ConvertTo-Expression

Serializes an object to a PowerShell expression.

Syntax

ConvertTo-Expression
    [-Object <Object>]
    [-Depth <Int32>]
    [-Expand <Int32>]
    [-Indentation <Int32>]
    [-IndentChar <String>]
    [-Strong]
    [-Explore]
    [-TypeNaming <String>]
    [-NewLine <String>]
    [<CommonParameters>]

Description

The ConvertTo-Expression cmdlet converts (serializes) an object to a
PowerShell expression. The object can be stored in a variable, file or
any other common storage for later use or to be ported to another
system.

An expression can be restored to an object using the native
Invoke-Expression cmdlet:

$Object = Invoke-Expression ($Object | ConverTo-Expression)

Or Converting it to a [ScriptBlock] and invoking it with cmdlets
along with Invoke-Command or using the call operator (&):

$Object = &([ScriptBlock]::Create($Object | ConverTo-Expression))

An expression that is stored in a PowerShell (.ps1) file might also
be directly invoked by the PowerShell dot-sourcing technique, e.g.:

$Object | ConvertTo-Expression | Out-File .\Expression.ps1
$Object = . .\Expression.ps1

Warning: Invoking partly trusted input with Invoke-Expression or
[ScriptBlock]::Create() methods could be abused by malicious code
injections.

Examples

Example 1

(Get-UICulture).Calendar | ConvertTo-Expression
[pscustomobject]@{
    'AlgorithmType' = 1
    'CalendarType' = 1
    'Eras' = , 1
    'IsReadOnly' = $False
    'MaxSupportedDateTime' = [datetime]'9999-12-31T23:59:59.9999999'
    'MinSupportedDateTime' = [datetime]'0001-01-01T00:00:00.0000000'
    'TwoDigitYearMax' = 2029
}

Example 2

(Get-UICulture).Calendar | ConvertTo-Expression -Strong
[pscustomobject]@{
    'AlgorithmType' = [System.Globalization.CalendarAlgorithmType]'SolarCalendar'
    'CalendarType' = [System.Globalization.GregorianCalendarTypes]'Localized'
    'Eras' = [array][int]1
    'IsReadOnly' = [bool]$False
    'MaxSupportedDateTime' = [datetime]'9999-12-31T23:59:59.9999999'
    'MinSupportedDateTime' = [datetime]'0001-01-01T00:00:00.0000000'
    'TwoDigitYearMax' = [int]2029
}

Example 3

Get-Date | Select-Object -Property * | ConvertTo-Expression | Out-File .\Now.ps1
PS> $Now = .\Now.ps1	# $Now = Get-Content .\Now.Ps1 -Raw | Invoke-Expression
PS> $Now
Date        : 1963-10-07 12:00:00 AM
DateTime    : Monday,  October 7,  1963 10:47:00 PM
Day         : 7
DayOfWeek   : Monday
DayOfYear   : 280
DisplayHint : DateTime
Hour        : 22
Kind        : Local
Millisecond : 0
Minute      : 22
Month       : 1
Second      : 0
Ticks       : 619388596200000000
TimeOfDay   : 22:47:00
Year        : 1963

Example 4

@{Account="User01";Domain="Domain01";Admin="True"} | ConvertTo-Expression -Expand -1	# Compress the PowerShell output
@{'Admin'='True';'Account'='User01';'Domain'='Domain01'}

Example 5

WinInitProcess = Get-Process WinInit | ConvertTo-Expression	# Convert the WinInit Process to a PowerShell expression

Example 6

Get-Host | ConvertTo-Expression -Depth 4	# Reveal complex object hierarchies

Parameters

-Object

Type:	Object
Position:	1
Default value:
Accept pipeline input:	true (ByValue)
Accept wildcard characters:	false

-Depth

Specifies how many levels of contained objects are included in the
PowerShell representation. The default value is 9.

Type:	Int32
Position:	2
Default value:	9
Accept pipeline input:	false
Accept wildcard characters:	false

-Expand

Specifies till what level the contained objects are expanded over
separate lines and indented according to the -Indentation and
-IndentChar parameters. The default value is equal to the -Depth value.

A negative value will remove redundant spaces and compress the
PowerShell expression to a single line (except for multi-line strings).

Xml documents and multi-line strings are embedded in a "here string"
and aligned to the left.

Type:	Int32
Position:	3
Default value:	$Depth
Accept pipeline input:	false
Accept wildcard characters:	false

-Indentation

Specifies how many IndentChars to write for each level in the
hierarchy.

Type:	Int32
Position:	4
Default value:	4
Accept pipeline input:	false
Accept wildcard characters:	false

-IndentChar

Specifies which character to use for indenting.

Type:	String
Position:	5
Default value:
Accept pipeline input:	false
Accept wildcard characters:	false

-Strong

By default, the ConvertTo-Expression cmdlet will return a weakly typed
expression which is best for transfing objects between differend
PowerShell systems.
The -Strong parameter will strickly define value types and objects
in a way that they can still be read by same PowerShell system and
PowerShell system with the same configuration (installed modules etc.).

Type:	SwitchParameter
Position:	named
Default value:	False
Accept pipeline input:	false
Accept wildcard characters:	false

-Explore

In explore mode, all type prefixes are omitted in the output expression
(objects will cast to to hash tables). In case the -Strong parameter is
also supplied, all orginal (.Net) type names are shown.
The -Explore switch is usefull for exploring object hyrachies and data
type, not for saving and transfering objects.

Type:	SwitchParameter
Position:	named
Default value:	False
Accept pipeline input:	false
Accept wildcard characters:	false

-TypeNaming

Accepted values:	Name, Fullname, Auto
Type:	String
Position:	6
Default value:	Auto
Accept pipeline input:	false
Accept wildcard characters:	false

-NewLine

Type:	String
Position:	7
Default value:	[System.Environment]::NewLine
Accept pipeline input:	false
Accept wildcard characters:	false

Inputs

Any. Each objects provided through the pipeline will converted to an

expression. To concatinate all piped objects in a single expression, use the unary comma operator, e.g.: ,$Object | ConvertTo-Expression

Outputs

String[]

Related Links

• https://www.powershellgallery.com/packages/ConvertFrom-Expression