: 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 .
: Common types include integers, real numbers (decimals), strings (text), and lists. Lists are the heart of the language and can store anything from a simple set of coordinates to complex drawing data.
AutoLISP excels at interacting with the AutoCAD environment and its drawing database.
: The (command ...) function allows a routine to execute standard AutoCAD commands just as a user would type them.
The fundamental rule of AutoLISP is that every statement must be enclosed in parentheses. This structure is known as an S-expression (symbolic expression).
: Use the setq function to assign a value to a variable, such as (setq myWidth 10.5) . Essential Functions for Automation