让Windows控制台应用程序支持VT100---原理篇

微软的操作系统在历史上对VT的支持可追溯到 DOS 年代，那时候有一个设备驱动程序名字叫 ANSI.SYS(泄露的dos6.0代码里面有，位于 ms_dos_6_0_source_code\dos-6.0\dev\ansi，是汇编语言实现的)，加载后就可以让终端支持VT控制符，后来进入桌面时代后就没有类似的支持了。直到Windows 10的Anniversary Update(1607)，微软追加了对VT的支持，这可能是得益于微软在内核层面支持Linux kernel的努力（WSL）。下面是详细的介绍和示例内容

https://docs.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences

测试代码

//
// Copyright (C) Microsoft. All rights reserved.
//
//https://docs.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences

#define DEFINE_CONSOLEV2_PROPERTIES

// System headers
#include <windows.h>

// Standard library C-style
#include <wchar.h>
#include <stdlib.h>
#include <stdio.h>

#define ESC "\x1b"
#define CSI "\x1b["

#ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING
#define ENABLE_VIRTUAL_TERMINAL_PROCESSING 0x0004
#endif

bool EnableVTMode()
{
    // Set output mode to handle virtual terminal sequences
    HANDLE hOut = GetStdHandle(STD_OUTPUT_HANDLE);
    if (hOut == INVALID_HANDLE_VALUE)
    {
        return false;
    }

    DWORD dwMode = 0;
    if (!GetConsoleMode(hOut, &dwMode))
    {
        return false;
    }

    dwMode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
    if (!SetConsoleMode(hOut, dwMode))
    {
        return false;
    }
    return true;
}

void PrintVerticalBorder()
{
    printf(ESC "(0"); // Enter Line drawing mode
    printf(CSI "104;93m"); // bright yellow on bright blue
    printf("x"); // in line drawing mode, \x78 -> \u2502 "Vertical Bar"
    printf(CSI "0m"); // restore color
    printf(ESC "(B"); // exit line drawing mode
}

void PrintHorizontalBorder(COORD const Size, bool fIsTop)
{
    printf(ESC "(0"); // Enter Line drawing mode
    printf(CSI "104;93m"); // Make the border bright yellow on bright blue
    printf(fIsTop? "l" : "m"); // print left corner 

    for (int i = 1; i < Size.X - 1; i++) 
        printf("q"); // in line drawing mode, \x71 -> \u2500 "HORIZONTAL SCAN LINE-5"

    printf(fIsTop? "k" : "j"); // print right corner
    printf(CSI "0m");
    printf(ESC "(B"); // exit line drawing mode
}

void PrintStatusLine(char* const pszMessage, COORD const Size)
{
    printf(CSI "%d;1H", Size.Y);
    printf(CSI "K"); // clear the line
    printf(pszMessage); 
}

int __cdecl wmain(int argc, WCHAR* argv[])
{ 
    argc; // unused
    argv; // unused
    //First, enable VT mode
    bool fSuccess = EnableVTMode();
    if (!fSuccess)
    {
        printf("Unable to enter VT processing mode. Quitting.\n");
        return -1;
    }
    HANDLE hOut = GetStdHandle(STD_OUTPUT_HANDLE);
    if (hOut == INVALID_HANDLE_VALUE)
    {
        printf("Couldn't get the console handle. Quitting.\n");
        return -1;
    }

    CONSOLE_SCREEN_BUFFER_INFO ScreenBufferInfo;
    GetConsoleScreenBufferInfo(hOut, &ScreenBufferInfo);
    COORD Size;
    Size.X = ScreenBufferInfo.srWindow.Right - ScreenBufferInfo.srWindow.Left + 1;
    Size.Y = ScreenBufferInfo.srWindow.Bottom - ScreenBufferInfo.srWindow.Top + 1;

    // Enter the alternate buffer
    printf(CSI "?1049h");

