在后台运行的Qt应用程序中监听linux命令？

#include <QCoreApplication>
#include <QDebug>
#include <QSocketNotifier>

class CommandListener : public QObject {
    Q_OBJECT
public:
    CommandListener() {
        QSocketNotifier *notifier = new QSocketNotifier(STDIN_FILENO, QSocketNotifier::Read, this);
        connect(notifier, &QSocketNotifier::activated, this, &CommandListener::readCommand);
    }

private slots:
    void readCommand(int socket) {
        QByteArray data = readAll(socket);
        qDebug() << "Received command:" << data;
    }
};

int main(int argc, char *argv[]) {
    QCoreApplication app(argc, argv);
    CommandListener listener;
    return app.exec();
}

#include <QCoreApplication>
#include <QFileSystemWatcher>
#include <QDebug>

class CommandListener : public QObject {
    Q_OBJECT
public:
    CommandListener() {
        QFileSystemWatcher *watcher = new QFileSystemWatcher(this);
        watcher->addPath("/path/to/command/file");
        connect(watcher, &QFileSystemWatcher::fileChanged, this, &CommandListener::readCommand);
    }

private slots:
    void readCommand(const QString &path) {
        QFile file(path);
        if (file.open(QIODevice::ReadOnly | QIODevice::Text)) {
            QTextStream in(&file);
            QString command = in.readAll();
            qDebug() << "Received command:" << command;
        }
    }
};

int main(int argc, char *argv[]) {
    QCoreApplication app(argc, argv);
    CommandListener listener;
    return app.exec();
}