AppleScript in a Nutshell-@Team LiB

Standard Additions

Dictionary commands

adding folder items to alias: This is a Folder Action command covered in Section of Chapter 26.

ASCII character integer: This command returns the ASCII character associated with the number provided as a parameter. For example, ASCII character 80 returns the string "P."

ASCII number integer: You can find the ASCII number of a character by using code, such as ASCII number "P" (this returns an integer of 80).

beep integer: This makes the beep sound integer number of times, or once if a parameter is not included.

choose application

This command opens the choose application dialog box, which only lists the programs running at the moment. Figure A-3 shows this dialog. Figure A-4 shows what this dialog looks like in the OS X release. The following example lists the running applications, then opens the user's choice. Note that choose application also displays faceless background applications that the user cannot interact with (they can quit some of these apps, however).

Figure A-3. The OS 9 choose application window

Figure A-4. The choose application window in OS X

try -- capture error if they choose a 'background only' app
   tell (choose application application label "Choose one program"¬ 
   with prompt "Here are the running applications") to activate
   on error errmesg
   display dialog errmesg
end try

application label string: This string appears at the top of the application list.
with prompt string: This string appears at the top of the dialog box.

Mac OS 9.1 adds two parameters to the choose application scripting addition: multiple selections allowed and as class type (these are described elsewhere in this note). The Mac OS X Standard Additions dictionary alters the choose application osax to remove the application label parameter and add three new optional parameters: with title, multiple selections allowed, and as type. with title lets you specify the title for the dialog window, as in:

choose application with title "Choose your favorite Apps"

multiple selections allowed is a boolean value that if true, allows the user to choose more than one application. as type is designed to let the scripter get the choose application return values as application, alias, or file types. However, in AppleScript 1.6, this return value was only available as an application type.

choose file

This osax opens a dialog box, allowing the user to choose a file to open, which can then be stored in an alias variable, as in:

set f to (choose file with prompt "Choose a file on the local disk")

If the user presses the Cancel button on the choose file dialog instead, then an error is raised, and the script terminates. You can catch this error (error number -128) with a try block and thus allow the script to resume, as in the following example (Figure A-5 shows the choose file window):

try
   c_file(  ) (* call the scripts c_file subroutine which uses the choose file 
osax *)
   on error number ern
   if ern = -128 then (* the user clicked the cancel button on the dialog box *)
      display dialog "User cancelled"
   else
      display dialog "An unknown error occurred with file choosing."
   end if
end try
on c_file(  ) -- define the subroutine
   set f to choose file
   display dialog (f as text) -- display the file path as text
end c_file

Figure A-5. The choose file window

with prompt string

This optional labeled parameter allows you to include a message or prompt with the dialog box:

choose file with prompt "Choose a file on the local disk"

of type list

You can restrict the file types listed in the choose file dialog with this labeled parameter, as in:

choose file of type {"TEXT"}

choose file name

This Mac OS X osax replaces the new file osax of AppleScript in Mac OS 9.0.4. choose file name is also available in Mac OS 9.1. This scripting addition displays a dialog box to the user. The user can then create a filename and a location for a file that does not yet exist (a file specification object is created and returned from this command). The return value in Mac OS X looks like:

file "Mac OS X:users:bruceper:library:desktop:mydbfile"

In effect, a file specification is like a template for a file that you will create in the future. Figure A-6 shows what the choose file name dialog box looks like.

Figure A-6. The choose file name dialog box

with prompt string: This prompt or message appears on the dialog box, as in choose file name with prompt "Please choose the location and name for a new file" default name mydbfile.
default name string: If you want the choose file name dialog box to be displayed with a default file name already entered in the "Save As:" text box, use this parameter.

choose folder

Use this command if you want to interact with the user and get them to choose a directory or folder. For example:

choose folder with prompt "Choose a folder to save your files
in"

with prompt string: This optional labeled parameter adds a message to your dialog box so the user knows why your applet is producing the dialog box in the first place. See the choose folder example.

choose from list list

Lots of AppleScript commands return lists as data types. This handy scripting addition allows you to show the user a list of items in the form of a dialog box. Figure A-7 shows this window. The user can then choose one or more items from the list (depending on whether multiple selections are allowed). When the dialog box is dismissed, the script receives a list of the selected items as a return value:

set fruitList to (choose from list allFruits)

Figure A-7. The choose from list window

with prompt string

Use this optional labeled parameter to add a message to the top of the dialog box.

default items list

If you included this optional parameter, then the list of strings will be initially selected in the dialog box (if firstFruits was a variable that contained a list of strings):

choose from list allFruits default items firstFruits

OK button name string

You can give the OK button your own label, as in:

set fruitList to (choose from list allFruits OK button name "Submit fruits")

cancel button name string

You can give the Cancel button on the dialog box your own label, as in:

set fruitList to (choose from list allFruits cancel button name "Not now")

multiple selections allowed boolean

If you want to give the user the option to make more than one choice in the dialog box's list, then set this labeled parameter to true.

