PowerShell

All references to PowerShell version 2.0 downloaded May 2010.

1. Getting PowerShell installed 1. What is PowerShell?

PowerShell is a powerful scripting language from Microsoft.

2. How do I get it?

You can download PowerShell 2.0 from here. PowerShell is only officially supported on the Windows platform.

3. How do I start it?

Start Menu / Programs / Accessories / Windows PowerShell / Windows PowerShell

A command window similiar to "cmd" will open and be ready for your input.

2. Interacting with PowerShell

At the command prompt you can enter simple commands like,

PS C:\> 7 * 6 42

PowerShell will try to intelliqently decide when you want multiple line entries:

PS C:\> 7 *>> 6>>42

It will also respect quotes:

PS C:\> "hello"helloPS C:\> "hello>> there">>hellotherePS C:\>

You can force it to expect more input by using the backtick character (`) at the end of the line

PS C:\> 7`>> * 6>>42PS C:\>

The "up" and "down" arrows allow you to scroll through your history and select previous commands, also try "F9".

3. The magic of Tab

When you want PowerShell to suggest a completion to your command enter "Tab"

PS C:>Hel(Tab)

will complete to "help".

4. You can always Escape

If you want to start over on a line just hit "ESC"

5. Comments

The "#" character starts a comment

PS C:\> $g = 9.81 #set value for gravity

6. You can use wildcards in commands 7. PS C:\> cd p*les

PS C:\Program Files>

8. Piping and Redirects

Using the pipe character, "|" you can redirect the output of one command into the input of another. For example, the "Get-ChildItem" command will return a list of files that you can redirect to "Sort-Object" to get a sorted list.

PS C:\> Get-ChildItem | Sort-Object -Property LastWriteTime

Using the ">" character will redirect all the output to a file.

PS C:\> Get-ChildItem | Sort-Object -Property LastWriteTime > SortedFiles.txt

Using ">>" will append to a file.

9. Editing files

To open a file in your editor give part of the path name

PS C:\> .\SortedFiles.txt

10. Storing output in variables

You can execute a command and store the result in a variable (names start with "$").

PS C:\> $a = date.exePS C:\> $aTue May 4 10:00:36 CDT 2010

11. Simple Calculations

PowerShell does simple math:

PS C:\> 7*6

42PS C:\> "abc"*4abcabcabcabcPS C:\> 20mb / 7kb2925.71428571429PS C:\> 6 * 0x77714

12. Executables

Some executable names can be entered into powershell:

PS C:\> tracert fincher.org

Tracing route to fincher.org [208.97.191.221]over a maximum of 30 hops:

1 1 ms <1 ms <1 ms 172.30.78.1 2 1 ms <1 ms <1 ms 192.168.65.26 3 29 ms 28 ms 44 ms 10.255.240.249 4 40 ms 40 ms 40 ms 10.255.240.241

Only some can be entered because not all executables are within the default "Path".

To see what directories are in your path,

PS C:\> $env:PathC:\Program Files\Windows Resource Kits\Tools\;

To add directories,

PS C:\> $env:path += ";C:\home\mfincher\bin"

The "&" preceeding a string tells powershell to execute the string as a command:

PS C:\> & "C:\home\mfincher\bin\backup.exe"

13. Saving your current directory location

Sometimes you need to temporarily change directories. The unix "pushd" and "popd" are availible (aliases for "Push-Location" and "Pop-Location".

PS C:\> pushdPS C:\> cd tmpPS C:\tmp> popdPS C:\>

14. Cmdlets Cmdlets are real powershell commands. They have the form "verb-noun", like "Get-Date". These are the most common verbs:

o Add o Clear o Compare o Convert o Copy o Export o Format o Get o Group o Import

o Measure o Move o New o Out o Read o Remove o Rename o Resolve o Restart o Resume o Select o Set o Sort o Split o Start o Stop o Suspend o Tee o Test o Trace o Update o Write

2. Help

1. The "Get-Command" cmdlet

The command "Get-Command -verb get" will return all the commands with the verb "Get"

PS C:\> Get-Command -verb get

2. Get-Command for cmdlet

This will show all cmdlets

PS C:\home\mfincher> Get-Command -commandType cmdlet

CommandType Name Definition

Cmdlet Add-Computer Add-Computer [-DomainName] <String> [-Credential...

Cmdlet Add-Content Add-Content [-Path] <String[]> [-Value] <Object[...

Cmdlet Add-History Add-History [[-InputObject] <PSObject[]>] [-Pass...

Cmdlet Add-Member Add-Member [-MemberType] <PSMemberTypes> [-Name]...

Cmdlet Add-PSSnapin Add-PSSnapin [-Name] <String[]> [-PassThru] [-Ve...

Cmdlet Add-Type Add-Type [-TypeDefinition] <String> [-Language <...

Cmdlet Checkpoint-Computer Checkpoint-Computer [-Description] <String> [[-R...

Cmdlet Clear-Content Clear-Content [-Path] <String[]> [-Filter <Strin...

Cmdlet Clear-EventLog Clear-EventLog [-LogName] <String[]> [[-Computer...

Cmdlet Clear-History Clear-History [[-Id] <Int32[]>] [[-Count] <Int32...

Cmdlet Clear-Item Clear-Item [-Path] <String[]> [-Force] [-Filter ...

Cmdlet Clear-ItemProperty Clear-ItemProperty [-Path] <String[]> [-Name] <S...

Cmdlet Clear-Variable Clear-Variable [-Name] <String[]> [-Include <Str...

Cmdlet Compare-Object Compare-Object [-ReferenceObject] <PSObject[]> [...

Cmdlet Complete-Transaction Complete-Transaction [-Verbose] [-Debug] [-Error...

Cmdlet Connect-WSMan Connect-WSMan [[-ComputerName] <String>] [-Appli...

Cmdlet ConvertFrom-Csv ConvertFrom-Csv [-InputObject] <PSObject[]> [[-D...

Cmdlet ConvertFrom-SecureString ConvertFrom-SecureString [-SecureString] <Secure...

Cmdlet ConvertFrom-StringData ConvertFrom-StringData [-StringData] <String> [-...

Cmdlet Convert-Path Convert-Path [-Path] <String[]> [-Verbose] [-Deb...

Cmdlet ConvertTo-Csv ConvertTo-Csv [-InputObject] <PSObject> [[-Delim...

Cmdlet ConvertTo-Html ConvertTo-Html [[-Property] <Object[]>] [[-Head]...

Cmdlet ConvertTo-SecureString ConvertTo-SecureString [-String] <String> [[-Sec...

Cmdlet ConvertTo-Xml ConvertTo-Xml [-InputObject] <PSObject> [-Depth ...

Cmdlet Copy-Item Copy-Item [-Path] <String[]> [[-Destination] <St...

Cmdlet Copy-ItemProperty Copy-ItemProperty [-Path] <String[]> [-Destinati...

