Writing a SHELL backend database

Modify

The input format for a MODIFY request is as follows:

   MODIFY
   msgid: integer
   [suffix: dn]+
   dn: entrydn
   [add: attrtype
    [attrtype: attrvalue]+]
   [delete: attrtype
    [attrtype: attrvalue]]
   [replace: attrtype
    [attrtype: attrvalue]+]

The add, delete and replace constructs indicate the modifications to make.