about_EventLogs
Applies To: Windows PowerShell 2.0
TOPIC
about_EventLogs
SHORT DESCRIPTION
Windows PowerShell creates a Windows event log that is
named "Windows PowerShell" to record Windows PowerShell events. You can
view this log in Event Viewer or by using cmdlets that get events, such as
the Get-EventLog cmdlet. By default, Windows PowerShell engine and provider
events are recorded in the event log, but you can use the event log
preference variables to customize the event log. For example, you can add
events about Windows PowerShell commands.
LONG DESCRIPTION
The Windows PowerShell event log records details of Windows PowerShell
operations, such as starting and stopping the program engine and starting
and stopping the Windows PowerShell providers. You can also log details
about Windows PowerShell commands.
In Windows Vista and later versions, the Windows PowerShell event log
is in the Application and Services Logs group. The Windows PowerShell log
is a classic event log that does not use the Windows Eventing technology.
To view the log, use the cmdlets designed for classic event logs, such as
Get-EventLog.
Viewing the Windows PowerShell Event Log
You can view the Windows PowerShell event log in Event Viewer or by
using the Get-EventLog and Get-WmiObject cmdlets. To view the contents
of the Windows PowerShell log, type:
get-eventlog -logname "Windows PowerShell"
To examine the events and their properties, use the Sort-Object cmdlet,
the Group-Object cmdlet, and the cmdlets that contain the Format verb
(the Format cmdlets).
For example, to view the events in the log grouped by the event ID, type:
get-eventlog "Windows PowerShell" | format-table -groupby eventid
Or, type:
get-eventlog "Windows PowerShell" | sort-object eventid `
| group-object eventid
To view all the classic event logs, type:
get-eventlog -list
You can also use the Get-WmiObject cmdlet to use the event-related
Windows Management Instumentation (WMI) classes to examine the event log.
For example, to view all the properties of the event log file, type:
get-wmiobject win32_nteventlogfile | where `
{$_.logfilename -eq "Windows PowerShell"} | format-list -property *
To find the Win32 event-related WMI classes, type:
get-wmiobject -list | where {$_.name -like "win32*event*"}
For more information, type "get-help get-eventlog" and
"get-help get-wmiobject".
Selecting Events for the Windows PowerShell Event Log
You can use the event log preference variables to determine which events
are recorded in the Windows PowerShell event log.
There are six event log preference variables; two variables for each of
the three logging components: the engine (the Windows PowerShell
program), the providers, and the commands. The LifeCycleEvent variables
log normal starting and stopping events. The Health variables log error
events.
The following table lists the event log preference variables.
Variable Description
-------------------------- ----------------------------------------
$LogEngineLifeCycleEvent Logs starting and stopping of
Windows PowerShell.
$LogEngineHealthEvent Logs Windows PowerShell program errors.
$LogProviderLifeCycleEvent Logs starting and stopping of
Windows PowerShell providers.
$LogProviderHealthEvent Logs Windows PowerShell provider errors.
$LogCommandLifeCycleEvent Logs starting and completion of commands.
$LogCommandHealthEvent Logs command errors.
(For information about Windows PowerShell providers,
type: "get-help about_providers".)
By default, only the following event types are enabled:
$LogEngineLifeCycleEvent
$LogEngineHealthEvent
$LogProviderLifeCycleEvent
$LogProviderHealthEvent
To enable an event type, set the preference variable for that event type
to $true. For example, to enable command life-cycle events, type:
$LogCommandLifeCycleEvent
Or, type:
$LogCommandLifeCycleEvent = $true
To disable an event type, set the preference variable for that event type
to $false. For example, to disable command life-cycle events, type:
$LogProviderLifeCycleEvent = $false
You can disable any event, except for the events that indicate that the
Windows PowerShell engine and the core providers are started. These events
are generated before the Windows PowerShell profiles are run and before
the host program is ready to accept commands.
The variable settings apply only for the current Windows PowerShell
session. To apply them to all Windows PowerShell sessions, add them to
your Windows PowerShell profile.
Security and Auditing
The Windows PowerShell event log is designed to indicate activity and
to provide operational details for troubleshooting.
However, like most Windows-based application event logs, the
Windows PowerShell event log is not designed to be secure. It should not
be used to audit security or to record confidential or proprietary
information.
Event logs are designed to be read and understood by users. Users can
read from and write to the log. A malicious user could read an event log
on a local or remote computer, record false data, and then prevent the
logging of their activities.
SEE ALSO
Get-EventLog
Get-WmiObject
about_Preference_Variables