about 1986 R.C. Bradlee published a Xeroxed page book “Programming Autocad” which featured the Autolisp command set as of autocad version 2.5. Selection Sets had just been added. Entity names could be retrieved and properties modified but new entitities had to be added with the Command function (command “Line” pnt1 …). This would be a good starter section for learning the language, not overwhelming but not trivial. Some or most of the links seem to paste in from the Autodesk 2017 help reference. I rearranged and edited the entries into my own idea of fuzzy categories. A disclaimer – this is not an official list of Lisp 2.5 but just my reconstruction. Some functions i left out either inadvertently, or i assume they are obsolete, or simply i dont see a need for them.
Descriptions below all belong to Autodesk. Here is there notice cut / pasted from their help page.
Except where otherwise noted, this (Autodesk) work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. Please see the Autodesk Creative Commons FAQ for more information.
Math and booleans are first and easiest to master.
| + (add) | (+ [number number …]) | Returns the sum of all numbers |
| – (subtract) | (- [number number …]) | Subtracts the second and following numbers from the first and returns the difference |
| * (multiply) | (* [number number …]) | Returns the product of all numbers |
| / (divide) | (/ [number number …]) | Divides the first number by the product of the remaining numbers and returns the quotient |
| 1+ (increment) | (1+ number) | Returns the argument increased by 1 (incremented) |
| 1- (decrement) | (1- number) | Returns the argument reduced by 1 (decremented) |
| abs | (abs number) | Returns the absolute value of the argument |
| atan | (atan num1 [num2]) | Returns the arctangent of a number in radians |
| cos | (cos ang) | Returns the cosine of an angle expressed in radians |
| exp | (exp number) | Returns the constant e (a real) raised to a specified power (the natural antilog) |
| expt | (expt base power) | Returns a number raised to a specified power |
| fix | (fix number) | Returns the conversion of a real into the nearest smaller integer |
| float | (float number) | Returns the conversion of a number into a real |
| gcd | (gcd int1 int2) | Returns the greatest common denominator of two integers |
| log | (log number) | Returns the natural log of a number as a real |
| max | (max [number number …]) | Returns the largest of the numbers given |
| min | (min [number number …]) | Returns the smallest of the numbers given |
| rem | (rem [num1 num2 …]) | Divides the first number by the second, and returns the remainder |
| sin | (sin ang) | Returns the sine of an angle as a real expressed in radians |
| sqrt | (sqrt number) | Returns the square root of a number as a real |
| ~ (bitwise NOT) | (~ int) | Returns the bitwise NOT (1’s complement) of the argument |
| logand | (logand [int int …]) | Returns the result of the logical bitwise AND of a list of integers |
| logior | (logior [int int …]) | Returns the result of the logical bitwise inclusive OR of a list of integers |
| lsh | (lsh [int numbits]) | Returns the logical bitwise shift of an integer by a specified number of bits |
| atom | (atom item) | Verifies that an item is an atom |
| boundp | (boundp sym) | Verifies whether a value is bound to a symbol |
| listp | (listp item) | Verifies that an item is a list |
| not | (not item) | Verifies that an item evaluates to nil |
| null | (null item) | Verifies that an item is bound to nil |
| numberp | (numberp item) | Verifies that an item is a real or an integer |
| minusp | (minusp number) | Verifies that a number is negative |
| zerop | (zerop number) | Verifies that a number evaluates to zero |
| = (equal to) | (= numstr [numstr …]) | Returns T if all arguments are numerically equal, and returns nil otherwise |
| /= (not Equal to) | (/= numstr [numstr …]) | Returns T if the arguments are not numerically equal, and nil if the arguments are numerically equal |
| > (greater than) | (< numstr [numstr …]) | Returns T if each argument is numerically less than the argument to its right, and returns nil otherwise |
| >= (greater than or equal to) | (<= numstr [numstr …]) | Returns T if each argument is numerically less than or equal to the argument to its right, and returns nil otherwise |
| < (less than) | (> numstr [numstr …]) | Returns T if each argument is numerically greater than the argument to its right, and returns nil otherwise |
