Hide Table of Contents

Lisp Files

Loading Lisp Files

You can enter Lisp expressions and Lisp functions at the command prompt. You can also load commands and functions from Lisp files.

A file containing Lisp code must be stored in an ASCII text file. The commonly used file extension is .lsp. However, you can use any file extension.

Use the load function to load a Lisp file.

Note: An extension other than ".lsp" needs to be passed to the load function.


: (load "test")

: (load "my.lsp")

Defining Functions and Commands

Normally a Lisp file contains one or more function definitions.

To define a function, use the defun function, which allows you to create your own functions and your own commands.


(defun C:XYZ ()
   (princ "My new command 'XYZ'!")

Comments in Lisp Files

A semicolon (;) in a program's line indicates that the following text part to the line end is interpreted as a comment. This text part is not evaluated.

The text string ;| starts a multi-line comment. The following text lines are ignored up to the closing string |; that terminates a comment.

Related Functions



Provide feedback on this topic

SOLIDWORKS welcomes your feedback concerning the presentation, accuracy, and thoroughness of the documentation. Use the form below to send your comments and suggestions about this topic directly to our documentation team. The documentation team cannot answer technical support questions. Click here for information about technical support.

* Required

Subject:   Feedback on Help Topics
Page:   Lisp Files
*   I acknowledge I have read and I hereby accept the privacy policy under which my Personal Data will be used by Dassault Systèmes

Print Topic

Select the scope of content to print:


We have detected you are using a browser version older than Internet Explorer 7. For optimized display, we suggest upgrading your browser to Internet Explorer 7 or newer.

 Never show this message again

Web Help Content Version: API Help (English only) 2023 SP04

To disable Web help from within SOLIDWORKS and use local help instead, click Help > Use SOLIDWORKS Web Help.

To report problems encountered with the Web help interface and search, contact your local support representative. To provide feedback on individual help topics, use the “Feedback on this topic” link on the individual topic page.