Introducing Windows PowerShell

UNIX administrators won't be laughing anymore

From the August 2006 Edition
of Windows IT Pro
Paul Robichaux
Cover Story
InstantDoc #50565
Windows IT Pro

Let's look at another more powerful example of cmdlets. The command

get-OWAVirtualDirectory | 
   set-OWAVirtualDirectory 
   -FileAccessControlOnPublicComputers 
   blockAllExceptTranscoded

enumerates every OWA virtual directory in an organization, then sets the WebReady Document Viewing controls to block all attachment access, except for files that can be rendered by the Document Viewing layer. Presto! With this one line, you've effectively prevented users on public computers from saving or accessing attachments unless those attachments can be transcoded, which greatly lowers the risk of accidental exposure of confidential data. If you had to apply this setting manually to each OWA virtual directory, it would be easy to miss one or more servers, leaving your protection incomplete.

Favorite Features
As you work with PowerShell, you'll find features that you use constantly. Here are a few of my favorite features:

Start-transcript and its partner stop-transcript. The start-transcript cmdlet tells PowerShell to keep a complete log of your interactions with the shell, making it easy to go back to a previous session to find out exactly what you did. You can even use this log to turn sets of commands into a reusable script. The stoptranscript cmdlet tells PowerShell to stop this logging.
Get-command with the -synopsis flag. If you don't know what a certain cmdlet does, you can use the get-command cmdlet with the -synopsis flag to get a summary of the specified cmdlet. For example, if you run the command
```
get-command -name get-service 
      -synopsis 
```
PowerShell will give you a usage synopsis for the get-service cmdlet.
Get-excommand. If you don't know what cmdlet you're looking for, you can use get-excommand to find cmdlets that might be of interest. When you use getexcommand with wildcards, it's fairly easy to find what cmdlets exist. For example, the command
```
get-excommand *ailbox* 
```
returns cmdlets, properties, and methods that are related to mailboxes. To get only cmdlets, you can use the where cmdlet to filter the get-excommand cmdlet's output:
```
get-excommand *ailbox* | 
    where {$.Name -eq "Cmdlet"}
```

Powering Up for PowerShell
Initially, your PowerShell scripts won't be pretty. They're probably going to look like the first scripts you created when you learned your first scripting language (only with slightly different syntax). So, until you get fluent in PowerShell and learn its ways, it might be best to think of PowerShell as a complement to existing scripting methods. The Learning Path box provides some resources to help you with the learning curve. I recommend Andy Oakley's book Monad and the Windows PowerShell Quick Start Web page, which is part of the Windows PowerShell Wiki on Microsoft's Channel9 (http://channel9.msdn.com/wiki/default.aspx/Channel9.WindowsPowerShellQuickStart).

End of Article

Previous 1 2 [3] Next

FYI: "where" is not a cmdlet that fails to follow the Windows PowerShell strong naming conventions as incorrectly stated in this article; "where" is an alias for the where-object cmdlet.

Bob Wells August 03, 2006 (Article Rating:

)

Thanks for the update, Bob-- but "where-object" still doesn't follow the verb-object command structure :)

paulrobichaux August 03, 2006 (Article Rating:

)

The command line:

"Get-EventLog application | Where {$_.ID eq "-1030"}"

should read

"Get-EventLog application | Where {$_.EventID -eq "1030"}

The hyphen is misplaced, and the property is EventID rather than ID.

Schell May 25, 2007 (Article Rating:

)

Thanks for the fix, Michael!

paulrobichaux May 28, 2007 (Article Rating:

)

You must log on before posting a comment.

If you don't have a username & password, please register now.