To get a sense of how a script works, create a text file named layer.scr and type the following lines. Be careful not to create extra lines or spaces anywhere in the file. However, enter

LAYER
New
fl1,fl1-dim,fl1-txt
Color
2
fl1
Color
3
fl1-dim
Color
4
fl1-txt

If you highlight the entire file in Notepad you can see whether you have any extra spaces or lines. Notice the location of the cursor in the image.

You can also type the script file on one line, with a single space between the commands. The same setup script looks like this:

Layer new fl1,fl1-dim,fl1-txt color 2 fl1 color 3 fl1-dim color 4 fl1-txt

Save the file (don't forget the .scr extension). Run the script in AutoCAD. If everything goes right, three new layer names are created, with their colors set to 2, 3, and 4.

The simple script in the previous section can be expanded to automatically set up limits, units, variables, a text style, and so on. If you use good template files, much of this setup is already be in place, but I can think of a few reasons why a script may be a better choice than a template file:

Let's take the script layer.scr and rewrite it with a few additional functions:

;Create new layers
LAYER New obj,hid,cen,txt,dim Color 1 hid Color 3 cen
Color 4 txt Color 5 dim L hidden hid L center cen S obj

;Create new text style
STYLE romans romans 0 1 0 N N N
;Reset variable values
APERTURE 5 ATTDIA 1 AUNITS 0 AUPREC 1 BLIPMODE 0
CECOLOR bylayer CELTSCALE 1 CELTYPE bylayer
CMDDIA 1 CMDECHO 1 CURSORSIZE 5 DRAGMODE A ELEVATION 0
EXPERT 0 FACETRES 1 FILEDIA 1 FILLETRAD 0 GRIPCOLOR 5
GRIPHOT 1 GRIPS 1 GRIPSIZE 3 HIGHLIGHT 1 LTSCALE 1
MBUTTONPAN 1 MIRRTEXT 0 OSMODE 4133 PELLIPSE 0 PICKADD 1
PICKAUTO 1 PICKBOX 3 PICKFIRST 1 PICKSTYLE 1 PLINEGEN 1
PSLTSCALE 1 SAVETIME 15 SDI 0 SORTENTS 23 THICKNESS 0
UCSICON off UCS w UCSVP 1

The following graphic shows the result of highlighting this file. In this case the cursor is directly below the beginning of the last line. There is no need for a blank line to exit the previous command.

This script sets up layers, an acceptable text style, and set key variables. The purpose of a setup script is to restore standard settings if something goes wrong with AutoCAD and you can't figure out why.

Note

Make sure there are no extra spaces or lines anywhere in this file. (There's a reason why I'm mentioning this over and over.) Each of them is interpreted as the

If you've ever wondered how well AutoCAD will run on a particular workstation, the script function gives you a handy way to find out. You may want to duplicate a colleague's problem with AutoCAD crashing (unless, of course, AutoCAD has never crashed for you). Or, you may want to compare a variety of computers to decide which one to buy.

I wrote the following script because, as the person responsible for all the computers in my department, I'm all too familiar with the Law of Unintended Consequences. Whenever it's time for the college to upgrade or add computers to a lab, I load AutoCAD on each station and then run a version of the following script. You'd be surprised at the amount of variation between systems with similar specs.

Before running this script you must start a new Imperial drawing from scratch.

TIME R

BOX 0,0 10,10,10 SPHERE 5,5,5 5 SUBTRACT NON 0,0  L

VPOINT 1,−1,1 SLICE L   5,0 5,5 5,5,5 −1,0
3DARRAY L  R 4 4 4 10 10 10
ZOOM ALL HIDE
VPORTS 4
CVPORT 5 UCS X 90 PLAN C
CVPORT 4 UCS W PLAN C
CVPORT 2 UCS X 90 UCS Y 90 PLAN C
TILEMODE 0 ERASE ALL  MVIEW R  F
MSPACE CVPORT 3 SOLPROF ALL  Y Y Y
CVPORT 4 SOLPROF ALL  Y Y Y
CVPORT 5 SOLPROF ALL  Y Y Y
CVPORT 6 SOLPROF ALL  Y Y Y
TIME

To make sure you have no spaces at the end of each line, highlight the entire file by dragging the mouse with the left button held down, and make sure it looks like the following image. Note that the cursor is by itself on the last line, which is below TIME. If you have trouble running this script, try turning off running object snaps or setting APERTURE to 3.