Cmdlet Debug-Process Debug-Process [-Name] <String[]> [-Verbose] [-De...

Cmdlet Disable-ComputerRestore Disable-ComputerRestore [-Drive] <String[]> [-Ve...

Cmdlet Disable-PSBreakpoint Disable-PSBreakpoint [-Breakpoint] <Breakpoint[]...

Cmdlet Disable-PSSessionConfiguration

Disable-PSSessionConfiguration [[-Name] <String[...

Cmdlet Disable-WSManCredSSP Disable-WSManCredSSP [-Role] <String> [-Verbose]...

Cmdlet Disconnect-WSMan Disconnect-WSMan [[-ComputerName] <String>] [-Ve...

Cmdlet Enable-ComputerRestore Enable-ComputerRestore [-Drive]

<String[]> [-Ver...

Cmdlet Enable-PSBreakpoint Enable-PSBreakpoint [-Id] <Int32[]> [-PassThru] ...

Cmdlet Enable-PSRemoting Enable-PSRemoting [-Force] [-Verbose] [-Debug] [...

Cmdlet Enable-PSSessionConfiguration

Enable-PSSessionConfiguration [[-Name] <String[]...

Cmdlet Enable-WSManCredSSP Enable-WSManCredSSP [-Role] <String> [[-Delegate...

Cmdlet Enter-PSSession Enter-PSSession [-ComputerName] <String> [-Crede...

Cmdlet Exit-PSSession Exit-PSSession [-Verbose] [-Debug] [-ErrorAction...

Cmdlet Export-Alias Export-Alias [-Path] <String> [[-Name] <String[]...

Cmdlet Export-Clixml Export-Clixml [-Path] <String> [-Depth <Int32>] ...

Cmdlet Export-Console Export-Console [[-Path] <String>] [-Force] [-NoC...

Cmdlet Export-Counter Export-Counter [-Path] <String> [-FileFormat <St...

Cmdlet Export-Csv Export-Csv [-Path] <String> [[-Delimiter] <Char>...

Cmdlet Export-FormatData Export-FormatData [-InputObject <ExtendedTypeDef...

Cmdlet Export-ModuleMember Export-ModuleMember [[-Function] <String[]>] [-C...

Cmdlet Export-PSSession Export-PSSession [-Session] <PSSession> [-Output...

Cmdlet ForEach-Object ForEach-Object [-Process] <ScriptBlock[]> [-Inpu...

Cmdlet Format-Custom Format-Custom [[-Property] <Object[]>] [-Depth <...

Cmdlet Format-List Format-List [[-Property] <Object[]>] [-GroupBy <...

Cmdlet Format-Table Format-Table [[-Property] <Object[]>] [-AutoSize...

Cmdlet Format-Wide Format-Wide [[-Property] <Object>] [-AutoSize] [...

Cmdlet Get-Acl Get-Acl [[-Path] <String[]>] [-Audit] [-Filter <...

Cmdlet Get-Alias Get-Alias [[-Name] <String[]>] [-Exclude <String...

Cmdlet Get-AuthenticodeSignature Get-AuthenticodeSignature [-FilePath] <String[]>...

Cmdlet Get-ChildItem Get-ChildItem [[-Path] <String[]>] [[-Filter] <S...

Cmdlet Get-Command Get-Command [[-ArgumentList] <Object[]>] [-Verb ...

Cmdlet Get-ComputerRestorePoint Get-ComputerRestorePoint [[-

RestorePoint] <Int32...

Cmdlet Get-Content Get-Content [-Path] <String[]> [-ReadCount <Int6...

Cmdlet Get-Counter Get-Counter [[-Counter] <String[]>] [-SampleInte...

Cmdlet Get-Credential Get-Credential [-Credential] <PSCredential> [-Ve...

Cmdlet Get-Culture Get-Culture [-Verbose] [-Debug] [-ErrorAction <A...

Cmdlet Get-Date Get-Date [[-Date] <DateTime>] [-Year <Int32>] [-...

Cmdlet Get-Event Get-Event [[-SourceIdentifier] <String>] [-Verbo...

Cmdlet Get-EventLog Get-EventLog [-LogName] <String> [[-InstanceId] ...

Cmdlet Get-EventSubscriber Get-EventSubscriber [[-SourceIdentifier] <String...

Cmdlet Get-ExecutionPolicy Get-ExecutionPolicy [[-Scope] <ExecutionPolicySc...

Cmdlet Get-FormatData Get-FormatData [[-TypeName] <String[]>] [-Verbos...

Cmdlet Get-Help Get-Help [[-Name] <String>] [-Path <String>] [-C...

Cmdlet Get-History Get-History [[-Id] <Int64[]>] [[-Count] <Int32>]...

Cmdlet Get-Host Get-Host [-Verbose] [-Debug] [-ErrorAction <Acti...

Cmdlet Get-HotFix Get-HotFix [[-Id] <String[]>] [-ComputerName <St...

Cmdlet Get-Item Get-Item [-Path] <String[]> [-Filter <String>] [...

Cmdlet Get-ItemProperty Get-ItemProperty [-Path] <String[]> [[-Name] <St...

Cmdlet Get-Job Get-Job [[-Id] <Int32[]>] [-Verbose] [-Debug] [-...

Cmdlet Get-Location Get-Location [-PSProvider <String[]>] [-PSDrive ...

Cmdlet Get-Member Get-Member [[-Name] <String[]>] [-InputObject <P...

Cmdlet Get-Module Get-Module [[-Name] <String[]>] [-All] [-Verbose...

Cmdlet Get-PfxCertificate Get-PfxCertificate [-FilePath] <String[]> [-Verb...

Cmdlet Get-Process Get-Process [[-Name] <String[]>] [-ComputerName ...

Cmdlet Get-PSBreakpoint Get-PSBreakpoint [[-Script] <String[]>] [-Verbos...

Cmdlet Get-PSCallStack Get-PSCallStack [-Verbose] [-Debug] [-ErrorActio...

Cmdlet Get-PSDrive Get-PSDrive [[-Name] <String[]>]

[-Scope <String...

Cmdlet Get-PSProvider Get-PSProvider [[-PSProvider] <String[]>] [-Verb...

Cmdlet Get-PSSession Get-PSSession [[-ComputerName] <String[]>] [-Ver...

Cmdlet Get-PSSessionConfiguration Get-PSSessionConfiguration [[-Name] <String[]>] ...

Cmdlet Get-PSSnapin Get-PSSnapin [[-Name] <String[]>] [-Registered] ...

Cmdlet Get-Random Get-Random [[-Maximum] <Object>] [-SetSeed <Null...

Cmdlet Get-Service Get-Service [[-Name] <String[]>] [-ComputerName ...

Cmdlet Get-TraceSource Get-TraceSource [[-Name] <String[]>] [-Verbose] ...

Cmdlet Get-Transaction Get-Transaction [-Verbose] [-Debug] [-ErrorActio...

