yp_next
err = yp_next(nis_mydomain, my_mapname, key, kl,
err = yp_next(nis_mydomain, my_nismap, key, kl,
if (err = yp_next(domain, map, key, keylen, &outkey, &outkeylen,
if (err = yp_next(domain_alias, ypservers, key, keylen,
extern int yp_next(char *, char *, char *, int, char **, int *, char **, int *);