Executive Summary:
In Windows PowerShell, providers facilitate access to data stores, such as the Windows file system and registry. Despite their important role, providers are, for the most part, invisible to you within PowerShell. What are visible, however, are the PowerShell drives you use to access the providers. In this lesson, you'll learn about the available drives and how to implement them. |
In Windows PowerShell, you access folders and files by providing a pathname, such as C: Windows\System32. In this case, the pathname begins with C, which is the drive name. Whenever
you access a file-system resource, you must provide the drive name, or the drive must be
implicit within the context of the command, such as when you’re retrieving a list of objects in
the current working location.
File-system drives aren’t the only type of drives that PowerShell supports. PowerShell supports
a number of drives that provide access to different data stores. For example, as I demonstrated in
Lesson 5, you use the Variable drive to access built-in variables and the Env drive to access environment
variables.
In this last lesson of the PowerShell 101 series, you’ll learn about the available drives and how to
implement them through PowerShell providers that facilitate access to the data stores. You’ll also learn
how to work with PowerShell’s built-in drives and how to create additional drives. By the end of the
lesson, you’ll know how to access not only the file system but also the certificate store, the registry, and
other data stores.
Understanding PowerShell Providers
At the heart of data-store access lies the PowerShell providers. A provider is a Microsoft .NET program
that provides a data-access layer between PowerShell and the data. Providers abstract data access so that
you can use the same mechanisms within PowerShell to interact with the various stores. For example,
you can use the Get-ChildItem cmdlet to access the file system, registry, and certificate store.
PowerShell supports a number of built-in providers. To
view a list of providers currently available on your system,
you can use the Get-PSProvider cmdlet in the command
Get-PSProvider | select Name
Table 1 lists the providers that currently ship with Power-
Shell. Because PowerShell is extensible, custom providers
can be developed to access other types of data stores. You can then install those providers and
access the data stores as you would access
the data stores supported by the built-in
providers. However, a discussion about
custom providers is beyond the scope of this
article. See the about_provider Help file for
information.
Despite the important role that providers
play, they are, for the most part, invisible to
you within PowerShell. What are visible,
however, are the PowerShell drives you use
to access the providers.
Working with the Built-In Drives
Providers expose data through one or more
PowerShell drives. For example, the File-
System provider exposes file-system data
through PowerShell drives that have a direct
correlation to your Windows drives. For
instance, the FileSystem provider exposes
your Windows C drive through the Power-
Shell C drive.
To view a list of PowerShell drives and
their associated providers, you can use the
Get-PSDrive cmdlet, as shown in the statement
Get-PSDrive | sort Provider, Name
This statement sorts the results first by provider,
then by name so that the providers are
grouped together, as Figure 1 shows. Notice
that on my system, the FileSystem provider
supports six drives, the Registry provider
supports two drives, and the other providers
each support only one drive.
The preceding statement also displays
root information. The root refers to the
location within the target data store that
the PowerShell drive maps to. For example,
the HKCU drive maps to the HKEY_
CURRENT_USER hive in the registry. For
drives that access nonhierarchical data
stores, such as PowerShell aliases and
variables, the root
value is blank.
You can also
use Get-PSDrive to
retrieve information
about a specific
drive. For example,
the following statement
retrieves data
about the Function
drive:
Get-PSDrive Function | Format-List
As Figure 2 shows, this statement returns
details such as the name of the provider and
a description of the drive. Notice that the
figure also shows the statement
Get-PSDrive -PSProvider Registry
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