Generating a command-line interface

The command-line interface can be a wonderful way to start your application with specific options. The Qt framework provides an easy way to define your options, with the QCommandLineParser class. You can provide a short (for example, -t) or a long (for example, --test) option name. The application version and help menu are automatically generated. You can easily check  in your C++ code whether an option is set or not. An option can take a value and you can define a default value.

For example, we can create a CLI to configure the log files. We want to define three options, as follows:

• The -debug command, if set, enables the log file writing
• The -f or --file command defines where to write the logs
• The -l or --level <level> command specifies the minimum log level

Look at the following snippet:

QCoreApplication app(argc, argv); 
 
QCoreApplication::setApplicationName("ch14-hat-tips"); 
QCoreApplication::setApplicationVersion("1.0.0"); 
 
QCommandLineParser...