Cmdlet Get-UICulture Get-UICulture [-Verbose] [-Debug] [-ErrorAction ...

Cmdlet Get-Unique Get-Unique [-InputObject <PSObject>] [-AsString]...

Cmdlet Get-Variable Get-Variable [[-Name] <String[]>] [-ValueOnly] [...

Cmdlet Get-WinEvent Get-WinEvent [[-LogName] <String[]>] [-MaxEvents...

Cmdlet Get-WmiObject Get-WmiObject [-Class] <String> [[-Property] <St...

Cmdlet Get-WSManCredSSP Get-WSManCredSSP [-Verbose] [-Debug] [-ErrorActi...

Cmdlet Get-WSManInstance Get-WSManInstance [-ResourceURI] <Uri> [-Applica...

Cmdlet Group-Object Group-Object [[-Property] <Object[]>] [-NoElemen...

Cmdlet Import-Alias Import-Alias [-Path] <String> [-Scope <String>] ...

Cmdlet Import-Clixml Import-Clixml [-Path] <String[]> [-Verbose] [-De...

Cmdlet Import-Counter Import-Counter [-Path] <String[]> [-StartTime <D...

Cmdlet Import-Csv Import-Csv [-Path] <String[]> [[-Delimiter] <Cha...

Cmdlet Import-LocalizedData Import-LocalizedData [-BindingVariable] <String>...

Cmdlet Import-Module Import-Module [-Name] <String[]> [-Global] [-Pre...

Cmdlet Import-PSSession Import-PSSession [-Session] <PSSession> [[-Comma...

Cmdlet Invoke-Command Invoke-Command [-ScriptBlock] <ScriptBlock> [-In...

Cmdlet Invoke-Expression Invoke-Expression [-Command]

<String> [-Verbose]...

Cmdlet Invoke-History Invoke-History [[-Id] <String>] [-Verbose] [-Deb...

Cmdlet Invoke-Item Invoke-Item [-Path] <String[]> [-Filter <String>...

Cmdlet Invoke-WmiMethod Invoke-WmiMethod [-Class] <String> [-Name] <Stri...

Cmdlet Invoke-WSManAction Invoke-WSManAction [-ResourceURI] <Uri> [-Action...

Cmdlet Join-Path Join-Path [-Path] <String[]> [-ChildPath] <Strin...

Cmdlet Limit-EventLog Limit-EventLog [-LogName] <String[]> [-ComputerN...

Cmdlet Measure-Command Measure-Command [-Expression] <ScriptBlock> [-In...

Cmdlet Measure-Object Measure-Object [[-Property] <String[]>] [-InputO...

Cmdlet Move-Item Move-Item [-Path] <String[]> [[-Destination] <St...

Cmdlet Move-ItemProperty Move-ItemProperty [-Path] <String[]> [-Destinati...

Cmdlet New-Alias New-Alias [-Name] <String> [-Value] <String> [-D...

Cmdlet New-Event New-Event [-SourceIdentifier] <String> [[-Sender...

Cmdlet New-EventLog New-EventLog [-LogName] <String> [-Source] <Stri...

Cmdlet New-Item New-Item [-Path] <String[]> [-ItemType <String>]...

Cmdlet New-ItemProperty New-ItemProperty [-Path] <String[]> [-Name] <Str...

Cmdlet New-Module New-Module [-ScriptBlock] <ScriptBlock> [-Functi...

Cmdlet New-ModuleManifest New-ModuleManifest [-Path] <String> -NestedModul...

Cmdlet New-Object New-Object [-TypeName] <String> [[-ArgumentList]...

Cmdlet New-PSDrive New-PSDrive [-Name] <String> [-PSProvider] <Stri...

Cmdlet New-PSSession New-PSSession [[-ComputerName] <String[]>] [-Cre...

Cmdlet New-PSSessionOption New-PSSessionOption [-MaximumRedirection <Int32>...

Cmdlet New-Service New-Service [-Name] <String> [-BinaryPathName] <...

Cmdlet New-TimeSpan New-TimeSpan [[-Start] <DateTime>] [[-End] <Date...

Cmdlet New-Variable New-Variable [-Name] <String> [[-Value] <Object>...

Cmdlet New-WebServiceProxy New-WebServiceProxy [-Uri]

<Uri> [[-Class] <Stri...

Cmdlet New-WSManInstance New-WSManInstance [-ResourceURI] <Uri> [-Selecto...

Cmdlet New-WSManSessionOption New-WSManSessionOption [-ProxyAccessType <ProxyA...

Cmdlet Out-Default Out-Default [-InputObject <PSObject>] [-Verbose]...

Cmdlet Out-File Out-File [-FilePath] <String> [[-Encoding] <Stri...

Cmdlet Out-GridView Out-GridView [-InputObject <PSObject>] [-Title <...

Cmdlet Out-Host Out-Host [-Paging] [-InputObject <PSObject>] [-V...

Cmdlet Out-Null Out-Null [-InputObject <PSObject>] [-Verbose] [-...

Cmdlet Out-Printer Out-Printer [[-Name] <String>] [-InputObject <PS...

Cmdlet Out-String Out-String [-Stream] [-Width <Int32>] [-InputObj...

Cmdlet Pop-Location Pop-Location [-PassThru] [-StackName <String>] [...

Cmdlet Push-Location Push-Location [[-Path] <String>] [-PassThru] [-S...

Cmdlet Read-Host Read-Host [[-Prompt] <Object>] [-AsSecureString]...

Cmdlet Receive-Job Receive-Job [-Job] <Job[]> [[-Location] <String[...

Cmdlet Register-EngineEvent Register-EngineEvent [-SourceIdentifier] <String...

Cmdlet Register-ObjectEvent Register-ObjectEvent [-InputObject] <PSObject> [...

Cmdlet Register-PSSessionConfiguration

Register-PSSessionConfiguration [-Name] <String>...

Cmdlet Register-WmiEvent Register-WmiEvent [-Class] <String> [[-SourceIde...

Cmdlet Remove-Computer Remove-Computer [[-Credential] <PSCredential>] [...

Cmdlet Remove-Event Remove-Event [-SourceIdentifier] <String> [-Verb...

Cmdlet Remove-EventLog Remove-EventLog [-LogName] <String[]> [[-Compute...

Cmdlet Remove-Item Remove-Item [-Path] <String[]> [-Filter <String>...

Cmdlet Remove-ItemProperty Remove-ItemProperty [-Path] <String[]> [-Name] <...

Cmdlet Remove-Job Remove-Job [-Id] <Int32[]> [-Force] [-Verbose] [...

Cmdlet Remove-Module Remove-Module [-Name] <String[]> [-Force] [-Verb...

Cmdlet Remove-PSBreakpoint Remove-PSBreakpoint [-

Breakpoint] <Breakpoint[]>...

Cmdlet Remove-PSDrive Remove-PSDrive [-Name] <String[]> [-PSProvider <...