What does this script do? Let's take one line at a time; see Table 7.1

Table 7.2. benchtest.scr

SCRIPT LINE	PURPOSE
TIME R	Resets the time.
	A
BOX 0,0 10,10,10 SPHERE 5,5,5 5 SUBTRACT NON 0,0 L	Creates a solid box and a sphere, and subtracts the sphere from the box. The use of NON cancels any running object snaps. Giving a location of 0,0 selects the box. An extra space is a
	A
VPOINT 1,−1,1 SLICE L 5,0 5,5 5,5,5 −1,0	Creates an isometric view, and slices the resulting solid using a plane defined by the coordinates given. Note the 3 spaces after L.
3DARRAY L R 4 4 4 10 10 10	Creates a rectangular 3D array of the sliced object. The larger the values used for the number of entities, the more entities are created in the array. To decrease the amount of time it takes to run this test, lower the value from 10. To increase the amount of time, increase the value.
ZOOM ALL HIDE	Displays the entire array, and displays it as hidden.
VPORTS 4	Sets up four tiled viewports.
CVPORT 5 UCS X 90 PLAN C	Makes viewport 5 active, and creates a front view.
CVPORT 4 UCS W PLAN C	Makes viewport 4 active, and creates a top view.
CVPORT 2 UCS X 90 UCS Y 90	Makes viewport 2 active, and creates a right view.
PLAN C
TILEMODE 0 ERASE ALL MVIEW R F	Switches to a layout, and creates four views.
MSPACE CVPORT 3 SOLPROF ALL Y Y Y	Creates a solid profile in viewport 3.
CVPORT 4 SOLPROF ALL Y Y Y	Creates a solid profile in viewport 4.
CVPORT 5 SOLPROF ALL Y Y Y	Creates a solid profile in viewport 5.
CVPORT 6 SOLPROF ALL Y Y Y	Creates a solid profile in viewport 6.
TIME	Activates the TIME command, and displays the total elapsed time.

I use these particular functions because they have caused me past problems in AutoCAD. You can easily adjust the program to increase or decrease the time it takes to run by changing the number of objects in the 3D array. When I ran this program on my current workstation, I got the following result at the end.

You can automate AutoCAD at startup with switches by using the RUN option or using a startup icon. One of those switches, /b, allows you to name a script that runs each time AutoCAD starts.

Figure 7.1 shows the Properties window of an AutoCAD desktop icon. In the Target field, I've added the /b switch and the name and path of a script file. The entire line reads like this:

"C:Program FilesAutoCAD 2007acad.exe" /b R:setup.scr

When you select the icon, AutoCAD starts up and executes the named script, which is on a network drive. I use this script to easily change the setup for plotters and specific variables; I can also send a message to users by adding an Alert box. AutoCAD system variables, such as REMEMBERFOLDERS, can be set directly; you need AutoLISP code to set environmental variables. Here's a sample startup script:

Figure 7.1. Running a script on startup

;;No blank lines!
rememberfolders 0
ACADLSPASDOC 1
Savefilepath S:
(if (= 120 (getvar "savetime"))(setvar "savetime" 5))
(setenv "HideSystemPrinters" "1")
(setvar "pickadd" 1)
(setenv "PrinterConfigDir" "r:\plotters")
(setenv "PrinterStyleSheetDir" "")
(setenv "PrinterDescDir" "r:\plotters\pmp files")
(startapp "net start spooler")
(alert "Message text begins after the quote, for display
in an AutoCAD Message box.

 A new line would start after the backslash n and appear here.

