Category Archives: Where

Where-Object

NAME
    Where-Object

SYNOPSIS
    Creates a filter that controls which objects will be passed along a command pipeline.

SYNTAX
    Where-Object [-FilterScript] <scriptblock> [-InputObject <psobject>] [<CommonParameters>]

DESCRIPTION
    The Where-Object cmdlet selects objects from the set of objects that are passed to it. It uses a script block as a filter and evaluates the script block for each object. If the result of the evaluation is True, the object is returned. If the result of the evaluation is not True, the object is ignored.

PARAMETERS
    -FilterScript <scriptblock>
        Specifies the script block that is used to filter the objects. Enclose the script block in braces ( {} ).

        Required?                    true
        Position?                    1
        Default value
        Accept pipeline input?     false
        Accept wildcard characters? false

    -InputObject <psobject>
        Specifies the objects to be filtered. You can also pipe the objects to Where-Object.

        Required?                    false
        Position?                    named
        Default value
        Accept pipeline input?     true (ByValue)
        Accept wildcard characters? false

    <CommonParameters>
        This cmdlet supports the common parameters: Verbose, Debug,
        ErrorAction, ErrorVariable, WarningAction, WarningVariable,
        OutBuffer and OutVariable. For more information, type,
        “Get-Help about_CommonParameters“.

INPUTS
    System.Management.Automation.PSObject
        You can pipe the objects to be filtered to Where-Object.

OUTPUTS

NOTES

    ————————– EXAMPLE 1 ————————–

    C:\PS>Get-Service | Where-Object {$_.Status -eq “Stopped”}

    Description
    ———–
    This command gets a list of all services that are currently stopped. The “$” symbol represents each object that is passed to the Where-Object cmdlet.

    ————————– EXAMPLE 2 ————————–

    C:\PS>Get-Process | Where-Object {$_.workingset -gt 25000*1024}

    Description
    ———–
    This command lists processes that have a working set greater than 25,000 kilobytes (KB). Because the value of the WorkingSet property is stored in bytes, the value of 25,000 is multiplied by 1,024.

    ————————– EXAMPLE 3 ————————–

    C:\PS>Get-Process | Where-Object { $_.ProcessName -match “^p.*” }

    Description
    ———–
    This command gets the processes with a ProcessName property that begins with the letter “p”. The match operator enables you to use regular expressions within a Where clause.

    ————————– EXAMPLE 4 ————————–

    C:\PS>Get-Process -name svchost | Where-Object {$True}

    Description
    ———–
    This command lists all of the processes named “svchost”.

    The Where-Object cmdlet evaluates the script block, which typically includes a reference to the object currently in the pipeline ($_), and casts the results to a Boolean type: True or False. If the result is True, the object is returned. Otherwise, it is discarded.

    In this case, the script block just returns True, so all the objects are returned.

RELATED LINKS
    Online version: http://go.microsoft.com/fwlink/?LinkID=113423