/**
* A pointer to the filter's command line parser.
*
- * If this optional function pointer is not NULL, any filter options are passed
- * from the main program to this command line parser once at application
- * startup. The command line parser should check its command line options given
- * by \a argc and \a argv and abort on errors. On success, it should return a
- * pointer to the filter-specific configuration data determined by \a argc and
- * \a argv.
+ * If this optional function pointer is not NULL, any filter options
+ * are passed from the main program to this command line parser once at
+ * application startup. The command line parser should check its
+ * command line options given by \a argc and \a argv and abort on
+ * errors. Success must be indicated by a non-negative return value. In
+ * this case the function should return a pointer to the
+ * filter-specific configuration data determined by \a argc and \a
+ * argv. On failure, a negative paraslash error code must be returned.
*/
- void *(*parse_config)(int argc, char **argv);
+ int (*parse_config)(int argc, char **argv, void **config);
};
void close_filters(struct filter_chain *fc);