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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:significant reason:default
#include "qplatformdefs.h"
#include "qfilesystemiterator_p.h"
#ifndef QT_NO_FILESYSTEMITERATOR
#include <qvarlengtharray.h>
#include <private/qstringconverter_p.h>
#include <stdlib.h>
#include <errno.h>
QT_BEGIN_NAMESPACE
/*
Native filesystem iterator, which uses ::opendir()/readdir()/dirent from the system
libraries to iterate over the directory represented by \a entry.
*/
QFileSystemIterator::QFileSystemIterator(const QFileSystemEntry &entry)
: dirPath(entry.filePath())
{
dir.reset(QT_OPENDIR(entry.nativeFilePath().constData()));
if (!dir) {
lastError = errno;
} else {
if (!dirPath.endsWith(u'/'))
dirPath.append(u'/');
}
}
QFileSystemIterator::QFileSystemIterator(const QFileSystemEntry &entry, QDirListing::IteratorFlags)
: QFileSystemIterator(entry)
{}
QFileSystemIterator::QFileSystemIterator(const QFileSystemEntry &entry, QDir::Filters)
: QFileSystemIterator(entry)
{
}
QFileSystemIterator::~QFileSystemIterator() = default;
QFileSystemNativeId QFileSystemIterator::nativeId() const
{
if (!dir)
return {};
#if QT_CONFIG(dirfd)
// We can use dirfd() to fstat() the open directory - no race condition.
return QFileSystemEngine::nativeId(dirfd(dir.get()));
#else
// We must stat() the name - possible race condition, but already present
// in QDirListing because we use full file names.
return QFileSystemEngine::nativeId(
QFileSystemEntry(dirPath, QFileSystemEntry::FromInternalPath()));
#endif
}
std::optional<QDirEntryInfo> QFileSystemIterator::advance()
{
auto asFileEntry = [this](QStringView name) {
#ifdef Q_OS_DARWIN
// must match QFile::decodeName
QString normalized = name.toString().normalized(QString::NormalizationForm_C);
name = normalized;
#endif
return QFileSystemEntry(dirPath + name, QFileSystemEntry::FromInternalPath());
};
if (!dir)
return std::nullopt;
for (;;) {
// From readdir man page:
// If the end of the directory stream is reached, NULL is returned and errno is
// not changed. If an error occurs, NULL is returned and errno is set to indicate
// the error. To distinguish end of stream from an error, set errno to zero before
// calling readdir() and then check the value of errno if NULL is returned.
errno = 0;
dirEntry = QT_READDIR(dir.get());
if (dirEntry) {
// POSIX allows readdir() to return a file name in struct dirent that
// extends past the end of the d_name array (it's a char[1] array on QNX, for
// example). Therefore, we *must* call strlen() on it to get the actual length
// of the file name. See:
QByteArrayView name(dirEntry->d_name, strlen(dirEntry->d_name));
// name.size() is sufficient here, see QUtf8::convertToUnicode() for details
QVarLengthArray<char16_t> buffer(name.size());
QStringDecoder toUtf16(QStringDecoder::Utf8);
auto *end = toUtf16.appendToBuffer(buffer.data(), name);
buffer.resize(end - buffer.constData());
if (!toUtf16.hasError()) {
QFileSystemMetaData metaData;
metaData.fillFromDirEnt(*dirEntry);
return QDirEntryInfo{asFileEntry(buffer), std::move(metaData)};
} else {
errno = EILSEQ; // Invalid or incomplete multibyte or wide character
}
} else {
break;
}
}
lastError = errno;
return std::nullopt;
}
QT_END_NAMESPACE
#endif // QT_NO_FILESYSTEMITERATOR