topic Re: BURST command in lisp in Visual LISP, AutoLISP and General Customization Forum

BURST command in lisp

davidEPN6Z — Mon, 08 Sep 2025 12:30:49 GMT

I have this line in my script :

(command "_.BURST" (ssadd ent) "")

I'm getting an error "Unknown command"

Why???

Re: BURST command in lisp

tramber — Mon, 08 Sep 2025 12:50:01 GMT

  (sssetfirst nil  (ssadd ent)) ;makes your selection both gripped and selected. 
  (c:burst)

To me, that's the way to send the command.

Re: BURST command in lisp

ВeekeeCZ — Mon, 08 Sep 2025 13:00:15 GMT

Why? Because it's not a regular built-in command. It's just another LISP function being part of Express tools.

Re: BURST command in lisp

tramber — Mon, 08 Sep 2025 13:22:49 GMT

(or c:burst(load "burst.lsp"))

Before ?

Re: BURST command in lisp

ryanatkins49056 — Mon, 08 Sep 2025 23:02:54 GMT

BURST is an Express Tools command written in AutoLISP. To call it you would need to use

(c:burst)

If you are feeding items from a selection set into it as part of your script you will need to dig down into the AutoLISP file itself.

Re: BURST command in lisp

Sea-Haven — Tue, 09 Sep 2025 01:10:11 GMT

Something like this.

(prompt "\nSelect object\n") (setq ent (ssget "_+.:E:S")) (command "BURST" ent "")

Re: BURST command in lisp

Kent1Cooper — Tue, 09 Sep 2025 02:18:56 GMT

@Sea-Haven wrote:
.... (command "BURST" ent "")

That has the same problem as in Message 1, because BURST is not a native AutoCAD command, so it cannot be used in an AutoLisp (command) function. The suggestion by @tramber in Message 2 is the approach to take. The way to call an AutoLisp-defined command is the (C:YourCommandName) approach. And since that cannot take User selection or inputs or variables internally, as native AutoCAD commands in a (command) function can, you need to have your selection already selected/highlighted when you call it, which is what the (sssetfirst) function does. [And it can be a selection of more than one object when you need that.]

Re: BURST command in lisp

davidEPN6Z — Tue, 09 Sep 2025 07:23:03 GMT

Thank you all. I used tramber approch and its working. Thanks tramber/