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Where-Object

Selects objects from a collection based on their property values.

Syntax

Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     [-EQ]
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-FilterScript] <ScriptBlock>
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -Match
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -CEQ
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -NE
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -CNE
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -GT
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -CGT
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -LT
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -CLT
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -GE
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -CGE
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -LE
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -CLE
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -Like
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -CLike
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -NotLike
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -CNotLike
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -CMatch
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -NotMatch
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -CNotMatch
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -Contains
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -CContains
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -NotContains
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -CNotContains
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -In
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -CIn
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -NotIn
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -CNotIn
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -Is
     [<CommonParameters>]
Where-Object
     [-InputObject <PSObject>]
     [-Property] <String>
     [[-Value] <Object>]
     -IsNot
     [<CommonParameters>]

Description

The Where-Object cmdlet selects objects that have particular property values from the collection of objects that are passed to it. For example, you can use the Where-Object cmdlet to select files that were created after a certain date, events with a particular ID, or computers that use a particular version of Windows.

Starting in Windows PowerShell 3.0, there are two different ways to construct a Where-Object command.

  • Script block. You can use a script block to specify the property name, a comparison operator, and a property value. Where-Object returns all objects for which the script block statement is true.

    For example, the following command gets processes in the Normal priority class, that is, processes where the value of the PriorityClass property equals Normal.

    Get-Process | Where-Object {$_.PriorityClass -eq "Normal"}

    All PowerShell comparison operators are valid in the script block format. For more information, see about_Comparison_Operators.

  • Comparison statement. You can also write a comparison statement, which is much more like natural language. Comparison statements were introduced in Windows PowerShell 3.0.

    For example, the following commands also get processes that have a priority class of Normal. These commands are equivalent and you can use them interchangeably.

    Get-Process | Where-Object -Property PriorityClass -EQ -Value "Normal"

    Get-Process | Where-Object PriorityClass -EQ "Normal"

    Starting in Windows PowerShell 3.0, Where-Object adds comparison operators as parameters in a Where-Object command. Unless specified, all operators are case-insensitive. Before Windows PowerShell 3.0, the comparison operators in the PowerShell language were only usable in script blocks.

When you provide a single Property to Where-Object, the cmdlet treats the value of the property as a boolean expression. When the value of the property's Length isn't zero, the expression evaluates to $true. For example: ('hi', '', 'there') | Where-Object Length

The previous example is functionally equivalent to:

  • ('hi', '', 'there') | Where-Object Length -GT 0
  • ('hi', '', 'there') | Where-Object { $_.Length -gt 0 }

For more information about how PowerShell evaluates booleans, see about_Booleans.

Examples

Example 1: Get stopped services

These commands get a list of all services that are stopped. The $_ automatic variable represents each object that's passed to the Where-Object cmdlet.

The first command uses the script block format, the second command uses the comparison statement format. The commands filter the services the same way and return the same output. Only the syntax is different.

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

Example 2: Get processes based on working set

These commands list processes that have a working set greater than 250 megabytes (MB). The commands filter the processes the same way and return the same output. Only the syntax is different.

Get-Process | Where-Object { $_.WorkingSet -GT 250MB }
Get-Process | Where-Object WorkingSet -GT 250MB

Example 3: Get processes based on process name

These commands get the processes that have a ProcessName property value that begins with the letter p. The Match operator lets you use regular expression matches.

The commands filter the processes the same way and return the same output. Only the syntax is different.

Get-Process | Where-Object { $_.ProcessName -Match "^p.*" }
Get-Process | Where-Object ProcessName -Match "^p.*"

Example 4: Use the comparison statement format

This example shows how to use the new comparison statement format of the Where-Object cmdlet.

The first command uses the comparison statement format. It doesn't use any aliases and includes the name for every parameter.

The second command is the more natural use of the comparison command format. The command substitutes the where alias for the Where-Object cmdlet name and omits all optional parameter names.

The commands filter the processes the same way and return the same output. Only the syntax is different.

Get-Process | Where-Object -Property Handles -GE -Value 1000
Get-Process | where Handles -GE 1000

Example 5: Get commands based on properties

This example shows how to write commands that return items that are true or false or have any value for a specified property. Each example shows both the script block and comparison statement formats for the command.

The commands filter their input the same way and return the same output. Only the syntax is different.

