What Is a Lisp Routine AutoCAD?

Understanding Lisp Routines in AutoCAD

Lisp routines in AutoCAD refer to scripting commands written in AutoLISP, a specialized dialect of the Lisp programming language tailored for CAD applications. These routines enhance the functionality of AutoCAD by allowing users to automate tasks and create custom commands, thereby improving efficiency in design work.

How to Create a Lisp Routine in AutoCAD

1. Access the Visual LISP Editor

   • Launch AutoCAD and navigate to the "Tools" menu.
   • Choose "AutoLISP," then select "Visual LISP Editor" to open the workspace where you can write your custom scripts.

2. Start a New Program

   • Once the Visual LISP Editor (VLISP) is open, click on "File" and then "New" to create a new LISP file.
   • You’ll find a console window where you can input your commands.

3. Write Your LISP Routine

   • In the editor, write your LISP code. This could range from simple commands to complex functions that utilize AutoCAD’s extensive features.
   • Be sure to include proper syntax and formatting as per LISP conventions to ensure the routine runs without errors.
4. Save Your Routine
   • After writing your code, save your file with the .lsp extension. This is crucial as AutoCAD identifies LISP routines by their file extension.

Where to Find and Store LISP Routines

LISP routines can be stored in specific directories within the AutoCAD installation. By default, these routines may reside in locations similar to:

• C:\Program Files\Autodesk\AutoCAD 2025\Support
• Ensure that these directories are included in the support file search paths. You can check this via the Options dialog in AutoCAD.

How to Load a LISP Routine in AutoCAD 2025

1. Using the APPLOAD Command

   • Type APPLOAD into the command line and press Enter.
   • This opens the "Load Application" dialog.
2. Add to Startup Suite
   • Click on the "Startup Suite" button.
   • Select "Add" to browse for your saved .lsp file and click "Open."
   • Once you add it, exit the dialog by clicking "Close." Your LISP routine will now be available whenever AutoCAD is launched.

Executing a LISP Routine

After loading your LISP file, executing a routine can be done directly via the command line. Simply type the name of the function defined in your LISP code, and the routine will run.

Using Acaddoc.lsp

The acaddoc.lsp file is a special initialization file associated with AutoCAD sessions. Including routine calls in this file ensures that specific LISP commands are executed automatically upon starting a new drawing or opening an existing one. This is particularly useful for frequently used functions.

Lisp Support in AutoCAD LT

It’s important to note that AutoCAD LT does not support AutoLISP or allow for custom routines. The APPLOAD command is not available, limiting users to the features provided within the standard AutoCAD LT environment.

FAQs

What types of tasks can I automate with LISP routines?

LISP routines can automate various tasks such as batch plotting, modifying object properties, performing calculations, or creating custom entities, among others.

Do I need programming experience to write LISP routines?

While basic programming knowledge is helpful, many AutoCAD users with little programming experience can learn to write simple LISP routines with practice and available resources.

Is there a community or resources for learning AutoLISP?

Yes, there are numerous online forums, tutorials, and documentation available for AutoLISP. Engaging with the AutoCAD community can provide valuable insights and support for learning the language.