Windows脚本编程核心技术精解Chapter16.pdf

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1、Chapter 16Getting System InformationIn This Chapter?Determine the location of Windows special folders such as Desktop and MyDocuments?Delete your Documents menu to ensure privacy?Delete references to document types you dont work with anyway?Find out important networking details such as username and

2、computer name?Retrieve memory statistics and determine current work load,physicalmemory,and virtual memory management details?Detect wheel mouse,sound card,and boot mode?Retrieve current video resolution and change resolution and video refreshrate on-the-fly?List all installed fonts and create your

3、personal font sampler page?Analyze your processor type and Windows version?Find out if specific DLLfunctions are available on your systemScript developers need information.This chapter provides methods toretrieve all kinds of information about your system,your configuration,and your installation fol

4、ders.Finding Out Important Path InformationWhere does Windows live?The true name of the Windows folder may varyfrom system to system,and so do the names of all the other special foldersWindows uses.For your scripts,its extremely important to know the special Windows folderlocations.Maybe you want to

5、 insert your script into the StartUp programgroup to start it automatically at logon.Or maybe you need access to theRecentDocsfolder to delete references you dont need.The following sections demonstrate how to retrieve the path names of allyour special Windows folders.4684-8 ch16.f.qc 3/3/00 9:40 AM

6、 Page 483Retrieving special folder path namesThe WScript.Shellobject is your solution.It offers the SpecialFodersmethod.This method returns the actual path name of any special Windowsfolder(see Figure 16-1).Heres how to retrieve the path to your programgroups(the groups you see when you open Program

7、s in the Start menu):16-1.VBSset wshshell=CreateObject(“WScript.Shell”)path=wshshell.SpecialFolders(“Programs”)MsgBox“The path to your private Programs folder:”&vbCr&pathFigure 16-1:Retrieve path names of special Windows folders.On Windows 98,NT,and 2000,there may be individual user profiles.This is

8、 whythese Windows versions divide many user settings into private settings andcommon settings that apply to all users.To retrieve the location of the programgroups for all users,just replace“Programs”with“AllUsersPrograms”.See how you can take advantage of this:16-2.VBSset wshshell=CreateObject(“WSc

9、ript.Shell”)set fs=CreateObject(“Scripting.FileSystemObject”)path=wshshell.SpecialFolders(“Programs”)for each folder in fs.GetFolder(path).subfolderslist=list&folder.name&vbCrnextMsgBox“List of your private program groups:”&vbCr&listTable 16-1 lists all the special folder names you can use with Spec

10、ialFolders:484Part IV:Accessing the Operating SystemII4684-8 ch16.f.qc 3/3/00 9:40 AM Page 484Table 16-1Key Names for Windows FoldersNameDescriptionAllUsersDesktopDesktop items for all usersAllUsersStartMenuStart menu custom items for all usersAllUsersProgramsProgram groups for all usersAllUsersStar

11、tupAuto-starting shortcuts for all usersDesktopDesktop items for current userFavoritesFavorites items for current userFontsInstalled system fontsMyDocumentsPrivate document folder for current userNetHoodCustom items for Network Neighborhood virtual folderPrintHoodCustom items for Printers virtual fo

12、lderProgramsProgram groups for current userRecentList of recently used documents for current userSendToSendTo itemsStartMenuStart menu custom items for current userStartupAuto-starting shortcuts for current userTemplatesTemplate files for New menu itemsThe“AllUsers.”settings apply to common objects

13、only.On Windows 95,they are unavailable,and if you dont use multiple user profiles,chances arethese folders are empty.Cleaning up your Documents menuThe Documents menu inside your Start menu stores the most recently used15 files for easy access.Unfortunately,Windows doesnt care about the filetypes,s

14、o the Documents menu records just any file you happen to open.Therefore,important files can get kicked out of this menu easily by other not-so-important files.Furthermore,the Documents menu becomes unwieldy andconfusing if it contains a lot of unwanted files.You can do something about it.Clean your

15、menu up!Have a script go throughall the shortcuts,determine their targets,and delete any reference thatpoints to a file type you are not interested in!Chapter 16:Getting System Information485II4684-8 ch16.f.qc 3/3/00 9:40 AM Page 485 16-3.VBSset wshshell=CreateObject(“WScript.Shell”)set fs=CreateObj

16、ect(“Scripting.FileSystemObject”)find out location of special folderrecent=wshshell.SpecialFolders(“Recent”)access folderset folder=fs.GetFolder(recent)go through all shortcutsfor each file in folder.files get extension typeext=lcase(fs.GetExtensionName(file.name)is it a shortcut?It should be!if ext

17、=”lnk”then open shortcutset scut=wshshell.CreateShortcut(file.path)find targettarget=scut.TargetPath target still valid?if not fs.FileExists(target)then no,deletefile.deleteelse does target reference“important”file type?ext=lcase(fs.GetExtensionName(target)select case ext add extensions for all file

18、 references you want to keep:case“doc”case“bmp”case“vbp”case else points to something else,deletefile.deleteend selectend ifend ifnextwshshell.Popup“Cleaned Documents Menu!”,2Take a look at your Documents menu,then launch the script.When yourecheck your Documents menu,youll see that the script has d

