How Do I Create a LISP File in AutoCAD?

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Creating a LISP File in AutoCAD

AutoCAD is a powerful software used by professionals in various industries to create precise and detailed drawings. One of the most useful features of AutoCAD is its ability to automate repetitive tasks using LISP (LISt Processing) programming language. In this tutorial, we will explore how to create a LISP file in AutoCAD.

Step 1: Understanding LISP

LISP is a programming language that allows you to write custom commands and functions for AutoCAD. It provides a way to extend the functionality of AutoCAD beyond what is available by default. With LISP, you can automate complex tasks, create custom commands, and enhance your productivity.

Step 2: Creating a New LISP File

To create a new LISP file in AutoCAD, follow these steps:

  1. Open Notepad or any text editor of your choice.

  2. Create a new file and save it with a .lsp extension. For example, “mycustomcommand.lsp”.

Step 3: Writing LISP Code

Now that you have created a new LISP file, it’s time to write some code. Let’s start with a simple example that draws a line:

(defun c:mycustomcommand ()
  (command "line" pause)
)

The above code defines a new command called “mycustomcommand”. When this command is executed in AutoCAD, it will run the “line” command and pause for user input.

Explaining the Code:

  • The defun function defines a new command.

  • The c:mycustomcommand is the name of the command that can be executed in AutoCAD’s command line.

  • The (command “line” pause) is the AutoCAD command to draw a line and pause for user input.

Step 4: Loading the LISP File

After writing your LISP code, you need to load it into AutoCAD. Follow these steps:

  1. In AutoCAD, type “Appload” in the command line and press Enter.

  2. In the “Load/Unload Applications” dialog box, click on the “Contents..” button.

  3. In the “Loaded Applications” dialog box, click on the “Add.” button and navigate to your LISP file.

  4. Select your LISP file and click on the “Load” button.

Your LISP file is now loaded into AutoCAD.

Step 5: Running Your Custom Command

To run your custom command, simply type its name (in this case, “mycustomcommand”) in AutoCAD’s command line and press Enter. The “line” command will be executed as defined in your LISP code.

Note:

If you make changes to your LISP file, you need to reload it using the Appload command for those changes to take effect.

Conclusion

In this tutorial, we have learned how to create a LISP file in AutoCAD. We explored writing simple LISP code to draw a line and loading the LISP file into AutoCAD. With this knowledge, you can start exploring more advanced features of LISP and create custom commands to automate your workflow in AutoCAD.