extern int cgit_open_filter(struct cgit_filter *filter, ...);
extern int cgit_close_filter(struct cgit_filter *filter);
extern void cgit_fprintf_filter(struct cgit_filter *filter, FILE *f, const char *prefix);
extern void cgit_exec_filter_init(struct cgit_exec_filter *filter, char *cmd, char **argv);
extern struct cgit_filter *cgit_new_filter(const char *cmd, filter_type filtertype);
extern int cgit_open_filter(struct cgit_filter *filter, ...);
extern int cgit_close_filter(struct cgit_filter *filter);
extern void cgit_fprintf_filter(struct cgit_filter *filter, FILE *f, const char *prefix);
extern void cgit_exec_filter_init(struct cgit_exec_filter *filter, char *cmd, char **argv);
extern struct cgit_filter *cgit_new_filter(const char *cmd, filter_type filtertype);