Quick reference

There is a wide variety of quick references available for PowerShell. This particular reference is intended to kick-start the book, as a lot of this is either not explicitly explained or used often before in a more detailed explanation.

Comments

Refer to the following table:

Line comment	#	# This is a line comment
Block comment	<# #>	<# This is a block or multi-line comment #>

Special characters

Refer to the following table:

Statement separator	;	Get-Command Get-Process; Get-Command Get-Help
Call operator	&	& ‘Get-Process’ # Invoke the string as a command & { Get-Process –Id $PID } # Invoke the script block
Dot-source operator	.	. C:\script.ps1 # Execute the script in the current scope (instead of its own scope)

Tick in PowerShell

PowerShell uses a tick as a multipurpose escaped character.

A tick may be used as a line continuation character. Consider the following example:

'one' -replace 'o', 't' ` 
      -replace 'n', 'w' ` 
      -replace 'e', 'o' 

When using a tick to split a long statement across several lines, the tick must be the last character (it cannot be followed by a space or any other character).

A tick is used to construct several characters that can be used in strings:

Description	String	ASCII character code
Null	`0	0
Bell sound	`a	7
Backspace	`b	8
New page form feed	`f	12
Line feed	`n	10
Carriage return	`r	13
Horizontal tab	`t	9
Vertical tab	`v	11

 

The tab character, for example, may be included in a string:

PS> Write-Host "First`tSecond" 
First Second  

Alternatively, the bell sound may be played in the PowerShell console (but not ISE):

Write-Host "`a"

Common operators

Refer to the following table:

Equal to	-eq	1 –eq 1 # Returns $true 1 –eq 2 # Returns $false
Not equal to	-ne	1 –ne 2 # Returns $true 1 –ne 1 # Returns $false
And	-and	$true –and $true # Returns $true $true –and $false # Returns $false $false –and $false # Returns $false
Or	-or	$true –or $true # Returns $true $true –or $false # Returns $true $false –or $false # Returns $false
Addition and concatenation	+	1 + 1 # Equals 2 “one” + “one” # Equals oneone
Subexpression operator	$( )	“Culture is $($host.CurrentCulture)” “Culture is $(Get-Culture)”

Dropping unwanted output

Refer to the following table:

Assign to null	$null = Expression	$null = Get-Command
Cast to void	[Void](Expression)	[Void](Get-Command)
Pipe to Out-Null	Expression | Out-Null	Get-Command | Out-Null
Redirect to null	Expression > $null	Get-Command > $null

Creating arrays and hashtables

Refer to the following table:

Using the array operator	@()	$array = @() # Empty array $array = @(1, 2, 3, 4)
Implicit array	Value1, Value2, Value3	$array = 1, 2, 3, 4 $array = “one”, “two”, “three”, “four”
Using the hashtable operator	@{}	$hashtable = @{} # Empty hashtable $hashtable = @{Key1 = “Value1”} $hashtable = @{Key1 = “Value1”; Key2 = “Value2”}

Strings

Refer to the following table:

Expanding string	“ “	“Value” $greeting = “Hello”; “$greeting World” # Expands variable
Expanding here-string	@” “@	$one = ‘One’ @” Must be opened on its own line. This string will expand variables like $var. Can contain other quotes like “ and ‘. Must be closed on its own line with no preceding white space. “@
Non-expanding string	‘ ‘	‘Value’ ‘$greeting World’ # Does not expand variable
Non-expanding here-string	@’ ‘@	@’ Must be opened on its own line. This string will not expand variables like $var. Can contain other quotes like “ and ‘. Must be closed on its own line with no preceding white space. ‘@
Quotes in strings	“ `” “ “ ““ “ ‘ `’ ‘ ‘ ‘‘ ‘	“Double-quotes may be escaped with tick like `”.” “Or double-quotes may be escaped with another quote ““.” ‘Single-quotes may be escaped with tick like `’.’ ‘Or single-quotes may be escaped with another quote like ‘‘.’

Common reserved variables

Refer to the following table:

Errors	$Error	$Error[0] # The last error
Formats the enumeration limit. Dictates the number of elements displayed for objects with properties based on arrays. The default is 4.	$FormatEnumerationLimit	$object = [PSCustomObject]@{ Array = @(1, 2, 3, 4, 5) } $object # Shows 1, 2, 3, and 4 $formatenumerationlimit = 1 $object # Shows 1
Holds data of the current PowerShell host.	$Host	$host $host.UI.RawUI.WindowTitle
The matches found when using the -match operator.	$Matches	‘text’ –match ‘.*’ $matches
The output field separator. The default is a single space. Dictates how arrays are joined when included in an expandable string.	$OFS	$arr = 1, 2, 3, 4 “Joined based on OFS: $arr” $ofs = ‘, ‘ “Joined based on OFS: $arr”
Current PowerShell process ID.	$PID	Get-Process –Id $PID
Holds the path to each of the profile files.	$PROFILE	$profile.AllUsersAllHosts $profile.AllUsersCurrentHost $profile.CurrentUserAllHosts $profile.CurrentUserCurrentHost
PowerShell version information.	$PSVersionTable	$PSVersionTable.PSVersion
Present working directory.	$PWD	$PWD.Path

Quick commands and hot keys

Refer to the following table:

ise ise <file>	Opens PowerShell ISE. Opens a file with ISE if a filename is given.
code code <file or folder>	If Visual Studio Code is installed (and in %PATH%). Opens the VS Code. Opens a file or folder with the VS Code.
Get-History history	Shows command history for the current session.
<Text><Tab>	Autocompletes in context. Tab can be used to complete command names, parameter names, and some parameter values.
#<Text><Tab>	Autocompletes against history (beginning of the line). Typing #get- and repeatedly pressing Tab will cycle through all commands containing Get- from your history.
ii	ii is an alias for the invoke-item. Opens the current directory in Explorer.
start iexplore	start is an alias for the start-process. Opens Internet Explorer.
start <name> -verb runas	Runs a process as administrator.