Cmdlet Remove-PSSession Remove-PSSession [-Id] <Int32[]> [-Verbose] [-De...

Cmdlet Remove-PSSnapin Remove-PSSnapin [-Name] <String[]> [-PassThru] [...

Cmdlet Remove-Variable Remove-Variable [-Name] <String[]> [-Include <St...

Cmdlet Remove-WmiObject Remove-WmiObject [-Class] <String> [-AsJob] [-Im...

Cmdlet Remove-WSManInstance Remove-WSManInstance [-ResourceURI] <Uri> [-Sele...

Cmdlet Rename-Item Rename-Item [-Path] <String> [-NewName] <String>...

Cmdlet Rename-ItemProperty Rename-ItemProperty [-Path] <String> [-Name] <St...

Cmdlet Reset-ComputerMachinePassword

Reset-ComputerMachinePassword [-Server <String>]...

Cmdlet Resolve-Path Resolve-Path [-Path] <String[]> [-Relative] [-Cr...

Cmdlet Restart-Computer Restart-Computer [[-ComputerName] <String[]>] [[...

Cmdlet Restart-Service Restart-Service [-Name] <String[]> [-Force] [-Pa...

Cmdlet Restore-Computer Restore-Computer [-RestorePoint] <Int32> [-Verbo...

Cmdlet Resume-Service Resume-Service [-Name] <String[]> [-PassThru] [-...

Cmdlet Select-Object Select-Object [[-Property] <Object[]>] [-InputOb...

Cmdlet Select-String Select-String [-Pattern] <String[]> -InputObject...

Cmdlet Select-Xml Select-Xml [-XPath] <String> [-Xml] <XmlNode[]> ...

Cmdlet Send-MailMessage Send-MailMessage [-To] <String[]> [-Subject] <St...

Cmdlet Set-Acl Set-Acl [-Path] <String[]> [-AclObject] <ObjectS...

Cmdlet Set-Alias Set-Alias [-Name] <String> [-Value] <String> [-D...

Cmdlet Set-AuthenticodeSignature Set-AuthenticodeSignature [-FilePath] <String[]>...

Cmdlet Set-Content Set-Content [-Path] <String[]> [-Value] <Object[...

Cmdlet Set-Date Set-Date [-Date] <DateTime> [-DisplayHint <Displ...

Cmdlet Set-ExecutionPolicy Set-ExecutionPolicy [-ExecutionPolicy] <Executio...

Cmdlet Set-Item Set-Item [-Path] <String[]> [[-

Value] <Object>] ...

Cmdlet Set-ItemProperty Set-ItemProperty [-Path] <String[]> [-Name] <Str...

Cmdlet Set-Location Set-Location [[-Path] <String>] [-PassThru] [-Ve...

Cmdlet Set-PSBreakpoint Set-PSBreakpoint [-Script] <String[]> [-Line] <I...

Cmdlet Set-PSDebug Set-PSDebug [-Trace <Int32>] [-Step] [-Strict] [...

Cmdlet Set-PSSessionConfiguration Set-PSSessionConfiguration [-Name] <String> [-Ap...

Cmdlet Set-Service Set-Service [-Name] <String> [-ComputerName <Str...

Cmdlet Set-StrictMode Set-StrictMode -Version <Version> [-Verbose] [-D...

Cmdlet Set-TraceSource Set-TraceSource [-Name] <String[]> [[-Option] <P...

Cmdlet Set-Variable Set-Variable [-Name] <String[]> [[-Value] <Objec...

Cmdlet Set-WmiInstance Set-WmiInstance [-Class] <String> [[-Arguments] ...

Cmdlet Set-WSManInstance Set-WSManInstance [-ResourceURI] <Uri> [[-Select...

Cmdlet Set-WSManQuickConfig Set-WSManQuickConfig [-UseSSL] [-Force] [-Verbos...

Cmdlet Show-EventLog Show-EventLog [[-ComputerName] <String>] [-Verbo...

Cmdlet Sort-Object Sort-Object [[-Property] <Object[]>] [-Descendin...

Cmdlet Split-Path Split-Path [-Path] <String[]> [-LiteralPath <Str...

Cmdlet Start-Job Start-Job [-ScriptBlock] <ScriptBlock> [[-Initia...

Cmdlet Start-Process Start-Process [-FilePath] <String> [[-ArgumentLi...

Cmdlet Start-Service Start-Service [-Name] <String[]> [-PassThru] [-I...

Cmdlet Start-Sleep Start-Sleep [-Seconds] <Int32> [-Verbose] [-Debu...

Cmdlet Start-Transaction Start-Transaction [-Timeout <Int32>] [-Independe...

Cmdlet Start-Transcript Start-Transcript [[-Path] <String>] [-Append] [-...

Cmdlet Stop-Computer Stop-Computer [[-ComputerName] <String[]>] [[-Cr...

Cmdlet Stop-Job Stop-Job [-Id] <Int32[]> [-PassThru] [-Verbose] ...

Cmdlet Stop-Process Stop-Process [-Id] <Int32[]> [-PassThru] [-Force...

Cmdlet Stop-Service Stop-Service [-Name] <String[]> [-Force] [-PassT...

Cmdlet Stop-Transcript Stop-Transcript [-Verbose] [-Debug] [-ErrorActio...

Cmdlet Suspend-Service Suspend-Service [-Name] <String[]> [-PassThru] [...

Cmdlet Tee-Object Tee-Object [-FilePath] <String> [-InputObject <P...

Cmdlet Test-ComputerSecureChannel Test-ComputerSecureChannel [-Repair] [-Server <S...

Cmdlet Test-Connection Test-Connection [-ComputerName] <String[]> [[-So...

Cmdlet Test-ModuleManifest Test-ModuleManifest [-Path] <String> [-Verbose] ...

Cmdlet Test-Path Test-Path [-Path] <String[]> [-Filter <String>] ...

Cmdlet Test-WSMan Test-WSMan [[-ComputerName] <String>] [-Authenti...

Cmdlet Trace-Command Trace-Command [-Name] <String[]> [-Expression] <...

Cmdlet Undo-Transaction Undo-Transaction [-Verbose] [-Debug] [-ErrorActi...

Cmdlet Unregister-Event Unregister-Event [-SourceIdentifier] <String> [-...

Cmdlet Unregister-PSSessionConfiguration

Unregister-PSSessionConfiguration [-Name] <Strin...

Cmdlet Update-FormatData Update-FormatData [[-AppendPath] <String[]>] [-P...

Cmdlet Update-List Update-List [[-Property] <String>] [-Add <Object...

Cmdlet Update-TypeData Update-TypeData [[-AppendPath] <String[]>] [-Pre...

Cmdlet Use-Transaction Use-Transaction [-TransactedScript] <ScriptBlock...

Cmdlet Wait-Event Wait-Event [[-SourceIdentifier] <String>] [-Time...

Cmdlet Wait-Job Wait-Job [-Id] <Int32[]> [-Any] [-Timeout <Int32...