19、eleted allreferences to file types you did not specify in your script.Now,theDocuments menu only contains references to files you really work with.It looks much cleaner and has gained room for new references.486Part IV:Accessing the Operating SystemII4684-8 ch16.f.qc 3/3/00 9:40 AM Page 486When you

20、call the script for the first time,it may take some seconds tocomplete the cleaning process.This is due to a Windows bugtheDocuments menu stores only the most recent 15 documents.Internally,whenever the limit is reached,Windows deletes old entries to make room for new entries.This works perfectly we

21、ll and happens inside the Registry.Outside,in your RECENTfolder,Windows often leaves behind unusedshortcuts.Over time,hundreds of shortcuts may be left behind in yourRECENTfolder,and its a good idea to clean them up.Use your new script whenever you find your Documents menu crammed withentries.Even b

22、etter,you can launch your script automatically at Windowslogon so that you always start with a clean Documents menu.See Chapter 13for details.Cleaning the Documents menu automaticallyIf you want your script to clean up the Documents menu automatically atgiven intervals,you can use this script instea

23、d:16-4.VBSset wshshell=CreateObject(“WScript.Shell”)set fs=CreateObject(“Scripting.FileSystemObject”)recent=wshshell.SpecialFolders(“Recent”)set folder=fs.GetFolder(recent)dofor each file in folder.filesext=lcase(fs.GetExtensionName(file.name)if ext=”lnk”thenset scut=wshshell.CreateShortcut(file.pat

24、h)target=scut.TargetPathif not fs.FileExists(target)thenfile.deleteelseext=lcase(fs.GetExtensionName(target)select case extcase“doc”case“bmp”case“vbp”case elsefile.deleteend selectend ifend ifnext sleep for a minuteWScript.Sleep 1000*60loopChapter 16:Getting System Information487II4684-8 ch16.f.qc 3

25、/3/00 9:40 AM Page 487This script runs forever.It cleans your Documents menu,and then it sleepsfor a minute and cleans again.You have no way of stopping this script exceptby calling the Task List and closing down WScript.exemanually.If you runscripts this way,always make sure you include a“sleep pha

26、se”so your scriptwont eat up all your CPU power.In Chapter 17,you also get a new way ofinserting a“script icon”into the tray area.With this tray icon,you can stopscripts anytime.Check it out:Open a file with a file type not listed in your script.Then,checkyour Documents menu:It contains a reference

27、to this file.Now,wait a minuteand check again.The document reference is gone.Your script has silentlydone its job in the background.Finding the Windows folderSpecialFoldersgives access to any special folder,but it cant return theWindows folder name.What now?Actually,you have two choices.Windows alwa

28、ys stores the Windows folder inan environment variable called%WINDIR%.Use ExpandEnvironmentStringsto retrieve the path name.Or you can use the Scripting.FileSystemObjectmethod called GetSpecialFolder.This method returns a folder object youcan use to access the folder content directly.Where does Wind

29、ows live?Heres how to retrieve the Windows folder path name(see Figure 16-2):16-5.VBSset wshshell=CreateObject(“WScript.Shell”)windir=wshshell.ExpandEnvironmentStrings(“%WINDIR%”)MsgBox“Windows Folder:“&windirFigure 16-2:Find out your current Windows folder.488Part IV:Accessing the Operating SystemI

30、I4684-8 ch16.f.qc 3/3/00 9:40 AM Page 488ExpandEnvironmentStringscan retrieve other environment variables,too.For example,to find out the name of your DOS command interpreter,use thisscript:16-6.VBSset wshshell=CreateObject(“WScript.Shell”)compath=wshshell.ExpandEnvironmentStrings(“%COMSPEC%”)MsgBox

31、“DOS Interpreter:“&compathAccessing the Windows folder directlyIf you need to get access to the Windows folder contents anyway,get thefolder handle directly:16-7.VBSset fs=CreateObject(“Scripting.FileSystemObject”)set windir=fs.GetSpecialFolder(0)MsgBox“Windows Folder:“&windir.Pathfor each subfolder

32、 in windir.subfolderslist=list&subfolder.name&vbCrnextMsgBox“Windows folder subfolders:“&vbCr&listGetSpecialFoldercan retrieve other special folders,too,as shown in Table16-2.Table 16-2Key Codes for Windows FoldersIndexDescription0Windows Folder1System Folder2Temp FolderReading Network InformationTh

33、e WScript.Networkobject provides a basic set of networking methodsand properties.You can use them to find out the current username,and toremotely install network printers.Inside view:WScript.NetworkTable 16-3 provides a complete list of all the properties and methodsprovided by WScript.Network.Chapt

34、er 16:Getting System Information489II4684-8 ch16.f.qc 3/3/00 9:40 AM Page 489Table 16-3WScript.Network Properties and MethodsProperty/MethodDescriptionSub AddPrinterConnection(ByVal Maps the remote printer to a local bstrLocalName As String,ByVal resource namebstrRemoteName As String,pvarUpdateProfi

