Lesson 5.13 - Creating Loadable Routines

⚙️ Lesson 5.13 – Creating Loadable Routines with AutoLISP

Learn how to make your AutoLISP scripts load automatically using startup scripts and autoload techniques.

📚 What You’ll Learn

By the end of this lesson, you’ll be able to:

Organize your AutoLISP code into separate, reusable files
Enable AutoCAD to load your code automatically at startup
Use autoload to delay loading until needed
Configure your environment with a startup script

🧠 Why It Matters

If you use AutoLISP tools regularly, you don’t want to reload them manually each time you open AutoCAD. By setting up autoloading and startup routines, you can save time, reduce friction, and maintain a clean, modular codebase.

🛠️ Tools You’ll Use

Tool / Function	Purpose
`load`	Loads an AutoLISP file immediately
`autoload`	Delays loading until a specific function is called
`acad.lsp`	AutoCAD script that runs at session start
`startup.lsp`	Custom file that runs after AutoCAD finishes loading
`APPLOAD`	Dialog box to manage startup loading

🧭 Lesson Structure

1️⃣ Create a Loadable LISP File

Save your function in a standalone .lsp file. For example:

📄 greeting.lsp

(defun c:greet ( / )
  (alert "Welcome to your custom AutoCAD workspace!")
  (princ)
)

2️⃣ Load Manually with `load`

You can test it manually:

(load "greeting.lsp")
(greet)

🔎 Ensure the .lsp file is in a support path (Options → Files → Support File Search Path)

3️⃣ Use `autoload` for On-Demand Loading

Add this to startup.lsp or acad.lsp:

(autoload '("greet") "greeting.lsp")

AutoCAD won’t load the file until greet is called—saving memory and boot time.

4️⃣ Add to `startup.lsp` for Session Load

The startup.lsp file runs after AutoCAD fully initializes. You can load multiple routines:

📄 startup.lsp

(princ "\\nCustom AutoLISP startup script running...")

(load "greeting.lsp")
(load "layer_setup.lsp")
(princ)

Place this file in AutoCAD’s Support File Search Path.

✅ Lesson Checklist

Task	Completed
Created reusable LISP files	☐
Used `load` to test manually	☐
Applied `autoload` for performance	☐
Created and used `startup.lsp`	☐
Added LISP files to Support File Search Path	☐

📌 Quick Tips

Tip	Why It Helps
Keep routines modular (1 file = 1 tool)	Easier maintenance and reuse
Use `autoload` for tools used occasionally	Improves AutoCAD launch performance
Use `APPLOAD` to test or manage loaded files	Graphical way to manage LISP files
Always add `(princ)` at end of startup scripts	Suppresses unwanted command line output

🧩 Real-World Applications

Use Case	What Loads	Why It Helps
Office-wide toolset	Block insertion, layer setup	Reduces need for manual loading
Developer toolkit	LISP function library	Share common tools across projects
Custom welcome routine	Greeting, logging, tips	Improves user engagement

📁 Files and Resources

File / Resource	Description
`greeting.lsp`	Simple tool with alert message
`startup.lsp`	Sample file to load multiple LISP routines at startup
`autoload_example.lsp`	Template showing how to defer load with `autoload`
`load_order_checklist.docx`	Printable checklist to help you organize routine loading

📖 Review Table

Function	Description	Example
`load`	Loads a LISP file	`(load "file.lsp")`
`autoload`	Delays load until function is called	`(autoload '("func") "file.lsp")`
`princ`	Ends routine quietly	`(princ)`
`APPLOAD`	GUI for loading apps/scripts	Type `APPLOAD` in the command line