# Use Where-Object to get commands that have any value for the OutputType
# property of the command. This omits commands that do not have an OutputType
# property and those that have an OutputType property, but no property value.
Get-Command | Where-Object OutputType
Get-Command | Where-Object { $_.OutputType }

# Use Where-Object to get objects that are containers. This gets objects that
# have the **PSIsContainer** property with a value of $True and excludes all
# others.
Get-ChildItem | Where-Object PSIsContainer
Get-ChildItem | Where-Object { $_.PSIsContainer }

# Finally, use the -not operator (!) to get objects that are not containers.
# This gets objects that do have the **PSIsContainer** property and those
# that have a value of $False for the **PSIsContainer** property.
Get-ChildItem | Where-Object { !$_.PSIsContainer }
# You cannot use the -not operator (!) in the comparison statement format
# of the command.
Get-ChildItem | Where-Object PSIsContainer -eq $False

Example 6: Use multiple conditions

Get-Module -ListAvailable | Where-Object {
    ($_.Name -notlike "Microsoft*" -and $_.Name -notlike "PS*") -and $_.HelpInfoUri
}

This example shows how to create a Where-Object command with multiple conditions.

This command gets non-core modules that support the Updatable Help feature. The command uses the ListAvailable parameter of the Get-Module cmdlet to get all modules on the computer. A pipeline operator (|) sends the modules to the Where-Object cmdlet, which gets modules whose names don't begin with Microsoft or PS, and have a value for the HelpInfoURI property, which tells PowerShell where to find updated help files for the module. The -and logical operator connects the comparison statements.

The example uses the script block command format. Logical operators, such as -and,-or, and -not are valid only in script blocks. You can't use them in the comparison statement format of a Where-Object command.

Parameters

-CContains

Indicates that this cmdlet gets objects from a collection if the property value of the object is an exact match for the specified value. This operation is case-sensitive.

For example: Get-Process | Where-Object ProcessName -CContains "svchost"

CContains refers to a collection of values and is true if the collection contains an item that is an exact match for the specified value. If the input is a single object, PowerShell converts it to a collection of one object.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-CEQ

Indicates that this cmdlet gets objects if the property value is the same as the specified value. This operation is case-sensitive.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-CGE

Indicates that this cmdlet gets objects if the property value is greater than or equal to the specified value. This operation is case-sensitive.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-CGT

Indicates that this cmdlet gets objects if the property value is greater than the specified value. This operation is case-sensitive.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-CIn

Indicates that this cmdlet gets objects if the property value includes the specified value. This operation is case-sensitive.

For example: Get-Process | Where-Object -Value "svchost" -CIn ProcessName

CIn resembles CContains, except that the property and value positions are reversed. For example, the following statements are both true.

"abc", "def" -CContains "abc"

"abc" -CIn "abc", "def"

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-CLE

Indicates that this cmdlet gets objects if the property value is less-than or equal to the specified value. This operation is case-sensitive.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-CLike

Indicates that this cmdlet gets objects if the property value matches a value that includes wildcard characters (*). This operation is case-sensitive.

For example: Get-Process | Where-Object ProcessName -CLike "*host"

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-CLT

Indicates that this cmdlet gets objects if the property value is less-than the specified value. This operation is case-sensitive.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-CMatch

Indicates that this cmdlet gets objects if the property value matches the specified regular expression. This operation is case-sensitive. When the input is a single object, the matched value is saved in the $Matches automatic variable.

For example: Get-Process | Where-Object ProcessName -CMatch "Shell"

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-CNE

Indicates that this cmdlet gets objects if the property value is different than the specified value. This operation is case-sensitive.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-CNotContains

Indicates that this cmdlet gets objects if the property value of the object isn't an exact match for the specified value. This operation is case-sensitive.

For example: Get-Process | Where-Object ProcessName -CNotContains "svchost"

NotContains and CNotContains refer to a collection of values and are true when the collection doesn't contain any items that are an exact match for the specified value. If the input is a single object, PowerShell converts it to a collection of one object.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-CNotIn

Indicates that this cmdlet gets objects if the property value isn't an exact match for the specified value. This operation is case-sensitive.

For example: Get-Process | Where-Object -Value "svchost" -CNotIn -Property ProcessName

NotIn and CNotIn operators resemble NotContains and CNotContains, except that the property and value positions are reversed. For example, the following statements are true.

"abc", "def" -CNotContains "Abc"

"abc" -CNotIn "Abc", "def"

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-CNotLike

Indicates that this cmdlet gets objects if the property value doesn't match a value that includes wildcard characters. This operation is case-sensitive.

For example: Get-Process | Where-Object ProcessName -CNotLike "*host"

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-CNotMatch

Indicates that this cmdlet gets objects if the property value doesn't match the specified regular expression. This operation is case-sensitive. When the input is a single object, the matched value is saved in the $Matches automatic variable.

For example: Get-Process | Where-Object ProcessName -CNotMatch "Shell"

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-Contains

Indicates that this cmdlet gets objects if any item in the property value of the object is an exact match for the specified value.

For example: Get-Process | Where-Object ProcessName -Contains "Svchost"

If the input is a single object, PowerShell converts it to a collection of one object.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Aliases:IContains
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-EQ

Indicates that this cmdlet gets objects if the property value is the same as the specified value.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Aliases:IEQ
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-FilterScript

Specifies the script block that's used to filter the objects. Enclose the script block in braces ({}).

