POWERSHELL 101 – WHAT IS IT

AND WHY IT MATTERS

Thomas Lee (tfl@psp.co.uk)MCT and PowerShell MVP

What is it/Why it Matters

What IS PowerShell? What are Cmdlets, Objects and the

Pipeline? Language fundamentals How do I install and setup PowerShell> How do I use PowerShell? PowerShell profiles Getting the most from PowerShell Why does it matter?

What IS PowerShell?

PowerShell is Microsoft’s task automation platform. Part of Microsoft’s Common Engineering Criteria Included with every version of Windows

7/Server 2008 R2 (and as a OS patch for earlier versions)

In a couple of years, if you don’t know PowerShell you may not have a job as an IT Pro!

What’s IN PowerShell

Shell Unix like (console.exe) Lightweight IDE (sort of VS Lite)

Scripting Language Power of Perl/Ruby

Extensible Create your own cmdlets/providers/types/etc Leverage the community

Built on .NET and Windows MS-centric/MS-focused

PowerShell Architecture

Remoting with PowerShell

PowerShell Fundamentals

Cmdlets Objects Pipeline

Community

Discovery

PowerShell Language Features

What Are Cmdlets?

The fundamental unit of functionality Implemented as a .NET Class Get some, buy some, find some, or build

your own Cmdlets take parameters

Parameters have names (prefaced with “-”) Parameter names can be abbreviated

Cmdlets can have aliases Built in or add your own Aliases do NOT include parameter aliasing

What Are Objects?

A computer abstraction of a real life thing A process A server An AD User

Objects have occurrences you manage The processes running on a computer The users in an OU The files in a folder

PowerShell Object Support

PowerShell supports: .NET objects COM objects WMI objects

Syntax and usage vary So similar, yet so different

LOTS more detail – just not in this session

What Is The Pipeline?

Connects cmdlets One cmdlet outputs objects Next cmdlet uses them as input

Pipeline is not a new concept Came From Unix/Linux PowerShell Pipes objects not text

What IS the Pipeline

Connects output from a cmdlet to the input of another cmdlet

Combination of the all cmdlets etc makes a pipeline

PS C:> Get-Process | Sort-ObjectSort-Object

CmdletSort-Object

Cmdlet

Get-Process Cmdlet

Get-Process Cmdlet

Process Object

Process Object

PipePipe

The Pipeline In Action

Why This Design Matters

Simple to use Just string cmdlets/scripts/functions together Simpler to write in many cases

Very powerful in operation Lets PowerShell do the heavy lifting

Integrates functionality stacks OS Application PowerShell Base Community

Discovery And Community

A key concept in PowerShell Built-in help (Get-Help, Get-Command) Automatic linking to online help Huge PowerShell ecosystem – the

community Social networking: eg Twitter, Facebook, etc Mailing lists and newsgroups Web sites and blogs User Groups 3rd party support – free stuff coming!

DEMO

Cmdlets, Objects, and the Pipeline

Variables

Variables contain objects during a session Variables named starting with ‘$’

$myvariable = 42

Variable’s Type is implied (or explicit) $myfoo = ls c:\foo

Variables can put objects into pipeline $myfoo | format-table name

Variables can be reflected on $myfoo | get-member

You can use variables in scripts and the command line

Built-in Variables

Some variables come with PowerShell $PSVersionTable $PSHome

Some variables tell PowerShell what to do $WarningPreference $MaximumHistoryCount

You can create variables in Profile(s) that persist Using your profile (more later)

See the variables in your current session ls Variable:

Scalar Values

Scalar variable contains a single value $i=42

Can use properties/methods directly $i=42; $i.tostring("p")

Use to calculate a value for use in formatting See more in discussion on Formatting (next

session)

Array Values

Array variables contain multiple values/objects

Array members addressed with [], e.g. $a[0] $a[0] is first item in array $a[-1] is last item

Use .GetType() $myfoo = LS c:\foo $myfoo.gettype()

Array members can be one or multiple types LS c:\ | Get-Member

Arrays used with loops

Hash Table

Special type of an array Also known as dictionary or property bag

Contains a set of key/value pairs Values can be read automagically

$ht=@{"singer"="Jerry Garcia“; "band"="Greatful Dead”}$ht.singer

Value can be another hash table! See Get-Help about_hash_tables

Sorting HashTables

$ht = @{Firstname=“Thomas"; Surname="Lee"; Country="UK";Town="Cookham}

$ht | sort name | ft -a

Name Value

---- -----

Surname Lee

County Berkshire

Town Cookham

Firstname Thomas

Country UK

Using Get-Enumerator()

$ht = @{Firstname=“Thomas"; Surname="Lee"; Country="UK";Town="Cookham}

$ht.GetEnumerator() | sort name | ft -a Name Value ---- ----- Country UK County Berkshire Firstname Thomas Surname Lee Town Cookham

