CN1266 Network Scripting V1.2

Kemtis KunanuraksapongMSIS with Distinction

MCTS, MCDST, MCP, A+

Agenda

Chapter 4: Shelling Out Commands and ScriptsChapter 5: When Dollars Turn into VariablesChapter 6: A Bit of Logic to Save the DayFlowchart and Pseudo codeChapter 26: The Ten Most Important Cmdlets (1,7)Chapter 27: Ten Common PowerShell Mistakes (5,6,7)

CMDLets

To see the list of the commandsGet-CommandGet-Command | MorePipe (|) is used to pass the output of any command to another. See Chapter 7

CMDLets (Cont.)

Get-HelpGet-Help Get-AliasGet-Help Get-Alias –detailed

More information

Get-Help Get-Alias -fullMore technical information

TryGet-help get-service

CMDLets (Cont.)

Try these:Get-service –name eventlog, spoolerGet-service eventlog, spooler

One shell to rule them all

Command Shell – dir, md, rdWindows script host

VBScript (.vbs) or JavaScript (.js)Use CScript.exe or WScript.exe

Variables

What is variable?Can contain character(s), symbol(s), and special character(s)$MyVar$A6${Var with Space}${V@r}

Camel case notation - $ThisIsAnExampleGet-Help Set-Variable

Data Types

Kinds of valuesVariants – can take on any data typePrimitive values – basic data types such as

BooleanCharDateIntegerSee more on Page 63

Working with data types

Try these code:$a = 2$b = 3$c =$a+$bWrite-output $c

Try put “2” in stead of 2$a = “2”$b=“3”

Working with data types (2)

By adding double quotation mark, it explicitly defines the variable as string or textPlus sign becomes to concatenate the string instead of addition

Why should we explicitly define

Unexpected valuesTo reduce the chance of type mismatch

ClarityImproved performance

PSH knows right away without checking the type

Why should we explicitly define (2)

Try this:[int]$IntOnly = 100$Sum = 2 + $IntOnlyWrite-output $sum$IntOnly = “PowerShell Rules!”Write-output $IntOnly +” Yes, it does”

$IntOnly.GetType().Name

Why should we explicitly define (3)

Table 5-1 on Page 67 shows the shortcut of data type for explicitly defined variableCasting – a process or way to convert data type

Why should we explicitly define (4)

Try these:$MyString = “ Windows PowerShell “$MyDouble = 2.0$OutString = $MyString + $MyDoubleWrite-output $OutString

Try these:$OutString = $MyDouble + $MyString

Why should we explicitly define (5)

Try these:$OutString = [string]$MyDouble + $MyString

OR$OutString = ($MyDouble –as [string]) + $MyString

Constant and Read-Only Var.

You have to useSet-Variable [-Option {None | ReadOnly | Constant | Private | AllScope}]Remove-Variable

Try:Set-Variable PI 3.141 –option constantSet-Variable School “Remington” –option ReadonlyWrite-output “Pi’s value is ” + $PI +

“ This code is run at “ + $School

Automatic Variables

What is automatic variables?Pre-assigned by PSHSee Table 5-2 on Page 72 - 73

Working with Objects

Properties?Method?Try code on Page 75 and 76

Star Trek Quiz Game

See HandoutChallenge: Modify the StarTrek Quiz so that it displays the correct answer for any question that the player misses

A Logic Primer

Automatic variables : $true, $falseAndOrExclusive (XOR)NotTry code on page 79

Order of Precedence

( )Negate (Not)AndOrXOR

Logical Operator

See table 6-5 on Page 79 - 80Try the code on page80

IF / Else

Remember the flow chart?$Name = “Kemtis”If ($name –eq “Kemtis”){

Write-host “Hello Kemtis!”} else {

Write-host “Hello sir”}

ORIf ($name –eq “Kemtis”){Write-host “Hello Kemtis!” }

IF / ElseIf/Else

If/Elseif/Else$grade = 60If ($grade –ge 90){ Write-host “A”}Else{ If ($grade –ge 80) { Write-host “B”} Else{If ($grade -lt 80){Write-host “F”}}}

IF / ElseIf/Else (3)

If/Elseif/Else#Grade V2.0$grade = 60If ($grade –ge 90){ Write-host “A”}ElseIf ($grade –ge 80) { Write-host “B”}ElseIf ($grade -lt 80){Write-host “F”}

Switch Statement

$size = “M”Switch($size){ “S” {Write-host “Small”} “M” {Write-host “Medium”} “L” {Write-host “Large”} default {Write-host “Unknown”}}

Looping

For loopForEach loopWhile loopDo While loopDo Until loopInfinite loop

For Loop

For ($i =1; $i –le 5; $i++){ Write-Host $i}

ForEach Loop

Foreach ($i in Get-Alias){ Write-Host $i.name}

While Loop

$objRandom = New-Object Random$val = $objRandom.Next(1,10)While ($val –ne 7){ Write-host (“You got a “ + $val + “…”) $val = $objRandom.Next(1,10)}Write-host “Congrat! You got a 7”

Do While Loop

$objRandom = New-Object Randomdo { $val = $objRandom.Next(1,10) Write-host (“You got a “ + $val + “…”)} While ($val –ne 7)Write-host “Congrat! You got a 7”

Do Until Loop

$objRandom = New-Object Randomdo { $val = $objRandom.Next(1,10) Write-host (“You got a “ + $val + “…”)} Until ($val –eq 7)Write-host “Congrat! You got a 7”

Infinite Loop

$objRandom = New-Object Random$val = $objRandom.Next(1,10)While ($val –ne 10){ Write-host (“You got a “ + $val + “…”) $val = $objRandom.Next(1,10)}Write-host “Congrat! You got a 11”

Guess My Number Game

See handoutHomework:

Make the game more intuitive by adding additional instructions and guidance. (IE. You are getting very close)Modify the game to allow the player to quit at any time, instead of just at the end of the current round of play.