PowerShell Eventing Library

New Post: Add-EventHandler dictionary issue

JoeyBradshaw — Wed, 11 Jun 2008 20:34:52 GMT

Ok, I looked at the source and it will be impossible to bind the same event name to the same ps variable more than once without completely re-writing the source code. I did resolve this, just needed to dynamically create my variable in the for loop so that each ps variable is unique.

# dynamic variable index
$StepIndex = 0

foreach ($ApplicationEntry in $($Project.Applications).GetEnumerator()))
{
...

$New-Variable "Step$StepIndex" -value $MiscPackage.Steps.Get_Item("Step XYZ")

# get a reference to the dynamic variable
$Step = (Get-Variable "Step$StepIndex" -ValueOnly)

... do some stuff to the step ...

Add-EventHandler (Get-Variable "Step$StepIndex") StepFailed { param($var) Write-Error "The step $($var.Value.Name) failed!" }

$Step.Execute();

# increment our step index by one
$StepIndex++
}

Write-Host "Waiting for events.."
Do-Events $true

cheers,
joey

New Post: Add-EventHandler dictionary issue

JoeyBradshaw — Tue, 10 Jun 2008 23:59:11 GMT

I'm wondering if there is a way to use PSEventing given my situation. In the code below you'll notice that in the foreach loop I attach and event handler during each iteration but this fails because the code for the Add-Eventhandler is a hashtable and you cannot add the same event name more than once. I'm hoping someone can provide me with more details on this line $events = @(read-event -wait) and what properties are avialable for each event that it returns. Is it possible to re-write Add-Eventhandler to use a unique event guid as the hashtables key rather than an event name?

foreach ($ApplicationEntry in $($Project.Applications).GetEnumerator()))
{
...

$Step = $MiscPackage.Steps.Get_Item("Step XYZ")

Add-EventHandler (get-variable Step) StepFailed { param($var) Write-Error "The step $($var.Value.Name) failed!" }

$Step.Execute();

}

Write-Host "Waiting for events.."
Do-Events $true

thx, joey

UPDATED RELEASE: PSEventing 1.1 (Jun 04, 2008)

Thu, 05 Jun 2008 17:40:48 GMT

_New Features_

* Multiple named queue support and default queue with -QueueName parameter
* Better COM support, window message pumping etc.
* NoFlush / Peek parameter support for queue reading
* Get-EventQueue command added for viewing queues and their message counts.

_Changes_

* Get-Event -> Read-Event
* Connect-EventListener -> Connect-Event
* Disconnect-EventListener -> Disconnect-Event

see [url:foreground / background swappable downloads in powershell|http://www.nivot.org/2007/12/05/ForegroundBackgroundSwappableDownloadsInPowerShell.aspx] for an advanced example.

UPDATED WIKI: Home

oisin — Thu, 05 Jun 2008 16:51:28 GMT

PSEventing 1.1 Released

Trap and respond to synchronous & asynchronous .NET, COM and WMI events within your powershell scripts with this easy to use suite of cmdlets. Compatible with PowerShell 1.0 and 2.0CTP.

Important

This is intended for PowerShell v1.0 only. PowerShell v2.0 CTP2 has introduced support for eventing with similarly named cmdlets, but with real-time (interrupt-based) event support.

New Features

Multiple named queue support and default queue with -QueueName parameter
Better COM support, window message pumping etc.
NoFlush / Peek parameter support for queue reading
Get-EventQueue command added for viewing queues and their message counts.

See foreground / background swappable downloads in powershell for an advanced example.

Cmdlet Name Changes

Get-Event -> Read-Event
Connect-EventListener -> Connect-Event
Disconnect-EventListener -> Disconnect-Event

64 bit PowerShell Support

To install for use with the 64bit version of PowerShell, please use the 64bit version of InstallUtil:

& "$env:windir\Microsoft.NET\Framework64\v2.0.50727\InstallUtil.exe" nivot.powershell.eventing.dll

How does it work?