 A third line would appear here. The closing quote and parenthesis
 is on the next line.
")
(defun C:AED()(startapp "C:\Program Files\Adobe\
Acrobat 6.0\Reader\AcroRd32.exe"
"r:\TECHNICAL GRAPHICS STANDARDS_rev8.pdf"))
(princ)

Let's say AutoCAD starts misbehaving: You know something's gone awry but can't target the problem. Sometimes the only solution is to reset all variables to their defaults.

If Express Tools are installed on your system, look for a file named defaults.scr in the Express folder under the AutoCAD folder in Program Files. That file is a script you can use to restore all default settings for AutoCAD variables. Unfortunately, it hasn't been updated for the past several releases. The website for this book contains contains an updated version of this file with the default values. It uses Lisp language to reset each variable, primarily because that approach allows more accuracy in values that must be calculated using pi. It also lets you set environmental variables like MAXHATCH that can only be set with AutoLISP.

Figure 7.2. System Variables dialog box

You can use another Express Tool, SYSVDLG (the System Variables editor), to save your current settings and then retrieve them, as shown in Figure 7.2. These won't be the default values if you've changed anything.

In these solutions, I use a batch file to edit multiple drawings primarily because doing so allows me to use the DOS function FOR. The FOR function lets you specify a directory and filenames using wildcards and have the operating system do something with those files. In this case, I use the batch file to start AutoCAD and open each DWG file in a specified directory. The key line of each batch file is in the following form:

FOR %%f in (C:dwg*.dwg) do start /wait acad.exe "%%f" /b
C:Sybexwbout.scr

To process drawings in subdirectories, you can add a /r switch to the FOR command in the batch file. Note that the path comes before the replaceable parameter, and the set (in parentheses) includes only the files, designated by a wildcard and file extensions. You can also reference a text file to specify a list of filenames, but this is the system I use. Consult the DOS help system for the FOR command if you want more details:

FOR /r C:SybexDWG %%f in (*.dwg) do start /wait
C:"Program Files""AutoCAD 2007"acad.exe "%%f" /b
C:Sybexwbout.scr

In addition to the batch file, I also use a script for these solutions because I can run a script on startup by pointing to it in the batch file. The following line shows the syntax to use at a DOS command prompt in the target window of a desktop icon, or in the Run window reached from the Windows Start button:

C:"Program Files""AutoCAD 2007"acad.exe C:dwghouse.dwg /b
C:Scriptsstartup.scr

This line starts AutoCAD (acad.exe), opens a specified drawing (house.dwg), and executes a named script (C:Scriptsstartup.scr) automatically.

Like both script files and batch files, an AutoLISP file is a text file, but it's designated by an .lsp extension. Lisp is a programming language, and its tie to AutoCAD makes it possible to do nearly anything to a drawing. Every experienced AutoCAD user should be familiar with it. In this system for updating drawings, AutoLISP generally does the real work.

Learning AutoLISP is beyond the scope of this chapter, but read Chapters 8 and 9, "AutoLISP by Example: Getting Started," and "AutoLISP by Example: Getting Better." For now, I'll provide you with the necessary AutoLISP code for these examples. Go ahead and copy it.

Because AutoLISP functions can be typed at the command line in AutoCAD, AutoLISP code can be placed directly within a script file as long as it is enclosed in parentheses. I use that feature in these solutions only to load an AutoLISP file. Most of the AutoLISP code resides in its own separate file.

For the purpose of these examples, specific folder names and filenames are used. To complete these exercises, create the following folders:

Once the folders exist, place some sample drawings in the C:SybexDWG folder.

All these files—batch, script, and Lisp—must work together to accomplish the task of updating a lot of drawings. That makes troubleshooting this system at least three times more difficult than if it used a single file. So, let me make a point about frustration. When you do any kind of programming, the chances are good that when you test it, it won't work. Why? For one thing, it's easy to overlook a little thing, like a

Example 1: Reducing File Size

The first example of a solution for automated updating involves reducing the size of all drawing files within one or more directories to their minimum. I use the WBLOCK command, but you can use the PURGE command instead. This solution was written for an office that wanted to clean up archived drawings, eliminating unused layer names, block definitions, dimension styles, and so on to reduce the amount of space they took up.

