extern int ndmchan_post_poll (struct ndmchan *chtab[], unsigned n_chtab);
extern void ndmchan_compress (struct ndmchan *ch);
extern int ndmchan_n_avail (struct ndmchan *ch);
+extern int ndmchan_n_avail_record (struct ndmchan *ch, unsigned long size);
extern int ndmchan_n_avail_total (struct ndmchan *ch);
extern int ndmchan_n_ready (struct ndmchan *ch);
extern enum ndmchan_read_interpretation