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since 10th September 1998
Basic AutoLisp Tutorial
This tutorial is aimed at the AutoCAD users who would
like to start learning AutoLisp.
I suggest that you go through this tutorial alongwith the Autocad
Programmers Reference Guide.
You can then lookup the relevant Autolisp commands for a more
detailed explanation. Hope this helps you
and Good Luck in your Lisping - Kenny Ramage
PRINCIPLES OF PROGRAMMING
All AutoLisp programs must contain the suffix LSP otherwise
AutoCAD will not access them when loading.(eg. CHTEXT.LSP).
Use a simple text processor such as Notepad or Dos Edit
to creat and edit your lisp files.
FUNCTION (Which is simply the program)
Is a pre-defined set of instructions that describes a set of
actions that AutoLisp is to perform, divided into three
sections :
1. OPERATOR - Getting input.
2. ARGUMENT - Manipulating the input.
3. COMMAND - Using the manipulated input.
CHARTING
Draw out or write out in English what you want your program to
do.
VARIABLES
These are like empty boxes in which to store data, to be used
later. In AutoLisp, variables may be a collection of letters
or numbers as long as they begin with the letters.
Example of legal variables are as follows :
A
ARC1
POINT1
PNT1
D3
An AutoLisp variable may contain more than one value in a
single variable. A value can be anything, such as
Real number
String
Integer
Pickset
Therefore a variable can store just about anything.
STRUCTURING
Structure your program in such a way that it is easy to
understand, by yourself and everyone else.
E.G. Keep input statements together.
Keep your arguments together.
Keep your commands together.
Track your work with the semicolon. When you begin a line with
a semicolon, anything you write after will be ignored by
AutoLisp. It is used for documentation and explanation of your
program. Write notes about your program, what you are doing
and what the variables are. A semicolon does not have to begin
the line.
E.G.
(PROMPT "THIS WILL PRINT"); This is a commandFrom where the semicolon begins, the remainder of the line is a
comment statement.
PARENTHESES ()
Parentheses are vital to writing AutoLisp programs. All
commands are surrounded by parentheses. AutoLisp uses
parentheses to nest, allowing you to write a command that
acts on (evaluates) another command. In turn, that command can
act on another. As you add parentheses, you're nesting
commands become deeper and deeper. Remember to come out of
the nest with an equal number of parentheses.
NOTE: Always close what you open.
THE DEFUN COMMAND
In AutoLisp the name of the program or function must be defined
in the first statement, which is done by using the command
DEFUN.
Defun is the first actual command and is followed by the name
of the function (or program). There are different ways of
starting a function for example
1. (Defun drawline ()
2.
(Defun drawline (/ pntl pnt2)3.
(Defun C:drawline ()4.
(Defun C:drawline (/ pntl pnt2)5.
(Defun drawline (a / pntl pnt2)
The first way, you are saying that all variables you plan to
use in the program are GLOBAL, which are variables that do
not lose their value after the program ends.
The second way, you are saying that the variables you are using
are LOCAL variables, which are variables that have value only
for that program and while that program is running.
The third way, as the first BUT the C: tells AutoCAD to treat
that function as any other AutoCAD command.
The fourth way, as the second, but an AutoCAD command.
The last, variable
a receives the first value to it fromoutside the program.
DATA TYPES
Integers - Is a number ranging between -32768 and +32767
without decimal points eg: 1
Reals - Is a number with a decimal point eg: 1.0
Strings - Strings can be up to a maximum length of 100
characters.
Lists - A list is a variable that has more than one
element. A point in your drawing is described by the value of
the X co-ordinate and the value of the Y co-ordinate. In
AutoLisp, that point can be described by a single variable, a
list of two elements, the first being the X value and the
second being the Y value eg:
( 7 10 )
( 5 9 7 2 )
(1.5 2.3 4.9 )
Atoms - If a variable has only one value it is an atom
eg: 6
The Type command - will return the data type of variable.