Cmdlet Wait-Process Wait-Process [-Name] <String[]> [[-Timeout] <Int...

Cmdlet Where-Object Where-Object [-FilterScript] <ScriptBlock> [-Inp...

Cmdlet Write-Debug Write-Debug [-Message] <String> [-Verbose] [-Deb...

Cmdlet Write-Error Write-Error [-Message] <String> [-Category <Erro...

Cmdlet Write-EventLog Write-EventLog [-LogName] <String> [-Source] <St...

Cmdlet Write-Host Write-Host [[-Object] <Object>] [-NoNewline] [-S...

Cmdlet Write-Output Write-Output [-InputObject] <PSObject[]> [-Verbo...

Cmdlet Write-Progress Write-Progress [-Activity] <String> [-Status] <S...

Cmdlet Write-Verbose Write-Verbose [-Message] <String> [-Verbose] [-D...

Cmdlet Write-Warning Write-Warning [-Message] <String> [-Verbose] [-D...

3. Help on individual commands

Use the "Get-Help" command followed by the command. (add "-detailed" for way more info than you need).

PS C:\> Get-Help Get-Process

4. Wildcards

You can use a wildcard "*" to expand the results. For example, "Get-Command *" will return all commands (5,426 on my machine, your results will vary).

5. Parameters

PowerShell has 3 types of parameters: Named, Switch, and Positional.

1. Named

Named parameters start with a "-" followed by the name, a space, and a value. They are like adding named value pairs to your cmdlet.

Get-ChildItem -path "C:\Program Files"

2. Switch

Switch parameters turn a feature "on" or "off". They have no value following themselves.

Get-ChildItem -recurse

3. Positional

Positional parameters follow a command in certain positions. For example, below "C:\home\mfincher" is the first position and "*.txt" is the second.

PS C:\home\mfincher> Get-ChildItem "C:\home\mfincher" *.txt

Directory: C:\home\mfincher

Mode LastWriteTime Length Name---- ------------- ------ -----a--- 11/15/2004 2:22 PM 392 ant.txt-a--- 11/7/2001 8:18 AM 4059 ascii.txt-a--- 10/10/2002 2:40 PM 13143 Day.txt-a--- 1/21/2010 1:50 PM 0 Defrag_2010-01-21-13-50-33.42.txt

The above command is the same as below, which explicitly tells the cmdlet what the parameters are:

Get-ChildItem -path "C:\home\mfincher" -filter *.txt

If you look for help on the "path" named parameter, it will tell you it has a postion of "1", meaning you can omit the "-path" and PowerShell will assume the first paramter is "path"

PS C:\home\mfincher> Get-Help Get-ChildItem -parameter path

-Path <string[]> Specifies a path to one or more locations. Wildcards are permitted. The default location is the current directory ( .).

Required? false Position? 1 Default value Accept pipeline input? true (ByValue, ByPropertyName) Accept wildcard characters? false

Parameters themselves can be abbreviated to their shortest, non-ambiguous length.

Get-ChildItem -pa "C:\home\mfincher" -fil *.txt

4. Common Parameters

All cmdlets can accept these common parameters: -Verbose, -Debug, -ErrorAction, -ErrorVariable, and -OutVariable. Enter "get-help about_commonparameters" for more details.

To see parameters use the "-full" parameter:

PS C:\> Get-Help Get-ChildItem -full

example:

PS C:\> get-childitem . -include *.exe -recurse -force

15. Aliases

Just as we give our friends and family members nicknames, you can assign a shorthand term for PowerShell commands.

Since typing "Get-ChildItem" is rather tedious, let's give it an alias of "l".

PS C:\> Set-Alias l Get-ChildItem

Now, whenever I type "l" PowerShell will list all the files in the current directory.

To see what an alias represents use the "Get-alias" command. Use with no arguments to get them all.

PS C:\> Get-Alias -name l

CommandType Name Definition----------- ---- ----------

Alias l Get-ChildItem

You can also use $alias: format. $

PS C:\> $alias:lGet-ChildItem

16. Functions

Functions are more powerful than aliases. You can do multiple lines and pass in arguments. Let's assume you want to see all processes containing "devenv".

PS C:\> Get-Process | Out-String -Stream | Select-String "devenv"PS C:\> function proc { Get-Process | Out-String -Stream | Select-String "devenv" }

Produces:

PS C:\> proc

713 30 51768 85420 285 4.42 532 devenv 1538 56 193080 207940 643 20.95 4884 devenv

You can use "$args" in a function definition to pass in arguments making it more flexible

PS C:\> function proc { Get-Process | Out-String -Stream | Select-String $args }PS C:\> proc emacs

96 4 18668 20220 300 855.55 352 emacs

17. Creating PowerShell scripts

PowerShell scripts have the extension "ps1". Let's create one called "gd.ps1" and enter the following command into it. This should be in a directory that is in your PATH variable.

Get-Date

Let's run it.

PS C:\> gdFile C:\home\mfincher\bin\gd.ps1 cannot be loaded because the execution of scripts is disabled on this system. Please see "get-help about_signing" for more details.At line:1 char:3+ gd <<<< + CategoryInfo : NotSpecified: (:) [], PSSecurityException + FullyQualifiedErrorId : RuntimeException

Hmm.. We need to add permission to have a local PowerShell script run.

Set-ExecutionPolicy RemoteSigned

Now, it runs and shows the date

PS C:\> gd

Friday, June 18, 2010 2:21:13 PM

18. Command Hierarchy

PowerShell searches the following in order when interpreting a command: Alias, Function, Cmdlet, Application, Script, Files.

19. Virtual Drives

A virtual drive is a datastore that is treated as a real drive with a tree structure of items. Some examples are "env", "Function", "C", "Alias", and "HKCU". The contents of virtual drives can be listing by using "dir", "ls", or "Get-ChildItem". "Get-PSProvider" will show all PSProviders and their virtual drives.

PS C:\> get-PSProvider

Name Capabilities Drives---- ------------ ------WSMan Credentials {WSMan}Alias ShouldProcess {Alias}Environment ShouldProcess {Env}FileSystem Filter, ShouldProcess {C, D, M}Function ShouldProcess {Function}Registry ShouldProcess, Transactions {HKLM, HKCU}Variable ShouldProcess {Variable}Certificate ShouldProcess {cert}

20. Variables

6. Basics

Varibles names start with "$" and contain letters, numbers, or the underscore "_" and are case-insensitive. Variables can contain simple objects like strings and integers, or complex objects.

