The Application class implements the main subsystem in a process. The application class is responsible for initializing all its subsystems.

Subclasses can and should override the following virtual methods:

• initialize() (the one-argument, protected variant)
• uninitialize()
• reinitialize()
• defineOptions()
• handleOption()
• main()

The application's main logic should be implemented in the main() method.

There may be at most one instance of the Application class in a process.

The Application class maintains a LayeredConfiguration (available via the config() member function) consisting of:

• a MapConfiguration (priority -100) storing application-specific properties, as well as properties from bound command line arguments.
• a SystemConfiguration (priority 100)
• the configurations loaded with loadConfiguration().

The Application class sets a few default properties in its configuration. These are:

• application.path: the absolute path to application executable
• application.name: the file name of the application executable
• application.baseName: the file name (excluding extension) of the application executable
• application.dir: the path to the directory where the application executable resides
• application.configDir: the path to the directory where user specific configuration files of the application should be stored.
• application.cacheDir: the path to the directory where user specific non-essential data files of the application should be stored.
• application.dataDir: the path to the directory where user specific data files of the application should be stored.
• application.tempDir: the path to the directory where user specific temporary files and other file objects of the application should be stored.

If loadConfiguration() has never been called, application.configDir will be equal to application.dir.

The POCO_APP_MAIN macro can be used to implement main(argc, argv). POCO_APP_MAIN supports Unicode command line arguments.

Commonly used exit status codes. Based on the definitions in the 4.3BSD <sysexits.h> header file.

successful termination

command line usage error

data format error

cannot open input

addressee unknown

host name unknown

service unavailable

internal software error

system error (e.g., can't fork)

critical OS file missing

can't create (user) output file

input/output error

temp failure; user is invited to retry

remote error in protocol

permission denied

configuration error

Creates the Application.

Creates the Application and calls init(argc, argv).

Destroys the Application and deletes all registered subsystems.

Adds a new subsystem to the application. The application immediately takes ownership of it, so that a call in the form

Application::instance().addSubsystem(new MySubsystem);

is okay.

Returns reference to vector of the application's arguments as specified on the command line. If user overrides the Application::main(const ArgVec&) function, it will receive only the command line parameters that were not processed in Application::processOptons(). This function returns the full set of command line parameters as received in main(argc, argv*).

Returns the command name used to invoke the application.

Returns the full command path used to invoke the application.

Returns the application's configuration reference.

Returns the application's configuration smart pointer.

Returns the directory that contains the application executable.

Returns the file path of the application executable.

Returns a reference to the subsystem of the class given as template argument.

Throws a NotFoundException if such a subsystem has not been registered.

Ignore unknown options. So that we can skip those options we don't care about.

When your application command line has many options, calling this function can help you handle only the options you want to handle

Processes the application's command line arguments and sets the application's properties (e.g., "application.path", "application.name", etc.).

Note that as of release 1.3.7, init() no longer calls initialize(). This is now called from run().

Processes the application's command line arguments and sets the application's properties (e.g., "application.path", "application.name", etc.).

Note that as of release 1.3.7, init() no longer calls initialize(). This is now called from run().

Returns true if and only if the application is in initialized state (that means, has been initialized but not yet uninitialized).

Returns a reference to the Application singleton.

Throws a NullPointerException if no Application instance exists.

Loads configuration information from a default location.

The configuration(s) will be added to the application's LayeredConfiguration with the given priority.

The configuration file(s) must be located in the same directory as the executable or a parent directory of it, and must have the same base name as the executable, with one of the following extensions: .properties, .ini or .xml.

The .properties file, if it exists, is loaded first, followed by the .ini file and the .xml file.

If the application is built in debug mode (the _DEBUG preprocessor macro is defined) and the base name of the application executable ends with a 'd', a config file without the 'd' ending its base name is also found.

Example: Given the application "SampleAppd.exe", built in debug mode. Then loadConfiguration() will automatically find a configuration file named "SampleApp.properties" if it exists and if "SampleAppd.properties" cannot be found.

Returns the number of configuration files loaded, which may be zero.

This method must not be called before init(argc, argv) has been called.

Loads configuration information from the file specified by the given path. The file type is determined by the file extension. The following extensions are supported:

• .properties - properties file (PropertyFileConfiguration)
• .ini - initialization file (IniFileConfiguration)
• .xml - XML file (XMLConfiguration)

Extensions are not case sensitive.

The configuration will be added to the application's LayeredConfiguration with the given priority.

Returns the application's logger.

Before the logging subsystem has been initialized, the application's logger is "ApplicationStartup", which is connected to a ConsoleChannel.

After the logging subsystem has been initialized, which usually happens as the first action in Application::initialize(), the application's logger is the one specified by the "application.logger" configuration property. If that property is not specified, the logger is "Application".

See also: Poco::Util::Subsystem::name()

Returns the application's option set.

Runs the application by performing additional (un)initializations and calling the main() method.

First calls initialize(), then calls main(), and finally calls uninitialize(). The latter will be called even if main() throws an exception. If initialize() throws an exception, main() will not be called and the exception will be propagated to the caller. If uninitialize() throws an exception, the exception will be propagated to the caller.

Specify whether command line option handling is Unix-style (flag == true; default) or Windows/OpenVMS-style (flag == false).

This member function should be called from the constructor of a subclass to be effective.

Returns the application start time (UTC).

If called from an option callback, stops all further options processing.

If called, the following options on the command line will not be processed, and required options will not be checked.

This is useful, for example, if an option for displaying help information has been encountered and no other things besides displaying help shall be done.

Returns a reference to the subsystem list

Returns the application uptime.

Returns the current window size of the console window, if available.

Currently implemented for POSIX platforms (via TIOCGWINSZ ioctl()) and Windows (GetConsoleScreenBufferInfo()).

Returns zero width and height if the window size cannot be determined.

Called before command line processing begins. If a subclass wants to support command line arguments, it must override this method. The default implementation does not define any options itself, but calls defineOptions() on all registered subsystems.

Overriding implementations should call the base class implementation.

See also: Poco::Util::Subsystem::defineOptions()

Find the application config file.

loadConfiguration will call this function to find config file, you can override this function to find your own config file.

Searches for the file in path in the application directory.

If path is absolute, the method immediately returns true and leaves path unchanged.

If path is relative, searches for the file in the application directory and in all subsequent parent directories. Returns true and stores the absolute path to the file in path if the file could be found. Returns false and leaves path unchanged otherwise.

Called when the option with the given name is encountered during command line arguments processing.

The default implementation does option validation, bindings and callback handling.

Overriding implementations must call the base class implementation.

Common initialization code.

Initializes the application and all registered subsystems. Subsystems are always initialized in the exact same order in which they have been registered.

Overriding implementations must call the base class implementation.

See also: Poco::Util::Subsystem::initialize()

The application's main logic.

Unprocessed command line arguments are passed in args. Note that all original command line arguments are available via the properties application.argc and application.argv[<n>].

Returns an exit code which should be one of the values from the ExitCode enumeration.

Re-nitializes the application and all registered subsystems. Subsystems are always reinitialized in the exact same order in which they have been registered.

Overriding implementations must call the base class implementation.

See also: Poco::Util::Subsystem::reinitialize()

Sets the logger used by the application.

Uninitializes the application and all registered subsystems. Subsystems are always uninitialized in reverse order in which they have been initialized.

Overriding implementations must call the base class implementation.

See also: Poco::Util::Subsystem::uninitialize()