#include <QApplication>
#include <QLineEdit>
#include <cstdio>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QLineEdit edit;
    QObject::connect(&edit, &QLineEdit::textChanged, [](const QString &text) {
        std::printf("TEXT:%s\n", qPrintable(text));
        std::fflush(stdout);
    });
    edit.resize(400, 40);
    edit.show();
    edit.setFocus();
    return app.exec();
}