This function sets sorting criteria and enables Z39.50 Sort.
Call this function before yaz_search. Using this function alone does not have any effect. When used in conjunction with yaz_search, a Z39.50 Sort will be sent after a search response has been received and before any records are retrieved with Z39.50 Present (yaz_present.
The connection resource returned by yaz_connect.
A string that takes the form field1 flags1 field2 flags2 where field1 specifies the primary attributes for sort, field2 seconds, etc..
The field specifies either a numerical attribute combinations consisting of type=value pairs separated by comma (e.g. 1=4,2=1) ; or the field may specify a plain string criteria (e.g. title. The flags is a sequence of the following characters which may not be separated by any white space.
Case insensitive sorting
Case sensitive sorting
No value is returned.