Script Tips
Scripting Windows Installer Packages
Use scripts to determine the contents of MSI setup files.
One of the many benefits touted in the long list of reasons Windows Installer
is so great is that the setup (MSI) files are actually structured databases.
In addition to providing a universal schema for setup authors to follow,
the fact that you can reliably query a file for certain information adds
another sometimes overlooked value.
The best example I've seen that takes advantage of this among commercial
tools is the advent of conflict checking features available in products
like AdminStudio (Macrovision), Package Studio (Altiris) and MSI Studio
(ScriptLogic). These tools query MSI packages to find potential conflicts
between baseline snapshots and other packages in order to help you identify
(and even resolve) potential conflicts between them.
Tech Help—Just An
E-Mail Away |
|
Got a Windows, Exchange or virtualization question
or need troubleshooting help? Or maybe you want a better
explanation than provided in the manuals? Describe
your dilemma in an e-mail to the MCPmag.com editors
at [email protected];
the best questions get answered in this column and garner
the questioner with a nifty Redmond T-shirt.
When you send your questions, please include your
full first and last name, location, certifications (if
any) with your message. (If you prefer to remain anonymous,
specify this in your message, but submit the requested
information for verification purposes.)
|
|
|
Without the full implementation of comparing contents with
other packages (which you certainly could write in a script if you had
some serious time on your hands) you can query the MSI file database to
collect file information:
MSIFile = "C:\Windows\System32\webfldrs.msi"
Set MSIobj = CreateObject("WindowsInstaller.Installer")
Set MSIdb = MSIobj.OpenDatabase(MSIFile, 0)
WQL = "SELECT FileName,Version,FileSize FROM File"
Set MSIView = MSIdb.OpenView(WQL)
MSIView.Execute()
On Error Resume Next
Set MSIrecords = MSIView.Fetch
Do While Err.number = 0
WScript.Echo "Name: " & MSIrecords.StringData(1)
&_
", Version: " & MSIrecords.StringData(2) &_
", Size: " & MSIrecords.StringData(0)
Set MSIrecords = MSIView.Fetch
Loop
MSIView.Close
This can be helpful for generating documentation of MSI packages. You
can query any of the tables such as the registry table or property table
in the same way. In the script below, we continue from that above (to
avoid repetition in establishing object references) to get all of the
properties and their values:
WQL = "SELECT Property,Value FROM Property"
Set MSIView = MSIdb.OpenView(WQL)
MSIView.Execute()
Set MSIrecords = MSIView.Fetch
Do While Err.number = 0
WScript.Echo MSIrecords.StringData(1) & " =
" &_
MSIrecords.StringData(2)
Set MSIrecords = MSIView.Fetch
Loop
You can also obtain a specific property to just get what you want by
modifying the query:
WQL = "SELECT Property,Value FROM Property WHERE
Property='ProductVersion'"
Using these same techniques, I have created two tools you may obtain
freely along with the source code to see how it was done.
The first is MSI
Viewer which provides a graphical interface to show the results of
queries just like those above.
The second is MSI
Search, which enumerates the MSI files found below a specified root
location where you may then search them for any string and have their
results displayed to you. This can be helpful if you are having a problem
with a certain files and want to know which application installations
contain that file.
I hope seeing this capability and seeing some examples of how it may
be used helps you to think of ways you can write a script to help you
in our own environment.
About the Author
Bob Kelly is president and co-founder of AdminScriptEditor.com, home to an integrated suite of scripting tools and a shared library of scripts and language help. He has authored books on scripting and desktop administration and several white papers. Bob also owns and operates AppDeploy.com, where he writes and produces videos on topics related to software deployment.