Autolisp for autocad tutorial

To install CLISP on your machine Click on the link free in the first paragraph to go to the list of free implementations. Double-click the binaries folder to open it. Alternatively, see if you can use the shortcut Ctrl-c Ctrl-l in the editor to load the Lisp file.

Enter a Lisp expression, and SBCL will read and execute it, print any values returned, give you another prompt, and wait for your next input. NET, C. Some have experimented with other. Clojure, Scheme, and Common Lisp are still pretty widely used today, though there have been dozens of dialects over the years. Lisp is a functional programming language with imperative features.

In addition to an AutoLISP expression starting with a open parenthesis , an expression can also start with the! AutoLISP expressions can be nested inside of each other. When expressions are nested, they are always evaluated from the innermost expression to the outermost. The following are other examples of nested expressions:. The getreal function prompts the user for a real numeric value.

The value provided is then passed to the setq function and assigned to the nDist user-defined variable. For instances in which the point selecting the subentity is already defined, the…. Just as entnext works with old style polylines and attributes in a block, it may also be used to extract the entities that make up a block. This is done…. Since there are times when we need to access parts of polylines and blocks, we will need to get to the subentities using entnext and nentsel.

The [prompt] here and throughout is optional, though recommended, information for the user. The prompt must be in string form. The T , which always has a value of T or non-nil, is most commonly used as the flag, but anything that has value can be used, such as a number. This function pauses for point input and returns a point list of x y z. The point-list is not optional this time. This function pauses for real input and returns a real value. The user can enter a decimal number, or a number based on the current linear unit measurement setting, or can pick two points and the distance between those points will be returned.

This function returns a real number in radians of an angle entered either by pointing or by typing a value. The optional [point-list] lets you include a point usually a symbol that points back to information that gives you a point that defines the first point of the angle.

Type a number: 3 3.