Glib::Module Class Reference

Dynamic Loading of Modules These functions provide a portable way to dynamically load object files (commonly known as 'plug-ins'). More...

#include <glibmm/module.h>

Public Member Functions
	Module (const std::string& file_name, ModuleFlags flags=ModuleFlags(0))
	Opens a module. More...
	Module (const Module&)=delete
Module&	operator= (const Module&)=delete
	Module (Module&& other) noexcept
Module&	operator= (Module&& other) noexcept
virtual	~Module ()
	Close a module. More...
	operator bool () const
	Check whether the module was found. More...
void	make_resident ()
	Ensures that a module will never be unloaded. More...
bool	get_symbol (const std::string& symbol_name, void*& symbol) const
	Gets a symbol pointer from the module. More...
std::string	get_name () const
	Get the name of the module. More...
GModule*	gobj ()
const GModule*	gobj () const

Static Public Member Functions
static bool	get_supported ()
	Checks if modules are supported on the current platform. More...
static std::string	get_last_error ()
	Gets a string describing the last module error. More...
static std::string	build_path (const std::string& directory, const std::string& module_name)
	A portable way to build the filename of a module. More...

Protected Attributes
GModule*	gobject_

Detailed Description

Dynamic Loading of Modules These functions provide a portable way to dynamically load object files (commonly known as 'plug-ins').

The current implementation supports all systems that provide an implementation of dlopen() (e.g. Linux/Sun), as well as HP-UX via its shl_load() mechanism, and Windows platforms via DLLs.

Constructor & Destructor Documentation

Module() [1/3]

Glib::Module::Module ( const std::string &  file_name, ModuleFlags  flags = ModuleFlags(0)  )

explicit

Opens a module.

First of all it tries to open file_name as a module. If that fails and file_name has the ".la"-suffix (and is a libtool archive) it tries to open the corresponding module. If that fails and it doesn't have the proper module suffix for the platform (G_MODULE_SUFFIX), this suffix will be appended and the corresponding module will be opended. If that fails and file_name doesn't have the ".la"-suffix, this suffix is appended and it tries to open the corresponding module.

Use operator bool() to see whether the operation succeeded. For instance,

Glib::Module module("plugins/helloworld");
if(module)
{
  void* func = nullptr;
  bool found = get_symbol("some_function", func);
}

Parameters

file_name	The library filename to open
flags	Flags to configure the load process

Module() [2/3]

Glib::Module::Module ( const Module&  )

delete

Module() [3/3]

Glib::Module::Module ( Module&&  other )

noexcept

~Module()

virtual Glib::Module::~Module ( )

virtual

Close a module.

The module will be removed from memory, unless make_resident has been called.

Member Function Documentation

build_path()

static std::string Glib::Module::build_path ( const std::string &  directory, const std::string &  module_name  )

static

A portable way to build the filename of a module.

The platform-specific prefix and suffix are added to the filename, if needed, and the result is added to the directory, using the correct separator character.

The directory should specify the directory where the module can be found. It can be an empty string to indicate that the module is in a standard platform-specific directory, though this is not recommended since the wrong module may be found.

For example, calling build_path() on a Linux system with a directory of /lib and a module_name of "mylibrary" will return /lib/libmylibrary.so. On a Windows system, using \Windows as the directory it will return \Windows\mylibrary.dll.

Parameters

directory	The directory the module is in
module_name	The name of the module

Returns

The system-specific filename of the module A portable way to build the filename of a module. The platform-specific prefix and suffix are added to the filename, if needed, and the result is added to the directory, using the correct separator character.

The directory should specify the directory where the module can be found. It can be nullptr or an empty string to indicate that the module is in a standard platform-specific directory, though this is not recommended since the wrong module may be found.

For example, calling g_module_build_path() on a Linux system with a directory of /lib and a module_name of "mylibrary" will return /lib/libmylibrary.so. On a Windows system, using \\Windows as the directory it will return \\Windows\\mylibrary.dll.

Parameters

directory	The directory where the module is. This can be nullptr or the empty string to indicate that the standard platform-specific directories will be used, though that is not recommended.
module_name	The name of the module.

Returns

The complete path of the module, including the standard library prefix and suffix. This should be freed when no longer needed.

get_last_error()

static std::string Glib::Module::get_last_error ( )

static

Gets a string describing the last module error.

Returns

The error string

get_name()

std::string Glib::Module::get_name

(

)

const

Get the name of the module.

Returns

The name of the module

get_supported()

static bool Glib::Module::get_supported ( )

static

Checks if modules are supported on the current platform.

Returns

true if available, false otherwise

get_symbol()

bool Glib::Module::get_symbol	(	const std::string &	symbol_name,
		void *&	symbol
	)		const

Gets a symbol pointer from the module.

Parameters

symbol_name	The name of the symbol to lookup
symbol	A pointer to set to the symbol

Returns

True if the symbol was found, false otherwise.

gobj() [1/2]

GModule* Glib::Module::gobj ( )

inline

gobj() [2/2]

const GModule* Glib::Module::gobj ( ) const

inline

make_resident()

void Glib::Module::make_resident

(

)

Ensures that a module will never be unloaded.

Any calls to the Glib::Module destructor will not unload the module.

operator bool()

Glib::Module::operator bool ( ) const

explicit

Check whether the module was found.

operator=() [1/2]

Module& Glib::Module::operator= ( const Module&  )

delete

operator=() [2/2]

Module& Glib::Module::operator= ( Module&&  other )

noexcept

Member Data Documentation

gobject_

GModule* Glib::Module::gobject_

protected