ob);

    // do some work here

    // make sure to restore the original so we don't get a crash on close!
    std::cout.rdbuf(sb);
    return 0;
}

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