Valid on Alpha and Integrity server systems only.
    Generates a string that is suitable to be a file name and is
    guaranteed to be unique across the cluster. Unique file names can
    be useful when creating temporary files. (See CLOSE/DISPOSITION
    for an example.)
    The F$UNIQUE function has no arguments, but must be followed by a
    blank pair of parentheses.
    Format
      F$UNIQUE()
Additional Information:
explode
extract