Events in PowerShell - but how? Events in a .NET executable are generally raised and handled in realtime in an asynchronous fashion; at first glance, this doesn't seem possible with our favourite little shell. PowerShell lets us wire up scriptblocks to .NET events as handlers relatively easily, but unfortunately if the event is raised on a different thread (as is the case with WMI watchers, FileSystemWatchers and other asynchronous objects), there is no runspace available to execute our script. So, how do we get a runspace to execute a handler? Well, we ensure that we are in a running pipeline before processing events. This is achieved by disconnecting the process: we separate the occurance of events from the act of handling them. How does this work in practice? Let's play with System.IO.FileSystemWatcher :

Example with FileSystemWatcher

This example uses the Cmdlets directly to demonstrate how the Snap-In works; you may find it easier and more familiar to work with the simple wrapper functions supplied on the Releases page. See the bottom of this page to read about these functions, called Add-EventHandler, Remove-EventHandler and Do-Events respectively.

Step 1

1# Add-PSSnapin pseventing
 
2# $fsw = new-object system.io.filesystemwatcher
3# $fsw.Path = "c:\temp"
4# $fsw.EnableRaisingEvents = $true

This loads our snap-in, creates a FileSystemWatcher instance assigned to the variable named fsw and tells it to keep an eye on our temp directory. So, what events can we watch? Well, before you go running to MSDN...

Step 2

#5 Get-EventBinding fsw -IncludeUnboundEvents | Format-Table -Auto
 
VariableName EventName TypeName          Listening
------------ --------- --------          ---------
fsw          Changed   FileSystemWatcher     False
fsw          Created   FileSystemWatcher     False
fsw          Deleted   FileSystemWatcher     False
fsw          Disposed  FileSystemWatcher     False
fsw          Error     FileSystemWatcher     False
fsw          Renamed   FileSystemWatcher     False

This command lets us examine what events this variable exposes. Note that I say variable, and not object. This is a running theme throughout this library - all PSEventing Cmdlets only deal with PSVariable objects, or variable names so do not prefix your variable names with the $ symbol. This will end up passing the instance instead of the variable, which is not what we want. This is to keep the paradigm similar to other late-bound scripting languages, like vbscript; allowing direct object references would not have been very admin-friendly. Ok, so next, lets watch the Changed and Deleted events. Btw, Event names are not case sensitive, unless you provide the -CaseSensitive SwitchParameter.

Step 3

5# Connect-Event fsw changed,deleted

From this moment on, every time something is changed or deleted in c:\temp, a PSEvent object is added to our background event queue, even if you're busy running some other script or doing an unrelated task! Lets perform some related activity:

Step 4

6# "foo" > c:\temp\bar.txt
7# remove-item c:\temp\bar.txt

Now, we've just created and deleted a file. You could have also gone out to explorer and created and deleted the file; all events are captured, not just those triggered from within powershell. How do we find out whap's happened, and act on this info? with the read-Event cmdlet:

Step 5

8# $events = Read-Event
9# $events | Format-Table -Auto
 
Occurred            Source                                  Name    Args
--------            ------                                  ----    ----
5/9/2007 3:31:39 PM System.Management.Automation.PSVariable Changed System.IO.FileSystemEventArgs
5/9/2007 3:31:42 PM System.Management.Automation.PSVariable Deleted System.IO.FileSystemEventArgs

Two events occured since we wired up the listener (or since we last called read-Event since each call drains the queue). Lets have a look at the EventArgs for the first one:

Step 6

10# $events[0].Args | format-table -Auto
 
ChangeType FullPath        Name
---------- --------        ----
   Changed c:\temp\bar.txt bar.txt

And there you have it!

Download the 1.1 release and have a look at the sqlbackup.ps1 example script for more advanced uses.

