+/* \brief converts SRU/SRW 1.1 sortkeys to Z39.50 sortspec (WRBUF)
+ \param srw_sortkeys SRU sortkeys string
+ \param w resulting Z39.50 sortspec, WRBUF string
+ \retval 0 successful
+ \retval -1 failure
+*/
+int yaz_srw_sortkeys_to_sort_spec(const char *srw_sortkeys, WRBUF w);