The batch file starts AutoCAD, loads the first drawing in the named directory, executes the script file, and waits until AutoCAD finishes with that drawing so it can go on and load the next file in the directory. The script file loads the AutoLISP file, runs the command it defines, and then quits AutoCAD. The AutoLISP file gets the name of the drawing and uses the WBLOCK command to save it with the same name, but in a different directory. Once the script file quits AutoCAD, the whole process returns to the batch file and continues until all the files are processed.

STEP 1: WBOUT.BAT

Use a text editor to create the following batch file, and save it as wbout.bat in the folder C:Sybex. Type the entire FOR statement on one line. When you type it in a text editor, it will appear as a single line, even though it appears on multiple lines here. This batch file has only two lines of text:

MD C:SybexDWGwb
FOR %%f in (C:SybexDWG*.dwg) DO START /WAIT
C:"Program Files""AutoCAD 2007"acad.exe "%%f" /b
C:Sybexwbout.scr

When you execute this batch file, AutoCAD starts, and opens each drawing. Because of the /b switch, the script file named wbout.scr runs every time AutoCAD starts. When all files with a .dwg extension have been processed (made equal to variable %%f), the program stops.

Table 7.2 shows the purpose of each line.

Table 7.3. wbout.bat

LINE IN BATCH FILE	PURPOSE
MD C:SybexDWGwb	This line makes a new folder named wb within the C:SybexDWG folder. The drawing files created in this example are placed in this folder.
FOR %%f in (C:SybexDWG*.dwg) DO START /WAIT C:"Program Files""AutoCAD 2007"acad.exe "%%f" /b C:Sybexwbout.scr	FOR each filename represented by the replaceable parameter %%f, within the folder named C:SybexDWG, DO the following: START a Windows application, and WAIT for it to finish before continuing on to the next file in the directory.
	The Windows application is the ACAD.EXE program. When it's started, load the drawing whose name is represented by the replaceable parameter %%f, and run the script named wbout.scr, which is located in the C:Sybex folder.

Note

I used the default path for AutoCAD in all of these examples. If you installed AutoCAD in a location other than the default, edit this file so it uses your path. You can omit the path and use only the filename ACAD.EXE unless there is more than one ACAD.EXE file on your computer. This can happen if you have multiple releases of AutoCAD or if you have one or more vertical applications. It's generally better to be explicit in giving a path.

STEP 2: WBOUT.SCR

Use a text editor to create the following script file, and save it as wbout.scr in C:Sybex with wbout.bat. You should have five lines of text, with no extra spaces or extra lines anywhere. You must press

(load "C:\Sybex\wbout.lsp")
ZOOM All
WBOUT
QUIT
Y

When AutoCAD runs this script, an AutoLISP file is loaded that defines WBOUT, a new AutoCAD command. The script runs the WBOUT command and then quits AutoCAD.

Table 7.3 shows the purpose of each line.

Table 7.4. wbout.scr

LINE IN SCRIPT FILE	PURPOSE
(load "C:\Sybex\wbout.lsp")	This line of AutoLISP code loads the wbout.lsp file. Note the \.
ZOOM All	This is here to make a change in the drawing. Otherwise, AutoCAD won't allow a file to be saved by the WBLOCK command, which is used in the AutoLISP program.
WBOUT	This is the name of the new command defined in wbout.lsp. Placing it here executes that command.
QUIT	The AutoCAD QUIT command closes AutoCAD without saving the drawing file that was opened.
Y	This confirms that AutoCAD should quit without saving. See the following note for an explanation.

Note

The QUIT command, when used in a script, results in a different prompt than it does when used in AutoCAD directly. The prompt for the script version is Really want to discard all changes to drawing? <N>, which requires the response Y to quit without saving.

