Windows Powershell ForEach-Object Loop

Process pipeline objects one by one

If you use Get-WmiObject to obtain services in the system, Format-Table may also be used to tabularly type the results for typesetting.

Copy the codeThe code is as follows:

PS C:Powershell> Get-WmiObject Win32_Service | Format-Table status,DisplayName
-AutoSize

status DisplayName
------ -----------
OK     Adobe Acrobat Update Service
OK     Application Experience
OK     Application Layer Gateway Service
OK     Application Host Helper Service
OK     Application Identity
OK     Application Information
OK     Application Management
OK     State Service

However, if you want to process more customized for each service, use ForEach-Object

Copy the codeThe code is as follows:

PS C:Powershell> Get-WmiObject Win32_Service | ForEach-Object {"Name:"+ $_.Disp

layName, ", Is ProcessId more than 100:" + ($_.ProcessId -gt 100)}

Name:Adobe Acrobat Update Service , Is ProcessId more than 100:True

Name:Application Experience , Is ProcessId more than 100:False

Name:Application Layer Gateway Service , Is ProcessId more than 100:False

Name:Application Host Helper Service , Is ProcessId more than 100:True

Name:Application Identity , Is ProcessId more than 100:True

Name:Application Information , Is ProcessId more than 100:True

Name:Application Management , Is ProcessId more than 100:False

Name: State Service , Is ProcessId more than 100:False

Combined with conditions

The processing of ForEach-Object can contain any Powershell script, and of course also include conditional statements.

Copy the codeThe code is as follows:

Get-WmiObject Win32_Service | ForEach-Object {

    if ($_.ProcessId -gt 3000)

    { "{0}({1})" -f $_.DisplayName,$_.ProcessID}

}

Windows Presentation Foundation Font Cache 3.0.0.0(5408)

Microsoft Network Inspection(5260)

BranchCache(4112)

Windows Modules Installer(7656)

Calling methods

In ForEach-Object, $_ represents the current object, and of course, it is also allowed to call the supported methods of the object through $_.
The following example kills all IE browser processes:

Copy the codeThe code is as follows:

PS C:Powershell> Get-Process iexplore

Handles NPM(K)    PM(K)      WS(K) VM(M)   CPU(s)     Id ProcessName
------- ------    -----      ----- -----   ------     -- -----------
    883      29    14728      22432   181    34.26   4300 iexplore
    771      28    55552     129152   425     8.56   5732 iexplore
   1216      51   104324     143916   539   572.41   5912 iexplore
    801      25    49200      25372   285     5.99   6252 iexplore
    691      25    57564      95796   333     8.08   6388 iexplore
   1256      38    85848     127012   379    20.37   7856 iexplore

PS C:Powershell> Get-Process iexplore | ForEach-Object {$_.kill()}
PS C:Powershell> Get-Process iexplore
Get-Process: The process named "iexplore" cannot be found. Please verify the process name and call cmdlet again.
Location Line: 1 Character: 12
+ Get-Process <<<< iexplore
+ CategoryInfo : ObjectNotFound: (iexplore:String) [Get-Process],
ProcessCommandException
+ FullyQualifiedErrorId : NoProcessFoundForGivenName,.