TRUNC (Truncate Block) Macro

It allows you to write a short block of records. These short blocks do not include padding. Thus, the macro can be used for a function similar to that of the RELSE macro for input records. When the end of a category of records is reached, the last block can be written and the new category can be started at the beginning of a new block.

The TRUNC macro does not necessarily cause a physical write to an FBA disk. If this is desirable, code the PWRITE operand in the DTFSD macro for the affected file.