STEP 3: WBOUT.LSP

Use a text editor to create the following AutoLISP file, and save it as wbout.lsp in the folder C:Sybex:

(defun C:WBOUT(/ dn pa pawbdn)
   (setq dn (getvar "dwgname"))
   (setq pa (getvar "dwgprefix"))
   (setq pawbdn (strcat pa "wb\" dn))
   (command "WBLOCK" pawbdn "*")
)

This program gets the current drawing name, issues the WBLOCK command, selects all entities in the drawing (that's what the * does), and saves the drawing in the new WB folder with the same filename as the original drawing file.

Table 7.4 shows the purpose of each line.

Table 7.5. [.] wbout.lsp

LINE IN SCRIPT FILE	PURPOSE
(defun C:WBOUT(/ dn pa pawbdn)	This line defines the new function named WBOUT. The C: makes it an AutoCAD command. Leave a space after the forward slash.
(setq dn (getvar "dwgname"))	This line gets the name of the current drawing and saves it as a variable. Type both quotes.
(setq pa (getvar "dwgprefix"))	This line gets the path of the current drawing and saves it as a variable.
(setq pawbdn (strcat pa "wb\" dn))	This line creates a new path by adding the folder WB to the existing path where the current drawing is stored.
(command "WBLOCK" pawbdn "*")	This is the line that saves the drawing in the new WB folder using the same drawing name.
)	This line closes the opening parenthesis in the file. Every opening parenthesis must have a closing one.

Note

By using a Lisp program to change the drawing and then save it to a new location, you can get the current location and the current filename, modify them by appending a new folder name, and store them as variables. This can't be done using a script file alone.

STEP 4: RUN THE PROGRAM

Once there are drawing files in the C:Sybex folder, you can start this process by running the batch file. The batch file gets the whole thing moving, because it selects each drawing file and starts AutoCAD with the proper script. You can run this program from the Run window, a command prompt, Explorer, My Computer, or a desktop shortcut.

For now, use Explorer to find the C:Sybex folder. Double-click the wbout.bat icon; or select it, right-click, and select Open. See Figure 7.3. If everything goes well, you can sit back and watch AutoCAD opening and closing as it modifies each file. When the batch file is completed, the DOS window closes. Look in the C:SybexDWGWB folder, and see whether your new files are there.

Figure 7.3. Running a batch file

Note

Don't double-click a batch file if you only want to edit it. To change text, select Edit from the right-click menu. Double-clicking automatically launches the batch file. (You can also launch the batch file by selecting Open from the right-click menu.)

You may have to try this several times. If so, delete the WB folder before running the batch file a second time. Otherwise, you'll get a prompt asking you if you want to replace the existing drawings as AutoCAD tries to save files with the same name to the WB folder.

Using this collection of programs—a batch file, a script, and an AutoLISP routine—can greatly reduce the space used for archiving DWG files. However, as with any automated process, there are a number of things to consider, including whether you really want to eliminate all unused layers, block references, text styles, and dimension styles from the drawings.

This kind of programming should be tested carefully on a limited number of test files before you use it. Once you've run this program and are convinced that it did what you wanted, you can delete the old files and place the new files where you want them.

Example 2: Redefining Existing Block Definitions

I devised this second solution for a company that had been purchased and renamed. The company didn't want to send out or plot any existing drawings with the old name in the title block. Over a number of years, the company had inserted the same title block drawing into all of its AutoCAD drawings, and now it wanted to redefine the resulting block reference in all of them. I had one preliminary question: Did the company ever explode its title blocks? It hadn't, which is why this system worked. Except for the logo and company information, the new title block and the old title block were identical, so all it needed to do was replace the definition for the Border block in each drawing.

Note

If you want to try this example, you'll have to create a drawing with entities representing a title block in Model Space and save the drawing with the name new-border.dwg. Place it in the C:SybexDWG folder along with several drawings that have a block reference named border. The new-border.dwg file is used to update the border Block definitions in each drawing.