empty selection allowed boolean

If set to true, this labeled parameter allows the user to click the OK button without any list items selected and not raise an error.

choose URL

This command opens up the Network Browser and allows the user to choose a URL involving any of the network services (as constants) identified in the first labeled parameter.

showing list of constants

This parameter can be one or more of the following constants:

Directory services

News servers

File servers

Remote applications

FTP Servers

Telnet hosts

Media servers

Web servers

The return value is a string URL, as in http://my.yahoo.com. For example:

choose URL showing {Web servers,File servers} editable URL false

editable URL boolean

Set this parameter to true if you want to allow the user to enter a URL.

clipboard info

This command returns a list of lists. Each list contains two values separated by a comma: the data type and size of the item on the clipboard. For example, if you select and copy an image to the clipboard, then clipboard info would return a value such as {{picture, 14368}}. The second number is the size of the picture in bytes. If you selected and copied the word "HI", then this command would return {{string, 2}}, which is a string two bytes long. If you copied some styled text, for instance (i.e., text that has a certain font), then the clipboard information return value would involve more than one list inside the outer list, such as {{string, 65}, {styled Clipboard text, 42}.}

for class

Use this optional labeled parameter if you only want to see clipboard information of a certain data type:

clipboard info for string

Use the keyword for followed by the name of the class.

close access (file reference number, alias, or file specification): Use this command to close access to a file you are reading from and writing to.

closing folder window for alias: This is a Folder Action command covered in Section of Chapter 26.

current date

This command returns a date object of the form:

date "Wednesday, May 24, 2000 8:50:06 AM"

You will use this scripting addition all the time! Since the return value is a date object, you can get the various date-related properties from it, such as the time string ("8:50:06 AM"), day, month, and year. See Chapter 3,and the description of the date data type. The following example shows how to display various attributes of the current date:

set theDate to current date (* osax returns a date object and stores it in 
theDate *)
(* get various date properties *)
set d to day of theDate
set m to month of theDate
set y to year of theDate
set ts to time string of theDate
set mesg to "Here's info about today:" & return &¬
"time: " & ts & return &¬
"day: " & d & return &¬
"month: " & m & return &¬
"year: " & y & return
display dialog mesg

delay integer: This useful osax delays the script processing for integer number of seconds, as in delay 5. It is similar to the sleep function in Perl. There are many reasons to delay a script for a few moments, such as dealing with the unpredictable download time of web documents. You might want to pause a script as a browser attempts to download a page before the script reports an error in the download. By the way, use the download scripting addition to download web pages using AppleScript. download is covered in Chapter 18.

display dialog

This is one of the principal ways an applet can interact with the user, either by displaying a message or any script-processing results, or by requesting them to enter text in an edit field. display dialog may end up at the very top of your "indispensable scripting addition" list. This command can optionally add an edit field for receiving text entries from the user by including the default answer "" parameter (passing an empty string to this labeled parameter displays an edit field with no text in it). display dialog has five optional parameters. For example, you can automatically make the dialog go away with code, such as:

display dialog "I disappear after five sec." giving up after 5

display dialog returns a dialog reply object, which is just like a record data type. Chapter 3 describes the record type. See the dialog reply class description in this chapter.

default answer string

Include an empty string (as in default answer "") to display an empty edit field to the user, or include a non-empty string as a default value for the edit field. The string can be up to 255 characters long. If you do not include this parameter, then the dialog box does not have an edit field.

buttons list

You can add up to three of your own button labels to the dialog:

display dialog "Enter one of your names" buttons¬
{"first","last","middle"} default answer ""

The first button in the list is the dialog button on the left, and the next listed buttons are displayed left to right. If you do not include this parameter, then the dialog box has two buttons: Cancel and OK. You can detect which button dismissed the dialog by testing the button returned property of the reply, which looks like:

{text returned:"bruce", button returned:"first"}

In other words, the return value of display dialog is like a record data type, which gives you access to the returned text and button.

default button number or string

You can specify a default button that will have a dark border around it signifying it can also be activated by pressing the return key. If you do not include this parameter, then the dialog box has two buttons: Cancel and OK. Identify the default button by its string or order in the buttons list. In the following example, Keep It is the default button:

display dialog "how much of a reimbursement do you want?"¬ buttons 
{"Send It","Keep It"} default button 2

with icon number, string, or the constants stop, note, or caution

You can display one of the standard Apple dialog icons with this parameter. The dialogs are Stop (number 0), Note (1), and Caution (2). (See Figure A-8.) As an alternative, if you specify the name or number of an icon (as in with icon 9) stored as a resource in the script file or current application, then AppleScript displays that icon in the dialog box. AppleScript searches the script file, the current application (i.e., the one identified in a tell statement), and the System file, in that order, for the icon resource.

