c++ - Recursively iterate over all the files in a directory and its subdirectories in Qt

Question

I want to recursively scan a directory and all its sub-directories for files with a given extension - for example, all *.jpg files. How can you do that in Qt?

Answer 1

I suggest you have a look at QDirIterator.

QDirIterator it(dir, QStringList() << "*.jpg", QDir::Files, QDirIterator::Subdirectories);
while (it.hasNext())
    qDebug() << it.next();

You could simply use QDir::entryList() recursively, but QDirIterator is simpler. Also, if you happen to have directories with a huge amount of files, you'd get pretty large lists from QDir::entryList(), which may not be good on small embedded devices.

Example (dir is QDir::currentPath()):

luca @ ~/it_test - [] $ tree
.
├── dir1
│?? ├── image2.jpg
│?? └── image3.jpg
├── dir2
│?? └── image4.png
├── dir3
│?? └── image5.jpg
└── image1.jpg

3 directories, 5 files
luca @ ~/it_test - [] $ /path/to/app
"/home/luca/it_test/image1.jpg"
"/home/luca/it_test/dir3/image5.jpg"
"/home/luca/it_test/dir1/image2.jpg"
"/home/luca/it_test/dir1/image3.jpg"