;1.0 6/26/2014
;
(prompt " COPYCAT.lsp\n")

;;;Important variables
;blkname1 = name of block to modify
;attFROM = attribute tag within blkname1 to copy from
;attTO = attribure tag within blkname1 to copy to
;FROMvalue = value of attFROM
;TOvalue = value of attTO


(defun C:COPYCAT () 
				;defines function w/ no variable		
		
(setvar "cmdecho" 0)
				;turns off echoing
				
(setq I 0)
				;sets variable I to zero


(setq blkname1 (getstring "\nBlock name:  "))
				;sets blkname1 to user prompted input


(setq attFROM (getstring "\nFROM attribute tag: "))
				;sets attFROM to user prompted input


(setq attTO (getstring "\nTO attribute tag: "))
				;sets attTO to user prompted input
	

(setq sset (ssget "x" (list (cons 2 blkname1))))
				;list created, add 2 to front of blockname to create list to create (2 . blkname1)
				;select(get) everything that is (2 . blkname1) which is (insert with name blkname1)
				;set "sset" to the selected block or blocks



(if (= sset nil)(setq l 0)
				;if nothing selected, set l to zero

(setq l (sslength sset)))
				;set l to the integer length of sset (number of blocks that were selected)


(repeat l
				;repeat everything after this for 'l' number of blocks



;;Find FROM attribute in current block and copy it
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
      (setq stop 1)
				;set 'stop' to 1

        (setq name (ssname sset I))
				;set 'name' to the entity ID name of the first(i=0) of selection 'sset'
				;i.e this is the first block's entity name

                 (while (= stop 1)
				;while 'stop' is equal to 1


                        (setq name1 (entget (entnext name)))
				;set name1 to the entity's definition (tag) of the next attribute in "name" (block)

                        (setq ATT (cdr (assoc 2 name1)))
				;set 'ATT' to everything after the first thing in list, which is anything with (2=att TAG)

                        (if (= ATT attFROM)(setq go 1))
				;if 'att' is the name of attribute to copy, then set 'go' to 1

                        (setq name (cdr (assoc -1 name1)))  
				;don't actually know what's going on here
                        
                        (while (= go 1)
				;if we found the correct attribute ('go' = 1), then do what's after this

                                (setq FROMvalue (assoc 1 name1))
					;set 'FROMvalue' to the value of (1=attribute VALUE) in attribute 'name1'

                                (setq go nil)
					;set 'go' to nil

                                (setq stop nil)
					;set 'stop' to nil
                        )
			;end 'go' while loop

                )
		;end 'stop' while loop



;;Find TO attribute in current block and replace it with FROMvalue
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;


        (setq stop 1)
				;set 'stop' to 1

        (setq name (ssname sset I))
				;set 'name' to the entity ID name of the first(i=0) of selection 'sset'
				;i.e this is the first block's entity name

                 (while (= stop 1)
				;while 'stop' is equal to 1

                        (setq name1 (entget (entnext name)))
				;set name1 to the entity's definition (tag) of the next attribute in "name" (block)

                        (setq ATT (cdr (assoc 2 name1)))
				;set 'ATT' to everything after the first thing in list, which is anything with (2=att TAG)

                        (if (= ATT attTO)(setq go 1))
				;if 'att' is the name of attribute to change, then set 'go' to 1

                        (setq name (cdr (assoc -1 name1)))  
				;don't know what's going on here
                        
                        (while (= go 1)
				;if we found the correct attribute ('go' = 1), then do what's after this

                                (setq TOvalue (assoc 1 name1))
					;set 'TOvalue' to the selected value to overwrite
	
                                (setq d1 (subst TOvalue FROMvalue name1))
					;set d1 to a new list that substitutes FROMValue(new value) for TOvalue(old attribute value) in list name1(attribute entity)

                                (entmod d1)
					;update d1 list database which will update the attribute and block

                                (setq go nil)
					;set 'go' to nil

                                (setq stop nil)
					;set 'stop' to nil
                        )
			;end 'go' while loop

                )
		;end 'stop' while loop
   	 

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;


         (setq i (1+ i))
	  ;i++ so it will go to the next block in the selection set
		
)
;end repeat loop	


(command "_regen") ;regen the drawing

(princ);blank line i guess
);ends routine