extern int pw_close (void);
extern const struct passwd *pw_locate (const char *);
extern int pw_lock (void);
extern int pw_name (const char *);
extern const struct passwd *pw_next (void);
extern int pw_open (int);
extern int pw_remove (const char *);
extern int pw_rewind (void);
extern int pw_unlock (void);
extern int pw_update (const struct passwd *);
extern int pw_sort (void);