REPLACING EXISTING FILES

You can make this process replace existing drawings by altering the behavior of wbout.lsp. I don't recommend replacing drawings directly, but if you have a limited amount of drive space, you may not be able to store two copies of each drawing until you're done.

This requires some changes to the AutoLISP program. Before you try this, make sure you really understand what you're doing and are convinced the program works.

Remove the reference to the wb folder, set EXPERT to 4 in your AutoLISP program, and reset it when the program is finished, as follows:

(defun C:WBOUT (/  dn pa padn x)     ;define a new command WBOUT
   (setq x(getvar "expert"))           ;get current expert value
   (setq dn (getvar "dwgname"))        ;get name of current drawing
   (setq pa (getvar "dwgprefix"))      ;get location of current drawing
   (setq padn (strcat pa dn))          ;combine path and name of drawing
   (setvar "expert" 4)                 ;suppress warnings
   (command "wblock" padn "*")         ;replace existing drawing
   (setvar "expert" x)                 ;reset value of expert
)                                      ;closes the first parenthesis

It's wise to add an error-trapping function to this new program, to make sure the value for EXPERT is returned to its original setting, no matter what. See Chapter 9.

STEP 1: TBUPDATE.BAT

Use a text editor to create the following batch file, and save it as C:Sybex bupdate.bat. Type the entire FOR statement on one line. When you type it in a text editor, it will appear as a single line, even though it appears on multiple lines here. This file has only two lines of text:

MD C:SybexDWGNewBorder
FOR %%f in (C:SybexDWGd5*.dwg) DO START /WAIT
C:"Program Files""AutoCAD 2007"acad.exe "%%f" /b
C:Sybex	bupdate.scr

Table 7.5 shows the purpose of each line.

Table 7.6. tbupdate.bat

LINE IN SCRIPT FILE	PURPOSE
MD C:SybexDWGNewBorder	This line makes a new folder named NewBorder in the C:SybexDWG folder. The drawing files created in this example are placed in this folder.
FOR %%f in (C:SybexDWGd5*.dwg) DO START /WAIT C:"Program Files""AutoCAD 2007"acad.exe "%%f" /b C:Sybex bupdate.scr	FOR each file name represented by the replaceable parameter %%f, within the folder named C:SybexDWG, DO the following: START a Windows application, and WAIT for it to finish before continuing on to the next file whose name begins with D5 in the directory.
	The Windows application is the ACAD.EXE program. When it's started, load the drawing whose name is represented by the replaceable parameter %%f, and run the script named tbupdate.scr, which is located in the C:Sybex folder.

Note

This example is more selective about the files being processed than the first example. Only drawings whose names begin with the characters D5 are opened.

STEP 2: TBUPDATE.SCR

Use a text editor to create the following script file, and save it as tbupdate.scr in a folder named C:Sybex. You should have eight lines (one is blank), with no extra spaces anywhere. You must press

INSERT border=C:SybexDWG
ew-border.dwg
0,0 1 1 0
ERASE L

(load "C:\Sybex\tbupdate.lsp")
TBUPDATE
QUIT
Y

When AutoCAD runs this script, an AutoLISP file is loaded that defines TBUPDATE, a new AutoCAD command. The script runs the TBUPDATE command and then quits AutoCAD.

Table 7.6 shows the purpose of each line.

STEP 3: TBUPDATE.LSP

Use a text editor to create the following AutoLISP file, and save it as tbupdate.lsp in the folder C:Sybex:

(defun C:TBUPDATE(/  dn pa panbdn)
   (setq dn (getvar "dwgname"))
   (setq pa (getvar "dwgprefix"))
   (setq panbdn (strcat pa "NewBorder\" dn))
   (command "SAVE" panbdn)
)

It gets the current drawing name and saves the drawing in the new NewBorder folder with the same filename as the original drawing file. The WBLOCK command isn't used here because it isn't necessary. This system isn't designed to reduce the file sizes.

Table 7.7 shows the purpose of each line.