The parameter name, FilterScript, is optional.

Type:ScriptBlock
Position:0
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-GE

Indicates that this cmdlet gets objects if the property value is greater than or equal to the specified value.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Aliases:IGE
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-GT

Indicates that this cmdlet gets objects if the property value is greater than the specified value.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Aliases:IGT
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-In

Indicates that this cmdlet gets objects if the property value matches any of the specified values. For example:

Get-Process | Where-Object -Property ProcessName -in -Value "Svchost", "TaskHost", "WsmProvHost"

If the input is a single object, PowerShell converts it to a collection of one object.

If the property value of an object is an array, PowerShell uses reference equality to determine a match. Where-Object returns the object only if the value of the Property parameter and any value of Value are the same instance of an object.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Aliases:IIn
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-InputObject

Specifies the objects to filter. You can also pipe the objects to Where-Object.

When you use the InputObject parameter with Where-Object, instead of piping command results to Where-Object, the cmdlet treats the InputObject as a single object. This is true even if the value is a collection that's the result of a command, such as -InputObject (Get-Process).

Because InputObject can't return individual properties from an array or collection of objects, we recommend that, if you use Where-Object to filter a collection of objects for those objects that have specific values in defined properties, you use Where-Object in the pipeline, as shown in the examples in this topic.

Type:PSObject
Position:Named
Default value:None
Required:False
Accept pipeline input:True
Accept wildcard characters:False

-Is

Indicates that this cmdlet gets objects if the property value is an instance of the specified .NET type. Enclose the type name in square brackets.

For example, Get-Process | Where-Object StartTime -Is [DateTime]

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-IsNot

Indicates that this cmdlet gets objects if the property value isn't an instance of the specified .NET type.

For example, Get-Process | where StartTime -IsNot [DateTime]

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-LE

Indicates that this cmdlet gets objects if the property value is less than or equal to the specified value.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Aliases:ILE
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-Like

Indicates that this cmdlet gets objects if the property value matches a value that includes wildcard characters (*).

For example: Get-Process | Where-Object ProcessName -Like "*host"

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Aliases:ILike
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-LT

Indicates that this cmdlet gets objects if the property value is less than the specified value.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Aliases:ILT
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-Match

Indicates that this cmdlet gets objects if the property value matches the specified regular expression. When the input is a single object, the matched value is saved in the $Matches automatic variable.

For example: Get-Process | Where-Object ProcessName -Match "shell"

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Aliases:IMatch
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-NE

Indicates that this cmdlet gets objects if the property value is different than the specified value.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Aliases:INE
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-NotContains

Indicates that this cmdlet gets objects if none of the items in the property value is an exact match for the specified value.

For example: Get-Process | Where-Object ProcessName -NotContains "Svchost"

NotContains refers to a collection of values and is true if the collection doesn't contain any items that are an exact match for the specified value. If the input is a single object, PowerShell converts it to a collection of one object.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Aliases:INotContains
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-NotIn

Indicates that this cmdlet gets objects if the property value isn't an exact match for any of the specified values.

For example: Get-Process | Where-Object -Value "svchost" -NotIn -Property ProcessName

If the value of Value is a single object, PowerShell converts it to a collection of one object.

If the property value of an object is an array, PowerShell uses reference equality to determine a match. Where-Object returns the object only if the value of Property and any value of Value aren't the same instance of an object.

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Aliases:INotIn
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-NotLike

Indicates that this cmdlet gets objects if the property value doesn't match a value that includes wildcard characters (*).

For example: Get-Process | Where-Object ProcessName -NotLike "*host"

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Aliases:INotLike
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-NotMatch

Indicates that this cmdlet gets objects when the property value doesn't match the specified regular expression. When the input is a single object, the matched value is saved in the $Matches automatic variable.

For example: Get-Process | Where-Object ProcessName -NotMatch "PowerShell"

This parameter was introduced in Windows PowerShell 3.0.

Type:SwitchParameter
Aliases:INotMatch
Position:Named
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-Property

Specifies the name of a property of the input object. The property must be an instance property, not a static property. This is a positional parameter, so the name, Property, is optional.

This parameter was introduced in Windows PowerShell 3.0.

Type:String
Position:0
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-Value

Specifies a property value. The parameter name, Value, is optional. This parameter accepts wildcard characters when used with the following comparison parameters:

  • CLike
  • CNotLike
  • Like
  • NotLike

This parameter was introduced in Windows PowerShell 3.0.

Type:PSObject
Position:1
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:True

Inputs

PSObject

You can pipe any object to this cmdlet.

Outputs

Object

This cmdlet returns the selected items from the input object set.

Notes

Windows PowerShell includes the following aliases for Where-Object:

  • ?
  • where

Starting in Windows PowerShell 4.0, Where and ForEach methods were added for use with collections.

You can read more about these methods here about_arrays