If an ENGINE supports its own specific control commands and wishes the
framework to handle the above 'ENGINE_CMD_***'-manipulation commands on its
behalf, it should supply a null-terminated array of ENGINE_CMD_DEFN entries
to ENGINE_set_cmd_defns(). It should also implement a ctrl() handler that
supports the stated commands (ie. the "cmd_num" entries as described by the
array). NB: The array must be ordered in increasing order of cmd_num.
"null-terminated" means that the last ENGINE_CMD_DEFN element has cmd_num set
to zero and/or cmd_name set to null.
If an ENGINE supports its own specific control commands and wishes the framework to handle the above 'ENGINE_CMD_***'-manipulation commands on its behalf, it should supply a null-terminated array of ENGINE_CMD_DEFN entries to ENGINE_set_cmd_defns(). It should also implement a ctrl() handler that supports the stated commands (ie. the "cmd_num" entries as described by the array). NB: The array must be ordered in increasing order of cmd_num. "null-terminated" means that the last ENGINE_CMD_DEFN element has cmd_num set to zero and/or cmd_name set to null.