Chapter 8: Working with Files and Directories

Learn how to manage files and directories in PowerShell, including creating, reading, deleting, and modifying files and folders.

Managing files and directories is a fundamental task for any administrator. PowerShell provides a robust set of cmdlets for handling file system operations, making it easy to create, modify, move, and delete files and folders. In this chapter, we�ll cover how to use these cmdlets effectively.

Creating Files and Directories

To create files and directories, PowerShell offers the New-Item cmdlet. Use the -ItemType parameter to specify whether you�re creating a file or a directory:

# Creating a directory
New-Item -Path "C:\ExampleDir" -ItemType Directory

# Creating a file
New-Item -Path "C:\ExampleDir\example.txt" -ItemType File

The first command creates a new directory, and the second creates a text file within that directory.

Reading File Content

To read the contents of a file, use the Get-Content cmdlet. This cmdlet reads each line in a file and returns it as an array of strings:

# Reading file content
Get-Content -Path "C:\ExampleDir\example.txt"

This command outputs each line of example.txt to the console.

Writing to a File

To write content to a file, use the Set-Content cmdlet to overwrite or Add-Content to append:

# Overwriting content
Set-Content -Path "C:\ExampleDir\example.txt" -Value "New content"

# Appending content
Add-Content -Path "C:\ExampleDir\example.txt" -Value "Additional line"

The first command replaces the file�s content, while the second appends a new line.

Copying and Moving Files

PowerShell provides Copy-Item and Move-Item cmdlets to duplicate or relocate files and directories:

# Copying a file
Copy-Item -Path "C:\ExampleDir\example.txt" -Destination "C:\ExampleDir\backup\"

# Moving a file
Move-Item -Path "C:\ExampleDir\example.txt" -Destination "C:\NewLocation\"

The Copy-Item cmdlet duplicates the file, while Move-Item relocates it.

Deleting Files and Directories

To delete files or directories, use the Remove-Item cmdlet. Be cautious with this cmdlet, as deletions are permanent by default:

# Deleting a file
Remove-Item -Path "C:\ExampleDir\example.txt"

# Deleting a directory
Remove-Item -Path "C:\ExampleDir" -Recurse

The -Recurse parameter is required to delete a directory and all of its contents.

Checking for File and Directory Existence

Before performing actions on files or directories, it�s often useful to check if they exist. Use the Test-Path cmdlet to verify existence:

if (Test-Path -Path "C:\ExampleDir\example.txt") {
    Write-Output "File exists."
} else {
    Write-Output "File does not exist."
}

This example checks if example.txt exists and displays an appropriate message.

Getting File and Directory Properties

PowerShell�s Get-Item cmdlet retrieves properties of files and directories, including size, last modified date, and more:

$file = Get-Item -Path "C:\ExampleDir\example.txt"
Write-Output "File size: $($file.Length) bytes"
Write-Output "Last modified: $($file.LastWriteTime)"

This example retrieves the file�s size and last modified date, displaying each as output.

Working with File Paths Using Join-Path

To build file paths dynamically, use Join-Path. This cmdlet combines folder and file names, ensuring correct path separators:

$folder = "C:\ExampleDir"
$file = "example.txt"
$fullPath = Join-Path -Path $folder -ChildPath $file
Write-Output $fullPath

This example combines the folder and file into a full path, C:\ExampleDir\example.txt.

Summary and Next Steps

In this chapter, we covered essential file and directory management tasks in PowerShell, including creating, reading, writing, copying, moving, and deleting files and directories. We also explored checking for existence, retrieving properties, and dynamically constructing file paths. In the next chapter, we�ll dive into text processing tools, enabling you to manipulate text files and data more effectively in PowerShell.