TBLT_RETC TBLT_ENTRY BltUnlockDataHeader(TBLT_DH *dhPtr); dhPtr I:data file control structureThis routine unlocks the file header.
After making any changes to the data file and before unlocking, you must
call BltDataFlushHeader()
to update the data file header on disk.
Returns: Non-zero indicates an error, otherwise the data file header is unlocked.