Wait-Event

Waits until a particular event is raised before continuing to run.
Wait-Event [[-SourceIdentifier] [<String>]] [-Timeout [<Int32>]] [<CommonParameters>]

The Wait-Event cmdlet suspends execution of a script or function until a particular event is raised. Execution resumes when the event is detected. To cancel the wait, press CTRL+C.

This feature provides an alternative to polling for an event. It also allows you to determine the response to an event in two different ways: by using the Action parameter of the event subscription and by waiting for an event to return and then respond with an action.

Parameters
-SourceIdentifier [<String>]

Waits only for events with the specified source identifier. By default, Wait-Event waits for any event.

-Timeout [<Int32>]

Specifies the maximum time, in seconds, that Wait-Event waits for the event to occur. The default, -1, waits indefinitely. The timing starts when you submit the Wait-Event command.

If the specified time is exceeded, the wait ends and the command prompt returns, even if the event has not been raised. No error message is displayed.

<CommonParameters>

This cmdlet supports the common parameters: Verbose, Debug,ErrorAction, ErrorVariable, WarningAction, WarningVariable,OutBuffer, PipelineVariable, and OutVariable.

Inputs

System.String

Outputs

System.Management.Automation.PSEventArgs

Examples
  1. Wait for the next event:
    PS C:> Wait-Event
    

    This command waits for the next event that is raised.

  2. Wait for an event with a specified source identifier:
    PS C:> Wait-Event -SourceIdentifier "ProcessStarted"
    

    This command waits for the next event that is raised and that has a source identifier of ProcessStarted.

  3. Wait for a timer elapsed event:
    PS C:> $Timer.Interval = 2000
    PS C:> $Timer.Autoreset = $False
    PS C:> $Timer.Enabled = $True; Wait-Event Timer.Elapsed
    # After 2 seconds
    EventIdentifier  : 12
    Sender           : System.Timers.Timer
    SourceEventArgs  : System.Timers.ElapsedEventArgs
    SourceArgs       : {System.Timers.Timer, System.Timers.ElapsedEventArgs}
    SourceIdentifier : Timer.Elapsed
    TimeGenerated    : 6/10/2008 3:24:18 PM
    MessageData      : ForwardEvent     : False
    

    This command uses the Wait-Event cmdlet to wait for a timer event on a timer that is set for 2000 milliseconds.

  4. Wait for an event after a specified timeout:
    PS C:> Wait-Event -SourceIdentifier "ProcessStarted" -Timeout 90
    

    This command waits up to 90 seconds for the next event that is raised and that has a source identifier of “ProcessStarted”. If the specified time expires, the wait ends.

Additional Notes
 Events, event subscriptions, and the event queue exist only in the current session. If you close the current 
 session, the event queue is discarded and the event subscription is canceled.
Related Links

Get-Event
Get-EventSubscriber
New-Event
Register-EngineEvent
Register-ObjectEvent
Register-WmiEvent
Remove-Event
Unregister-Event
Wait-Event