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).