glib.Module.Module Class Reference

List of all members.

Detailed Description

Description 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. A program which wants to use these functions must be linked to the libraries output by the command pkg-config --libs gmodule-2.0. To use them you must first determine whether dynamic loading is supported on the platform by calling g_module_supported(). If it is, you can open a module with g_module_open(), find the module's symbols (e.g. function names) with g_module_symbol(), and later close the module with g_module_close(). g_module_name() will return the file name of a currently opened module. If any of the above functions fail, the error status can be found with g_module_error(). The GModule implementation features reference counting for opened modules, and supports hook functions within a module which are called when the module is loaded and unloaded (see GModuleCheckInit and GModuleUnload). If your module introduces static data to common subsystems in the running program, e.g. through calling g_quark_from_static_string ("my-module-stuff"), it must ensure that it is never unloaded, by calling g_module_make_resident(). Example12.Calling a function defined in a GModule /+* the function signature for 'say_hello' +/ typedef void (* SayHelloFunc) (const char *message); gboolean just_say_hello (const char *filename, GError **error) { SayHelloFunc say_hello; GModule *module; module = g_module_open (filename, G_MODULE_BIND_LAZY); if (!module) { g_set_error (error, FOO_ERROR, FOO_ERROR_BLAH, "%s", g_module_error ()); return FALSE; } if (!g_module_symbol (module, "say_hello", (gpointer *)say_hello)) { g_set_error (error, SAY_ERROR, SAY_ERROR_OPEN, "%s: %s", filename, g_module_error ()); if (!g_module_close (module)) g_warning ("%s: %s", filename, g_module_error ()); return FALSE; } if (say_hello == NULL) { g_set_error (error, SAY_ERROR, SAY_ERROR_OPEN, "symbol say_hello is NULL"); if (!g_module_close (module)) g_warning ("%s: %s", filename, g_module_error ()); return FALSE; } if (say_hello == NULL) { g_set_error (error, SAY_ERROR, SAY_ERROR_OPEN, "symbol say_hello is NULL"); if (!g_module_close (module)) g_warning ("%s: %s", filename, g_module_error ()); return FALSE; } /+* call our function in the module +/ say_hello ("Hello world!"); if (!g_module_close (module)) g_warning ("%s: %s", filename, g_module_error ()); return TRUE; }


Public Member Functions

GModulegetModuleStruct ()
 this (GModule *gModule)
 Sets our main struct and passes it to the parent class.
int symbol (char[] symbolName, void **symbol)
 Gets a symbol pointer from a module.
char[] name ()
 Gets the filename from a GModule.
void makeResident ()
 Ensures that a module will never be unloaded.
int close ()
 Closes a module.

Static Public Member Functions

static int supported ()
 Checks if modules are supported on the current platform.
static char[] buildPath (char[] directory, char[] moduleName)
 A portable way to build the filename of a module.
static Module open (char[] fileName, GModuleFlags flags)
 Opens a module.
static char[] error ()
 Gets a string describing the last module error.

Protected Member Functions

void * getStruct ()
 the main Gtk struct as a void*

Protected Attributes

GModulegModule
 the main Gtk struct


Constructor & Destructor Documentation

glib.Module.Module.this ( GModule gModule  ) 

Sets our main struct and passes it to the parent class.


Member Function Documentation

static char [] glib.Module.Module.buildPath ( char[]  directory,
char[]  moduleName 
) [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 NULL 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 as the directory it will return .dll. directory: the directory where the module is. This can be NULL 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.

int glib.Module.Module.close (  ) 

Closes a module.

module: a GModule to close. Returns: TRUE on success.

static char [] glib.Module.Module.error (  )  [static]

Gets a string describing the last module error.

Returns: a string describing the last module error.

GModule* glib.Module.Module.getModuleStruct (  ) 

void* glib.Module.Module.getStruct (  )  [protected]

the main Gtk struct as a void*

void glib.Module.Module.makeResident (  ) 

Ensures that a module will never be unloaded.

Any future g_module_close() calls on the module will be ignored. module: a GModule to make permanently resident.

char [] glib.Module.Module.name (  ) 

Gets the filename from a GModule.

module: a GModule. Returns: the filename of the module, or "main" if the module is the main program itself.

static Module glib.Module.Module.open ( char[]  fileName,
GModuleFlags  flags 
) [static]

Opens a module.

If the module has already been opened, its reference count is incremented. First of all g_module_open() 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 g_module_open() tries to open the corresponding module. If eventually that fails as well, NULL is returned. file_name: the name of the file containing the module, or NULL to obtain a GModule representing the main program itself. flags: the flags used for opening the module. This can be the logical OR of any of the GModuleFlags. Returns: a GModule on success, or NULL on failure.

static int glib.Module.Module.supported (  )  [static]

Checks if modules are supported on the current platform.

Returns: TRUE if modules are supported.

int glib.Module.Module.symbol ( char[]  symbolName,
void **  symbol 
)

Gets a symbol pointer from a module.

Note that a valid symbol can be NULL. Note that a valid symbol can be NULL. module: a GModule. symbol_name: the name of the symbol to find. symbol: returns the pointer to the symbol value. Returns: TRUE on success.


Member Data Documentation

GModule* glib.Module.Module.gModule [protected]

the main Gtk struct


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