Autocad - Autolisp In

AutoLISP excels at interacting with the AutoCAD environment and its drawing database.

AutoLISP is a powerful, high-level programming language specifically designed to extend and automate the functionality of AutoCAD. Based on the LISP (LISt Processing) language, it was first introduced in 1986 and has since become the most popular tool for CAD users to create custom commands and streamline repetitive drafting tasks. As an interpreted language, you can run code directly from the AutoCAD command line without needing to compile it first. Core Concepts and Syntax AutoLISP in AutoCAD

: To create a custom command that can be typed into the AutoCAD command line, use the defun function with a C: prefix. For instance, (defun C:HELLO () (prompt "\nHello World!")) defines a new command called HELLO . AutoLISP excels at interacting with the AutoCAD environment

The fundamental rule of AutoLISP is that every statement must be enclosed in parentheses. This structure is known as an S-expression (symbolic expression). As an interpreted language, you can run code

: Functions like getpoint , getreal , and getstring pause the routine to ask the user for specific data.

: Use ssget to pick multiple objects based on criteria (like layer or color), allowing you to modify hundreds of items at once.

: In AutoLISP, the function name always comes first, followed by its arguments. For example, to add two numbers, you write (+ 1 2) instead of 1 + 2 .