Displaying the Running Processes in a list Box and Optionally Closing Some of Them

The “CloseApps” script of the next example displays a list in a dialog window that the user may choose from. The list contains the names of all of the application processes that are running on the computer. These include the programs that have a user interface (e.g., windows and menus that you can interact with) and faceless background applications (FBAs) such as Time Synchronizer or File Sharing Extension. FBAs are programs that work invisibly in the background without interacting with the user. CloseApps is similar to one of the functions of the Windows NT Task Manager utility, which lets you select and shut down a process. Figure 14-5 shows the dialog window displayed by this script. Users may choose one or more processes, and the script will quit the selected programs.

Figure 14-5. A dialog window displays running processes

The script shown in Example 14-3 uses the choose from list scripting addition and a list of application processes. An application process is an element of the Finder’s application class. You can get a list of all of the currently running app processes simply by requesting all of the Finder’s application processes, as in:

tell app "Finder" to application processes

This phrase does not sound syntactically pleasing, but it does the job. The script gets a list of all application processes with the code:

set applist to application processes

It then creates a list of all of the process names by getting the name property of each member of applist (which contains the application process objects) and adding the name to the list (stored in the namelist variable). An example of the name property of process “Application Switcher” is naturally enough “Application Switcher.” The choose from list scripting addition populates the window with the list of process names in namelist. The user can select one or more of the list names and click the Close Em button, and the script will send a quit Apple event withto each of the selected processes.

Example 14-3. The choose from list Script

set applist to {} -- will contain list of process objects
set namelist to {} -- will contain list of process names
set closelist to {} (* will contain list of process names that the user wants 
to shut down *)
tell application "Finder"
   set applist to application processes
   repeat with proc in applist
      set namelist to namelist & (name of proc) (* get names of each 
running process *)
   end repeat
end tell
Choose from list namelist with prompt "Which open applications do you " &¬
"want to close ?" OK button name "Close Em" cancel button name "Outta Here"¬ 
with multiple selections allowed
set closelist to the result
try
   set closelist_len to (length of closelist)
   if closelist_len is greater than 0 then
      repeat with proc in closelist
         try -- trap any errors caused by quitting the program
            tell application proc (* send a quit command to each of the selected 
programs *)
               quit
            end tell
         on error number errNum
            activate
            display dialog (proc & "reported error number " & errNum & ¬
            " when trying to respond to the quit Apple event.")
         end try
      end repeat
   end if
on error number errNum (* this error triggered when the user cancels the 
program *)
   if errNum is equal to -1728 then
      set theMessage to 
      display dialog theMessage
   else
      display dialog
   end if
end try