Included Cmdlets

All cmdlets have -? help support, and you can also get more information via get-help about_pseventing

Connect-Event : Start tracking one or more event(s) for one or more variable(s)

Connect-Event [-VariableName] <String> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [-QueueName <identifier>] [<CommonParameters>]
Connect-Event [-Variable] <PSVariable> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [-QueueName <identifier>] <CommonParameters>]

Disconnect-Event : Stop tracking one or more event(s) for one or more variable(s)

Disconnect-Event [-VariableName] <String> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [<CommonParameters>]
Disconnect-Event [-Variable] <PSVariable> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] <CommonParameters>]

Get-EventBinding : Retrieve event binding information for variables

Get-EventBinding [[-Variable] [<PSVariable[]>]] [-IncludeUnboundEvents [<SwitchParameter>]] [<CommonParameters>]
Get-EventBinding [[-VariableName] [<String[]>]] [-IncludeUnboundEvents [<SwitchParameter>]] [<CommonParameters>]

Hint : bind or unbind all events at once for a variable

  1# $fsw = New-Object System.IO.FileSystemWatcher
  2# Get-EventBinding fsw -IncludeUnboundEvents | Connect-Event

New-Event : Create a custom event for insertion into the queue with an optional object payload

New-Event [-EventName] <String> [[-Data] [<PSObject>]] [-QueueName <identifier>] [<CommonParameters>]

Read-Event : Retrieve one or more PSEvent objects representing tracked .NET events that have been raised since the last invocation of this command.

Read-Event [-Wait [<SwitchParameter>]] [-QueueName <identifier>] [-NoFlush <SwitchParameter>] [<CommonParameters>]

Get-EventQueue : Shows information about the default queue and/or named queues.

Get-EventQueue [[-QueueName] <String[]>] [-ShowEmpty] [<CommonParameters>]

Start-KeyHandler : Start generating PSEvent objects for break (cltr+c) and/or keydown events.

Start-KeyHandler [-CaptureCtrlC [<SwitchParameter>]] [-CaptureKeys [<SwitchParameter>]] [<CommonParameters>]

Stop-KeyHandler : Stop generating PSEvent objects for break (ctrl+c) and/or keydown events.

Stop-KeyHandler [<CommonParameters>]

Read some more Syntax Hints for a quick start.

- Oisin Grehan / x0n

UPDATED WIKI: Home

oisin — Thu, 05 Jun 2008 16:47:19 GMT

PSEventing 1.1 Released

Trap and respond to synchronous & asynchronous .NET, COM and WMI events within your powershell scripts with this easy to use suite of cmdlets. Compatible with PowerShell 1.0 and 2.0CTP.

Important

This is intended for PowerShell v1.0 only. PowerShell v2.0 CTP2 has introduced support for eventing with similarly named cmdlets, but with real-time (interrupt-based) event support.

New Features

Multiple named queue support and default queue with -QueueName parameter
Better COM support, window message pumping etc.
NoFlush / Peek parameter support for queue reading
Get-EventQueue command added for viewing queues and their message counts.

See foreground / background swappable downloads in powershell for an advanced example.

Cmdlet Name Changes

Get-Event -> Read-Event
Connect-Event -> Connect-Event
Disconnect-Event -> Disconnect-Event

64 bit PowerShell Support

How does it work?

Example with FileSystemWatcher

Step 1

1# Add-PSSnapin pseventing
 
2# $fsw = new-object system.io.filesystemwatcher
3# $fsw.Path = "c:\temp"
4# $fsw.EnableRaisingEvents = $true

Step 2

#5 Get-EventBinding fsw -IncludeUnboundEvents | Format-Table -Auto
 
VariableName EventName TypeName          Listening
------------ --------- --------          ---------
fsw          Changed   FileSystemWatcher     False
fsw          Created   FileSystemWatcher     False
fsw          Deleted   FileSystemWatcher     False
fsw          Disposed  FileSystemWatcher     False
fsw          Error     FileSystemWatcher     False
fsw          Renamed   FileSystemWatcher     False