Input Commands -(Getting info from the user)
1.
getpoint - Needs you to pick a point on the screen.2.
getint - Needs a Integer eg: 13.
getreal - Needs a real number eg: 10.004.
getcorner - Needs a second point on the screen and drawsan elastic window from a previous point.
5.
getstring - Needs a string of text.6.
getdist - Needs a value either by picking on the screenor a number from the keyboard.
7.
getangle - Needs an angle either by pointing on the screenor by typing an angle, which will be returned
in radians.
8.
getkword - Needs a keyword from the user.9.
getvar - Will get the value of an AutoCAD systemvariable.
10.
initget - Establishes various options for use by the nextGET XXX function.
11.
getorient - Is similar to the GETANGLE but is affected bythe zero-degree base and the direction. It will
always give you the absolute angle using 0
degree base as EAST.
Input Command Examples
1.
(getpoint "\n Pick POINT on the screen:")a. \n - The n MUST always be lower case, \n takes you to the
next line.
b. Your prompt must always be between " " (Quotes), and after
picking a point will return a value of that point.
2.
(getint "\Enter your age :") Type a number and AutoLispwill return that number.
3.
(getreal "\nEnter a number:") Type a real number eg10.51 and AutoLisp will return that number.
4.
(getcorner pntl "\n Pick second point:") Will create anelastic window from variable
pntl.5.
(getstring 1 "\What is the day today ?:") Type some textand Autolisp will return that text.
6.
(getdist "\nHow long is the line ?:") Pick two points ortype a length and AutoLisp will return that length.
7.
(getangle "\nWhat is the angle ?:") Pick two points forthe angle or type an angle and AutoLisp will return that
angle in radians.
8.
(initget 1 "Yes No")(getkword "\nAre you going? ("Yes or NO):") Initget will
control the next getxxx function, getkword will accept only
one word. The initget will accept that one word only to be
Yes or No.
9. (getvar "FILLETRAD") Would return the set fillet radius
eg : 0. 5
Initget Bits
1 Disallow null input
2 Disallow zero values
4 Disallow negative values
8 DO not check limits, even if
LIMECHECK is on.
16 Return 3D points rather than 2D
points.
32 Use dashed lines when drawing rubber
band or box.
(initget (+ 1 2 4))
(getint "\nHow old are you?:") Will only accept an Integer
eg : 21
11. (getorient "\nWhat is the angle?:") Pick two points for
the angle or type an angle and AutoLisp will return an
angle in radians relative to 0 degrees at East.
Setq Command (Set Equal)
(Setq) is an assignment command, eg : it assigns the value of
one variable or constant to another variable.
NOTE : (Setq) is the primary assignment command in AutoLisp.
The = is not used as an assignment. = does exist but only
as a non assignment statement. It does not have the ability to
make one variable equal to another. (It is used for a
comparison of variables, numbers or strings)
(setq a b)
This statement assigns the value of
b to the variable a.NOTE : The first variable after the
(setq) is the one thatreceives the value.
Print Commands
Prompt This command is used simply to print a message on the command line. A line feed
(\n) is not included so two consecutiveprompt commands will print both messages on the same line.
Therefore , any printing after the prompt must have the
(terpri) or \n command.
(terpri)
This is a line feed that causes the next printed text to appear
on the next line.
It generally follows the prompt command.
eg:
(prompt "Hello, how are you ?")(terpri) or
(prompt "\nHello, how are you ?")
Prin1
This function prints the expression on the screen and returns
the expression. It can be any expression and need not only be
a string. The expression can also be written to a file and
will appear in the file exactly as it would on the screen.
(prin1 "Hello") would print Hello
(prin1 a) would print the value of variable a
(prin1 a f) would print the value of variable a to an
open file named in variable
f
Princ
Is the same as
prinl except that the control characters("") are not printed. Can also be used to print a blank line
by using no statement after
princ.
