How to Load AutoLISP Plotting Routines with APPLOAD
Learn the simplest safe workflow for loading a plotting LSP file, running its command and making it available again later.
Main idea: APPLOAD is the easiest place for a beginner to start because you can load one LSP file without editing startup files.
Best use: Free LSP downloads, one-off tests and first-time installation.
Start with the manual workflow
Download or save the LSP file in a folder you control. Do not put random code into an office-wide startup file before you have tested it.
Before automating a production workflow, review AutoLISP Plotting & PDF Automation, CAD Plotting Downloads, and CAD Plotting Tools & Calculators.
Build the automation in small layers
Step 1 — Put the LSP in a trusted folder
Where: A dedicated CAD support folder
Do this: Create or choose a folder used for approved AutoLISP files.
Check: The folder is easy to back up and, if required, is included in TRUSTEDPATHS.
Step 2 — Open APPLOAD
Where: Command line > APPLOAD
Do this: Browse to the LSP file and click Load.
Check: AutoCAD reports that the application loaded.
Step 3 — Run the command
Where: Command line
Do this: Type the command named in the article or README.
Check: You see the expected prompt or output.
Step 4 — Test on a copy
Where: A non-production DWG
Do this: Run the routine once and inspect what changed.
Check: No unexpected Layout, plot-style or file changes occur.
Step 5 — Decide whether to auto-load it
Where: APPLOAD Startup Suite or acaddoc.lsp
Do this: Only after testing, add frequently used routines to your controlled startup process.
Check: The routine loads consistently on the intended workstations.
What a beginner should expect after loading an LSP
An LSP file normally defines one or more commands. Loading the file does not mean AutoCAD has already plotted or changed anything; it means the functions are now available in memory. A routine whose source contains (defun c:CPLOCKVPS ...) creates a command named CPLOCKVPS. That is the name you type after APPLOAD reports that the file loaded.
Keep the file name, command name and purpose together in your documentation. When a team accumulates many utilities, the biggest usability problem is often not the code—it is that nobody remembers which command belongs to which file or which copy of the file is current.
What the code should control
- APPLOAD file location
- SECURELOAD / TRUSTEDPATHS
- Startup Suite versus manual loading
- Command name defined by c:FUNCTION
- Support File Search Path
What you should deliberately leave manual at first
Do not edit reserved Autodesk acad.lsp files. Keep your custom routines in your own support files or use APPLOAD/Startup Suite.
Failure modes to design for
- The LSP is downloaded into an untrusted folder and SECURELOAD blocks it.
- The file loads but the user types the file name instead of the command name.
- A routine is added to startup before it has been tested.
- Two different LSP files define the same command name.
When this becomes a production tool
For office deployment, keep a controlled folder, version the LSP files, document each command and use a consistent startup method. A workstation should not silently load different copies of the same routine.
Official Autodesk references
Frequently asked questions
What is the difference between loading a file and running a command?
Loading evaluates the LSP file and defines its functions. You then type the command name created by a c: function.
Should I use Startup Suite for every LSP?
No. Use it for routines you want available every session. Keep occasional or experimental routines manual.
Why does AutoCAD say the file is not trusted?
Secure loading can restrict executable code to TRUSTEDPATHS. Move approved code into a trusted location instead of disabling security globally.
Explore more in AutoLISP Plotting & PDF Automation.