main.cpp

#include <QCoreApplication>
#include <QDebug>
#include <QFileSystemWatcher>
#include <QThread>
#include <QTimer>
#include <cstdlib>
#include <QProcess>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QFileSystemWatcher watcher;
    QObject::connect(&watcher, &QFileSystemWatcher::directoryChanged, [&](const QString& changed){
        qDebug() << "Changed DIRECTORY" << changed << " and watcher monitor the following dirs" << watcher.directories() << "and files "<< watcher.files();
    });
    QObject::connect(&watcher, &QFileSystemWatcher::fileChanged, [&](const QString& changed){
        qDebug() << "Changed FILE " << changed << " and watcher monitor the following dirs" << watcher.directories() << "and files "<< watcher.files();
    });

    QTimer timer;
    QObject::connect(&timer, &QTimer::timeout, [&] {
        ::system("rm -rf /tmp/test");

        ::system("mkdir -p /tmp/test/subdir");
        ::system("touch /tmp/test/subdir/subfile.txt");

        watcher.addPath("/tmp/test/");
        watcher.addPath("/tmp/test/subdir");
        watcher.addPath("/tmp/test/subdir/subfile.txt");

        ::system("mv /tmp/test/subdir /tmp/test/subdir2");

        QThread::currentThread()->wait(1000);

        ::system("echo \"OK\" >> /tmp/test/subdir2/subfile.txt");
    });

    timer.setSingleShot(true);
    timer.start(2000);

    return a.exec();
}