AutoCAD

How to Create a Lisp Routine in AutoCAD

Understanding LISP Routines for AutoCAD

LISP routines are custom scripts that enhance the functionality of AutoCAD. These routines allow users to automate repetitive tasks, simplifying complex commands and increasing overall productivity. Anything from drafting commands to advanced functionalities can be scripted using LISP, making it a powerful tool for users looking to optimize their workflows.

Steps to Create a LISP Routine in AutoCAD

Step 1: Setting Up the Environment

Before you can create a LISP routine, ensure you have a suitable text editor installed. Programs like Notepad or specialized editors such as Notepad++ can be utilized for coding. Familiarize yourself with basic LISP syntax, which includes parentheses and functions.

Step 2: Writing Your LISP Code

Begin coding your LISP routine by defining the function. For example:

(defun c:MyCommand () 
   (princ "Hello, AutoCAD!"))

This simple routine, when called, prints a message to the command line. Expand your code with more complex functions as needed by utilizing AutoCAD commands within the LISP structure.

Step 3: Saving the Code

Once your routine is written, save the file with a .lsp extension. For instance, you might name your file MyRoutine.lsp. Store this file in a recognizable directory for easy access in the future.

Step 4: Loading the LISP Routine in AutoCAD 2025

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

  1. Open AutoCAD 2025.
  2. Type the command APPLOAD in the command line and press Enter.
  3. In the dialog that appears, select Contents under the Startup Suite.
  4. Click the Add button, and browse to the location of your .lsp file.
  5. Select your file and click Open.
  6. Close the dialog box after adding your routine.

Step 5: Running Your LISP Routine

To execute your LISP routine, simply type the command name you defined in your routine into the command line. For the earlier example, you would input MyCommand and hit Enter. The functionality you scripted should now activate in your AutoCAD session.

Creating an LSP File

To create an LSP (LISP Source Code) file, follow the initial coding steps outlined above. After writing your script, save it using the .lsp extension. This conversion allows AutoCAD to recognize and execute your scripts effectively. You may also set AutoCAD to automatically load LSP files from designated folders during startup, enhancing accessibility.

FAQ

Can I run LISP routines in AutoCAD LT?

No, AutoCAD LT does not support LISP routines or the APPLOAD command, limiting advanced automation capabilities compared to the full version of AutoCAD.

What is the role of Visual LISP in AutoCAD?

Visual LISP provides a more advanced programming environment for creating LISP routines in AutoCAD. It features debugging tools, an enhanced editor, and allows for a more user-friendly approach to developing complex scripts.

Where can I learn more about LISP programming for AutoCAD?

Numerous resources are available, including online tutorials, forums, and books specifically focused on LISP programming for AutoCAD. Engaging with community forums and seeking recommendations can further enhance your learning experience.

About the author

Wei Zhang

Wei Zhang

Wei Zhang is a renowned figure in the CAD (Computer-Aided Design) industry in Canada, with over 30 years of experience spanning his native China and Canada. As the founder of a CAD training center, Wei has been instrumental in shaping the skills of hundreds of technicians and engineers in technical drawing and CAD software applications. He is a certified developer with Autodesk, demonstrating his deep expertise and commitment to staying at the forefront of CAD technology. Wei’s passion for education and technology has not only made him a respected educator but also a key player in advancing CAD methodologies in various engineering sectors. His contributions have significantly impacted the way CAD is taught and applied in the professional world, bridging the gap between traditional drafting techniques and modern digital solutions.