Figure A-8. Display dialog with a Note icon

giving up after integer

This command usually displays a modal dialog, meaning that it is the frontmost window, and the user has to dismiss it to access any other windows. Since the scripter is never sure about the context of script execution (what if the applet is executed over a network and the machine happens to be unused at the moment?), it is often a good idea to make the dialog box disappear automatically after a reasonable period, such as several seconds. For example:

display dialog "Are you there?" default answer "Yes" giving up¬ after 10.

get eof

This command returns the length in bytes of a file's contents, as in:

get eof (alias "macintosh hd:desktop folder:myfile.txt")

The return value is an integer. get eof does not return the size of the file on disk, just the number of bytes of data that can be read from the file using the read osax. See the info for scripting addition for getting the actual disk size of the file, as in:

(size of (info for theFile))

See the open for access command for a description of reading and writing to files with AppleScript.

Handling User Interaction with Mac OS X

Due to Mac OS X's Unix origins, only the applications that can execute AppleScripts, such as Script Editor, Script Runner, and the applications that have a built-in Scripts menu, will load and recognize the commands and properties of scripting additions that require user interaction. This means that, according to Apple Computer, an application such as TextEdit will not display a dialog if you use a display dialog command inside a TextEdit tell block:
tell app "TextEdit" activate display dialog "Hi" -- this code will fail to display a dialog end tell

Apple Computer suggests two strategies to deal with this Mac OS X issue:

Execute scripts with Script Runner. Chapter 1, describes the Script Runner. Script Runner is designed to execute the scripts saved as compiled script files (as opposed to Mac OS X applets). To work around this user-interaction problem with Mac OS X, you do not need to change a script that already runs under Mac OS 9.1 as long as it is saved as a compiled script and is executed by Script Runner.

Alter scripts to bring the script applet to the foreground when using display dialog. The script applet will display the dialog, then the script can return any other applications, such as TextEdit, to the foreground. Here is a simple example that does not do anything special with TextEdit but offers a solution to the user-interaction problem described by this sidebar:
tell app "TextEdit" activate set userName to my showDialog( ) (* call the script's showDialog handler *) end tell on showDialog( ) tell me to activate (* bring the applet itself to the foreground *) set theResult to (the text returned of (display dialog¬ "Enter your name please" default answer "")) tell app "TextEdit" to activate return theResult end showDialog

This applet temporarily leaves the TextEdit application context to call a user-defined handler, which displays a dialog and gets some user input. Then the applet activates TextEdit again.

handle CGI request string

If you are using the Mac as a web server, you can use AppleScript and the handle CGI request scripting addition to process Common Gateway Interface (CGI) scripts. In older implementations of Mac Web CGI programs, you had to define a handler using raw syntax such as <<on event WWW?sdoc>>... but this has changed with the new Standard Additions. CGI scripts are used in web applications that process HTML form data, among other web-related tasks. When the web user submits the form to the web server, the CGI script intercepts the form and processes its data. The string parameter contains the path of the CGI program on the server, which might look something like /cgi-bin/myCGI.acgi. The following example shows what the structure of a handle CGI request CGI looks like. The web server generates most of these parameter values, and you will not have to look at them in your CGI program. They are the equivalent of what Unix CGI programmers call environment variables, which are data the web server generates reflecting information about the web page request.

on handle CGI request the_path¬
searching for query_string¬
with posted data post_string¬
of content type mime_string¬
using access method acc_string¬
from address ip_string¬
from user user_string¬
using password passw_string¬
with user info info_string¬
from server serv_string¬
via port port_string¬
executing by path_string¬
referred by ref_string¬
from browser agent_string¬
using action cgi_string¬
of action type typ_string¬
from client IP address ipc_address¬
with full request req_string¬
with connection ID id_integer
end handle CGI request
searching for string

This is the data that follows the "?" character in the URL when the HTTP GET method is used. For example, the entire URL for sending form data might look like: http://www.formcorp.com/cgi-bin/myCGI?first=Bruce&last=Perry. searching for would contain the string "first=Bruce&last=Perry."

with posted data string: This contains the data sent with the POST HTTP method. This string could look like "first=Bruce&last=Perry."
of content type string: This is the Multipurpose Internet Mail Extensions (MIME) type for the data sent to the CGI program. For example, the MIME type for a web page is "text/html." The MIME type for form data sent with an POST HTTP method is "application/x-www-form-urlencoded."
using access method string: This string is either "GET" or "POST."
from address string: This labeled parameter contains the IP address of the entity making an HTTP request to the web server. For example, if the person sending the form data to the CGI program has an IP address of "24.169.24.11," then the from address string contains this value.
from user string: If the user is being authenticated on the web server for security reasons, then this string contains the username.
using password string: If the user is being authenticated on the web server for security reasons, then this string contains the password of the user.
with user info string: This string may contain additional user information such as an email address.
from server string: This is the name of the server application sending the request.
via port string: This string is the TCP/IP port number of the server, such as "80."
executing by string: This string is the path to the CGI script, as in /cgi-bin/mycgi.acgi.
referred by string: This is the URL from which the user linked to the CGI program. For example, this could be the web form the user filled out before they submitted the form to the CGI program, as in http://www.formcorp.com/form.html.
from browser string: This string contains the name of the user agent or browser the web user is using.
using action string: This string also contains the path to the CGI program, as in "/cgi-bin/mycgi.acgi."
of action type string: This string returns one of these values: PREPROCESSOR, POSTPROCESSOR, CGI, or ACGI.
from client IP address string: If the client has his own IP address (for instance, if he is a client on a Local Area Network), then this string contains that address. An example is 192.168.0.5.
with full request string: This is the full request sent to the server. It might look like http://www.formcorp.com/cgi-bin/mycgi.acgi?first=Bruce&last=Perry.
with connection ID integer: This integer parameter represents the server-to-client connection.