| <= (less than or equal to) | (>= numstr [numstr …]) | Returns T if each argument is numerically greater than or equal to the argument to its right, and returns nil otherwise |
| and | (and [expr …]) | Returns the logical AND of a list of expressions |
| boole | (boole func int1 [int2 …]) | Serves as a general bitwise Boolean function |
| eq | (eq expr1 expr2) | Determines whether two expressions are identical |
| equal | (equal expr1 expr2 [fuzz]) | Determines whether two expressions are equal |
| or | (or [expr …]) | Returns the logical OR of a list of expressions |
| angtos | (angtos angle [mode [precision]]) | Converts an angular value in radians into a string |
| ascii | (ascii string) | Returns the conversion of the first character of a string into its ASCII character code (an integer) |
| atof | (atof string) | Returns the conversion of a string into a real |
| atoi | (atoi string) | Returns the conversion of a string into an integer |
| chr | (chr integer) | Returns the conversion of an integer representing an ASCII character code into a single-character string |
| itoa | (itoa int) | Returns the conversion of an integer into a string |
| rtos | (rtos number [mode [precision]]) | Converts a number into a string |
Lists and Loops contain the core LIST Processing commands
| type | (type item) | Returns the type of a specified item |
| eval | (eval expr) | Returns the result of evaluating an AutoLISP expression |
| quote | (quote expr) | Returns an expression without evaluating it |
| repeat | (repeat int [expr …]) | Evaluates each expression a specified number of times, and returns the value of the last expression |
| while | (while testexpr [expr …]) | Evaluates a test expression, and if it is not nil, evaluates other expressions; repeats this process until the test expression evaluates to nil |
| if | (if testexpr thenexpr [elseexpr]) | Conditionally evaluates expressions |
| cond | (cond [(test result …) …]) | Serves as the primary conditional function for AutoLISP |
| foreach | (foreach name lst [expr …]) | Evaluates expressions for all members of a list |
| progn | (progn [expr …]) | Evaluates each expression sequentially, and returns the value of the last expression |
| command | (command [arguments] …) | Executes an AutoCAD command |
| defun | (defun sym ([arguments] [/variables …]) expr … ) | Defines a function |
| setq | (setq sym1 expr1 [sym2 expr2 …]) | Sets the value of a symbol or symbols to associated expressions |
| getvar | (getvar “varname”) | Retrieves the value of an AutoCAD system variable |
| setvar | (setvar “varname” value) | Sets an AutoCAD system variable to a specified value |
| load | (load filename [onfailure]) | Evaluates the AutoLISP expressions in a file |
| *error* | (*error* string) | A user-definable error-handling function |
| list | (list [expr …]) | Takes any number of expressions and combines them into one list |
| length | (length lst) | Returns an integer indicating the number of elements in a list |
| last | (last lst) | Returns the last element in a list |
| nth | (nth n lst) | Returns the nth element of a list |
| reverse | (reverse lst) | Returns a list with its elements reversed |
| car | (car lst) | Returns the first element of a list |
| cdr | (cdr lst) | Returns the specified list, except for the first element of the list |
| caddr | ||
| cadr | ||
| cons | (cons new-first-element lst) | The basic list constructor |
| append | (append lst …) | Takes any number of lists and runs them together as one list |
| member | (member expr lst) | Searches a list for an occurrence of an expression and returns the remainder of the list, starting with the first occurrence of the expression |
| assoc | (assoc item alist) | Searches an association list for an element and returns that association list entry |
| apply | (apply function lst) | Passes a list of arguments to a specified function |
| mapcar | (mapcar function list1 … listn) | Returns a list of the result of executing a function with the individual elements of a list or lists supplied as arguments to the function |
| lambda | (lambda arguments expr …) | Defines an anonymous function |
Strings and File I/O are pretty straighforward
| read | (read [string]) | Returns the first list or atom obtained from a string |
| strcat | (strcat [string1 [string2 …]) | Returns a string that is the concatenation of multiple strings |
| strlen | (strlen [string …]) | Returns an integer that is the number of characters in a string |
