Example:

    GTM> W $ZGETDVI($ZPARSE("cus.dat","device"),"freeblocks")
    296697
    GTM>
    

This uses $ZGETDVI() and $ZPARSE() to display the number of free RMS blocks on the disk drive that holds the CUS.DAT file.

Example:

    IF $ZGETDVI($IO,"PRINTER") WRITE clrtop    
    

This uses $ZGETDVI() as the argument to an IF command, such that the WRITE command executes only if the current device has an attached printer port.