Block Swap AutoLisp

Attached and submitted to site for free use, with acknowledgements

if any improvments, please let me know, thank you

john

Block_Swap.lsp

My version is similar, except you select one of the original blocks, then the new block, then create a selection box around the blocks you want to replace.

(defun c:replace ( / old-block new-block block-sel lcv block)
(setq old-block (entget (car (entsel "\nSelect the old block: ")))
      new-block (entget (car (entsel "\nSelect the new block: ")))
      lcv (princ "\nSelect blocks to be replaced: ")
      block-sel (ssget (list (assoc 2 old-block)))
      lcv 0)
(while (< lcv (sslength block-sel))
 (setq block (entget (ssname block-sel lcv)))
 (entmod (subst (assoc 2 new-block) (assoc 2 old-block) block))
 (setq lcv (+ 1 lcv))
)
)

Thanks Eric

Have a look at attached it belongs to Aleksandr Smirnov

Lovely routine BUT....!!! when you swop/replace Blocks he REMOVES the Attributes of the Swopped Blocks which is a pity. Wish he would amend to retain attribute info as selected blocks are swopped over to a new block name..

Cheers john

cblock.LSP