Step 3

5# Connect-Event fsw changed,deleted

Step 4

6# "foo" > c:\temp\bar.txt
7# remove-item c:\temp\bar.txt

Step 5

8# $events = Read-Event
9# $events | Format-Table -Auto
 
Occurred            Source                                  Name    Args
--------            ------                                  ----    ----
5/9/2007 3:31:39 PM System.Management.Automation.PSVariable Changed System.IO.FileSystemEventArgs
5/9/2007 3:31:42 PM System.Management.Automation.PSVariable Deleted System.IO.FileSystemEventArgs

Two events occured since we wired up the listener (or since we last called read-Event since each call drains the queue). Lets have a look at the EventArgs for the first one:

Step 6

10# $events[0].Args | format-table -Auto
 
ChangeType FullPath        Name
---------- --------        ----
   Changed c:\temp\bar.txt bar.txt

And there you have it!

Download the 1.1 release and have a look at the sqlbackup.ps1 example script for more advanced uses.

Included Cmdlets

All cmdlets have -? help support, and you can also get more information via get-help about_pseventing

Connect-Event : Start tracking one or more event(s) for one or more variable(s)

Connect-Event [-VariableName] <String> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [-QueueName <identifier>] [<CommonParameters>]
Connect-Event [-Variable] <PSVariable> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [-QueueName <identifier>] <CommonParameters>]

Disconnect-Event : Stop tracking one or more event(s) for one or more variable(s)

Disconnect-Event [-VariableName] <String> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [<CommonParameters>]
Disconnect-Event [-Variable] <PSVariable> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] <CommonParameters>]

Get-EventBinding : Retrieve event binding information for variables

Get-EventBinding [[-Variable] [<PSVariable[]>]] [-IncludeUnboundEvents [<SwitchParameter>]] [<CommonParameters>]
Get-EventBinding [[-VariableName] [<String[]>]] [-IncludeUnboundEvents [<SwitchParameter>]] [<CommonParameters>]

Hint : bind or unbind all events at once for a variable

  1# $fsw = New-Object System.IO.FileSystemWatcher
  2# Get-EventBinding fsw -IncludeUnboundEvents | Connect-Event

New-Event : Create a custom event for insertion into the queue with an optional object payload

New-Event [-EventName] <String> [[-Data] [<PSObject>]] [-QueueName <identifier>] [<CommonParameters>]

Read-Event : Retrieve one or more PSEvent objects representing tracked .NET events that have been raised since the last invocation of this command.

Read-Event [-Wait [<SwitchParameter>]] [-QueueName <identifier>] [-NoFlush <SwitchParameter>] [<CommonParameters>]

Get-EventQueue : Shows information about the default queue and/or named queues.

Get-EventQueue [[-QueueName] <String[]>] [-ShowEmpty] [<CommonParameters>]

Start-KeyHandler : Start generating PSEvent objects for break (cltr+c) and/or keydown events.

Start-KeyHandler [-CaptureCtrlC [<SwitchParameter>]] [-CaptureKeys [<SwitchParameter>]] [<CommonParameters>]

Stop-KeyHandler : Stop generating PSEvent objects for break (ctrl+c) and/or keydown events.

Stop-KeyHandler [<CommonParameters>]

Read some more Syntax Hints for a quick start.

- Oisin Grehan / x0n

UPDATED WIKI: Home

oisin — Thu, 05 Jun 2008 16:45:37 GMT

PSEventing 1.1 Released

Trap and respond to synchronous & asynchronous .NET, COM and WMI events within your powershell scripts with this easy to use suite of cmdlets. Compatible with PowerShell 1.0 and 2.0CTP.

Important

This is intended for PowerShell v1.0 only. PowerShell v2.0 CTP2 has introduced support for eventing with similarly named cmdlets, but with real-time (interrupt-based) event support.

New Features

Multiple named queue support and default queue with -QueueName parameter
Better COM support, window message pumping etc.
NoFlush / Peek parameter support for queue reading
Get-EventQueue command added for viewing queues and their message counts.

See foreground / background swappable downloads in powershell for an advanced example.

Cmdlet Name Changes

Get-Event -> Read-Event
Connect-Event -> Connect-Event
Disconnect-Event -> Disconnect-Event

64 bit PowerShell Support

How does it work?

