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about_Path_Syntax

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Short description

Describes the full and relative path formats in PowerShell.

Long description

All items in a data store accessible through a PowerShell provider can be uniquely identified by their path names. A path is a combination of the item name, the container and subcontainers in which the item is located, and the PowerShell drive through which the containers are accessed.

In PowerShell, path names can be one of two types: fully qualified and relative. A fully qualified path consists of all elements that make up a path. The following syntax shows the elements in a fully qualified path:

[<provider>::]<drive>:[\<container>[\<subcontainer>...]]\<item>

The <provider> placeholder refers to the PowerShell provider through which you access the data store. For example, the FileSystem provider allows you to access the files and directories on your computer. This element of the syntax is optional and is never needed because the drive names are unique across all providers.

The <drive> placeholder refers to the PowerShell drive that's supported by a particular PowerShell provider. In the case of the FileSystem provider, the PowerShell drives map to the Windows drives that are configured on your system. For example, if your system includes an A: drive and a C: drive, the FileSystem provider creates the same drives in PowerShell.

After you have specified the drive, you must specify any containers and subcontainers that contain the item. The containers must be specified in the hierarchical order in which they exist in the data store. In other words, you must start with the parent container, then the child container in that parent container, repeating the pattern for each child container. In addition, each container must be preceded by a backslash.

Note

PowerShell allows you to use backslash or forward slash for compatibility with PowerShell on other platforms. This works for PowerShell commands, but may not work when used with native applications that only expect the native directory separator. Use [System.IO.Path]::DirectorySeparatorChar to find the character used for your platform.

After the container and subcontainers have been specified, you must provide the item name, preceded by a backslash. For example, the fully qualified path name for the Shell.dll file in the C:\Windows\System32 directory is as follows:

C:\Windows\System32\Shell.dll

In this case, the drive through which the containers are accessed is the C: drive, the top-level container is Windows, the subcontainer is System32, and the item is Shell.dll.

In some situations, you don't need to specify a fully qualified path and can instead use a relative path. PowerShell allows you to identify an item based on its location relative to the current working location.

PowerShell uses the following character sequences to specify relative paths.

  • (.) - Current location
  • (..) - Parent of current location
  • (\) - Root of current location

The following examples are based on the current working directory being set to C:\Windows.

  • The relative path .\System resolves as C:\Windows\System
  • The relative path ..\Program Files resolves as C:\Program Files
  • The relative path \Program Files resolves as C:\Program Files
  • The relative path System resolves as C:\Windows\System

When using a path in a command, you can use a fully qualified path or a relative one. For example, suppose that your current working directory is C:\Windows. The following Get-ChildItem command retrieves all items in the C:\TechDocs directory:

Get-ChildItem \TechDocs

The backslash indicates that the drive root of the current working location should be used. Because the working directory is C:\Windows, the drive root is the C: drive. Because the TechDocs directory is located off the root, you need to specify only the backslash.

You get the same results using the fully qualified path:

Get-ChildItem C:\TechDocs

Regardless of whether you use a fully qualified path or a relative path name, a path is important not only because it locates an item but also because it uniquely identifies the item even if that item shares the same name as another item in a different container.

For instance, suppose that you have two files that are each named Results.txt. The first file is in a directory named C:\TechDocs\Jan, and the second file is in a directory named C:\TechDocs\Feb. The path for the first file (C:\TechDocs\Jan\Results.txt) and the path for the second file (C:\TechDocs\Feb\Results.txt) allow you to clearly distinguish between the two files.

Support for the Win32 File namespace

On Windows, the cmdlets that support the FileSystem provider also support the paths that use the Win32 File namespace format. You can only use these paths with the LiteralPath parameter of the cmdlets.

Paths in Win32 File namespace are prefixed with \\?\. The prefix tells the Windows APIs to disable all string parsing and send the string that follows directly to the file system. For example, if the file system supports large paths and file names, you can exceed the MAX_PATH limits that are otherwise enforced by the Windows APIs.

For more information, see Win32 File Namespaces in Naming Files, Paths, and Namespaces.

See also