ref: 8f4053d1efa1ee75a7bea09e624f1134d71a289a
dir: /sys/src/cmd/upas/bayes/msgdb.h/
typedef struct Msgdb Msgdb; Msgdb *mdopen(char*, int); long mdget(Msgdb*, char*); void mdput(Msgdb*, char*, long); void mdenum(Msgdb*); int mdnext(Msgdb*, char**, long*); void mdclose(Msgdb*);