| substr | (substr string start [length]) | Returns a substring of a string |
| vl-string-subst | (vl-string-subst new-str pattern string [start-pos]) | Substitutes one string for another, within a string |
| open | (open filename mode) | Opens a file for access by the AutoLISP I/O functions |
| read-char | (read-char [file-desc]) | Returns the decimal ASCII code representing the character read from the keyboard input buffer or from an open file |
| read-line | (read-line [file-desc]) | Reads a string from the keyboard or from an open file |
| write-char | (write-char num [file-desc]) | Writes one character to the screen or to an open file |
| write-line | (write-line string [file-desc]) | Writes a string to the screen or to an open file |
| close | (close file-desc) | Closes an open file
|
The last category is Autocad graphic interfacing commands. ( I am leaving out a few things I think may be less useful or obsolete or inadvertently)
| angle | (angle pt1 pt2) | Returns an angle in radians of a line defined by two endpoints |
| distance | (distance pt1 pt2) | Returns the 3D distance between two points |
| inters | (inters pt1 pt2 pt3 pt4 [onseg]) | Finds the intersection of two lines |
| osnap | (osnap pt mode) | Returns a 3D point that is the result of applying an Object Snap mode to a specified point |
| polar | (polar pt ang dist) | Returns the UCS 3D point at a specified angle and distance from a point |
| getangle | (getangle [pt] [msg]) | Pauses for user input of an angle, and returns that angle in radians |
| getdist | (getdist [pt] [msg]) | Pauses for user input of a distance |
| getint | (getint [msg]) | Pauses for user input of an integer, and returns that integer |
| getorient | (getorient [pt] [msg]) | Pauses for user input of an angle, and returns that angle in radians |
| getpoint | (getpoint [pt] [msg]) | Pauses for user input of a point, and returns that point |
| getreal | (getreal [msg]) | Pauses for user input of a real number, and returns that real number |
| getstring | (getstring [cr] [msg]) | Pauses for user input of a string, and returns that string |
| entsel | (entsel [msg]) | Prompts the user to select a single object (entity) by specifying a point |
| entdel | (entdel ename) | Deletes objects (entities) or restores previously deleted objects |
| entget | (entget ename [applist]) | Retrieves an object’s definition data |
| entlast | (entlast) | Returns the name of the last non-deleted main object in the drawing |
| entmod | (entmod elist) | Modifies the definition data of an object |
| entnext | (entnext [ename]) | Returns the name of the next object in the drawing |
| entupd | (entupd ename) | Updates the screen image of an object |
| ssadd | (ssadd [ename [ss]]) | Adds an object (entity) to a selection set, or creates a new selection set |
| ssdel | (ssdel ename ss) | Deletes an object (entity) from a selection set |
| ssget | (ssget [mode] [pt1 [pt2]] [pt-list] [filter-list]) | Prompts the user to select objects (entities), and returns a selection set |
| sslength | (sslength ss) | Returns an integer containing the number of objects (entities) in a selection set |
| ssmemb | (ssmemb ename ss) | Tests whether an object (entity) is a member of a selection set |
| ssname | (ssname ss index) | Returns the object (entity) name of the indexed element of a selection set |
| grread | (grread [track] [allkeys [curtype]]) | Reads values from any of the AutoCAD input devices |
| grclear | ||
| graphscr | (graphscr) | Displays the AutoCAD graphics screen |
| grdraw | (grdraw from to color [highlight]) | Draws a vector between two points, in the current viewport |
| grtext | (grtext [box text [highlight]]) | Writes text to the status line or to screen menu areas |
| menucmd | (menucmd string) | Issues menu commands, or sets and retrieves menu item status |
| prin1 | (prin1 [expr [file-desc]]) | Prints an expression to the command line or writes an expression to an open file |
| princ | (princ [expr [file-desc]]) | Prints an expression to the command line, or writes an expression to an open file |
| (print [expr [file-desc]]) | Prints an expression to the command line, or writes an expression to an open file | |
| prompt | (prompt msg) | Displays a string on your screen’s prompt area |
| redraw | (redraw [ename [mode]]) | Redraws the current viewport or a specified object (entity) in the current viewport |
| terpri | (terpri) | Prints a newline to the Command line |