info for alias, file specification , or string path to the file or folder

You can grab a bunch of information on a file or folder, as long as you know its directory path, which you can pass to this osax as a string. For example:

info for "macintosh hd:desktop folder:"

The return value is a record that looks like this:

{name:"Desktop Folder", creation date:date "Thursday, December 07, 
1995 10:48:10 AM", modification date:date "Thursday, May 25, 2000 9:36:22 AM", 
icon position:{-1, -1}, visible:true, size:311307, folder:true, alias:false, 
folder window:{0, 20, 1024, 768}}.

You can use the path to scripting addition to fill out the details of an unknown file path.

In AppleScript 1.5 and later, info for now returns the size of a file or folder as a real data type (e.g., even "0.0" is given as the size of an empty folder using info for), rather than an integer, in order to accommodate the files or folders that are greater than two gigabytes in size.

For instance, if you know a file called cgi.txt is on your desktop, then the following code returns information about that file, such as its creation date and size:

info for ((path to desktop as text) &
"cgi.txt")

The full pathname of this file might be macintosh hd:desktop folder:cgi.txt, but the path to osax saved you some writing. The info for scripting addition returns the following type of record value:

{name:"cgi.txt", creation date:date "Thursday, May 25, 2000
9:36:22 AM", modification date:date "Thursday, May 25, 2000 10:03:19 AM", icon
position:{832, 92}, visible:true, size:2807, folder:false, alias:false,
locked:false, busy status:false, file creator:"R*ch", file type:"TEXT", short
version:"", long version:"", default application:alias "Macintosh HD:BBEdit
5.0:BBEdit 5.0:BBEdit 5.1"}.

list disks

This scripting addition returns a list of disk names mounted on your desktop. An example return value is:

{"Macintosh HD1", "H2gig", "HF2gig", "scratch"}.

list folder alias, file specification, or string path

This command lists the items in a folder, as in:

list folder "macintosh hd:myfolder"

The return value is a list of strings. The following example lists the contents of the desktop folder (it also uses the path to osax):

list folder (path to desktop) (* returns folders and files as a list of string 
names *)

load script alias

This command loads a script object into the script that contains the load script statement. The loading script can then use that script object's properties and methods as though the loaded script was a locally defined script. Chapter 9 describes script objects.

The following example loads a script object called DateLib and stores the object in a variable, dlib. It then calls that script object's parseDate method by using the statement dlib's parseDate (i.e., the parseDate method of the DateLib object, a reference to which is stored in the dlib variable). This method takes a date object and boolean variable as parameters and returns a reformatted date string that looks like "05/25/2000." If the boolean parameter is false, then the date string does not include leading zeros (the latter string would be "5/25/2000"). The following example includes the definition of parseDate so readers can examine the parseDate definition, but this method is already available from DateLib via the dlib variable:

(* use the path to osax to get a reference to a file on the desktop *)
set dlib to load script (path to desktop as text) & "DateLib"
dlib's parseDate(current date, true) (* returns a date string such as 
"05/25/2000" *)
(* parseDate definition *)
on parseDate(theDate, leadingZeros)
   local mydate
   local new_date_str
   try -- return "0" if the theDate or boolean parameter is invalid
      set mydate to theDate
      set month_part to my getMonthInt((month of mydate),¬
      leadingZeros) as string 
      -- getMonthInt method is defined in the DateLib script
      set day_part to (day of mydate) as string
      set year_part to (year of mydate) as string
      if leadingZeros then
         if (day_part as integer) < 10 then
            set new_date_str to (month_part & "/0" & day_part & "/"¬
            & year_part) as string
         else
            set new_date_str to (month_part & "/" & day_part & "/" ¬
            & year_part) as string
         end if
      else
         set new_date_str to (month_part & "/" & day_part & "/" &¬ 
         year_part) as string
      end if
      return new_date_str
      on error
      return "0"
   end try
end parseDate

mount volume string

Use this osax to mount a volume on your desktop from a remote computer.The on server labeled parameter is the only required parameter when using the AppleTalk form of mount volume (see the upcoming note on the TCP/IP form of mount volume). You have to add the Apple Filing Protocol (AFP) prefix ("afp://") if you are connecting with the volume via TCP/IP.

on server string

Specify the file server name with a string, as in on server "StacyMac". This parameter is required.

in AppleTalk zone string

Specify an AppleTalk zone with a string:

mount volume "macintosh hd" on server "StacyMac" in AppleTalk¬ Zone 
"graphics_dep" as user name "powerpc1" with password¬ "#go9$4r"

as user name string

If the user has to be authenticated with a username and password before mounting a remote volume, these parameters can be included with the mount volume osax. Pass the username as a string:

as user name "powerpc1"

with password string

Include a password as a string for the user identified in the as user name parameter, or omit this parameter for guest access.

