How Do I Create a LISP Routine in AutoCAD?

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Creating a LISP Routine in AutoCAD

LISP (LISt Processing) is a programming language that allows you to automate tasks in AutoCAD. With LISP, you can create custom commands, automate repetitive actions, and enhance your productivity. In this tutorial, we will guide you through the process of creating a LISP routine in AutoCAD.

Step 1: Understanding LISP Basics

Before diving into creating a LISP routine, it’s essential to have a basic understanding of the LISP syntax. LISP uses lists as its primary data structure and follows a prefix notation. Each command consists of an operator followed by its arguments enclosed within parentheses.

Step 2: Opening the Visual Lisp Editor

To start creating your LISP routine, open the Visual Lisp Editor in AutoCAD. You can find it by typing “VLIDE” in the command line or accessing it through the “Tools” menu.

Step 3: Writing Your First LISP Command

Let’s begin by writing a simple LISP command that displays “Hello World!” when executed. Type the following code into the Visual Lisp Editor:

(defun c:hello ()
   (princ "\nHello World!")
)
  • Explanation:
    • The defun command is used to define new functions.
    • The c:hello is the name of our custom command.
    • The (princ “\nHello World!”) prints “Hello World!” on the command line.

    Step 4: Saving and Loading Your LISP Routine

    To save your newly created LISP routine, follow these steps:

    1. Click on the “File” menu in the Visual Lisp Editor.
    2. Select “Save As” and choose a location to save your file.
    3. Provide a meaningful name for your LISP routine, such as “hello.lsp”.
    4. Click “Save” to save your file.

    To load your LISP routine into AutoCAD, do the following:

    1. Type “APPLOAD” in the command line and press Enter.
    2. Click on the “Contents” button in the Load/Unload Applications dialog box.
    3. Browse and select your saved LISP routine (e.g., hello.lsp) and click “Load”.

    Step 5: Testing Your LISP Routine

    To test your LISP routine, type “hello” in the command line and hit Enter. You should see “Hello World!” displayed on the command line.

    Conclusion

    Congratulations! You have successfully created a simple LISP routine in AutoCAD.

    This is just a starting point; with LISP’s power, you can accomplish much more. Explore further, learn additional commands, and unleash the full potential of automation in AutoCAD with LISP.

    Remember to save and load your LISP routines whenever you need them. Happy coding!