Same as
prinl except that a new line is printed before theexpression and a space is printed after the expression.
eg:
(print "Hello") would return "Hello" "Hello"
Setvar
This function sets an AutoCAD system variable to a given value
and returns that value. The variable name must be in double
quotes.
eg:
(setvar "blipmode" 0) returns 0
Will switch blipmode off.
1 would switch it on again.
Doing arithmetic
(+ 1 1) returns 2
(- 2 1) returns 1
(* 2 2) returns 4
(/ 2 1) returns 2
(1+ 1) returns 2 (Incremented)
(1- 2) returns 1 (Decremented)
FOR MORE - REFER AUTOLISP PROGRAMMERS REFERENCE
Polar
This function returns the point at an angle (in radians) and
distance from a point.
(polar pntl angl distl)
Inters
Examines two lines and returns the point where they intersect
even if they do not cross one another.
(inters pntl pnt2 pnt3 pnt4)
AutoCAD commands in AutoLISP
Any AutoCAD command can be used inside your lisp program
BUT one must remember that they have to be used exactly as
you would in AutoCAD and your RETURN is a double set
of Quotes ("").
eg:
(command "line" pnt1 pnt2 "") This will draw a line from
pntl to pnt2 and the ""
acts as a return to
terminate your line
command.
(graphscr) would return you to the graphics screen while the
program is running.
(textscr) would return you to the text screen while the
program is running.
Entities from a list
When you used
(setq a (getpoint)) you assigned the X andY coordinate numbers to variable
a. That Variable now is alist that may look like
(5 10).If you want to look at the list in variable
a, AutoLISP givesyou a convenient way to do that from the command line.
!a Placing the ! in front of the variable will display the
value or values of the variable.
(car) X COORDINATE (lst element)
The primary command for taking a list apart,
(car) gives youthe first element of the list. If the value of
a is a listof:
(5 10)Then
(setq b (car a)) would assign to the variable b thevalue of the first element in a which is
5.
(cdr) SECOND AND REMAINING
This is the secondary command for taking a list apart.
(cdr)gives you the second and remaining elements of the list. If
variable
a is a list of(2 5 7 9 11)
Then
(setq b (cdr a)) would assign to variable b the secondand remaining elements of the list in variable
a(5 7 9 11).
(cadr) Y COORDINATE (2nd element)
This always produces the second element of a list. Assuming a
still has the list (5 10),
Then (setq b (cadr a)) would produce 10.
(caddr) Z COORDINATE (3rd element)
This always produces the third element of a list. Assuming a
has a list (3 7 5)
Then (setq c (caddr a)) would produce 5.
This program draws a rectangle by pointing to two points.
(defun c:retan (/ pl p2 p3 p4)
(setq pl (getpoint "\nfirst corner of rectangle: "))
(setq p3 (getcorner "\nsecond corner of rectangle: "))
(setq p2 (list (car pl)(cadr p3)))
(setq p4 (list (car p3)(cadr pl)))
(command "line" pl p2 p3 p4 "c")
(princ)
)
DTR converts degrees to radians.
(defun dtr (a)
(* pi (/ a 180)) )
RTD converts radians to degrees.
(defun rtd (a)
(/ (* a 180) pi)
)
Things to strings
strcase (string case)
Changes a string of text from lower case to upper case,
leaving upper case characters as they are.
eg:
(strcase "Hello") returns "HELLO"
(strcase a) returns the alphabetic characters in
variable
a from lower case to upper case.strcat (string cat)
Returns two or more separate strings as one.
eg:
(strcat "H" "ello") returns "Hello"
(strcat a b) returns two strings in variable a & b
as one.
strlen (string length)
Returns the length, of the characters of a string.
eg:
(strlen "hello") returns 5.
(strlen a) returns the length of a string in variable a.
substr (substitute string)
Returns a part of a string, from a specified position,
ending either at the end or another specified position.
eg:
(substr "Hello 2) returns "ello".
(substr "Hello 2 1) returns "e".