The mount volume command takes the following form when mounting a volume over a TCP/IP network:
mount volume "afp://user:password@192.168.0.2/MacHD"

The command uses the Apple Filing Protocol ("afp://"), followed by the user name and password separated by a colon, the @ sign, the IP address of the server, and the name of the volume you want to mount. In Mac OS 9.1, mount volume will look in the Keychain for the user name and password information if you have left this information out of the mount volume URL, as in mount volume "afp://192.168.0.3/Mac HD".

moving folder window for alias: This is a Folder Action command covered in Section of Chapter 26.

new file

new file allows you to request a file specification from the user and then use that file spec to save a web page downloaded with the download osax (see Chapter 18). This osax displays a common Save As dialog box that allows the user to navigate to a directory and save a file. A file specification reserves a path and name for a file, even though the file does not yet exist. The following example gets a file spec from a user then downloads a web page to it:

AppleScript 1.5.5 on Mac OS 9 altered this osax and changed the name to choose file name. See the choose file name description.

set fspec to (new file default name "home_URL.html")
tell application "URL Access Scripting" to¬
download "http://www.parkerriver.com" to fspec with progress

with prompt string

You can add a message to the dialog box with this command.

default name string

Give the file specification a default name (the user can change this):

set fileSpec to (new file default name "myfile").

offset

This handy string-manipulation command finds the first occurrence of one string inside of another and returns the 1-based position of the interior string as an integer. It returns if the string is not located inside the outer string. For example, offset of "a" in "and" returns 1, because the "a" inhabits position 1 in the word "and." The following example shows how to use the offset osax in a function that checks to see if a string begins with "<," ends with ">," and has at least one character that is not a space character inside these tags (An actual HTML or XML tag-validation function would have to do much more than this demo subroutine!):

checkTag("<html>") -- call the function with a string parameter
(* function definition *)
on checkTag(str)
   (* initialize booleans  and string length variable *)
   set openTag to false
   set closeTag to false
   set notEmpty to false
   set len to length of str
   if (character 1 of str) = "<" then set openTag to true
   repeat with c in (characters of str) (* examines each character in the 
string *)
      set offs to (offset of c in str) (* what position does the char have in 
the string ? *)
      if offs = len then exit repeat (* we check the last string char after the
repeat loop, so exit here *)
      (* if the character is not the first or last character and not a space 
then the tags do not just surround a space character *)
      if (offs > 1 and offs < len) and (ASCII number c)  32 then
      set notEmpty to true
   end repeat
   if character len of str = ">" then set closeTag to true (* check last 
string character *)
   if openTag and closeTag and notEmpty then¬
   display dialog "It's not empty and has opening and closing tags."
end checkTag

of string

Specify the string you are looking for with the of keyword, as in:

offset of "a" in
"animal"

in string

Use the in keyword to identify the outer string you are searching for the inner string with, as in:

offset of "a" in "animal"

opening folder alias: This is a Folder Action command covered in Section of Chapter 26.

open for access alias

Use this osax to open a file and read and/or write to it. If the open for access parameter is a file specification for a file that does not yet exist, then a new file is created. This is a primary scripting addition for file input and output so you are likely to use it often. This scripting addition is closely related to the read, write, and close access scripting additions. You should close access to a file when you finish with it so you do not block any other operations that need access to that file. The following example reads a chunk of text from a file, then closes access to the file. open for access returns a file-reference number, which can be used with close access and other commands:

(* this script uses the path to, open for access, get eof, read, and close 
access scripting additions *)
set theFile to alias ((path to desktop as string) & "write.txt")
set fref to (open for access theFile)
set tsize to (get eof theFile)
read fref as string from 1 to tsize
close access fref

write permission boolean: If you want to write to the file, use the write permission true parameter. Otherwise, you get an error that write permission is not allowed. In other words, write permission is false by default.

open location string

This osax opens the URL, such as a web page (http://my.yahoo.com) or FTP site (ftp://park:.......@12.16.160.221/ ) in the application you have selected in the Internet control panel or in the Internet Config application. For example, if Netscape 6 is your default browser then open location "http://my.yahoo.com" opens that page in the Netscape browser.

error reporting boolean: If you include the error reporting true parameter, a dialog box reporting errors is displayed.

path to constant or application

path to returns the path to folders or applications, depending on the parameter you use. You can use one of the following constants to get the path as either an alias or string to a common location such as the desktop folder:

