;; RenameBlock.lsp (c) 2003, John F. Uhden, Cadlantic/CADvantage
;; Fixed up to validate (01-09-03)
;; Arguments:
;;   old - old block name as a string (case-insensitive)
;;   new - new block name as a string (case-sensitive in pre-R15 only)
;; Returns:
;;   T   - if successful
;;   nil - if it failed for any reason
(defun RenameBlock (old new / ent)
  (and
    (= (type old)(type new) 'STR)
    (/= new old)
    (snvalid new 0)
    (setq ent (tblobjname "block" old))
    (or
      ;; allow changing case of block name
      (= (strcase old)(strcase new))
      (not (tblobjname "block" new))
    )
    ;; then get the block record...
    (setq ent (cdr (assoc 330 (entget ent))))
    (setq ent (entget ent))
    (entmod (subst (cons 2 new)(assoc 2 ent) ent))
  )
)