(substr "Hello" 3 2) returns "ll".
List Manipulation
The apostrophe ' serves a special function in AutoLISP,
for example if a group of items is preceded by an apostrophe '
it is treated as a list.
eg:
'(20 10 5) is treated as a list.
Angle
Returns an angle between two points in radians. To use that
angle in AutoCAD you have to convert it back to decimal
degrees.
eg:
(setq a (angle pntl pnt2)) sets the angle between pntl
and
pnt2 to the variable a To use a:(command "text" pntl "40" a t) The text command with
a height of 40, rotation angle assigned to variable
a andtext to variable
t. But a is not thecorrect rotation angle because it is in radians.
Append
Takes any number of specified lists and joins them together
as one list.
eg:
(append '(10 20) '(30 40)) returns the list:
(10 20 30 40).
(append a b) returns the list in variable a and the
list in variable
b as one.
Distance
Measures the distance from two known points.
eg:
(setq distl (distance pntl pnt2)) returns the distance
between
pntl and pnt2 and assigns the distance to a variablecalled
dist1.Length
Returns the number of elements in a list. eg:
(length '(a b c d))
returns 4.
Member
Looks for a duplicate and returns that and the rest of the
list
eg:
(member 'c '(a b c d e)) returns (C D E).
nth
Returns the nth element in a list, where n is the
number of the element to return.(Zero is the first element)
eg:
(nth 3 '(a b c d)) returns d.
Assoc (associative)
Often used with (subst) command, this command lets you
search for a specific element, then assign that element
to a variable.
Lets assume variable b is the list ((10 5.5 2.7)(40 5))
and you looking for a code
40. You want to pull out theentire element and assign it to a variable
c.eg:
(setq c (assoc 40 b)) This assigns the entire element
containing the
40 in the list b to variable c. Now c isa list that looks like this:
(40 5).
Subst (subsitute)
Allows you to substitute one aspect for another. When
substituting ALWAYS substitute the new item for the old in
the list. Now lets substitute
20 for the 5 in thevariable
c.(setq bl (subst '(40 20) c b)) Now bl is the new list.
'(40 20) is the new element substituted for the old element
(40 5) c, found in list b.
If you want to use a variable which represents the value.
(setq bl (subst '(40 h) c b)), It looks like it should
work, but it does not. The new element will look like
this:
(40 h).(subst) cannot interpret variables. You need to construct a
new variable containing the entire list element, then use
the new variable in the
(subst) command.
Cons (Construct)
Constructs a new list with the new element placed at the
begining. Assume variable c contains the following
list:
(40 5).Also, assume variable
h contains the real number 20.0then:
(setq d (cons (car c) h)) Remember (car c) gives
you
40. Therefore, (car c) is the new first element, followedby the value
h. Thus it produces a new list d (40 20.0).Now we substitute:
(setq bl (subst d c b)) That substitutes the
new element found in variable
d for the old element found invariable
c. (In the list found in variable b) and assignsthe new list to
bl.
Conversions
Angtos
Takes an angle in radians and converts it into a string, into
a specific format.
ANGTOS MODE FORMAT
0 Degrees
1 Degrees/minutes/seconds
2 Grads
3 Radians
4 Surveyor's units
Assuming variable a has an angle in radians.
eg:
(angtos a 0 0) returns "180"
(angtos a 0 4) returns "180.0000"
(angtos a 1 4) returns "180d0"0""
Fix
This function returns the convention of a real number to
an Integer.
eg:
(fix 8) returns 8
(fix 8.6) returns 8
Float
This function returns the convention of an Integer to a
real number.(One can use either real or an Integer.)
eg:
(float 8) returns 8.0000
(float 8.6) returns 8.6000
Ascii
Returns the convention of the first character of a string
into its ASCII character code.(An Integer)
eg:
(ascii "a") returns 65
(ascii "BLUE") returns 66
Chr
Returns the convention of an Integer representing an ASCII character code into a single character string.
eg:
(chr 65) returns "A"
(chr 66) returns "B"
Atof
Returns the convention of a string into a real number.
eg:
(atof "9.3") returns 9.3000
(atof "2") returns 2.0000
Rtos
Returns the convention of a real number to a string into a
specified format.