STEP 4: RUN THE PROGRAM

Double-click the tbupdate.bat icon; or select it, right-click, and choose Open. This one goes by quickly. Look in the C:SybexDWGNewBorder folder and see whether your new files are there. Open one to see if the block did in fact update.

Table 7.7. tbupdate.scr

LINE IN SCRIPT FILE	PURPOSE
INSERT border=C:SybexDWG new-border.dwg	Using the INSERT command in this manner redefines the existing block reference border using the entities in Model Space in the drawing new-border.dwg.
0,0 1 1 0	The block reference created from the NEW-BORDER drawing is inserted at 0,0. X and Y scale factors and a rotation angle are required when inserting a block reference. Here, you use scale factors of 1 and a rotation angle of 0.
ERASE L	This line erases the last object created, which is the block reference just inserted. Why erase it? Because the only reason to insert it is to update the existing block reference. Once that is accomplished, this additional reference isn't needed.
	This blank line is used as a
(load "C:\Sybex\tbupdate.lsp")	This line loads the AutoLISP program that is used to save the drawing file.
TBUPDATE	This is the name of the new command defined in tbupdate.lsp that saves the resulting updated drawing file. Placing it here executes that command.
QUIT	The AutoCAD QUIT command closes AutoCAD without saving the drawing file that was opened.
Y	This confirms that AutoCAD should quit without saving.

Table 7.8. tbupdate.lsp

LINE IN SCRIPT FILE	PURPOSE
(defun C:TBUPDATE(/ dn pa panbdn)	This line defines the new command TBUPDATE.
(setq dn (getvar "dwgname"))	This line gets the name of the current drawing file and saves it to a variable named dn.
(setq pa (getvar "dwgprefix"))	This line gets the path of the current drawing file and saves it to the variable pa.
(setq panbdn (strcat pa "NewBorder\" dn))	This line creates a new path by adding NewBorder\ to the existing path where the drawings are saved.
(command "SAVE" panbdn)	This line saves the drawing in the NewBorder folder using the same drawing name.
)	This line closes the opening parenthesis in the file.

Example 3: Creating Drawings from Block Definitions

I wrote this one for an architectural firm that decided to change its system for managing its library of symbols. The company had been using single drawings with related groups of block definitions to store symbol libraries. It decided it would prefer to have a separate drawing file for each of the block definitions used and assigned the task of creating them to a recently hired designer. After doing a few, he called me to see if there was some way to reduce the tedium of manually creating the drawing files.

The purpose of this final example is to automatically open a group of drawings that contain block definitions and create a new drawing file from each of them. It uses the same process as in examples 1 and 2, but with a somewhat more involved AutoLISP program.

STEP 1: BLOCKOUT.BAT

Use a text editor to create the following batch file, and save it as C:Sybexlockout.bat. Type the entire FOR statement on one line. When you type it in a text editor, it will appear as a single line, even though it appears on multiple lines here. Like the earlier examples, this file has only two lines of text. For an explanation for what this file does, see Table 7.8:

MD C:SybexDWGNewBlocks
FOR %%f in (C:SybexDWGsym*.dwg) DO START /WAIT
C:"Program Files""AutoCAD 2007"acad.exe "%%f" /b
C:Sybexlockout.scr

STEP 2: BLOCKOUT.SCR

Use a text editor to create the following script file, and save it as blockout.scr in the folder named C:Sybex. You should have four lines with no blank lines anywhere in the file. You must press

(load "C:\Sybex\blockout.lsp")
BLOCKOUT
QUIT
Y

Table 7.9. tbupdate.bat

LINE IN SCRIPT FILE	PURPOSE
MD C:SybexDWGNewBlocks	This line makes a new folder named NewBlocks in the C:SybexDWG folder. The drawing files created in this example are placed in this folder.
FOR %%f in (C:SybexDWGsym*.dwg) DO START /WAIT C:"Program Files""AutoCAD 2007"acad.exe "%%f" /b C:Sybexlockout.scr	FOR each filename represented by the replaceable parameter %%f, in the folder named C:SybexDWG, DO the following: START a Windows application, and WAIT for it to finish before continuing on to the next file whose name begins with Sym in the directory.
	The Windows application is the ACAD.EXE program. When it's started, load the drawing whose name is represented by the replaceable parameter %%f, and run the script named blockout.scr, which is located in the C:Sybex folder.

