making clangd happy and making script to compile/build with run.sh

app/main.cpp

@@ -0,0 +1,36 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "mainwindow.h"
+#include <QApplication>
+#include <QCommandLineParser>
+
+using namespace Qt::StringLiterals;
+
+int main(int argc, char *argv[])
+{
+    QApplication app(argc, argv);
+    QCoreApplication::setOrganizationName("QtProject"_L1);
+    QCoreApplication::setApplicationName("DocumentViewer"_L1);
+    QCoreApplication::setApplicationVersion("1.0"_L1);
+
+    QCommandLineParser parser;
+    parser.setApplicationDescription(QApplication::translate("main",
+                                                     "A viewer for JSON, PDF and text files"));
+    parser.addHelpOption();
+    parser.addVersionOption();
+    parser.addPositionalArgument("File"_L1, QApplication::translate("main",
+                                                                    "JSON, PDF or text file to open"));
+    parser.process(app);
+
+    const QStringList &positionalArguments = parser.positionalArguments();
+    const QString &fileName = (positionalArguments.count() > 0) ? positionalArguments.at(0)
+                                                                : QString();
+
+    MainWindow w;
+    w.show();
+    if (!fileName.isEmpty())
+        w.openFile(fileName);
+
+    return app.exec();
+}