RTOS MODE FORMAT
1 Scientific
2 Decimal
3 Engineering(feet & decimal inches)
4 Architectural(feet & fractional inches)
5 Arbituary fractional units
The real number can be set according to mode and precision.
eg:
(rtos 7.2 1 4) returns "7.200OE+00"
(rtos 7.2 2 2) returns "7.20"
Itoa
Returns the convention of an Integer into a string.
eg:
(itoa 25) returns "25"
Atoi
Returns the convention of a string into an Integer.
eg:
(itoi "25") returns 25
Conditionals
(=)
Is not an assignment command, only
(setq) is. The (=)command is used only to test if items are equal. It does
not make them equal.
if
(if) is the standard if-then-else statement. In AutoLISP you
may only match one if statement with a then statement.
eg:
(if (= a b) (setq b 5 (setq b 6)) If a is equal to b,
then
b will be assigned the value of 5.If it is not then
b will be assigned the value of 6.Cond (Conditional)
This function accepts any number of lists as arguments. It
evaluates the first item in each list (in order supplied)
until one of these items are a value other than nil.
eg: A user's response string is variable
s,(cond
((= s "Y") 1)
((= s "y") 1)
((= s "N") 0)
((= s "n") 0)
(t nil)
)
This function tests the response and returns 1 if it is "Y" or "y", and 0 if it is "N" or "n", and nil otherwise. Repeat Similar to a loop but repeat will only go through the commands as many times as is told. eg:
(setq b 100)
(repeat 4
(setq a (+ a 10))
(setq b (+ b 10))
Returns
140.
While
Is another loop control command available in AutoLISP.
A loop is necessary if you want to repeat a command.
However, unless you have a way of controlling it, the
program will run forever and hang you up.
eg:
(setq a "w")
Sets up the controlling variable to a
value other than nil.
(while a
The loop will continue, begining with the
commands that follow, until the variable a
is set to
nil.(xxxx)
(xxxx) Are the commands that are performed in
the loop.
Evaluates if c is equal to
d, and if so, sets the
loop controlling variable a
to
nil to end the loop.)
While parenthesis closes loop, and program will
continue with the commands after this.
Entities
An entity is the smallest object you can place on your
screen.
The following are entities: LINE, CIRCLE, ARC, TEXT,
POLYLINES, etc
Entities are stored and referenced in the drawing database.
They can be changed and manipulated using AutoLISP to suit
your needs.
Each entity has a massive definition in AutoCAD's database.
eg: The data for a single line contains the following info:
Entity name, Entity type, Layer, Color, Beginning X Y coordinate,
Ending X Y coordinate, Line type, etc.
You can modify any of the above aspects.
An example of an entity list:
( - 1 <Entity name: 60000014) (0 "CIRCLE") (8 . "LAYER1")
(10 . 50.000 100.000) (40 . 60.000)
It is an entity list of a circle on layer LAYER1, center point
relative to 0,0 of 50.0,100.0 , and a radius of 60.0
Ssget and Entsel (select entities)
Both give you a way of selecting the entities for the
selection set.
(entsel) only selects one entity at a time.
You may not use WINDOW or CROSSING to
select entities.
(ssget) however lets use WINDOW or CROSSING as well as
other selection techniques.
You will mostly be using
(ssget).(setq a (ssget)) will prompt you to select objects. You have
now created a selection set with a specific
name, <Selection set:l> , assigned to
variable
a.or use filter option
(setq a (ssget "X" '((0 . "TEXT"))))to search database for certain entities or codes.
Ssname (get entity name)
Lets you secure the name of the entity. The name of the
entity is realy a hexadecimal number, therefore don't expect
to see a name like LINE, or CIRCLE etc. The name of your
entity might be 60000018.