At Ease applications

At Ease documents

apple menu

application support

control panels

control strip modules

desktop Preferences

modem scripts

editors

desktop pictures folder

Folder Action scripts

extensions

fonts

frontmost application

internet plugins

Help

launcher items folder

keychain folder

plugins

modem scripts

printer drivers

printer descriptions

scripts

printmonitor

shared libraries folder

scripting additions folder

stationery folder

speakable items

trash folder

shutdown items

temporary items folder

startup items

voices folder

users folder

Or, you can get the path to a running program by specifying the application, as in:

path to application "BBEdit 5.1" as string

You can get the path as an alias (which is the default—you do not have to specify as alias) or a string.

as alias or as string

Since an alias return value is the default, path to desktop returns an alias path, as in:

alias "macintosh hd:desktop folder:"

and:

path to desktop as string

returns a string type, as in:

"macintosh hd:desktop folder:"

The OS X Standard Additions file added a from...domain optional parameter to the path to scripting addition. For instance, using this parameter, path to provides the location to the desktop folder based on the domain you specify. The from parameter can take any one of the four constants: System domain, local domain, network domain,or user domain. For example:

set dpath to (path to desktop from user domain)

The latter code phrase returns a value that looks like:

alias "Mac OS X:Users:bruceper:Library:Desktop:"

Whereas if you used the local domain parameter, the return value might be:

alias "Mac OS X:Library:Desktop:"

random number number

You can generate a random number with this osax, optionally including an upper-limit number, as in:

set num to (random number 100)

If the upper-limit value is a real number, as in random number 100.0, then the random result will be a real type. A real number type has a fractional part or decimal point, whereas an integer type does not. (see the description of the real data type in Chapter 3). If the upper-limit number is an integer or whole number, then the result will be an integer. Finally, if the upper-limit number is omitted, as in:

set num to random number

then you will get a real number between and 1 that looks like 0.408063409023. The result will have a scale of 12, meaning that there will be 12 digits on the right side of the decimal point. The following example chooses a random number that could help pick a card in a playing-card game by generating a random number between 1 and 52:

cardNumber(  ) -- call the method defined below
on cardNumber(  )
   set cd to (random number 100000) mod 52 + 1
   return cd
end cardNumber

from number integer or real

You can produce a random integer or real within a range of numbers, such as:

random number from 100.1 to 500.3

If you include this from number parameter, you have to use the to number parameter as well. The latter code returns a number such as 319.675894353425. If you included two integers, then the return value will also be an integer. If either one of these numbers is a real, the result will be a real. For example:

random number from 100 to 200.5

returns a number with a decimal point and fractional part (i.e., a real number).

to integer or real

Specify the upper level of a range with the to keyword followed by an integer or real. If you use the from parameter with random number then you have to use this to parameter. If the number used with this parameter is a real then the random result will be a real data type.

with seed number

Use this parameter if you want to produce a random number that steadily increases in value. The following example shows the random numbers generated by using a seed that increases by one each time the random number statement is executed:

on ranNumber(  )
   set counter to 0
   repeat 5 times
      set counter to counter + 1
      set num to random number with seed counter
      log num
   end repeat
end ranNumber

(* results from Script Editor's event log *)
random number with seed 1
--> 0.293460940421
random number with seed 2
--> 0.500003913185
random number with seed 3
--> 0.603275399567
random number with seed 4
--> 0.706546885948
random number with seed 5
--> 0.758182629139

read reference number, alias, or file specification for a disk file

Use this command to read bytes from a file. Use the keyword read followed by the file reference, such as an alias or the number returned by the open for access command. Generally, you get the amount of readable data from the file first with the get eof command, as in:

set theSize to (get eof theFile)

This command returns an integer number of bytes. Then you can read the first half of a file, say, with the code:

read theFile from 1 to (theSize div 2)

Close the file after you have finished reading it with:

close access theFile

using delimiter anything

This optional labeled parameter specifies the value you can use to separate the chunks of read bytes or text. For instance:

read theFile using delimiter return as text

uses a return character as the delimiter. This code returns a list in which each line of the text file is a list member, as in:

{"Hi readers this is a short bit of text.", "Separated by a line."}

You could use this parameter to read from a tab- or comma-delimited file, for instance, and then transfer the values into a database-management system. The as class (e.g., as text) parameter is required if you use using delimiter.

using delimiters list

You can use more than one delimiter to generate a list of read-in values, as in:

read theFile using delimiters {",",";"} as text

This reads in values separated by either a comma or a semi-colon and returns these values as the members of a list. The list does not contain the delimiters; they are just used to separate or delimit each value. The as class (e.g., as text) parameter is required if you use using delimiters. This parameter is optional.

