This specifies the sort option.
The Sort option (-sort), Merge option (-merge), and Copy option (-copy) are mutually in the exclusive relationship. When the Sort option (-sort), Merge option (-merge), and Copy option (-copy) are omitted, it is assumed that the Sort option (-sort) having the entire record as a key is specified. For information about each operand, refer to the descriptions in the Merge option (-merge).
Format
-sort [ key=key-definition [ ,key-definition ...] [ key= ...] ]