It isn't necessary to do a ZOOM ALL in this example. Once the Block definitions have been extracted using the blockout.lsp program, the drawing can be closed.

Table 7.9 shows the purpose of each line.

Table 7.10. blockout.scr

LINE IN SCRIPT FILE	PURPOSE
(load "C:\Sybex\blockout.lsp")	This line of AutoLISP code loads the blockout.lsp file. Note the \.
BLOCKOUT	This is the name of the new command defined in blockout.lsp. Placing it here executes that command.
QUIT	The AutoCAD QUIT command closes AutoCAD without saving the drawing file that was opened.
Y	This confirms that AutoCAD should quit without saving.

STEP 3: BLOCKOUT.LSP

Use a text editor to create the following AutoLISP file, and save it as blockout.lsp in the folder C:Sybex. Table 7.10 shows the purpose of each line:

(defun C:BLOCKOUT (/  dn pa s1 blkdata blname fullname)
   (setq dn (getvar "dwgname"))
    (setq pa (getvar "dwgprefix"))
    (setq s1 (strcat pa "NewBlocks\"  dn))
    (setq blkdata (tblnext "BLOCK" T))
       (while blkdata
          (setq blname (cdr (assoc 2 blkdata)))
          (setq fullname (strcat s1 blname))
          (command "WBLOCK" fullname blname)
          (setq blkdata (tblnext "BLOCK"))
        )
)

STEP 4: RUN THE PROGRAM

Put some DWG files that contain block definitions into the C:SybexDWG folder. Then, double-click the blockout.bat icon; or select it, right-click, and choose Open. This one is fun because it shows you each drawing file in a preview window as the program creates it from a block definition. Look in the C:SybexDWGNewBlocks folder, and see whether your new files are there. Open one to see if it contains the entities used to define the original block.

Table 7.11. blockout.lsp

LINE IN SCRIPT FILE	PURPOSE
(defun C:BLOCKOUT (/ dn pa s1 blkdata blname fullname)	This line defines the new command BLOCKOUT.
(setq dn (getvar "dwgname"))	This line gets the name of the current drawing and saves it to the variable dn.
(setq pa (getvar "dwgprefix"))	This line gets the path of the current drawing and saves it to the variable pa.
(setq s1 (strcat pa "NewBlocks\" dn))	This line adds a new folder name to the path, appends the drawing name to the end of the path, and saves the result to the variable s1.
(setq blkdata (tblnext "BLOCK" T))	This line sets the variable blkdata to the first entity name in the list of clock definitions.
(while blkdata	This line uses the while function to begin the loop through the following steps while blkdata has a value.
(setq blname (cdr (assoc 2 blkdata)))	This line sets blname equal to the name of the next block definition in the list.
(setq fullname (strcat s1 blname))	This line creates a variable fullname from the path and block name set in the variables s1 and blname. The result is a drawing file whose name is a combination of the name of the current drawing file and the name of the block definition.
(command "WBLOCK" fullname blname)	This is the line that does the work. It uses the WBLOCK command to create a drawing file from the block definition and save it to the new location with the new filename.
(setq blkdata (tblnext "BLOCK"))	This sets blkdata equal to the next block definition in the list, which causes the While function to repeat the previous three lines. Once all the block definitions have been used, blkdata is nil, and the WHILE function causes the program to execute the next line.
)	This ends the WHILE function.
)	This ends the program.

In your own company or practice, you'll find many other possibilities for using this updating system. I certainly have. I've used it for lots of different companies, all of whom have specific, even unique, needs. Here's a short list of applications:

Even if you don't have a specific use for this system right now, try it anyway. It's a great way to develop troubleshooting skills with each of these types of files. The more you understand this system, the more likely you are to find a use for it.