PS C:\> $name = "Inigo Montoya"PS C:\> $secs = 6PS C:\> "My name is $name, you killed my father, prepare to die in $secs seconds"My name is Inigo Montoya, you killed my father, prepare to die in 6 seconds

If you must have strange characters in a variable name, enclose the name in curly braces

PS C:\> ${my variable with wierd $%^ characters} = "Howdy"PS C:\> ${my variable with wierd $%^ characters}Howdy

or complex objects

PS C:\> $myfiles = Get-ChildItemPS C:\> $myfiles

Directory: C:\

Mode LastWriteTime Length Name---- ------------- ------ ----d---- 8/10/2009 11:09 AM 8ac45b2e935881d6d92e68d---- 11/21/2003 10:00 AM alphabloxd---- 8/11/2008 3:14 PM Cheops3d---- 6/1/2007 4:13 PM delld---- 9/25/2009 4:54 AM Documents and Settingsd---- 2/19/2007 2:56 PM driversd---- 7/16/2009 3:55 PM e-tabsd---- 2/20/2006 7:08 PM edd---- 10/9/2009 3:13 PM home

7. Multiple variables can be set at the same time. 8. PS C:\> $a = $b = $c = 0

9. Multiple variables can be set on one line 10. PS C:\> $one,$two,$three = 1,2,3

11. Swapping values

Using the comma syntax below you can swap the contents of two variables

PS C:\> $var1 = 1; $var2 = 2;PS C:\> $var1, $var2 = $var2, $var1PS C:\> $var12

12. Directory of Variables

PowerShell remembers all your variables in the "variable" virtual drive. More on these below. You can get a list of variables using "dir variable:". (I've removed some of them).

PS C:\> dir variable:

Name Value---- -----a 0b 0c 0myfiles {8ac45b2e935881d6d92e68, alphablox, Cheops3, dell...}name Inigo Montoyaone 1secs 6three 3two 2var1 2var2 1

13. Does a variable exist?

Use the Test-Path cmdlet with the "variable" virtual drive.

PS C:\> Test-Path variable:oneTruePS C:\> Test-Path variable:four

False

14. Variable Meta-data

Using "New-Variable" you can set metadata associated with a variable.

PS C:\> New-Variable life -value 42 -Description "Meaning of life, the universe and everything."

To see the description you can use "Format-Table"

PS C:\> dir variable:\life | Format-Table Name, Value, Description -autosize

Name Value Description---- ----- -----------life 42 Meaning of life, the universe and everything.

15. Readonly

You can set a variable to be readonly. Let's delete our old variable first.

PS C:\> del variable:\lifePS C:\> New-Variable life -value 42 -option ReadOnlyPS C:\> $life42PS C:\> $life = 43Cannot overwrite variable life because it is read-only or constant.At line:1 char:6+ $life <<<< = 43 + CategoryInfo : WriteError: (life:String) [], SessionStateUnauthorizedAccessException + FullyQualifiedErrorId : VariableNotWritable

16. Deleting Variables

To delete we use "-force"

PS C:\> del variable:\life -force

17. Constants

For variables that really are constants we can use the "Constant" option.

PS C:\> New-Variable gravity -value 9.81 -option ConstantPS C:\> del variable:\gravity -forceRemove-Item : Cannot remove variable gravity because it is constant or read-only. If the variable is read-only, try the operation again specifying the Force option.At line:1 char:4+ del <<<< variable:\gravity -force + CategoryInfo : WriteError: (gravity:String) [Remove-Item], SessionStateUnauthorizedAccessException + FullyQualifiedErrorId : VariableNotRemovable,Microsoft.PowerShell.Commands.RemoveItemCommand

18. System Variables

PowerShell uses internal variables some of which are shown below:

PS C:\> dir variable: | Sort-Object Name | Format-Table Name, Description -autosize

Name Description---- -----------$? Execution status of last command.^_aamountargsbcConfirmPreference Dictates when confirmation should be requested. Confirmation is requested when the Con...ConsoleFileName Name of the current console file.DebugPreference Dictates action taken when an Debug message is delivered.ErrorErrorActionPreference Dictates action taken when an Error message is delivered.ErrorView Dictates the view mode to use when displaying errors.ExecutionContext The execution objects available to cmdlets.

19. Environmental Variables

The virtual drive "$env:" contains the environmental variables.

PS C:\> $env:PATHC:\Program Files\Windows Resource Kits\Tools\;c:\program files\imagemagick-6.3.6-q16;C:\WINDOWS\SYSTEM32;C:\WINDOWS;C:\WINDOWS\SYSTEM32\WBEM;C:\MINGPATH;C:\E-TABS\BIN;C:\PROGRAM FILES\ATI TECHNOLOGIES\ATI CONTROL PANEL;c:\mingspec;C:\Prog

20. Operations on Environmental Variables

These only affect your processes local copy, not the system's values

PS C:\> $env:myNewEnvVar = 12 #create a new environmental variablePS C:\> del env:\CLASSPATH #deletes the environmental variablePS C:\> $env:TMP = "C:\NewTemp" #replace the contents of an environmental variablePS C:\> $env:PATH += ";C:\newBinDir" # append to variable

21. Encoding

PowerShell by default uses Unicode. So when you do something like this it will write in Unicode

PS C:\> get-date >> t1.txt

Produces:

Monday, June 21, 2010 2:52:25 PM

but if you are using an older text editor you may see this:

Produces:

^M^@

^@M^@o^@n^@d^@a^@y^@,^@ ^@J^@u^@n^@e^@ ^@2^@1^@,^@ ^@2^@0^@1^@0^@ ^@2^@:^@5^@2^@:^@2^@5^@ ^@P^@M^@^M^@^@

Using and Encoding option will let you write in something other than Unicode.

PS C:\> get-date | Out-File -Encoding UTF8 c:\t1.txt

22. To view the contents of a file

Either of these will work:

PS C:\> cat "C:\defrag.txt"PS C:\> ${c:\defrag.txt}

23. PS C:\> echo "testme" > "$env:TEMP\temp.tmp"24. PS C:\> cat "$env:TEMO\temp.tmp"25. Get-Content : Cannot find path 'C:\temp.tmp' because it does not26. At line:1 char:427. + cat <<<< "$env:TEMO\temp.tmp"28. + CategoryInfo : ObjectNotFound: (C:\temp.tmp:Strin29. + FullyQualifiedErrorId : PathNotFound,Microsoft.PowerShell.30.31. PS C:\> cat C:\temp.tmp32. Get-Content : Cannot find path 'C:\temp.tmp' because it does not33. At line:1 char:434. + cat <<<< C:\temp.tmp35. + CategoryInfo : ObjectNotFound: (C:\temp.tmp:Strin36. + FullyQualifiedErrorId : PathNotFound,Microsoft.PowerShell.37.38. PS C:\> cat "C:\temp.tmp"39. Get-Content : Cannot find path 'C:\temp.tmp' because it does not40. At line:1 char:441. + cat <<<< "C:\temp.tmp"42. + CategoryInfo : ObjectNotFound: (C:\temp.tmp:Strin43. + FullyQualifiedErrorId : PathNotFound,Microsoft.PowerShell.44.45. PS C:\> echo "$env:TEMP"46. c:\windows\temp47. PS C:\> $mycommand = 'echo "testme" > "$env:TEMP\temp.tmp"'48. PS C:\> Invoke-Expression $mycommand49. PS C:\> cat "C:\windows\temp\temp.tmp"50. testme51. PS C:\>

52.53. To see code behind a function

Enter the name of the function and PowerShell will return the code

PS C:\> $function:prompt$(if (test-path variable:/PSDebugContext) { '[DBG]: ' } else { '' }) + 'PS ' + $(Get-Location) + $(if ($nestedpromptlevel -ge 1) { '>>' }) + '> '

54. Variable Scope

Variables and functions in PowerShell have a scope in which they are accessible. PowerShell has four scopes (from "Get-Help scope"):

Global: The scope that is in effect when Windows PowerShell starts. Variables and functions that are present when Windows PowerShell starts have been created in the global scope. This includes automatic variables and

preference variables. This also includes the variables, aliases, and functions that are in your Windows PowerShell profiles.

