Scripting 101–

Powershell

Published 2011

Clyde G. Johnson, MCSE,MCSA,MCITP, A+

Windows Boston

Powershell v2

Released August 2009

Part of Windows 7 and Server 2008 R2

Versions are available for download

XP, Server 2003, Vista and Server 2008

32 bit AND 64 bit

NOT enabled by default

Automate repetitive Tasks

Login Scripts

UserID Creation

Inventory Scripts

Mass file changes

Data Migrations

Types of Admin Scripts

WMI (inventory)

ADSI (Manipulating Active Directory)

File manipulation

Registry Manipulation

Remote vs. local

Software configuration and manipulation

Script basics

Modular code

Write it once – use it many times

Comments!

The next person to read your code might be you!!

Header

What the name should be.

Your name and the Date.

Attribution – whom you “borrowed” it from.

Sample

#Serial.ps1

# Gets the serial # of strserver

# Author: Clyde G. Johnson 3-5-2012

# http: somewhere on the web…

$strserver=“.”

Get-WmiObject -ComputerName $strserver -Class

Win32_BIOS | Select-Object SerialNumber

Disabled by default

Set-ExecutionPolicy RemoteSigned

Get-Help About_Signing

Powershell basics

Cmdlets

implement specific functions

Verb-noun

Pipelines

Output of one command is input to another

Modules

5 Key cmdlets

Get-Help

Get-Command

Get-Member

Get-Psdrive

Format-List

Piping

Connects one command to another

Pass output from command to command

Each command refines the output

Export to CSV, XML or HTML

Pipe to a file or a Printer

The Pipeline, Illustrated

11

Get-Mailbox

Sort

Size

-Descend

Select

-First

100

Move-Mailbox

Not the exact syntax –

but you get the idea!

Extending powershell with Modules

Get-Module –listavailable

Import-Module name

Get-Command –module name (You must import

the module before running this – why demo

failed)

Powershell

Variables

Functions

Branching (if-then-else)

Loops (while, do for and foreach)

Structured error/exception handling

Variables

Variables

Start with $

Will expand within quotes

Special Variables

$args (command line arguments to a function)

$_ (current object in the pipeline

Branch Statements

if (condition) {code block}

elseif (condition) {code block}

else {code block}

switch (expression)

{

(test) {code block}

value {code block}

default {code block}

}

Loops

do { code block } while (condition)

while (condition) { code block }

do { code block } until (condition)

for (init; condition; increment) { code block }

foreach ($var in $array) { code block }

break

continue

PowerShell scripting.

Command line and Scheduled task

Powershell.exe c:\dev\script.ps1

Debug

PowerShell Integrated Scripting Environment (ISE)

PowerShell Scriptomatic

Powershell (v3)

490 cmdlets / 55 Modules (4)

Print management

DHCP

Powershell (ISE) has also gotten an upgrade

Now has intellisense

Bracketing highlight

Powershell Workflows?

Powershell ISE v3 (beta server 8)

Demo Scriptomatic

Power Shell Scriptomatic

Password Sample

Creating a encrypted password

Read-Host -assecurestring | ConvertFrom-securestring |

out-file C:\dev\securestring.txt

Bits-Transfer

Import-Module BitsTransfer

$pass = cat "C:\dev\CopyBits\SecureTransfer.txt" | convertto-

securestring

$mycreds = New-object -typename

System.Management.Automation.PSCredential -argumentlist

“domainname/securetransfer",$pass

Start-BitsTransfer -Source \\10.30.0.224\c$\test\*.* -Destination

C:\Temp\ -transfertype Download -Credential $mycreds

Send an email

$mail = New-Object System.Net.Mail.MailMessage

$mail.From = New-Object

System.Net.Mail.MailAddress(“mary@microsoft.com”);

$mail.To.Add(“cjohnson@frank.com”);

$mail.Subject = “bob’s breakfast”

$mail.Body =“ at one o’clock today”

$smtp = New-Object System.Net.Mail.SmtpClient(“10.30.0.22”);

$smtp.Send($mail);

Event Log Sample

#pulls all event id 901’s in the last hour,

$colItems=Get-Eventlog application -after (get-Date).addHours(-1)|

where {$_.EventId -eq 901}

if($colItems -eq $Null) {} else{

foreach ($item in $colItems){

“Do something”

}

}

Backup all your GPO’s sample

#get domain of local machine

$mydomain = get-ADDomain -current LocalComputer

#pull all the GPO’s in the domain.

$AllGPOs = get-gpo -domain $mydomain.DNSRoot –all

# loop thru them

Foreach ($GPO in $ModGPOs) {

# Backup the GPO to the specified path

$GPOBackup = backup-GPO $GPO.DisplayName -path "C:\GPOBackup“

}

http://technet.microsoft.com/en-

us/library/ee692944.aspx

http://blogs.msdn.com/powershell

http://thepowershellguy.com

http://technet.microsoft.com/en-

us/scriptcenter/dd742419.aspx

http://morelunches.com/recommended/classroom-kit-

for-trainers/

Provided Variables (part 1)

Name Description

$_ The current pipeline object; used in script blocks, filters, the process clause

of functions, where-object, foreach-object and switch

$^ contains the first token of the last line input into the shell

$$ contains the last token of last line input into the shell

$? Contains the success/fail status of the last statement

$Args Used in creating functions that require parameters

$Error If an error occurred, the object is saved in the $error PowerShell variable

$foreach Refers to the enumerator in a foreach loop.

$HOME The user's home directory; set to %HOMEDRIVE%\%HOMEPATH%

$Host Information about the currently executing host

$Input Input piped to a function or code block

Provided Variables (part 2)

Name Description

$LastExitCode The exit code of the last native application to run

$Match A hash table consisting of items found by the –match operator.

$MyInvocation Information about the currently script or command-line

$true Boolean TRUE

$false Boolean FALSE

$null A null object

$OFS Output Field Separator, used when converting an array to a string.

By default, this is set to the space character.

$profile Path to a script file that will execute each time PS is opened.

$ShellID The identifier for the shell. This value is used by the shell to

determine the ExecutionPolicy and what profiles are run at startup.

$StackTrace contains detailed stack trace information about the last error

Files

Get with Get-Item or Get-ChildItem

Call methods on files: (Get-item books.txt).isReadOnly = $true

(gi books.txt).set_isReadOnly($true)

Create file: ni or New-Item

Remove file: rm or Remove-Item

Check if a file exists: Test-Path

Check if directory: Get-Item * | where {$_.PSISContainer}

Search

File by name

Get-Item -path path -filter pattern

Get-Childitem -recurse -path path -filter pattern

File contents

Select-String –path path –pattern pattern

Get-Childitem -recurse * | select-string -pattern

pattern

Service by name:

Get-Service pattern

Get-Service | Where-Object {$_.Status -eq "Stopped"}

Process by name

Get-Process -Name pattern

Get-Process | Sort-Object cpu | select-object -last

5

Variable by name: Get-Variable -Name pattern

Compare File Contents

diff -referenceobject $(get-content

reference file) -differenceobject $(get-

content compare file)

diff -referenceobject $(get-content

reference file) -differenceobject $(get-

content compare file) –includeequal

Comparison Operators

Operation Operator

Equal to -eq

Less than -lt

Greater than -gt

Greater than or equal to -ge

Less than or equal to -le

Not equal to -ne

Not -not, !

And -and

Or -or