PowerShell 101

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

POWERSHELL 101 – WHAT IS IT

AND 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?

 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!

 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

 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 

 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 supports:
 .NET objects
 COM objects
 WMI objects
 Syntax and usage vary
 So similar, yet so different
 LOTS more detail – just not in this session

 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

 Connects output from a cmdlet to the input of
another cmdlet
 Combination of the all cmdlets etc makes a
pipeline

Process
Object

Get-Process
Cmdlet
Pipe

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

 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

 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!

Cmdlets, Objects, and the Pipeline

DEMO

 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

 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 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 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

 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

$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

 $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

 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()

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

Also See Get-Help about_operators

Operator Type Operator
Redirection operators >, >> 2> 2>&1
See: get-help about-redirection
Split/Join operators -split, -join
See: about_split,about_join
Type operators -is, -isnot, -as
See: about_type_operators
Urinary operators ++, --

Operator Function Operator
Call &
Property dereference .
Range Operator ..
Format operator -f
Subexpression operator $( )
Array Subexpression operator @( )
Array operator ,

 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"

 History
 Redirection etc a historical reality
 Keep the parser simple
 PowerShell does more than simple ">"!!
 Case insensitive vs. case sensitive comparisons

 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!

Objects,Variables, Types, etc

DEMO

 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

 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

 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

 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!

 Set up prompt
 Function prompt {“Psh`[$(pwd)]: “}
 Add personal aliases
 Set-Alias gh get-help
 Create PSDrives
 New-PsDrive demo file e:pshdemo
 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

 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

 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

 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

 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.

 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

 I will answer what I can now

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

PowerShell 101

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PowerShell 101