Local: The current scope. The local scope can be the global scope or any other scope.

Script: The scope that is created while a script file runs. Only the commands in the script run in the script scope. To the commands in a script, the script scope is the local scope.

Private: Items in private scope cannot be seen outside of the current scope. You can use private scope to create a private version of an item with the same name in another scope.

Numbered Scopes: You can refer to scopes by name or by a number that describes the relative position of one scope to another. Scope 0 represents the current, or local, scope. Scope 1 indicates the immediate parent scope. Scope 2 indicates the parent of the parent scope, and so on. Numbered scopes are useful if you have created many recursive scopes.

You can modify the scope of a variable or function by prefacing its name with the scope, $global:rate, $local:cost.

variables inside scripts by default have a local scope. After they run the outer environment is unchanged.

test.ps1:$song = "Hero"

PS C:\home\mfincher> $song = "Mirror, Mirror"PS C:\home\mfincher> .\test.ps1PS C:\home\mfincher> $song

Now if we change our tiny script we get the following:

test.ps1:$global:song = "Hero"

PS C:\home\mfincher> .\test.ps1PS C:\home\mfincher> $songHero

55. Types PowerShell is a weakly typed language, it tries to assign a type to a variable based on usage. To see the type use ".Get-Type().Name"

56. $song.GetType().Name57. String58. PS C:\home\mfincher> (12).GetType().Name59. Int3260. PS C:\home\mfincher> (12.6).GetType().Name61. Double

You can specify a date by prepending the variable with "[" type "]" as shown below. This allows you to access member methods.

PS C:\home\mfincher> $date = "January 1, 2012"PS C:\home\mfincher> $date.GetType().NameStringPS C:\home\mfincher> [datetime]$realdate = "Janaury 1, 2010"PS C:\home\mfincher> $realdate.DayOfWeekFriday

Common Types: array, bool, byte, char, datetime, decimal, double, guid, hashtable, int16, int32, int64, nullable, psobject, regex, regex, sbyte, single, string, switch, timespan, type, uint16, uint32, uint64, xml

Declaring a variable to be XML datatype brings many advantages

PS C:\home\mfincher> [xml]$periodic = "<atoms>" +>> "<atom name='actinium' atomic_number='89'></atom>" +>> "<atom name='aluminum' atomic_number='13'></atom>" +>> "</atoms>">>PS C:\home\mfincher> $periodic.atoms

atom----{actinium, aluminum}

PS C:\home\mfincher> $periodic.atoms.atom

name atomic_number---- -------------actinium 89aluminum 13

PS C:\home\mfincher> $periodic.atoms.atom[0]

name atomic_number---- -------------actinium 89

PS C:\home\mfincher> $periodic.atoms.atom[0].atomic_number89

62. PSVariables

When you create a variable, PowerShell creates a backend object to store information about the variable - it's value is only the tip of the iceberg. You can get at the real variable object by using "Get-Variable".

PS C:\home\mfincher> $psvar = Get-Variable periodicPS C:\home\mfincher> $psvar | Format-List

Name : periodicDescription :Value : #documentVisibility : PublicModule :ModuleName :Options : NoneAttributes : {System.Management.Automation.ArgumentTypeConverterAttribute}

You can even change properties of the variable by modifying its PSVariable.

PS C:\home\mfincher> $psvar.Description = "Periodic table, well the first two elements"PS C:\home\mfincher> $psvar | Format-List

Name : periodicDescription : Periodic table, well the first two elementsValue : #documentVisibility : PublicModule :ModuleName :Options : NoneAttributes : {System.Management.Automation.ArgumentTypeConverterAttribute}

You can also set its "Options" to "None", "ReadOnly", "Constant", "Private", or "AllScope":

PS C:\home\mfincher> $psvar.OptionsNonePS C:\home\mfincher> $psvar.Options = "Private"

63. Validating Variables

An interesting feature of PowerShell is variable validation. You can set a variable to have a range of length, match a regular expression, be between a range of values, or be in a set of values. Below is a simple example of using regular expressions.

$phonenum = "622-333-3444"$varObject = Get-Variable phonenum$pattern = "[0-9]{3}-[0-9]{3}-[0-9]{4}"$varObject.Attributes.Add($(New-Object System.Management.Automation.ValidatePatternAttribute -argumentList $pattern))$phonenum = "444-332-3433"$phonenum = "AR4-332-3433" #bad

64. Arrays

21. Basics

PowerShell commands return arrays when more than one object is returned.

PS C:\home\mfincher> $myfiles = dir c:\PS C:\home\mfincher> $myfiles

Directory: C:\

Mode LastWriteTime Length Name---- ------------- ------ ----d---- 8/10/2009 11:09 AM 8ac45b2e935881d6d92e68d---- 11/21/2003 10:00 AM alphabloxd---- 8/11/2008 3:14 PM Cheops3d---- 6/1/2007 4:13 PM dell

d---- 9/25/2009 4:54 AM Documents and Settings...

PS C:\home\mfincher> $myfiles.Count67PS C:\home\mfincher> $myfiles -is [Array]True

You can access an individal element with [num].

PS C:\home\mfincher> $myfiles[3]

Directory: C:\

Mode LastWriteTime Length Name---- ------------- ------ ----d---- 6/1/2007 4:13 PM dell

22. PowerShell almost always return an array

PowerShell will return a single object if only one object is returned. This could be a little confusing to your programs because it returns arrays sometimes and single objects at other times. For example above "dir c:" returned an array, but below it returns a single object.

PS C:\home\mfincher> $myfiles = dir c:\del*PS C:\home\mfincher> $myfiles.CountPS C:\home\mfincher> $myfiles

Directory: C:\

Mode LastWriteTime Length Name---- ------------- ------ ----d---- 6/1/2007 4:13 PM dell

PS C:\home\mfincher> $myfiles -is [Array]False

To force a command to return an array use @().

