slapo−valsort — Value Sorting overlay to slapd
ETCDIR/slapd.conf
The Value Sorting overlay can be used with a backend database to sort the values of specific multi-valued attributes within a subtree. The sorting occurs whenever the attributes are returned in a search response.
Sorting can be specified in ascending or descending order,
      using either numeric or alphanumeric sort methods.
      Additionally, a "weighted" sort can be specified, which uses
      a numeric weight prepended to the attribute values. The
      weighted sort is always performed in ascending order, but may
      be combined with the other methods for values that all have
      equal weights. The weight is specified by prepending an
      integer weight {<weight>} in front of each
      value of the attribute for which weighted sorting is desired.
      This weighting factor is stripped off and not returned in
      search results unless the valsort control is specified
      (1.3.6.1.4.1.4203.666.5.14).
The valsort control requires a value consisting of a Sequence that contains a boolean flag. The weighting factor is only returned if the boolean value is TRUE. In lber-encode(3) format, the required value must conform to "{b}" syntax.
These slapd.conf
      options apply to the Value Sorting overlay. They should
      appear after the overlay directive.
valsort−attr <attribute>
          <baseDN>(<sort-method>
          | weighted [<sort-method>])Configure a sorting method for the specified
            attribute in
            the subtree rooted at baseDN. The sort-method may be one
            of alpha−ascend,
            alpha−descend,
            numeric−ascend,
            or numeric−descend.
            If the special weighted method is
            specified, a secondary sort-method may also be
            specified. It is an error to specify an alphanumeric
            sort-method
            for an attribute with Integer or NumericString syntax,
            and it is an error to specify a numeric sort-method for an
            attribute with a syntax other than Integer or
            NumericString.
        database bdb
        suffix dc=example,dc=com
        ...
        overlay valsort
        valsort−attr member ou=groups,dc=example,dc=com alpha−ascend
      To invoke ldapsearch(1) with the valsort control, the control value must be set appropriately. The following octets represent the desired "{b}" encoding:
        0x30 0x03 0x01 0x01 0xff
      The control can be sent from the command-line using the base64 encoding of the value:
        ldapsearch -E 1.3.6.1.4.1.4203.666.5.14=::MAMBAf8=