C++ 下划线输出

C++ underline output

提问by user2326844

How can I underline a text which is supposed to be an output of a c++ code?

如何在应该是 C++ 代码输出的文本下划线？

Somewhere in the web I saw this:

我在网上的某个地方看到了这个：

cout<<underline<<"This is the text which is going to be underlined.";

But, for me this "underline" is not working. Any idea is very welcome.

但是，对我来说，这个“下划线”不起作用。任何想法都非常受欢迎。

回答by r3mainer

Are you outputting to an ANSI terminal? If so, the following escape sequence should work:

您是否正在输出到 ANSI 终端？如果是这样，以下转义序列应该有效：

#define underline "3[4m"

More information on ANSI escape sequences is available here.

此处提供了有关 ANSI 转义序列的更多信息。

Note: To turn underlining off again, use "\033[0m".

注意：要再次关闭下划线，请使用"\033[0m"。

回答by Paul R

Probably the simplest and most portable method is just this:

可能最简单和最便携的方法就是这样：

cout << "This is the text which is going to be underlined." << endl;
cout << "-------------------------------------------------" << endl;

回答by Fedele

The following is an extensive example written for G++:

以下是为 G++ 编写的扩展示例：

#include <iostream>
using namespace std;
int  main()
{
    char normal[]={0x1b,'[','0',';','3','9','m',0};
    char black[]={0x1b,'[','0',';','3','0','m',0};
    char red[]={0x1b,'[','0',';','3','1','m',0};
    char green[]={0x1b,'[','0',';','3', '2','m',0};
    char yellow[]={0x1b,'[','0',';','3', '3', 'm',0};
    char blue[]={0x1b,'[','0',';','3','4','m',0};
    char Upurple[]={0x1b,'[','4',';','3','5','m',0};
    char cyan[]={0x1b,'[','0',';','3','6','m',0};
    char lgray[]={0x1b,'[','0',';','3','7','m',0};
    char dgray[]={0x1b,'[','0',';','3','8','m',0};
    char Bred[]={0x1b,'[','1',';','3','1','m',0};
    //for bold colors, just change the 0 after the [ to a 1
    //for underlined colors, just change the 0 after the [ to a 4
    cout<<"This text is "<<black<<"Black "<<red<<"Red ";
    cout<<green<<"Green "<<yellow<<"Yellow "<<blue<<"Blue\n";
    cout<<Upurple<<"Underlined Purple "<<cyan<<"Cyan ";
    cout<<lgray<<"Light Gray "<<dgray<<"Dark Gray ";
    cout<<Bred<<"and Bold Red."<<normal<<"\n";
    return 0;
}

回答by Jérémy Pouyet

To complete Paul R answer, I sometimes create this function in my consol programs:

为了完成 Paul R 的回答，我有时会在我的控制台程序中创建这个函数：

std::string underline(const std::string &s) {
    return std::string(s.length(), '-');
}

Then you can do:

然后你可以这样做：

int main() {
    constexpr auto TEXT = "I am underlined";
    std::cout << TEXT << std::endl << underline(TEXT) << std::endl;
    return 0;
}

other possibilities:

其他可能性：

void underlineAndDisplay(const std::string &s);
std::string underlineWith(const std::string &s, char c);

Well, let's go back to my code...

好吧，让我们回到我的代码......