    // Clear screen, tab stops, set, stop at columns 16, 32
    printf(CSI "1;1H");
    printf(CSI "2J"); // Clear screen

    int iNumTabStops = 4; // (0, 20, 40, width)
    printf(CSI "3g"); // clear all tab stops
    printf(CSI "1;20H"); // Move to column 20
    printf(ESC "H"); // set a tab stop

    printf(CSI "1;40H"); // Move to column 40
    printf(ESC "H"); // set a tab stop

    // Set scrolling margins to 3, h-2
    printf(CSI "3;%dr", Size.Y-2);
    int iNumLines = Size.Y - 4;

    printf(CSI "1;1H");
    printf(CSI "102;30m");
    printf("Windows 10 Anniversary Update - VT Example"); 
    printf(CSI "0m");

    // Print a top border - Yellow
    printf(CSI "2;1H");
    PrintHorizontalBorder(Size, true);

    // // Print a bottom border
    printf(CSI "%d;1H", Size.Y-1);
    PrintHorizontalBorder(Size, false);

    wchar_t wch;

    // draw columns
    printf(CSI "3;1H"); 
    int line = 0;
    for (line = 0; line < iNumLines * iNumTabStops; line++)
    {
        PrintVerticalBorder();
        if (line + 1 != iNumLines * iNumTabStops) // don't advance to next line if this is the last line
            printf("\t"); // advance to next tab stop

    }

    PrintStatusLine("Press any key to see text printed between tab stops.", Size);
    wch = _getwch();

    // Fill columns with output
    printf(CSI "3;1H"); 
    for (line = 0; line < iNumLines; line++)
    {
        int tab = 0;
        for (tab = 0; tab < iNumTabStops-1; tab++)
        {
            PrintVerticalBorder();
            printf("line=%d", line);
            printf("\t"); // advance to next tab stop
        }
        PrintVerticalBorder();// print border at right side
        if (line+1 != iNumLines)
            printf("\t"); // advance to next tab stop, (on the next line)
    }

    PrintStatusLine("Press any key to demonstrate scroll margins", Size);
    wch = _getwch();

    printf(CSI "3;1H"); 
    for (line = 0; line < iNumLines * 2; line++)
    {
        printf(CSI "K"); // clear the line
        int tab = 0;
        for (tab = 0; tab < iNumTabStops-1; tab++)
        {
            PrintVerticalBorder();
            printf("line=%d", line);
            printf("\t"); // advance to next tab stop
        }
        PrintVerticalBorder(); // print border at right side
        if (line+1 != iNumLines * 2)
        {
            printf("\n"); //Advance to next line. If we're at the bottom of the margins, the text will scroll.
            printf("\r"); //return to first col in buffer
        }
    }

    PrintStatusLine("Press any key to exit", Size);
    wch = _getwch();

    // Exit the alternate buffer
    printf(CSI "?1049l");

}

那如果windows版本低于win10 1607怎么办呢？我感觉可以实现一个兼容层，例如微软的telnet客户端，他就是支持VT的，查看前一段时间nt5泄露代码，确实找到相关的代码。

位于 F:\nt5src\Source\Win2K3\NT\net\tcpip\services\telnet\client\trmio.c

代码非常多，简单摘一些里面代码声明吧。

static UCHAR pchNBBuffer[ READ_BUF_SZ ];
static void NewLineUp(WI *, TRM *);
static void NewLine(WI *pwi, TRM *);
static void SetBufferStart(TRM *);
static BOOL FAddTabToBuffer( TRM *, DWORD );
static BOOL FAddCharToBuffer(TRM *, UCHAR);
static void FlushBuffer(WI *pwi, TRM *);
static void CursorUp(TRM *);
static void CursorDown(TRM *);
static void CursorRight(TRM *);
static void CursorLeft(TRM *);
static void ClearLine(WI *pwi, TRM *, DWORD);
static void SetMargins(TRM *, DWORD, DWORD);

另外微软win10 的cmd和conhost是开源的，在

https://github.com/microsoft/terminal

搜索 ENABLE_VIRTUAL_TERMINAL_PROCESSING 可找到相关的代码