as class

Use this optional parameter to specify the data type of the return value. Use as text or as string unless you are reading in a series of numbers, dates, or other valid alternative data types. The following example reads three lines of numbers separated by tabs and stores them as integers in a list. You could take those numbers and use AppleScript to put them in a database. The code uses the before return labeled parameter to prevent AppleScript from reading in a return character and trying to convert it to an integer, which would raise an error:

set theFile to (open for access (path to desktop as text) &¬ "write.txt")
(* we know there are three lines in the data file; you could find out how many
 lines there are first by reading in the text and counting the return 
characters *)
repeat 3 times
   read theFile using delimiter tab before return as integer
end repeat
close access theFile
(* return values look like: 
{233,244}
{265,234}
{10,9}
*)

for integer

Use this to specify the number of bytes to read from the disk (for 20, for instance). This code reads 20 bytes from the file. If you omit this labeled parameter, then read reads to the end of the file. You get an error of type "End of file error" if the integer parameter exceeds the number of bytes in the file. For example, read theFile for 50 would return an error if the file has only 40 bytes of data. If you use read in a repeat statement, then the read statement sequentially reads through the file and does not just read the same line over and again.

before string

If you want to read up to but not including a character (such as a period "." or return character), use code, such as:

read theFile before return or read theFile before "."

If you know how many lines are in a file (pretty easy to find out in a programmer's editor such as BBEdit or HomeSite), you can use code, such as the read theFile before return in a repeat number_of_file_lines times statement, and AppleScript will neatly read the file line by line. This parameter is optional.

until string

Unlike before string, until string reads up to and includes the string character, as in:

read theFile until string "."

This code returns the "." with the other file values.

from integer

You can specify the number of bytes the read should start from, as in:

read theFile from 20

(which starts reading from and including the 20th byte). If you omit this labeled parameter, AppleScript starts reading from the beginning of the file or from the byte after the last-read byte. Use the from integer parameter with the to integer parameter to read a range of bytes from the disk file. This parameter is optional.

to integer

Stop the read at this byte position, as in:

read thefile to 100

This code reads the first 100 bytes of the disk file. Use this parameter with the from integer parameter to read a range of bytes, as in:

read theFile from 50 to 100

removing folder items from alias: This is a Folder Action command covered in Section of Chapter 26.

round real

This osax rounds a real number (such as 45.65) to an integer and, of course, returns the integer. For example, round 45.65 returns 46, because by default round rounds to the nearest integer (i.e., round 45.45 returns 45).

rounding up/down/toward zero/to nearest

You might want to specify rounding up, down, or toward zero instead of accepting the default of rounding to nearest. For example:

round 45.65 rounding down

returns 45 rather than the default of 46. rounding down and rounding toward zero are different for negative numbers. For example:

round -0.1 rounding toward zero

returns 0, but:

round -0.1 rounding down

returns -1. In other words, for positive numbers, rounding down is the same as rounding toward zero. For negative numbers, rounding up is the same as rounding toward zero.

The Mac OS 9.1 and OS X version of round adds the as taught in school parameter to the other four parameters. as taught in school always rounds 0.5 away from 0. For example:
round 2.5 rounding as taught in school

returns 3. But:
round 2.5

(using the default parameter of rounding to nearest) returns 2, because rounding to nearest rounds .5 numbers to the nearest even number. However:
round -46.5 rounding as taught in school

will return -47, rounding the real number argument 0.5 away from 0.

run script alias

You can call a script outside of the running script (i.e., the script that uses the run script command) by passing run script an alias to the external script file. For example:

run script (alias ((path to desktop as text) & "scr_2914"))

This code runs a script named "scr_2914" on the desktop. For the run script parameter, you can also use a string file path, in other words, without the alias reserved word. Actually run script calls the implicit or explicit run handler of the script file (see the "Run handler" section of Chapter 8). All scripts have an implicit run handler (on run...end run) that encompasses all statements except for property definitions, function definitions, and script objects. run script returns the result (if any) of calling the script's run handler. The following example defines a run handler that takes two numerical arguments. The first parameter is rounded then a dialog displays whether the result is even or odd; the second parameter is simply returned to the calling script. The code used to call this script is identified in comment characters at the top of this example:

(*
run script (alias ((path to desktop as text) & "scr_2914"))
with parameters {345.45, 45.6}
*)
on run {num, num2}
   if (class of num is real) then
      if ((round num) mod 2) = 0 then
         display dialog "A real number rounded to even integer."
      else
         display dialog "A real number rounded to odd integer."
      end if
   end if
   return num2
end run

with parameters list

You can optionally pass parameters to the script you want to call. If the run handler takes two or more parameters, you can specify them in the form of:

run script scriptAlias with parameters {345.5,233.4}

But if the run handler only takes one argument, a line such as:

run script scriptAlias with parameters {345.5}

will pass the list type as a parameter as opposed to the single numerical argument (at least under AppleScript 1.4). You can work around this condition by making sure the run handler takes its single argument and handles it as a list.

in string

You can specify the scripting component to use, such as in "JavaScript" (if you have installed the JavaScript OSA component from Late Night Software) if you want to use a component other than the default component. The default component I use in Script Editor is none other than AppleScript.

