User Exit Reference › FORMAT User Exit › Description

Description

Because of the requirements of issuing macro primitives, the FORMAT user exit cannot be written in Assembler. It must be coded in REXX or EXEC2.

When moving a minidisk from one location to another and the device type, block size, or number of cylinders of the disk has not changed, CA VM:Secure uses DDR to move the minidisk to its new location instead of using the FORMAT and COPYFILE commands. This means that only the source minidisk is formatted; therefore, the FORMAT user exit is called only for the source minidisk.

The FORMAT user exit uses CA VM:Secure macro primitives, commands that are issued within the user exit, to communicate with the user or servant user ID. The user or servant user ID is the user ID where the minidisk and the SFS directory are accessed.

The CA VM:Secure macro primitives that are most likely to be used are:

• USER EXECUTE or SERVANT EXECUTE—Issues a command on the user or servant virtual machine. The command text arguments that follow are issued on the indicated machine using CMSCALL.
• USER STACK or SERVANT STACK—Places data that you will need later on, such as for a subsequent command, on the user or servant virtual machine program stack. The etx arguments that follow are stacked in LIFO order on the appropriate program stack.
• USER READ or SERVANT READ—Causes the data that exists on the user or servant virtual machine stack to be read to storage on the user or servant virtual machine.

To use any of these primitives, precede it with the token TEST. This token allows the primitive to pass a nonzero return code back to the exit.

The sample (prototype) user exit contains examples of the use of these primitives.