Variable Type

Variables can be implicitly typed PowerShell works it out by default $I=42;$i.gettype()

Variables can be explicitly typed [int64] $i = 42 $i.gettype()

Typing an expression $i = [int64] (55 – 13); $i.gettype() $i = [int64] 55 – [int32] 13; $i.gettype() $i = [int32] 55 – [int64] 13; $i.gettype()

Operators

Operator Type Operator

Arithmetic operator +, -, *, /, %See: about_arithmetic operator

Assignment operators =, +=, -=, *=, /=, %=See: about_assignment_operators

Comparison Operators -eq, -ne, -gt, -lt, -le, -ge, -like,-notlike, -match, -notmatch-band, -bor, -bxor,-bnotSee: about_comparison_operators

Logical Operators -and, -or, -xor –not, !See: about_logical_operators

Also See Get-Help about_operators

More Operators

Operator Type Operator

Redirection operators >, >> 2> 2>&1See: get-help about-redirection

Split/Join operators -split, -joinSee: about_split,about_join

Type operators -is, -isnot, -asSee: about_type_operators

Urinary operators ++, --

Special Operators

Operator Function Operator

Call &

Property dereference .

Range Operator ..

Format operator -f

Subexpression operator $( )

Array Subexpression operator

@( )

Array operator ,

Expressions

Variables plus operators Produce some value Value can be an object too!

Simple expressions $i+1; $j-1; $k*2, $l/4

Boolean expression General format is: <value> -<operator>

<value> $a –gt $b $name –eq "Thomas Lee"

Why not use > or < etc??

History Redirection etc a historical reality

Keep the parser simple PowerShell does more than simple ">"!! Case insensitive vs. case sensitive

comparisons

What else?

Lots! Modules

Way of managing PowerShell code in an enterprise

Remoting 1:1 or 1:many Remoting

XML Support Native XML

More, more, more Discover, discover, discover!

DEMO

Objects,Variables, Types, etc

How Do I Install PowerShell? Built in to Win7, Server 2008 R2

On Server, add ISE Feature On Server Core PowerShell – add feature

(and .NET) Down-level operating systems

Shipped as an OS Patch with WinRM – KB 968929

Get it from the net - http://tinyurl.com/pshr2rtm

NB: Different versions i386 vs x64, XP/Vista/2008

No version for IA64 or Windows 2000(Or earlier)

Beware of search engine links to beta versions

How Do I Use PowerShell?

From the Console Start/PowerShell

From the PowerShell ISE Start/PowerShellISE

Part of an application GUI layered on PowerShell Application focused console

Third Party IDEs PowerShell Plus PowerGUI

How Do I Configure PowerShell Add third party tools

There are lots! Using Built-in tools

This will vary with what OS you use and which applications you are running

Configure PowerShell using Profiles

What are Profiles?

Special scripts that run at startup Multiple Profiles

Per User vs. Per System Per PowerShell Console vs. for ALL consoles ISE profile – just for ISE

Creating a profile Leveraging other people’s work If you use it - stick it in your profile!

Common Profile Contents

Set up prompt Function prompt {“Psh`[$(pwd)]: “}

Add personal aliases Set-Alias gh get-help

Create PSDrives New-PsDrive demo file e:\psh\demo

Set size/title of of PowerShell console $host.ui.rawui.WindowTitle = "PowerShell Rocks!!!" $host.ui.rawui.buffersize.width=120 $host.ui.rawui.buffersize.height=9999 $host.ui.rawui.windowsize.width=120 $host.ui.rawui.windowsize.height=42

Getting More From PowerShell Start with replacing CMD.Exe with

PowerShell Get some good training Use shared code where possible Use great tools Don’t re-invent the wheel Leverage the community

PowerShell Training

Official MOC 6434 – 3 day based on PowerShell V1 10325 – upcoming 5 day course (due 8/10)

PowerShell Master Class http://www.powershellmasterclass.com

New Horizons CWL V2 course coming

Resources

Use your favorite search engine!!! PowerShell Owner’s Manual

http://technet.microsoft.com/en-us/library/ee221100.aspx

PowerShell – Getting Started Guide http://tinyurl.com/pshgsg

PowerShell references http://www.reskit.net/psmc

And for your dev trainers…

PowerShell is not just an IT Pro tool Developers need it too

Build cmdlets Build providers Build Management GUIs

More on this topic in some other day.

Let’s Summarise

PowerShell: Combines cmdlets, objects and the pipeline Provides a programming language and

many more features we’ve not looked at today

Enables local and remote management Is easy to get and easy to customise via

profiles Is supported by discovery and a vibrant

community PowerShell is the future of managing

Windows and Windows applications

Questions?

I will answer what I can now

More questions – email me at: doctordns@gmail.com

THE END