How to MODIFY block attributes? DATESTAMP

;;;; FAQ: [22.2] How to MODIFY block attributes? DATESTAMP

;;; Change all DATESTAMP attributes in all inserted PLOT* blocks

(defun C:DATESTAMP ()
  (std-ssmap
   '(lambda (ele)
      (std-attchg ele "DATESTAMP" (std-today))
      (entupd ele))
    (ssget "X" '((0 . "INSERT")(2 . "PLOT*")))
  )
)