Working with files and folders

Article
10/18/2023

Navigating through PowerShell drives and manipulating the items on them is similar to manipulating files and folders on Windows disk drives. This article discusses how to deal with specific file and folder manipulation tasks using PowerShell.

Listing all files and folders within a folder

You can get all items directly within a folder using Get-ChildItem. Add the optional Force parameter to display hidden or system items. For example, this command displays the direct contents of PowerShell Drive C:.

Get-ChildItem -Path C:\ -Force

The command lists only the directly contained items, much like using the dir command in cmd.exe or ls in a UNIX shell. To show items in subfolder, you need to specify the Recurse parameter. The following command lists everything on the C: drive:

Get-ChildItem -Path C:\ -Force -Recurse

Get-ChildItem can filter items with its Path, Filter, Include, and Exclude parameters, but those are typically based only on name. You can perform complex filtering based on other properties of items using Where-Object.

The following command finds all executables within the Program Files folder that were last modified after October 1, 2005 and that are neither smaller than 1 megabyte nor larger than 10 megabytes:

Get-ChildItem -Path $env:ProgramFiles -Recurse -Include *.exe |
    Where-Object -FilterScript {
        ($_.LastWriteTime -gt '2005-10-01') -and ($_.Length -ge 1mb) -and ($_.Length -le 10mb)
    }

Copying files and folders

Copying is done with Copy-Item. The following command backs up your PowerShell profile script:

if (Test-Path -Path $PROFILE) {
    Copy-Item -Path $PROFILE -Destination $($PROFILE -replace 'ps1$', 'bak')
}

The Test-Path command checks whether the profile script exists.

If the destination file already exists, the copy attempt fails. To overwrite a pre-existing destination, use the Force parameter:

if (Test-Path -Path $PROFILE) {
    Copy-Item -Path $PROFILE -Destination $($PROFILE -replace 'ps1$', 'bak') -Force
}

This command works even when the destination is read-only.

Folder copying works the same way. This command copies the folder C:\temp\test1 to the new folder C:\temp\DeleteMe recursively:

Copy-Item C:\temp\test1 -Recurse C:\temp\DeleteMe

You can also copy a selection of items. The following command copies all .txt files contained anywhere in C:\data to C:\temp\text:

Copy-Item -Filter *.txt -Path c:\data -Recurse -Destination C:\temp\text

You can still run native commands like xcopy.exe and robocopy.exe to copy files.

Creating files and folders

Creating new items works the same on all PowerShell providers. If a PowerShell provider has more than one type of item—for example, the FileSystem PowerShell provider distinguishes between directories and files—you need to specify the item type.

This command creates a new folder C:\temp\New Folder:

New-Item -Path 'C:\temp\New Folder' -ItemType Directory

This command creates a new empty file C:\temp\New Folder\file.txt

New-Item -Path 'C:\temp\New Folder\file.txt' -ItemType File

Important

When using the Force switch with the New-Item command to create a folder, and the folder already exists, it won't overwrite or replace the folder. It will simply return the existing folder object. However, if you use New-Item -Force on a file that already exists, the file is overwritten.

Removing all files and folders within a folder

You can remove contained items using Remove-Item, but you will be prompted to confirm the removal if the item contains anything else. For example, if you attempt to delete the folder C:\temp\DeleteMe that contains other items, PowerShell prompts you for confirmation before deleting the folder:

Remove-Item -Path C:\temp\DeleteMe

Confirm
The item at C:\temp\DeleteMe has children and the Recurse parameter wasn't
specified. If you continue, all children will be removed with the item. Are you
sure you want to continue?
[Y] Yes  [A] Yes to All  [N] No  [L] No to All  [S] Suspend  [?] Help
(default is "Y"):

If you don't want to be prompted for each contained item, specify the Recurse parameter:

Remove-Item -Path C:\temp\DeleteMe -Recurse

Mapping a local folder as a drive

You can also map a local folder, using the New-PSDrive command. The following command creates a local drive P: rooted in the local Program Files directory, visible only from the PowerShell session:

New-PSDrive -Name P -Root $env:ProgramFiles -PSProvider FileSystem

Just as with network drives, drives mapped within PowerShell are immediately visible to the PowerShell shell. To create a mapped drive visible from File Explorer, use the Persist parameter. However, only remote paths can be used with Persist.

Reading a text file into an array

One of the more common storage formats for text data is in a file with separate lines treated as distinct data elements. The Get-Content cmdlet can be used to read an entire file in one step, as shown here:

Get-Content -Path $PROFILE
# Load modules and change to the PowerShell-Docs repository folder
Import-Module posh-git
Set-Location C:\Git\PowerShell-Docs

Get-Content treats the data read from the file as an array, with one element per line of file content. You can confirm this by checking the Length of the returned content:

PS> (Get-Content -Path $PROFILE).Length
3

This command is most useful for getting lists of information into PowerShell. For example, you might store a list of computer names or IP addresses in the file C:\temp\domainMembers.txt, with one name on each line of the file. You can use Get-Content to retrieve the file contents and put them in the variable $Computers:

$Computers = Get-Content -Path C:\temp\DomainMembers.txt

$Computers is now an array containing a computer name in each element.

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