为什么std :: ofstream添加额外的#13(换行符)字符? [英] Why does std::ofstream add extra #13 (newline) characters?

问题描述

我正在使用如下创建的基本std::ofstream对象:

I'm working with a basic std::ofstream object, created as follows:

output_stream = std::ofstream(output_file.c_str());

这将创建一个文件，并在其中放置一些信息.让我显示此类消息的示例:(监视"窗口摘录)

This creates a file, where some information is put in. Let me show an example of such a message: (Watch window excerpt)

full_Message    "Error while processing message:\r\n\tForecast Request:"

这一切都可以，但是启动以下命令后，就会出现问题:

All this is ok, but after having launched following commands, there is a problem:

output_stream << full_Message;
output_stream.flush();

为了查看出什么问题，让我们看一下文件的十六进制转储:(这是文件的十六进制显示，如在Notepad ++中所示.为清楚起见，我拍摄了屏幕截图.)

In order to see what is wrong, let's look at the hexadecimal dump of the file: (this is a hexadecimal display of the file, as seen in Notepad++. For clarity reasons I've taken a screenshot.)

如您所见，字符0d被加倍，从而显示以下内容:

As you can see, the character 0d is doubled, resulting in following display:

Error while processing message:

    Forecast Request:

(换行过多，两行应直接接在另一行之后)

(There's a newline too much, both lines should be directly one after the other)

在从UNIX/Linux到Windows的文件转换中，我知道添加了#13字符，但这在这里无关紧要:我只是在Windows系统上处理Windows文件，因此应该无需添加任何#13字符.

I am aware of the addition of #13 characters while doing file conversion from UNIX/Linux to Windows, but this is not relevant here: I'm purely working with a Windows file, on a Windows system, so there should be no need to add any #13 character.

有人知道如何避免增加这个额外的字符吗?

Does anybody have an idea how I can avoid this extra character being added?

预先感谢

推荐答案

流默认为文本模式，这意味着在Windows中，如果您编写\n，则文件将获得\r\n .因此，如果您编写\r\n，则文件将获得\r\r\n.

The streams default to text mode, which means that in Windows, if you write \n then the file gets \r\n. Therefore , if you write \r\n then the file gets \r\r\n.

要解决此问题，只需在代码中编写\n即可；或以 binary模式打开文件:

To fix this, either just write \n in your code; or open the file in binary mode:

auto output_stream = std::ofstream(output_file.c_str(), std::ios::binary);

这篇关于为什么std :: ofstream添加额外的#13(换行符)字符?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！