QDir and QDirIterator ignore files with non-ASCII filenames

Question

The following code somehow fails to notice any files with non-ASCII characters in their names (Cyrillic characters, specifically):

for (int path = 1; path < argc; path++) {
  QFileInfo fi(argv[path]);
  if (fi.isDir()) {
    QDir dir(argv[path], "", QDir::LocaleAware, QDir::AllEntries);
    qDebug() << dir.entryList();
    QDirIterator it(QString(argv[path]), QDirIterator::Subdirectories);
    while (it.hasNext()) {
      it.next();
      qDebug() << it.fileInfo().absoluteFilePath();
      /* Processing; irrelevant in the context of the question */
    }
  }
}

What exactly am I doing wrong here? How should I handle QDir and QDirIterator to make them aware of Cyrillic filenames?

The system locale is en_US.UTF-8.

Update: On Windows, everything works correctly.

Answer 1

Which part is failing? Reading the initial directory specified argv[path] or the iterator? If it's the former, you should convert byte strings to QString for file processing using QFile::decodeName. The default char* => QString conversion uses Latin-1, which is not what you want for file names.

Answer 2

Don't use argv[path] just like that when constructing the QStrings. This will treat the string as a latin1 string (which doesn't care about cyrillic characters). Try using

const QString dirName = QString::fromLocal8Bit( argv[path] );

at the top of your loop and then use dirName everywhere instead of argv[path].

Answer 3

Get cmd line parameters out of QApplication itself.

So

QApplication app(argc, argv);

QStringList args = app.arguments();

for(...)

Qt will handle encoding properly. But that will only fix problems with unicode on cmd line. Not sure if that is your main problem though.

EDIT: fromLocal8Bit() probably doesn't work because it wasn't local encoding, but utf8. So fromUtf8() would work on linux and osx (but it won't work on windows). On *nuxes it depends on some environment variables (LS_LANG or something). I guess Qt takes everything into account and converts it properly. You can look at the constructor code for QApplication if you want to know exactly what they do.