mysql_load_plugin()

You can call the mysql_load_plugin() function to load an OBClient plug-in of the specified name and type.

Syntax

struct st_mysql_client_plugin *
mysql_load_plugin(MYSQL *mysql,
                  const char *name,
                  int type,
                  int argc,
                  ...)

Arguments

• mysql: a pointer to a MYSQL structure. The plug-in API does not require a connection to the OBServer, but this structure must be properly initialized. The structure is used to obtain connection-related information.

• name: The name of the plug-in that you want to load.

• type: The type of the plug-in that you want to load. You can set it to -1 to disable type checking. If type is not -1, only plug-ins that match the type are considered for loading.

• argc: The number of following arguments. Set it to 0 if no following argument exists.

Return values

A pointer to the plug-in is returned after the plug-in is loaded. NULL is returned if an error occurred.

Errors

Call the mysql_error() or mysql_errno() function to check for errors.

Notes

An error occurs if the type is invalid or the plug-in cannot be loaded. You cannot load multiple plug-ins of the same type. An error occurs if you try to load a plug-in of a type already loaded.

Alternatively, you can load plug-ins by setting the LIBMYSQL_PLUGINS environment variable to a list of plug-in names separated with semicolons (;). Example:

export LIBMYSQL_PLUGINS="myplugin1;myplugin2;myplugin3"

Plug-ins named by LIBMYSQL_PLUGINS are loaded when the client program calls mysql_library_init(). No error is reported if problems occur in loading these plug-ins. The LIBMYSQL_PLUGIN_DIR environment variable can be set to the path name of the directory in which client plug-ins are searched for. This variable is used in two ways:

• During the preloading of client plug-ins, the value of the --plugin-dir option is not available. Therefore, client plug-in loading fails unless the plug-ins are located in the hardwired default directory. If the plug-ins are located elsewhere, LIBMYSQL_PLUGIN_DIR environment variable can be set to the proper directory to enable plug-in preloading to succeed.

• For explicit client plug-in loading, the mysql_load_plugin() and mysql_load_plugin_v() functions are used. C API functions use the LIBMYSQL_PLUGIN_DIR value if it exists and the --plugin-dir option is not given. If --plugin-dir is given, mysql_load_plugin() and mysql_load_plugin_v() ignore LIBMYSQL_PLUGIN_DIR.