How Do I Run an AutoLISP in AutoCAD?

Running an AutoLISP in AutoCAD can greatly enhance your productivity and efficiency in completing design tasks. AutoLISP is a dialect of the LISP programming language that allows you to automate repetitive tasks, customize commands, and create complex functions within the AutoCAD environment. In this article, we will explore how to run an AutoLISP script in AutoCAD.

Step 1: Create or Obtain an AutoLISP Script
To run an AutoLISP script, you first need to have one. You can either create your own script or obtain one from various online sources. Once you have the script file with a .lsp extension, follow the next steps.

Step 2: Load the AutoLISP Script
To load the script into AutoCAD, you need to use the “Appload” command. You can access it by either typing “Appload” in the command line or navigating through “Tools > Load Application.”

Note: Ensure that the directory containing your .lsp file is included in the “Support File Search Path” under “Files” tab in Options.

Step 3: Select and Run the Script
After opening the Appload dialog box, browse and select your .lsp file from its location on your computer. Once selected, click on the “Load” button to load it into AutoCAD.

Running an AutoLISP File Automatically at Startup

If you want a specific AutoLISP file to load automatically every time you start AutoCAD, follow these steps:

Step 1: Open the “Acad.lsp” File
Navigate to your support files search path folder (usually located at C:\Users\%username%\AppData\Roaming\Autodesk\AutoCAD XXXX\RXX.X\enu\Support) and find the acad.lsp file.

Step 2: Edit the “Acad.lsp” File
Open the acad.lsp file using a text editor such as Notepad. If the file doesn’t exist, you can create it.

Step 3: Add the AutoLISP Script
Inside the acad.lsp file, add the following line: (load “C:\\Path\\to\\YourScript.lsp”).

Note: Replace “C:\\Path\\to\\YourScript.lsp” with the actual path to your AutoLISP script file.

Step 4: Save and Close the File
Save the changes made to acad.lsp and close the text editor.

Troubleshooting Common Issues

Error: Bad argument type: stringp nil

This error occurs when AutoCAD fails to locate and load your script. Double-check if your .lsp file is in a directory listed in AutoCAD’s support files search path.

Error: Unknown command “YourCommand”

If you encounter this error, it means that your AutoLISP script is not loaded correctly. Ensure that you have followed all the steps correctly and recheck if your script is loading without any errors.

  • Check for Syntax Errors: Make sure that there are no syntax errors or typos in your AutoLISP code.
  • Capturing Error Messages: Use an error capturing tool such as Visual LISP Editor (VLIDE) to debug and correct errors in your code.
  • Contacting Script Author: If you obtained the script from an external source, consider reaching out to the author for support or finding alternative scripts.

In Conclusion

Running an AutoLISP script in AutoCAD can significantly improve your workflow and productivity. By automating repetitive tasks and creating custom commands, you can save a considerable amount of time and effort.

Remember to load your script using the Appload command and troubleshoot any issues that may prevent successful execution. With practice and experimentation, you can harness the power of AutoLISP to streamline your design process.