Lets assume variable
a is the selection set and variablei is set to 0.
(setq i 0) To set Counter variable.
(setq na (ssname a i)) This assigns na the entity name
found in the selection set
a atindex number
i.Remember that a selection set may contain more than one
entity name. You can point to each entity by using its
relative number in the selection set.
eg:
Entity 1 is Index 0 , Entity 2 is Index 1 , etc.
Entget (get entity list)
This command actually pulls out, or extracts, the entity
list. The entity list can be assigned to a variable.
(setq b (entget na)) That assigns to b the entire
entity list for that entity name.
Subst (substitute new for old)
Allows you to substitute one aspect for another.
Assume variable
b is the name of the list and variablec contains the value of the element: (40 . 60.0000)
(setq bl (subst '(40 . 30.0000) c b)) ;bl is now the new list.
'(40 . 30.0000) is the new element substituted for the old element
c found in list b.
Sslength
Gives you the length or number of selections made.
Entmod (entity modification)
Gives you the ability to take the newly modified entity list
and write it back to the database to update the drawing.
Now that you have a new list in the variable
b1, you wantto make
bl the permanent list in your drawing database.(entmod bl) You should see the change appear on the screen.
Change Cross Hair Angle
This program permits you to draw lines perpendicular to other
lines. The program measures the angle of the line chosen,
and shifts the SNAP ANGLE to the angle of that line.
Use ORTHO ON and draw perpendicular to your chosen line.
(defun c:perpdon (/ a b pntl pnt2 angl)
(graphscr)
(setq a (entsel))
(setq b (entget (car a)))
(setq pntl (cdr (assoc 10 b)))
(setq pnt2 (cdr (assoc 11 b)))
(setq angl (angle pntl pnt2))
(setvar "snapang" ang1)
(princ)
)
(defun c:perpdoff
(setvar "snapang" 0)
(princ)
)
Erase Screen
Erases everything on the drawing screen. If you are in a
ZOOM ALL position, the program erases everything within the
limits of the drawing.
Note: if you accidentally invoke this command, you can
recover with OOPS.
(defun c:erasescr (/ l u)
(setq l (getvar "limmin"))
(setq u (getvar "limmax"))
(command "erase" "w" l u "")
(princ)
)
Change Layer
Lets you select objects by any selection method and change
their layer. The target layer is chosen by simply pointing
to an object on the desired layer. All objects selected
will then change to that target layer. To test this program,
you will need to create a drawing with objects on different
layers.
(defun c:chlayer (/ a1 a2 n index b1 b2 d1 d2 b3)
(graphscr)
(prompt "\nselect entities to be changed: ")
(setq a1 (ssget))
(prompt "\npoint to entity on target layer: ")
(setq a2 (entsel))
(setq n (sslength a1))
(setq index 0)
(setq b2 (entget (car a2)))
(setq d2 (assoc 8 b2))
(repeat n
(setq b1 (entget (ssname a1 index)))
(setq d1 (assoc 8 b1))
(setq b3 (subst d2 d1 b1))
(entmod b3)
(setq index (+ index 1))
)
(princ)
)
Now examine the program line by line.
(defun c:chlayer (/ a1 a2 n index b1 b2 d1 d2 b3)
Defines the function with all local variables.
(graphscr)
Changes to graphics screen.
(prompt "\nSelect entities to be changed: ")
This is a prompt statement.
(setq a1 (ssget))
Allows you to select the objects to be changed. The
selection set is assigned to variable
al.(prompt "\npoint to entity on target layer: ")
This is a prompt statement.
(setq a2 (entsel))
This is a special type of selection statement that allows
you to select only one entity.
(setq n (sslength a1))
Measures the number of entities in the selection set in
variable
a1.(setq index 0)
Sets the variable called
index to 0.(setq b2 (entget (car a2)))
This statement gets the entity list from
a2. Thus, a2is assigned the entity list.
