How Do I Edit a LISP in AutoCAD?

LISP (LISt Processing) is a programming language commonly used in AutoCAD to automate repetitive tasks and enhance productivity. If you’re looking to edit a LISP program in AutoCAD, this tutorial will guide you through the process step by step.

Firstly, it’s important to understand that LISP programs in AutoCAD are stored as plain text files with a .lsp extension. To begin editing a LISP program, follow these steps:

Step 1: Launch AutoCAD and open the drawing file where the LISP program is located.

Step 2: Access the “Visual LISP Editor” by typing VLIDE in the command line and pressing Enter. Alternatively, you can click on “Tools” menu > “AutoLISP” > “Visual LISP Editor.”

Step 3: The Visual LISP Editor window will appear. Here, you can see the existing LISP program code. To make changes, simply locate the section you wish to edit.

Note: It’s always a good practice to create a backup of the original code before making any modifications. This way, you can revert back to it if needed.

Step 4: Select the desired portion of code that requires editing using your mouse or keyboard shortcuts (Ctrl + A selects all). Make sure not to select more than what needs modification.

Step 5: Once selected, press Delete or Backspace key on your keyboard to remove the existing code.


If you want to add new lines of code within an existing function or create a new function altogether:

  • Type the new code directly into the Visual LISP Editor at an appropriate location.
  • If creating a new function, enclose your code within parentheses and define a name for your function.


If you want to modify the existing code:

  • Place your cursor at the desired location within the code.
  • Type the necessary changes directly into the Visual LISP Editor, replacing or modifying the existing code.


If you want to delete a specific line or section of code:

  • Select the portion of code you wish to delete using your mouse or keyboard shortcuts (Shift + Arrow keys).
  • Press Delete or Backspace key to remove the selected code.

Once you have made all your desired changes, save the modified LISP program by clicking on “File” > “Save” (or Ctrl + S).

Note: Saving frequently is highly recommended, especially if you’re making significant modifications.

Now that you’ve successfully edited a LISP program in AutoCAD, you can test your changes by running the program. To run a LISP program, follow these steps:

Step 1: Make sure your drawing file is open in AutoCAD.

Step 2: Type APPLOAD in the command line and press Enter. This will open the “Load/Unload Applications” window.

Step 3: Click on “Contents..” and navigate to your modified LISP program (.lsp) file. Select it and click on “Load.”

Step 4: After loading, close the “Load/Unload Applications” window.

Now, when you run AutoCAD commands related to your modified LISP program, they will utilize your updated code.

In this tutorial, we discussed how to edit a LISP program in AutoCAD using the Visual LISP Editor. Remember, understanding LISP syntax is crucial for making accurate modifications. With practice, you’ll become more comfortable editing and creating LISP programs to streamline your AutoCAD workflow.