35、le,pvarUserName,pvarPassword)Property ComputerName As StringRetrieves the computer networknameFunction EnumNetworkDrives As Lists all current network connectionsIWshCollectionFunction EnumPrinterConnections Lists all current network printer As IWshCollectionconnectionsSub MapNetworkDrive(ByVal Maps

36、the network drive to a local bstrLocalName As String,ByVal resourcebstrRemoteName As String,pvarUpdateProfile,pvarUserName,pvarPassword)Sub RemoveNetworkDrive(ByVal Removes a mapped network drivebstrName As String,pvarForce,pvarUpdateProfile)Sub RemovePrinterConnection(ByVal Removes a network printe

37、rbstrName As String,pvarForce,pvarUpdateProfile)Sub SetDefaultPrinter(ByVal Sets the default printerbstrName As String)Property UserDomain As StringRetrieves the current user domainProperty UserName As StringRetrieves the current usernameProperty UserProfile As StringRetrieves the current user profi

38、leListing current usernameTo find out the name of the currently logged on user(see Figure 16-3),use thefollowing script:16-8.VBSset wshnet=CreateObject(“WScript.Network”)user=wshnet.UserNamedomain=wshnet.UserDomaincomputer=wshnet.ComputerName490Part IV:Accessing the Operating SystemII4684-8 ch16.f.q

39、c 3/3/00 9:40 AM Page 490msg=“This computer is called“”&computer&“”&vbCrmsg=msg&“You are logged on as“”&user&“”&vbCrmsg=msg&“Your domain is“”&domain&“”&vbCrMsgBox msg,vbInformationFigure 16-3:Determine logon name and domain name.Managing Memory ConsumptionMemory is valuable,so its a good idea to fin

40、d out the current memorysituation before scripts start extensive tasks.Controlling your systemsmemory statistics,you can also find out if your system has enough RAMinstalled or if it would benefit from some additional RAM(see Figure 16-4).Unfortunately,the WSH has no access to the memory statistics.

41、You do.Just install the memory COM object I have prepared(installmemorysetup.exe).Full source code is provided at componentsmemorymemory.vbp.Retrieving memory statisticsTable 16-4 describes what you can do with the new memory COM object:Table 16-4New Methods to Check Memory StatusMethodDescriptionFu

42、nction GetMemory As StringCurrent memory status as Text stringreportFunction Mem_load As LongCurrent memory load in percentFunction Mem_page_avail As LongMemory available in current page fileFunction Mem_page_total As LongMemory reserved in current page fileFunction Mem_phys_avail As LongTrue RAM me

43、mory availableFunction Mem_phys_total As LongTrue total RAM memory installedFunction Mem_virt_avail As LongMaximum virtual memory availableFunction Mem_virt_total As LongTotal virtual memory availableChapter 16:Getting System Information491II4684-8 ch16.f.qc 3/3/00 9:40 AM Page 491Figure 16-4:Check

44、memory consumption and work load.If you just need a general overview,use the convenient GetMemorymethod:16-9.VBSset tool=CreateObject(“memory.stats”)MsgBox tool.GetMemoryRunning in physical memory onlyIf you dont want to start a script under low memory conditions,check forthe current memory load.For

45、 example,you can start your script if memoryload is below 80 percent:16-10.VBSset tool=CreateObject(“memory.stats”)if tool.Mem_load80 thenMsgBox“Memory load below 80%-I do the job!”elseMsgBox“Memory load critical.Try again later!”WScript.Quitend ifLikewise,you can use Mem_phys_availto check whether

46、there is any“real”memory left.If this method returns 0,you know for sure that your systemneeds to resort to the slow paging memory.Checking memory installed and memory consumedYou can also use your new methods to find out how much RAM is installed inyour system.This script is smart enough to issue a

47、 recommendation whetheror not your system will benefit from additional RAM(see Figure 16-5).492Part IV:Accessing the Operating SystemII4684-8 ch16.f.qc 3/3/00 9:40 AM Page 492However,to get valid answers,you should launch your standard set ofapplications before you start the script so you have reali

48、stic memoryconditions to test:16-11.VBSset tool=CreateObject(“memory.stats”)ram=tool.Mem_phys_totalavail=tool.Mem_phys_availneeded=tool.Mem_page_total-tool.Mem_page_availmsg=“Your System has“&MB(ram)&“RAM installed.”&vbCrif avail=0 thenmsg=msg&“This is not enough!Your system currently“_&“borrows“&MB

49、(needed)&“from the file system.”elsemsg=msg&“Currently,your system doesnt need additional”_&“memory.In fact,“&MB(avail)&“RAM is currently”_&“unused!”end ifMsgBox msg,vbInformationfunction MB(bytes)MB=FormatNumber(bytes/10242,1)&“MB”end functionFigure 16-5:Automatically test whether your system needs

50、 additional RAM.Windows uses different types of RAM.If the physical(“real”)RAM is used up,it accesses the virtual RAM.This RAM is stored on the hard drive.Usingvirtual RAM slows down the system enormously,but its the only way to keepthe system running once your physical RAM is exploited.The page fil