Hack 8 Execute a Command on Each Computer in a Domain

figs/expert.gif figs/hack08.gif

This handy script lets you easily run any command on a specified subset of computers in your domain.

Running the same command on multiple computers in your domain can be tedious indeed, but such a scenario is common in an administrator's life. I've written this hack to make this chore easier. The script traverses member systems of a domain, executing a command against each system that has a name that matches a particular specification you specify in the command line. Note that regular expressions are legal in this script, which makes it a powerful and flexible addition to the administrator's toolkit.

The Code

To use this script, type it into a text editor such as Notepad (make sure Word Wrap is disabled) and save it with a .vbs extension as ExecuteAll.vbs. Alternatively, if you don't want to wear your fingers out, you can download the script from the O'Reilly web site.

'Script Name: ExecuteAll.vbs

Option Explicit

Dim oDomain, oService, oItem, oShell

Dim strDomain, strSpec, strCommand, intButton

Dim oArgs, strFinalCommand, oRegEx, boolConfirm

' Prepare to execute commands & do popups

Set oShell = CreateObject("WScript.Shell")


' Access the domain so we can traverse objects

WScript.Echo "Accessing NT Domain " & strDomain

Set oDomain = GetObject("WinNT://" & strDomain)

' Initiate our regular expression support

Set oRegEx = New RegExp

oRegEx.Pattern = strSpec

oRegEx.IgnoreCase = True

' Traverse each computer (WinNT) object in the domain

WScript.Echo "Searching for " & strSpec

oDomain.Filter = Array("Computer") ' only look at computers

For Each oItem In oDomain

If oRegEx.Test(oItem.Name) Then

WScript.Echo " Matched " & oItem.Name

strFinalCommand = Replace(strCommand, "$n", oItem.Name)

intButton = vbNo

If boolConfirm Then

intButton = oShell.Popup("Execute " & strFinalCommand & "?",,_

"System " & oItem.Name, vbYesno + vbQuestion)

End If

If (boolConfirm = False) Or (intButton = vbYes) Then

WScript.Echo " Executing: " & strFinalCommand

execute strFinalCommand

End If

End If


' All done; clean up

Set oItem = Nothing

Set oRegEx = Nothing

Set oDomain = Nothing

Set oShell = Nothing

Set oArgs = Nothing


' Glean the arguments for our run from the command line, if provided.

' If any are missing, prompt for input. A blank input signals an abort.


' /Y is an optional last argument

Sub GetArguments

Dim i, strConfirm, intButton

Set oArgs = WScript.Arguments

boolConfirm = True ' assume always confirm

strDomain = "" ' domain to be traversed

strSpec = "" ' name specification to be matched

strCommand = "" ' command to be executed on each match

strConfirm = "" ' track prompting for confirmation setting

' Look for our optional 4th argument

If oArgs.Length = 4 Then

If UCase(oArgs.Item(3)) = "/Y" Then

boolConfirm = False

strConfirm = "/Y" ' don't prompt below

End If

End If

' Look for any specified arguments, in order

If oArgs.Length >= 1 Then strDomain = oArgs(0)

If oArgs.Length >= 2 Then strSpec = oArgs(1)

If oArgs.Length >= 3 Then strCommand = oArgs(2)

' Prompt for any arguments not specified on the command line

If strDomain = "" Then

strDomain = InputBox _

("Enter the name of the NT Domain to be traversed", _

"NT Domain")

End If

If strDomain = "" Then WScript.Quit

strDomain = UCase(strDomain)

If strSpec = "" Then

strSpec = InputBox _

("Enter your name specification for the computer(s) " & _

"that will be matched within the " & strDomain & " Domain." & _

vbCrlf & "Regular Expressions are acceptable.", _

"Name Specification")

End If

If strSpec = "" Then WScript.Quit

If strCommand = "" Then

strCommand = InputBox _

("Enter the command to be executed on each computer matching " & _

strSpec & " within the " & strDomain & " Domain." & _

vbCrlf & "$n will be substituted for the computer name.", _

"Command to Execute")

End If

If strCommand = "" Then WScript.Quit

If strConfirm = "" Then

intButton = oShell.Popup("Confirm each command prior to execution?",,_

"Confirm?", vbYesNo + vbQuestion)

If intButton = vbNo Then

boolConfirm = False

End If

End If

End Sub

' Execute a command. Each is always run under a new instance of the command

' processor. This allows the use of built-in commands and I/O redirection.


' We won't wait for command completion.

Sub Execute(strCommand)

Dim RetVal

strCommand = "%COMSPEC% /c " & strCommand

RetVal = oShell.Run(strCommand, 1, False)

End Sub

Running the Hack

Here is the syntax for running the script:

ExexcuteAll.vbs <DomainToTraverse> <ComputerSpecification> <Command> [/Y]

When the script runs, the matched system's name will be substituted for the occurrence of $n in the command to be performed. By default, each command instance is confirmed before it is executed, but you can specify /Y to always answer Yes instead.

Here's an example of how to run the script:

ExexcuteAll.vbs MYDOMAIN WKSATL* "del \\$n\admin$\activitylog.txt"

This example traverses the MYDOMAIN domain, looking for computer names that start with WKSATL* (note the wildcard) and deletes the activitylog.txt file from the C:\Winnt folder.

?Hans Schefske