Win11 create log failed

[L-Super]

The utf-8 code used by my qt program code.When I use spdlog, it failed to create a log file under the Win11 Chinese user name.

demo code:

logTest::logTest(QWidget *parent)
    : QWidget(parent)
{
    ui.setupUi(this);
	QString standPath = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation);
	standPath.append("/logtest.log");

	auto str = "请截图此窗口\n" + standPath;

	spdlog::info("log widget {}",standPath.toUtf8());
	
	QMessageBox::information(this, "请截图此窗口", str);
	
	auto getLogger = spdlog::get("file_logger");

	std::vector<spdlog::sink_ptr> sinks;
	sinks.push_back(std::make_shared<spdlog::sinks::stderr_color_sink_mt>());

	sinks.push_back(std::make_shared<spdlog::sinks::rotating_file_sink_mt>(standPath.toStdString(), 1048576 * 5, 3));
	auto mLogger =
		std::make_shared<spdlog::logger>("log", std::begin(sinks), std::end(sinks));
	spdlog::register_logger(mLogger);

	try
	{
		mLogger->error("test log path");
		mLogger->flush();
	}
	catch (const spdlog::spdlog_ex& ex)
	{
		auto s = ex.what();
		QMessageBox::information(this, "请截图此窗口", s);

	}

}

The QMessageBox display path is normal, but the spdlog displays garbled code.

[tt4g]

There is no specification in the C++ standard specification that the character encoding of string literals in source code is UTF-8. It is platform dependent.
If it is garbled, that is the developer's responsibility.

If you are building with MSVC, please make sure that the characters in the source code are interpreted as UTF-8 by specifying the /utf-8 option.
See: https://learn.microsoft.com/en-us/cpp/build/reference/utf-8-set-source-and-executable-character-sets-to-utf-8?view=msvc-170

[L-Super]

My source code is UTF-8，and /utf-8 option added.
When I change some code
like this picture, It's normal.

But when the path is C:/Users/神/AppData/Roaming/logTest/logtest.log, it's create log file failed.So I think , when the Windows user called Chinese name, log will create a failure.

[tt4g]

Since the Windows directory separator is \, not /, the log file will never be created correctly.

[L-Super]

I don't think that's the problem.
They have the same effect

神\\AppData\\log.log = 神/AppData/log.log

[tt4g]

So do executing user have write permission to C:/神/AppData/log.log?
In any case, catch the exception that is causing the abort and check the error message from std::exception::what().

[L-Super]

catch Failed opening file C:/Users/刘彦辉/AppData/Roaming/TanggulaClient/VisionVera/logs/vvlog.log for writing: illegal byte sequence

I am normal on Win10, but Win11 has this problem.

[tt4g]

As per the error message, the file path string you are passing to spdlog contains a byte sequence that is considered invalid in the character encoding expected by the OS.

The Qt documentation says that QString::toStdString() returns a UTF-8 string.

The character encoding that the Windows API expects for char * is determined by the current locale setting (I don't know of a character encoding that corresponds to a Chinese locale).
Generate a char * from QString with the character encoding corresponding to the current locale and use it as the spdlog file path.

[artemyv]

What happens if you define following setting
///////////////////////////////////////////////////////////////////////////////
// Uncomment to enable usage of wchar_t for file names on Windows.
//
// #define SPDLOG_WCHAR_FILENAMES
///////////////////////////////////////////////////////////////////////////////
and pass path as UTF-16 (const wchar_t*)?

[tt4g]

If SPDLOG_WCHAR_FILENAMES is defined, It will accept filenames of type const wchar_t *.
So you can pass QString::toStdWString() to spdlog::sinks::rotating_file_sink_mt.

[L-Super]

Thank you very much. It is confirmed that it is a UTF-8 and GBK coding problem. I used the QString().toLocal8Bit().data() to solve it.