(setq d2 (assoc 8 b2))
This looks for the code
8 in entity list a2, then assignsthe sublist to
d2.(repeat n
This begins the loop that pages through the selection set.
(setq bl (entget (ssname a1 index)))
This gets the entity list and assigns it to
b1.(setq d1 (assoc 8 b1))
Gets the sublist code
8 (the layer).(setq b3 (subst d2 d1 b1))
Substitutes the new
d2 layer for the old d1 layer inthe entity list
a1, and assigns it to the new entity listb3.
(entmod b3)
Updates the new entity list in the database.
(setq index (+ index 1))
Increases the index variable by
1, making it ready forthe next loop.
The first
) closes the repeat loop. (princ) exits quitly. The second ) closes the function.
Substitute text
This program lets you choose a line of text and substitute
another line at exactly the same place.
(defun c:subtext (/ a b d e d1 b1 y)
(prompt "\nSelect text line: ")
(setq a (entsel))
(setq b (entget (car a)))
(setq d (assoc 1 b))
(prompt (cdr d))(terpri)
(setq e (getstring 1))
(setq d1 (cons (car d) e))
(setq b1 (subst d1 d b))
(entmod b1)
(setq y (getstring "\nIs this correct - Y : "))
(if (= (srtcase y) "N") (entmod b))
(princ)
)
TEXT- OWN DISTANCE, OWN TEXT HEIGHT
This program lets you change the distance between multiple text
lines. In addition to the standard start point and height, you
are asked to enter the distance between text lines. You may
enter as many text lines as you wish. To stop the program,
enter an asterix (*).
(defun tex (/ p1 a b c d e f)
(setq pl (getpoint "\nStarting point: "))
(setq a (getdist p1 "\nEnter height: "))
(setq c (getdist p1 "\nline spacing: "))
(setq d "T")
(while d
(setq e (getstring 1 "Text: "))
(command "text" pl a "0" e)
(setq pl (list (car p1)(- (cadr p1) c)))
(setq f (getstring))
(if (= f "*") (setq d nil))
)
(princ)
)
GLOBAL TEXT HEIGHT CHANGE
This program allows you to globally change the size of text
within a WINDOW or CROSSING without affecting other
entities.
(defun chtext (/ a ts n index b1 b c d b2)
(setq a (ssget))
(setq ts (getreal "\nEnter new text size"))
(setq n (sslength a))
(setq index 0)
(repeat n
(setq b1 (entget (ssname a index)))
(setq index (1+ index))
(setq b (assoc 0 b1))
(if (= "TEXT" (cdr b))
(progn
(setq c (assoc 40 b1))
(setq d (cons (car c) ts))
(setq b2 (subst d c b1))
(entmod b2))))
(princ)
)
OBJECT SNAP CODES
Center 4
Endpoint 1
Insert 64
intersection 32
Midpoint 2
Nearest 512
Node 8
Perpend 128
Quadrant 16
Tangent 256
None 0
ENTITY CODES
0 Identifies the start of an entity, table entry,
or file separator. The text value that follows
indicates which.
1 The primary text value for an entity.
2 Aname; Attribute tag, Block name, etc.
3-5 Other textual or name values.
6 Line type name (fixed).
7 Text style name (fixed).
8 Layer name (fixed).
9 Variable name identifier (used only in HEADER
section of the DXF file).
10 Primary X coordinate (start point of a Line or
Text entity, center of a Circle, etc.).
11-18 Other X coordinates.
20 Primary Y coordinate. (always corresponds to
primary x coordinate).
21-28 Other Y coordinate.
30 Primary Z coordinate. (always corresponds to
primary x and y coordinates).
31-36 Other Z coordinates.
38 Entity's elevation.
39 Entity's thickness.
40-48 Floating point values (text height, scale,
circle rad, etc.).
50-58 Angles.
62 Color number.
66 Entities follow
70-78 Integer values, such as repeat counts, flag
bits, or modes.