Example with FileSystemWatcher

Step 1

1# Add-PSSnapin pseventing
 
2# $fsw = new-object system.io.filesystemwatcher
3# $fsw.Path = "c:\temp"
4# $fsw.EnableRaisingEvents = $true

Step 2

#5 Get-EventBinding fsw -IncludeUnboundEvents | Format-Table -Auto
 
VariableName EventName TypeName          Listening
------------ --------- --------          ---------
fsw          Changed   FileSystemWatcher     False
fsw          Created   FileSystemWatcher     False
fsw          Deleted   FileSystemWatcher     False
fsw          Disposed  FileSystemWatcher     False
fsw          Error     FileSystemWatcher     False
fsw          Renamed   FileSystemWatcher     False

Step 3

5# Connect-Event fsw changed,deleted

Step 4

6# "foo" > c:\temp\bar.txt
7# remove-item c:\temp\bar.txt

Step 5

8# $events = Read-Event
9# $events | Format-Table -Auto
 
Occurred            Source                                  Name    Args
--------            ------                                  ----    ----
5/9/2007 3:31:39 PM System.Management.Automation.PSVariable Changed System.IO.FileSystemEventArgs
5/9/2007 3:31:42 PM System.Management.Automation.PSVariable Deleted System.IO.FileSystemEventArgs

Two events occured since we wired up the listener (or since we last called read-Event since each call drains the queue). Lets have a look at the EventArgs for the first one:

Step 6

10# $events[0].Args | format-table -Auto
 
ChangeType FullPath        Name
---------- --------        ----
   Changed c:\temp\bar.txt bar.txt

And there you have it!

Download the 1.1 release and have a look at the sqlbackup.ps1 example script for more advanced uses.

Included Cmdlets

All cmdlets have -? help support, and you can also get more information via get-help about_pseventing

Connect-Event : Start tracking one or more event(s) for one or more variable(s)

Connect-Event [-VariableName] <String> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [-QueueName <identifier>] [<CommonParameters>]
Connect-Event [-Variable] <PSVariable> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [-QueueName <identifier>] <CommonParameters>]

Disconnect-Event : Stop tracking one or more event(s) for one or more variable(s)

Disconnect-Event [-VariableName] <String> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [<CommonParameters>]
Disconnect-Event [-Variable] <PSVariable> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] <CommonParameters>]

Get-EventBinding : Retrieve event binding information for variables

Get-EventBinding [[-Variable] [<PSVariable[]>]] [-IncludeUnboundEvents [<SwitchParameter>]] [<CommonParameters>]
Get-EventBinding [[-VariableName] [<String[]>]] [-IncludeUnboundEvents [<SwitchParameter>]] [<CommonParameters>]

Hint : bind or unbind all events at once for a variable

  1# $fsw = New-Object System.IO.FileSystemWatcher
  2# Get-EventBinding fsw -IncludeUnboundEvents | Connect-Event

New-Event : Create a custom event for insertion into the queue with an optional object payload

New-Event [-EventName] <String> [[-Data] [<PSObject>]] [-QueueName <identifier>] [<CommonParameters>]

Read-Event : Retrieve one or more PSEvent objects representing tracked .NET events that have been raised since the last invocation of this command.

Read-Event [-Wait [<SwitchParameter>]] [-QueueName <identifier>] [-NoFlush <SwitchParameter>] [<CommonParameters>]

Start-KeyHandler : Start generating PSEvent objects for break (cltr+c) and/or keydown events.

Start-KeyHandler [-CaptureCtrlC [<SwitchParameter>]] [-CaptureKeys [<SwitchParameter>]] [<CommonParameters>]

Stop-KeyHandler : Stop generating PSEvent objects for break (ctrl+c) and/or keydown events.

Stop-KeyHandler [<CommonParameters>]

Read some more Syntax Hints for a quick start.