PS C:\home\mfincher> $myfiles = @(dir c:\del*)PS C:\home\mfincher> $myfiles -is [Array]TruePS C:\home\mfincher> $myfiles.Count1

23. Piping

The "|" character will pipe the contents of one command to another. With each line being its own object, you can search for a particular string in the output like this to find all files modified in 2009 (well, and all files that contain "/2009" in their name too).

PS C:\home\mfincher> $myfiles = dir c:\PS C:\home\mfincher> $myfiles | Select-String "/2009"

C:\SortedFiles.txt:38:d---- 2/12/2009 3:13 PM switchboardC:\SortedFiles.txt:39:-a--- 4/10/2009 10:14 AM 422 Shortcut to installs.lnkC:\SortedFiles.txt:40:d---- 5/11/2009 1:30 PM TEMPC:\SortedFiles.txt:41:d---- 7/16/2009 3:26 PM tmpsdC:\SortedFiles.txt:42:d---- 7/16/2009 3:55 PM e-tabs

24. Piping objects

While traditional shells like 'sh', 'csh', and bash process raw text, PowerShell processes objects. This is very cool.

PS C:\home\mfincher> $jobs = psPS C:\home\mfincher> $jobs

Handles NPM(K) PM(K) WS(K) VM(M) CPU(s) Id ProcessName------- ------ ----- ----- ----- ------ -- ----------- 294 10 6364 14656 68 0.75 5516 AdobeARM 108 5 1512 5740 33 0.06 2196 alg 258 4 1832 300 46 10.80 6040 ALMon 162 4 1756 1872 37 15.59 3040 ALsvc...

PS C:\home\mfincher> $jobs[1]

Handles NPM(K) PM(K) WS(K) VM(M) CPU(s) Id ProcessName------- ------ ----- ----- ----- ------ -- ----------- 108 5 1512 5740 33 0.06 2196 alg

PS C:\home\mfincher> $jobs[1] | Format-List *

__NounName : ProcessName : algHandles : 108VM : 34553856WS : 5877760PM : 1548288NPM : 5448Path : C:\WINDOWS\System32\alg.exeCompany : Microsoft Corporation... :

25. How to create an array26. PS C:\home\mfincher> $one2five = 1,2,3,4,527. PS C:\home\mfincher> $one2five28. 129. 230. 331. 432. 533. PS C:\home\mfincher> $one2file = 1..534. PS C:\home\mfincher> $one2five35. 1

36. 237. 338. 439. 5

Arrays can contain objects of different types

PS C:\home\mfincher> $mydate = "January 1, 2012", 1, 1, 2012PS C:\home\mfincher> $mydateJanuary 1, 2012112012

How to create an array of length 1 or empty

PS C:\home\mfincher> $one = @(1)PS C:\home\mfincher> $one.Length1PS C:\home\mfincher> $one -is [Array]TruePS C:\home\mfincher> $empty = @()PS C:\home\mfincher> $empty.Length0

40. Accessing the last element of an array

Like Ruby, PowerShell lets you access the last element by using a negative index

PS C:\home\mfincher> $colors = "red","green","blue"PS C:\home\mfincher> $colors[-1]bluePS C:\home\mfincher> $colors[-2]greenPS C:\home\mfincher> $colors[0]redPS C:\home\mfincher>

If you go to far negative, nothing is returned

PS C:\home\mfincher> $colors[-5]PS C:\home\mfincher>

41. Access multiple elements

Simply by using a comma separated list you can create a subset of an existing array.

PS C:\home\mfincher> $colors[1,2]greenblue

42. Reverse elements43. PS C:\home\mfincher> $colors[2..0]44. blue45. green46. red

47. Adding elements

The "+=" operator creates a new array with one more element and copies the old contents to the new array

PS C:\home\mfincher> $colors += "yellow"PS C:\home\mfincher> $colorsredgreenblueyellow

48. Hashtables

Hashtables are pretty much what you'd expect. You can access an element either with brackets, var["key"], or with dot notation, var.key. The brackets has to have the double quotes, the dot notation does not.

PS C:\home\mfincher> $capitals = @{Alabama = "Montgomery"; Alaska = "Juneau"; Arizona = "Phoenix"}PS C:\home\mfincher> $capitals

Name Value---- -----Alaska JuneauArizona PhoenixAlabama Montgomery

PS C:\home\mfincher> $capitals["Alaska"]JuneauPS C:\home\mfincher> $capitals.Alaska #using dot notationJuneauPS C:\home\mfincher> $capitals.keysAlaskaArizonaAlabamaPS C:\home\mfincher> $southern = "Alabama"PS C:\home\mfincher> $capitals.$southernMontgomery

You can add hashtable elements with either bracket or dot notation:

PS C:\home\mfincher> $capitals["Arkansas"] = "Little Rock"PS C:\home\mfincher> $capitals.Arkansas = "Little Rock"

"Remove" removes the hashtable entry

PS C:\home\mfincher> $capitals."Puerto Rico" = "San Juan"PS C:\home\mfincher> $capitals

Name Value---- -----Puerto Rico San JuanAlaska JuneauArkansas Little RockArizona PhoenixAlabama Montgomery

PS C:\home\mfincher> $capitals.Remove("Puerto Rico")PS C:\home\mfincher> $capitals

Name Value---- -----Alaska JuneauArkansas Little RockArizona Phoenix

Alabama Montgomery

49. Copying Arrays

An array variable really only contains a pointer to the real array object. When you assign one array to another you are merely copying the pointer to the array, not the contents of the array. Use the "Clone()" method to create a copy.

PS C:\home\mfincher> $colors2 = $colorsPS C:\home\mfincher> $colors2redgreenblueyellowPS C:\home\mfincher> $colors[0] = "pink"PS C:\home\mfincher> $colors2pinkgreenblueyellowPS C:\home\mfincher> $colors2 = $colors.Clone() # this creates a new array

50. Type Safe Arrays

Although the default is to have non-homogeneous arrays, you can specify that an array can only have one type. If you try to add something that cannot be coerced into the specified type, an error is thrown.

PS C:\home\mfincher> [int[]]$years = 2009,2010,2011PS C:\home\mfincher> $years += twentytwelveThe term 'twentytwelve' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.At line:1 char:23+ $years += twentytwelve <<<< + CategoryInfo : ObjectNotFound: (twentytwelve:String) [], CommandNotFoundException + FullyQualifiedErrorId : CommandNotFoundException

65. Misc

51. Print a line to the console

Use "write-host" to print a string to the console. Also see "write-debug", and "write-error".

Write-host "Hello World!"

52. Embed the date in a filename

This pipes the output of "mycommand" to the Tee-Object and then to a log file with the date in the name.

$filename = "MyImportLog-{0:yyyy-MM-dd}.txt" -f (Get-Date)mycommand | Tee-Object -file $filename

53. For Loop54. for ($i=1; $i -le 5; $i++)55. {56. Write-host $i

57. }58.

59. How to wait, or sleep

You can specify "-s" for seconds or "-m" for milliseconds.

Start-Sleep -s 1