CXBLKSELBlocks and attributesVersion 1.0.0Tested in AutoCAD

Select blocks by name or attribute value

Selects every block with a given name, or only those whose attribute has a given value, so you can then move, copy or edit them together.

Download cxblksel.lsp LISP terms

How to use it

Type CXBLKSEL and click a block, or choose Name and type it. Wildcards work.
Optionally narrow it down with TAG=value, for example SIZE=DN50.
The matching blocks are selected, ready for your next command.

Good to know

Searches the current model or layout tab.

Load it in AutoCAD

Save the file anywhere you like.
Type APPLOAD, pick the file and choose Load.
Type the command name: CXBLKSEL.

To have it at every start, add it to the Startup Suite in the same dialog, or load a whole folder at once with the optional loader. About the optional loader

Tested in AutoCAD (full version). Other programs that run AutoLISP may work, but they are not tested.

The code

Plain text, nothing hidden. Copy it into a file named cxblksel.lsp, or download it.

;;; ============================================================================
;;; CXBLKSEL - Select all blocks of one name or attribute value
;;; Version 1.0.0
;;; CADXChange LISP tools - https://cadxchange.net/resources/lisp/cxblksel
;;; Tested in: AutoCAD (full version). Other programs that run AutoLISP may work but are not tested.
;;; Copyright (c) CADXChange. Free for personal and commercial use; do not resell or
;;; republish it as a collection. Terms: https://cadxchange.net/legal/lisp-terms
;;; ============================================================================

;; Every block reference in the current layout whose block name matches NAME (wildcards allowed).
;; With TAG and VALUE, only those whose attribute TAG matches VALUE (wildcards allowed, any case).
;; Returns a selection set, or nil when nothing matches.
(defun cx:blksel-run (name tag value / ss out)
  (setq ss (ssget "X" (list '(0 . "INSERT") (cons 2 name) (cons 410 (getvar "CTAB")))))
  (if (and ss tag)
    (progn
      (setq out (ssadd))
      (foreach e (cx:ss->list ss)
        (if (and (cx:att-get e tag) (wcmatch (strcase (cx:att-get e tag)) (strcase value)))
          (ssadd e out)))
      (setq ss (if (> (sslength out) 0) out nil))))
  ss)

(defun c:CXBLKSEL ( / *error* cx:sv r name filter p tag value ss)
  (setq *error* cx:err)
  (initget "Name")
  (setq r (entsel "\nClick a block, or [Name]: "))
  (cond
    ((= r "Name") (setq name (cx:ask-str "Block name (wildcards allowed)" "-")))
    ((and r (= (cx:dxf 0 (entget (car r))) "INSERT")) (setq name (cx:dxf 2 (entget (car r)))))
    (r (princ "\nThat is not a block.")))
  (if (and name (/= name ""))
    (progn
      (setq filter (cx:ask-str "Only blocks where an attribute has a value, as TAG=value (- for all)" "-"))
      (if (and (/= filter "-") (/= filter "") (setq p (cx:find filter "=" 1)))
        (setq tag   (cx:trim (substr filter 1 (1- p)))
              value (cx:trim (substr filter (1+ p)))))
      (if (setq ss (cx:blksel-run name tag value))
        (progn
          (sssetfirst nil ss)
          (princ (strcat "\n" (itoa (sslength ss)) " block(s) selected.")))
        (princ "\nNo matching blocks in this layout."))))
  (princ))


;;; ---- Shared helpers (used by the command above; identical in every CADXChange tool) ----

;; Selection set to a list of entity names.
(defun cx:ss->list (ss / i out)
  (setq i 0)
  (if ss
    (repeat (sslength ss)
      (setq out (cons (ssname ss i) out)
            i   (1+ i))))
  (reverse out))

(defun cx:dxf (code ed)
  (cdr (assoc code ed)))

;; The ATTRIB entities of a block reference, in order.
(defun cx:attribs (ins / e out)
  (setq e (entnext ins))
  (while (and e (= (cx:dxf 0 (entget e)) "ATTRIB"))
    (setq out (cons e out) e (entnext e)))
  (reverse out))

;; The ATTRIB of a block reference with the tag TAG (any case), or nil.
(defun cx:att-find (ins tag / r)
  (foreach a (cx:attribs ins)
    (if (and (not r) (= (strcase (cx:dxf 2 (entget a))) (strcase tag))) (setq r a)))
  r)

(defun cx:att-get (ins tag / a)
  (if (setq a (cx:att-find ins tag)) (cx:dxf 1 (entget a))))

;; Close the undo step and put the system variables back.
(defun cx:end ()
  (foreach v cx:sv (setvar (car v) (cdr v)))
  (command "_.UNDO" "_End")
  (setq cx:sv nil)
  (princ))

;; Error handler: restores everything, stays quiet on Esc.
(defun cx:err (msg)
  (if (> (getvar "CMDACTIVE") 0) (command))
  (cx:end)
  (if (and msg (not (wcmatch (strcase msg) "*BREAK*,*CANCEL*,*EXIT*")))
    (princ (strcat "\nError: " msg)))
  (princ))

;; Ask for a string (spaces allowed) with a default; "-" means an empty string.
(defun cx:ask-str (msg def / v)
  (setq v (getstring T (strcat "\n" msg " <" def ">: ")))
  (cond ((= v "") def) ((= v "-") "") (T v)))

;; 1-based position of SUB in STR at or after START, or nil.
(defun cx:find (str sub start / n i r)
  (setq n (strlen sub) i start r nil)
  (if (> n 0)
    (while (and (not r) (<= i (1+ (- (strlen str) n))))
      (if (= (substr str i n) sub) (setq r i))
      (setq i (1+ i))))
  r)

;; Remove spaces and tabs at both ends.
(defun cx:trim (s / a b)
  (setq a 1 b (strlen s))
  (while (and (<= a b) (member (substr s a 1) '(" " "\t"))) (setq a (1+ a)))
  (while (and (>= b a) (member (substr s b 1) '(" " "\t"))) (setq b (1- b)))
  (substr s a (max 0 (1+ (- b a)))))

(princ "\nCXBLKSEL loaded. Type CXBLKSEL to start.")
(princ)

Version history

Version 1.0.0 · 27 de outubro de 2026

First release.