QNetworkInformation Class

#include <QCoreApplication>#include <QNetworkInformation>#include <QDebug>void onReachabilityChanged(QNetworkInformation::도달 가능성 도달 가능성) { switch (도달 가능성) { case QNetworkInformation::도달 가능성::알 수 없음:        qDebug() << "Network reachability is unknown.";
       break; case QNetworkInformation::도달 가능성::연결이 끊어졌습니다:        qDebug() << "Network is disconnected.";
       break; case QNetworkInformation::도달 가능성::로컬:        qDebug() << "Network is locally reachable.";
       break; case QNetworkInformation::도달 가능성::사이트:        qDebug() << "Network can reach the site.";
       break; case QNetworkInformation::도달 가능성::온라인:        qDebug() << "Network is online.";
       break; } }int main(int argc, char *argv[]) { QCoreApplication a(argc, argv); // QNetworkInformation 지원 여부 확인 if (!QNetworkInformation::loadDefaultBackend()) {!        qWarning() << "QNetworkInformation is not supported on this platform or backend.";
       반환 1; } QNetworkInformation* netInfo = QNetworkInformation::instance(); // 도달가능성 변경 신호에 연결   QObject::connect(netInfo, &.QNetworkInformation::reachabilityChanged, &onReachabilityChanged); // 초기 상태 출력onReachabilityChanged(netInfo->reachability()); return a.exec(); }

// IP 주소가 "로컬"인지 여부를 판단하는 간단한 헬퍼bool isLocalAddress(const QHostAddress &address) { return address.isInSubnet(QHostAddress("192.168.0.0"), 16) ||address.isInSubnet(QHostAddress("10.0.0.0"), 8)    ||address.isInSubnet(QHostAddress("172.16.0.0"), 12) ||address.isLoopback(); }int main(int argc, char *argv[]) { ... // 타겟 IP 주소 (기본값: Google DNS)   QString targetIpStr = argc > 1 ? argv[1]: "8.8.8.8";    QHostAddress targetIp(targetIpStr); if (targetIp.isNull()) {        qWarning() << "Invalid IP address:" << targetIpStr;
       반환 1; } // 타겟에 필요한 도달 가능성 수준을 결정합니다.   QNetworkInformation::도달 가능성 requiredReachability =isLocalAddress(targetIp) ? QNetworkInformation::도달 가능성::로컬 : QNetworkInformation::도달가능성::온라인; // 현재 시스템에서 보고된 도달가능성을 가져옵니다.    QNetworkInformation::도달 가능성 currentReachability =  networkInfo->reachability();
    qDebug() << "Target IP:" << targetIp.toString();
    qDebug() << "Target is considered"
            << (isLocalAddress(targetIp) ? "local/site.": "외부/온라인.");    qDebug() << "Required reachability level:" << requiredReachability;
    qDebug() << "Current reachability:" << currentReachability;

   if (currentReachability < requiredReachability) {        qWarning() << "Current network state may not allow reaching the target address.";
    } else {        qDebug() << "Target may be reachable based on current network state.";
    } ...