Learn AUTOCAD-AUTOLISP with Real Code Examples

AutoLISP allows the creation of custom commands, functions, and utilities within AutoCAD.

Supports automating repetitive drawing tasks and complex calculations.

Integrates directly with AutoCAD objects and drawing entities.

Widely used in architecture, engineering, and industrial design workflows.

Improves productivity by reducing manual drafting effort and errors.

Reading and writing AutoCAD entities (LINE, CIRCLE, POLYLINE, etc.)

Variable handling and list manipulation

Conditional logic (if, cond) and looping (while, repeat, foreach)

Custom command definition via (defun-c)

Error handling and debugging with (prompt) and (prin1)

Defun - define a function or command

Cons / List - fundamental LISP data structures

Entget / Entmod - read and modify drawing entities

Prompt - interact with user input

Command - execute built-in AutoCAD functionality programmatically

.lsp script files

Optional supporting .dcl dialog files

Command registration in AutoCAD

External references (Excel, CSV, DB) if needed

Documentation for function usage

Define main function for repetitive task

Access and manipulate AutoCAD entities via functions

Prompt user for input or selection if needed

Process entities with loops and conditional logic

Return results or update drawing automatically

Beginner: automate simple line or text creation

Intermediate: batch modify multiple entities

Advanced: parameterized geometry generation

Expert: integrate with Excel or external data sources

Architect: full CAD automation pipelines for large projects

AutoLISP vs VBA: AutoLISP native to AutoCAD, VBA supports forms and external integration

AutoLISP vs Python/COM: AutoLISP easier for drawing entities, Python offers broader ecosystem

AutoLISP vs manual drafting: AutoLISP automates repetitive tasks

AutoLISP vs .NET API: .NET allows complex apps, AutoLISP simpler for small scripts

AutoLISP vs Script (.scr): AutoLISP allows logic and interactivity, .scr is linear commands

1986 - AutoLISP introduced in AutoCAD 2.18

1990s - Expanded functions and drawing automation features

2000 - Integration with Visual LISP IDE

2005 - Support for ActiveX/COM integration

2010 - 64-bit AutoCAD support

2015 - Improved DCL and error handling features

2020 - Continued support with AutoCAD subscriptions

2025 - Latest updates for performance and integration enhancements

Defun - define function or command

SSGET - selection set of AutoCAD entities

ENTGET - retrieve entity data

ENTMOD - modify entity properties

DCL - dialog control language for AutoCAD UI