Windows PowerShell Cookbook

1. Start with the familiar: PowerShell runs your existing tools.

What surprises most people when they first launch PowerShell is its similarity to the command prompt that has long existed as part of Windows.

Low barrier to entry. PowerShell is designed to be immediately productive for users familiar with command-line interfaces. You can run standard Windows executables like ipconfig.exe or notepad.exe just by typing their names, exactly as you would in cmd.exe. This means you don't have to abandon your existing command-line knowledge or tools to start using PowerShell.

Compatibility features. PowerShell includes features to ensure compatibility with traditional command-line tools and scripts. For executables with spaces in their path or name, use the invoke operator (&) and quotes, like & 'C:\Program Files\MyApp\app.exe'. To run scripts or executables located in the current directory, prefix the name with .\, such as .\myscript.ps1, mirroring behavior in Unix shells for added security.

Foundation for growth. While starting with familiar commands is easy, PowerShell's true power lies in its native cmdlets and scripting capabilities. This compatibility provides a comfortable starting point before you delve into more advanced, object-oriented features, allowing you to learn and adopt PowerShell incrementally.

2. Embrace the object pipeline: Data manipulation made easy.

PowerShell passes full-fidelity .NET objects between its commands.

Beyond text. Unlike traditional shells that pass data as plain text, PowerShell pipelines transmit rich, structured objects. This eliminates the need for fragile text parsing tools like awk or grep to extract meaningful information from command output.

Seamless data flow. The pipe operator (|) connects commands, directing the object output of one command directly into the object input of the next. This allows you to chain together simple commands to perform complex data manipulation tasks efficiently. For example, Get-Process | Where-Object { $_.WorkingSet -gt 100mb } | Sort-Object Name retrieves processes, filters them by memory usage, and sorts the resulting objects by name, all while preserving the full process object data.

Simplified scripting. Working directly with objects makes scripting significantly easier and more reliable. You can access object properties (like .Name or .Length) and call methods (like .Kill()) directly within the pipeline or in scripts, leveraging the full capabilities of the underlying data.

3. Master variables and objects: The core of PowerShell's power.

With those objects in hand, PowerShell makes it trivial for you to access properties of objects (such as their process name or memory usage) and to access functionality on these objects (such as stopping them, starting them, or waiting for them to exit).

Structured data. PowerShell is built upon the .NET Framework, meaning data is handled as structured objects rather than simple text strings. These objects encapsulate both information (properties) and actions (methods) related to the data they represent.

Accessing object members. You interact with objects using dot notation: $process.Id accesses the Id property of a process object, and $process.Kill() invokes the Kill method. This consistent syntax applies whether the object comes from a cmdlet, a .NET class, or another source.

Variables as containers. Variables, denoted by a dollar sign ($), store these objects for later use. You can assign the output of any command or pipeline to a variable, preserving the object's structure and functionality. PowerShell also provides automatic variables (like $error or $PSVersionTable) that offer insights into the current session and environment.

4. Control your scripts: Logic and loops for automation.

Together, looping and flow control statements add significant versatility to your PowerShell toolbox.

Adapting to data. Flow control statements allow your scripts to make decisions and execute different commands based on conditions. The if, elseif, and else statements provide conditional execution, while the switch statement offers a cleaner way to handle multiple comparison cases, even supporting pattern matching and file input.

Repeating actions. Looping statements enable your scripts to perform operations multiple times without repeating code. PowerShell offers several loop types:

• for: Executes a block a specified number of times.
• foreach: Iterates through each item in a collection.
• while: Repeats a block as long as a condition is true.
• do: Repeats a block until a condition is met (checked after the first execution).

Pipeline processing. The Foreach-Object cmdlet (% alias) is particularly useful for processing items as they arrive through the pipeline, offering efficiency for large datasets. Combining loops and conditionals allows you to write sophisticated scripts that can handle diverse scenarios and data inputs dynamically.

5. Handle text and strings: Powerful manipulation tools.

Since PowerShell lets you manage the majority of your system in its full fidelity (using cmdlets and objects), the text processing tools can once again focus primarily on actual text processing tasks.

String types. PowerShell supports different ways to define strings, including literal strings (single quotes '...') where content is taken exactly as written, and expanding strings (double quotes "...") where variables ($variable) and escape sequences (\n, \t) are interpreted. Here-strings (@"..."@) allow for multi-line text blocks while preserving formatting.

