利用qt实现在linux系统自动获取dns配置

可以使用QtNetwork模块中的QNetworkConfigurationManager类来获取DNS配置信息。具体可以通过以下代码实现：

#include <QCoreApplication>
#include <QtNetwork>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    QNetworkConfigurationManager manager;
    QNetworkConfiguration config = manager.defaultConfiguration();
    QNetworkConfiguration::BearerType bearerType = config.bearerType();
    if (bearerType == QNetworkConfiguration::BearerUnknown) {
        qDebug() << "Unknown bearer type!";
    } else {
        qDebug() << "Bearer type:" << bearerType;
        QList<QNetworkConfiguration> configs = manager.allConfigurations(QNetworkConfiguration::Active);
        foreach (const QNetworkConfiguration &conf, configs) {
            qDebug() << "Configuration name:" << conf.name();
            qDebug() << "DNS servers:" << conf.nameServers();
            qDebug() << "Search domains:" << conf.searchDomains();
        }
    }
    return a.exec();
}

这段代码会输出系统的DNS服务器列表和搜索域列表。