say anything

This command says the text parameter to the say osax in the voice that is configured in the Speech control panel. You have to install the Speech Manager extension in the startup disk:System Folder:Extensions folder for this osax to work. Once it is working, you can even use it for debugging by saying the value of certain variables. The following example uses this osax to say the value of a variable each time it completes an iteration in a repeat loop:

checkVars(  ) -- call the method defined below
on checkVars(  )
   set v1 to 1234567
   repeat with n from 1 to 5
      (* This will say something like "5 times around the value is 3" *)
      say (n & " times around the value is " & (v1 mod n) as text)
   end repeat
end checkVars

displaying string

This parameter displays text in the SpeakableItems feedback window if you have the SpeakableItems extension installed.

using string

You can specify the voice you want to use, such as "Deranged" or "Hysterical," as in:

say "This project is disintegrating!" using "Hysterical"

waiting until completion boolean

The default is waiting until completion true, which does not return from the call to say until the speech has been uttered. This is important when you are using say in a repeat loop, since you do not want to move on to the next loop of repeat until the speaking voice has finished its speech. Chapter 7, describes the repeat loop.

scripting components: This command returns the scripting components installed on your machine as a list of strings. An example return value is {"JavaScript","AppleScript "}.

set eof file reference number

You can add or truncate the bytes in a file opened with the open for access osax (see open for access). The following example reduces a file to only its first 15 bytes. A file has to be open with write permission or this osax returns an error.

set theFile to (open for access (path to desktop as text) & "write.¬ txt" 
with write permission)
set eof theFile to 15
read theFile
close access theFile

to anything

This required parameter sets the new length of the file, as in:

set eof theFile to 10000

This file's length is set to 10000 bytes. You can enlarge or shrink a file with this command.

set the clipboard to anything

Use this osax inside of a tell statement to paste a program's data onto the clipboard. You have to activate the program before you use set the clipboard to. For example, you could activate BBEdit 5.1 then use the code:

set the clipboard to (contents of document 1)

set volume number: Use this osax to set the sound output volume to a number between (silent) and 7 (full volume).

store script

This osax stores a script object in a file, so you can then run that script using the run script osax (Chapter 9 explains script objects). They are essentially AppleScript statements such as property definitions and subroutines enclosed in a script script_name...end script block with similar behavior to object-oriented classes the programmer creates. The following example defines a script that resets the computer's volume. The example asks the user where to save the file, using the store script osax:

store script volume_setter in (new file with prompt¬
   "Pick a new file for the volume script.")
script volume_setter
   set vol to (the text returned of (display dialog¬
      "enter a volume number from 0 to 7" default answer "")) 
   if vol > 0 and vol < 8 then
      set volume vol -- set the new volume
      beep 2 -- test the sound output
   end if
end script

in file specification: You can have the user create a file specification object (a space that the operating system reserves for the new file) by using the new file scripting addition. This is a required parameter.
replacing ask/yes/no: If there is a chance that the store script scripting addition will replace another script, specify the saving behavior with this labeled parameter. ask displays a dialog asking the user whether to overwrite the existing script file, yes saves the script file (over the original if there is one), and no does not replace an existing file.

summarize text or an alias or file specification of a text file

This scripting addition attempts to summarize in an optionally specified number of sentences the text or text file you feed it. For example:

summarize alias ((path to desktop as text) & "thyroid1.txt") in 10

Summarize returns a string summary.

in integer

Specify a pithy summary, as in:

summarize alias ((path to desktop as text) & "thyroid1.txt")¬
in 1

This code attempts a one-sentence summary.

the clipboard

This command returns the contents of a program's clipboard, but you have to couch the osax in a tell block targeting the application. After activating the app with the activate command, you can use code such as:

return the Clipboard

This scripting addition returns a list type.

as class

You can optionally specify the return value of this command to a certain data type, as in:

the clipboard as text

time to GMT

This command returns the difference in seconds between local time and Greenwich Mean Time. You can convert this to minutes using:

time to GMT / 60

A negative number means that your local time is earlier than GMT (e.g.,-14400 is four hours earlier than GMT).

write anything

Use this scripting addition to write data to a file opened with the open for access command.

for integer

You can restrict the write to a certain number of bytes (for instance, if the script was reading from one file and writing to another, and you were not sure of the number of bytes that were read). For example

write theText to theFile for 100 -- write a 100-byte chunk

If you do not use this parameter, then all the data in theText will be written to the file.

starting at integer

Use this labeled parameter to specify a position in the file to do the write, as in:

write "More text" to theFile starting at 100 (* start writing at the 100-byte 
point in the file *)

This parameter is optional.

to anything

This required parameter specifies the reference number (open for access returns a file reference number), alias, or file specification of the file to write to. The following example uses the new file osax to let the user choose the file for writing with the write scripting addition:

set filespec to (new file with prompt "Pick the new file to¬ write to")
(* use "choose file name" osax with OS X and OS 9.1 *)
set theFile to (open for access filespec with write permission)
write "Welcome to the beginning of this file." to theFile
close access theFile

as class

You can optionally specify the writing of the data as text, a list, a real number, or some other data type. For example:

write 292.345 as real to filespec.