Operators for manipulation. Powerful operators are available for common text tasks. The -split operator breaks strings into arrays based on a delimiter or regular expression, while the -join operator combines array elements into a single string. The -replace operator performs text substitution, supporting both simple string replacement and complex regular expression patterns.

String methods. As .NET objects, strings also expose numerous methods for manipulation. Examples include .Length to get the string length, .Contains() to check for substrings, .IndexOf() to find substring positions, .ToUpper() and .ToLower() for case conversion, and .Trim() to remove leading/trailing whitespace.

6. Navigate and manage files: A consistent approach.

That complicated programmer-oriented script turns into a one-liner: Get-ChildItem -Recurse | Sort-Object -Descending Length | Select -First 10

Core file cmdlets. PowerShell provides a consistent set of cmdlets for interacting with the filesystem. Get-ChildItem (dir, ls) lists files and directories, Get-Item retrieves information about a specific item, New-Item creates files or directories, Remove-Item deletes them, and Move-Item and Rename-Item handle moving and renaming.

Powerful filtering. These cmdlets support robust filtering using wildcards (*, ?, []) directly in the -Path parameter or via the -Include and -Exclude parameters. For provider-specific filtering (like short filenames), the -Filter parameter is available. Additionally, the -Attributes parameter allows filtering by file attributes like ReadOnly, Hidden, or System.

Recursive operations. The -Recurse parameter enables operations on items within subdirectories, making it easy to perform tasks across an entire directory tree. Combined with the object pipeline, this allows for powerful, concise commands to find, filter, and act upon files based on their properties, as demonstrated by the quote example finding the largest files.

7. Administer the Registry: Treat it like a filesystem.

PowerShell tackles this problem by exposing the Windows Registry as a navigation provider: a data source that you navigate and manage in exactly the same way that you work with the filesystem.

Registry drives. PowerShell maps the main registry hives to drives, such as HKLM: for HKEY_LOCAL_MACHINE and HKCU: for HKEY_CURRENT_USER. This allows you to navigate the registry using familiar filesystem cmdlets like Set-Location (cd), Get-ChildItem (dir), Push-Location, and Pop-Location.

Key and value management. Registry keys are treated as items, and their values as properties of those items. You use Get-ItemProperty (gp) to view key values, Set-ItemProperty (sp) to modify them, New-ItemProperty to create new values, and Remove-ItemProperty to delete values.

Transactional safety. For related registry modifications, PowerShell supports transactions. Using Start-Transaction and applying changes with the -UseTransaction parameter ensures that either all changes are committed (Complete-Transaction) or none are (Undo-Transaction), preventing inconsistent states.

8. Work with Event Logs: Centralized system monitoring.

By building on PowerShell eventing, you can write scripts to quickly react to an ever-changing system.

Accessing logs. PowerShell provides Get-EventLog for accessing classic Windows event logs (Application, System, Security, etc.) and Get-WinEvent for accessing newer logs (Application and Services Logs) on Windows Vista and later. Get-EventLog -List or Get-WinEvent -ListLog * list available logs.

Filtering and analysis. Event log entries are returned as objects, enabling powerful filtering with Where-Object based on properties like Message, EntryType, EventID, or TimeGenerated. Get-WinEvent offers more efficient filtering options like -FilterHashtable and -FilterXPath for complex queries. Group-Object helps analyze event frequency.

Management tasks. Beyond retrieval, PowerShell cmdlets allow for comprehensive event log management. Write-EventLog adds custom entries, Clear-EventLog empties a log, and Limit-EventLog configures log size and retention policies. You can also export logs using wevtutil.exe or Export-CliXml for backup or offline analysis.

9. Manage Processes and Services: Control running applications.

Since PowerShell’s Get-Process cmdlet returns information as highly structured .NET objects, fragile text parsing becomes a thing of the past: Get-Process | Where-Object { $_.WorkingSet -gt 100mb } | Stop-Process -WhatIf

Process control. The Get-Process (gps) cmdlet retrieves running processes as rich objects, providing access to properties like Name, Id, WorkingSet, and StartTime. This object-based output allows for precise filtering and sorting without text parsing. Stop-Process (kill) terminates processes, and Wait-Process pauses script execution until a process exits.

Service management. Similarly, Get-Service retrieves system services as objects with properties like Name, DisplayName, and Status. You can filter services (e.g., Get-Service | Where-Object {$_.Status -eq 'Running'}) and manage their lifecycle.

Service actions. Dedicated cmdlets perform service actions: `
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Last updated: May 13, 2025