Change Console Code Page in Windows C++ - c++

Question

I'm trying to output UTF8 characters in the Windows command line. I can't seem to get the function, setConsoleOutputCP to work. I also heard that you had to change the font to "Lucida Grande" for it to work but I can't get that working either. Can someone please provide me with a short example of how to use these functions to correctly output UTF-8 characters to the console?
Also I heard that those functions don't work in Windows XP, is there a better alternative to those functions which will work in Windows XP?

Answer 1

[I know this question is old and was about Windows XP, but it still seemed like a good place to drop this information so I (and maybe others) can find it again in the future.]
Support for Unicode in CMD windows has improved in newer versions of Windows. This program will work on Windows 10.
#include <iostream>
#include <Windows.h>
class UTF8CodePage {
public:
UTF8CodePage() : m_old_code_page(::GetConsoleOutputCP()) {
::SetConsoleOutputCP(CP_UTF8);
}
~UTF8CodePage() { ::SetConsoleOutputCP(m_old_code_page); }
private:
UINT m_old_code_page;
};
int main() {
UTF8CodePage use_utf8;
const char *text = u8"This text is in UTF-8. ¡Olé! 佻\n";
std::cout << text;
return 0;
}
I made an RAII class to ensure the code page is restored because it would be rude to leave the code page changed if the user had purposely selected a specific one. All the Windows-specific code (SetConsoleOutputCP) is contained within that class. The definition of the use_utf8 variable in main changes the code page to UTF-8, and that code page will stay in effect until the variable is destructed at the end of the scope.
Note that I used the u8 prefix on the string literal, which is a newer feature of C++ to ensure that the string is encoded using UTF-8 regardless of the encoding used for the source file. You don't have to use that feature if you have another way to make a string of valid UTF-8 text.
You still have to be sure that the CMD window is using a font that supports the glyphs you need. I don't think there's a way to get font linking automatically.
But this will at least show a the replacement character if the font is missing the glyph. For example, on my window, the ¡Olé! looks right but the CJK glyph is shown approximately like �. If the user copies that replacement character, the clipboard will receive the original glyph, so they can paste it into other programs without any loss of fidelity.
Note that command line parameters you get from main's argv will be in the original code page. One way to work around this is to get the unconverted "wide" command line with GetCommandLineW, convert it to UTF-8 with WideToMultibyte, and then parse it yourself. Alternatively, you can pass the result of GetCommandLineW to CommandLineToArgvW, which will parse it, and then you'd convert each argument to UTF-8.
Finally, note that changing the code page affects only the output. If you input text from the user, it arrives encoded using the original code page (often called the OEM code page).
TODO: Figure out input. SetConsoleCP isn't doing what I think the documentation says it should do.

Answer 2

Windows console doesn't play nice with UNICODE and particularly with UTF-8.
Setting a console code page to utf-8 won't work.
One approach is to use WideCharToMultiByte() (or something else) to convert the text to UTF-16, then MultiByteToWideChar() (or something else) to convert to a localised ISO encoding. The set the console code page to the ISO code page.
Its ugly, but it sort of works.

Answer 3

In short: SetConsoleOutputCP CP_UTF8 and cout/wcout dont work together by default.
Though windows CRT supports utf-8 output, a robust way to output to console utf-8 chars is to convert them into a console current codepage, especially if you want to use count/wcout.
Standard high level functions of basic_ostream does not work properly with utf-8 by default.
I've seen usage of MultiByteToWideChar and WideCharToMultiByte with CP_OEMCP and CP_UTF8 parameters.
You may setup your application environment, including console font via SetCurrentConsoleFontEx but it works only from Vista and Server 2008.
Also, check this about cout and console.
_setmode and wprintf works together as well, but this may lead to crash for non-wide char functions.

Answer 4

The problem occurs because there is a difference of codepage that uses windows in your console with the encoding of your source code text file.
Qt uses utf-8 by default, but another editor can use another one. So you must to verify which one you're using.
To change to utf-8 use:
#include <windows.h>
SetConsoleOutputCP(CP_UTF8);