Registry Reading

Registry Reading

The WshShellobject is often used to read the local registry. To read or manipulate a remote registry, you must use Windows Management Instrumentation (WMI.) Assuming the user executing the script has the appropriate permissions, you can easily read and write information 

from the registry. Here is a quick example of reading owner and product information from the 

local registry.

dim objShell 

Set objShell=CreateObject("wscript.shell") 

strRegisteredUser=objShell.RegRead("HKLM\Software\Microsoft\" &_ 

"Windows NT\CurrentVersion\RegisteredOwner") 

strProduct=objShell.RegRead("HKLM\Software\Microsoft\Windows NT\" &_ 

"CurrentVersion\ProductName") 

WScript.Echo strRegisteredUser & " is running " & strProduct

Program Launching

You will often need to call another script or program from your main administrative script. 

Fortunately, the WshShellobject makes this possible, as shown in Listing 1-2.

WshShell RunSample

dim objShell 

'Window style 

Const WINDOWHIDDEN=0 

Const WINDOWNORMAL=1 

Const WINDOWMINIMIZE=2 

Const WINDOWMAXIMIZE=3 

6 Part I: The Basics of Advanced Windows Scripting

Set objShell=CreateObject("wscript.shell") 

'enter in full path to command or script if not in %Systemroot% 

strCommand="Notepad" 

objShell.Run strCommand,WINDOWNORMAL,True 

'this line won't echo until previous command finishes 

WScript.Echo "Script complete"

The important parameters are the window style and whether the command 

should wait before continuing with script execution. In this example, we set up constants for 

typical window styles. (Again, refer to the Windows Script Host 5.6 documentation for additional window styles.) You will likely want to run a program or script and hide it from the user. 

Depending on the program or script, you can do this by setting the window type parameter to 0.

If you want execution in your main script to wait for the command to finish, set the WaitOnReturnvariable to TRUE. In Listing 1-2, the line of code that displays Script Completewon’t 

execute until the command launched by the WshShellobject has completed.

Another way to execute a command is with the Execmethod. This technique is especially useful for parsing out the results of a command-line tool or utility. Often, you might find yourself 

developing a script that could use the output of another command for reporting or as parameters. Listing 1-3 takes the output of a Dircommand that displays all executables, and modifies it so that it displays only the directory name and file information. You must run this script 

from a command prompt using CScript.

WshShell ExecSample: Dir

Dim objShell,objExec 

Set objShell=CreateObject("wscript.shell") 

'command to Execute 

strCommand="cmd /c DIR c:\*.exe /s" 

'text to look for in the output 

strFind=".exe" 

'Create Exec object 

Set objExec=objShell.Exec(strCommand) 

'parse output and only display lines With 

'target text 

Do While objExec.StdOut.AtEndOfStream<>True 

strLine=objExec.StdOut.ReadLine 

'parse out lines 

If InStr(strLine,"Directory") Then 

WScript.Echo Trim(strLine) 

Elseif InStr(strLine,strFind) Then 

WScript.EchovbTab & strLine 

End If 

Loop

At run time, the script passes the specified command to the WshShellobject and executes it. 

The output of that command is then redirected to a new object, called objExecin our script. 

With this object, we can leverage the power of StdOutand manipulate the data that would 

ordinarily be written in the command prompt window. As long as the command is running, 

the AtEndOfStreamproperty will be FALSE. Because we want to display specific information 

from what would generally be a lengthy output, we set a variable, strLine, to the value of the 

next line of StdOut. Then we can use the InStrfunction to find strings of interest. If there is a 

match, the line is displayed. In Listing 1-3, we want to display the directory name as well as 

each line that includes the file name.

Tip With StdOut, you can use any text stream property from the FileSystemObjectlibrary, 

such as ReadLine, SkipLine, and AtEndOfStream.

WshShell ExecSample: Nslookup

Dim objShell,objExec 

Set objShell=CreateObject("wscript.shell") 

'command to execute 

strCommand="Nslookup www.microsoft.com" 

'Create Exec object 

Set objExec=objShell.Exec(strCommand) 

'skip lines that contain information about our DNS 

'server 

objExec.StdOut.SkipLine 

objExec.StdOut.SkipLine 

Do While objExec.StdOut.AtEndOfStream<>True 

strLine=objExec.StdOut.ReadLine 

WScript.Echo strLine 

Loop 

WScript.Quit

demonstrates another way to use the Execmethod: executing an Nslookupcommand. Our script parses out the lines of interest, namely the IP address of the specified name, 

and neatly displays them. The script simply skips the first two lines of any Nslookupoutput 

that contains the DNS server name and IP address.

Tip Although not an absolute requirement, you will find it easier and neater to run scripts 

that take advantage of StdOutand StdInfrom the command line by using CScript. For example, 

if you run the script in Listing 1-4 by double-clicking it, you will see a few blank popup windows. If you run the script from a command prompt by using CScript, you will get cleaner looking results.