- Oisin Grehan / x0n

Source code checked in

oisin — Wed, 04 Jun 2008 19:05:31 GMT

updated scripts for 1.1

UPDATED RELEASE: PSEventing 1.1 (Jun 04, 2008)

Wed, 04 Jun 2008 18:58:32 GMT

UPDATED WIKI: Home

oisin — Wed, 04 Jun 2008 18:19:31 GMT

PSEventing 1.1 Released

Trap and respond to synchronous & asynchronous .NET, COM and WMI events within your powershell scripts with this easy to use suite of cmdlets. Compatible with PowerShell 1.0 and 2.0CTP.

Important

This is intended for PowerShell v1.0 only. PowerShell v2.0 CTP2 has introduced support for eventing with similarly named cmdlets, but with real-time (interrupt-based) event support.

New Features

Multiple named queue support and default queue with -QueueName parameter
Better COM support, window message pumping etc.
NoFlush / Peek parameter support for queue reading
read-EventQueue command added for viewing queues and their message counts.

See foreground / background swappable downloads in powershell for an advanced example.

Cmdlet Name Changes

Get-Event -> Read-Event
Connect-Event -> Connect-Event
Disconnect-Event -> Disconnect-Event

64 bit PowerShell Support

How does it work?

Example with FileSystemWatcher

Step 1

1# Add-PSSnapin pseventing
 
2# $fsw = new-object system.io.filesystemwatcher
3# $fsw.Path = "c:\temp"
4# $fsw.EnableRaisingEvents = $true

Step 2

#5 Get-EventBinding fsw -IncludeUnboundEvents | Format-Table -Auto
 
VariableName EventName TypeName          Listening
------------ --------- --------          ---------
fsw          Changed   FileSystemWatcher     False
fsw          Created   FileSystemWatcher     False
fsw          Deleted   FileSystemWatcher     False
fsw          Disposed  FileSystemWatcher     False
fsw          Error     FileSystemWatcher     False
fsw          Renamed   FileSystemWatcher     False

Step 3

5# Connect-Event fsw changed,deleted

Step 4

6# "foo" > c:\temp\bar.txt
7# remove-item c:\temp\bar.txt

Step 5

8# $events = Read-Event
9# $events | Format-Table -Auto
 
Occurred            Source                                  Name    Args
--------            ------                                  ----    ----
5/9/2007 3:31:39 PM System.Management.Automation.PSVariable Changed System.IO.FileSystemEventArgs
5/9/2007 3:31:42 PM System.Management.Automation.PSVariable Deleted System.IO.FileSystemEventArgs

Two events occured since we wired up the listener (or since we last called read-Event since each call drains the queue). Lets have a look at the EventArgs for the first one:

Step 6

10# $events[0].Args | format-table -Auto
 
ChangeType FullPath        Name
---------- --------        ----
   Changed c:\temp\bar.txt bar.txt

And there you have it!

Download the 1.1 release and have a look at the sqlbackup.ps1 example script for more advanced uses.

Included Cmdlets

All cmdlets have -? help support, and you can also get more information via get-help about_pseventing

Connect-Event : Start tracking one or more event(s) for one or more variable(s)

Connect-Event [-VariableName] <String> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [-QueueName <identifier>] [<CommonParameters>]
Connect-Event [-Variable] <PSVariable> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [-QueueName <identifier>] <CommonParameters>]

Disconnect-Event : Stop tracking one or more event(s) for one or more variable(s)

Disconnect-Event [-VariableName] <String> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [<CommonParameters>]
Disconnect-Event [-Variable] <PSVariable> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] <CommonParameters>]

Get-EventBinding : Retrieve event binding information for variables

Get-EventBinding [[-Variable] [<PSVariable[]>]] [-IncludeUnboundEvents [<SwitchParameter>]] [<CommonParameters>]
Get-EventBinding [[-VariableName] [<String[]>]] [-IncludeUnboundEvents [<SwitchParameter>]] [<CommonParameters>]

Hint : bind or unbind all events at once for a variable

  1# $fsw = New-Object System.IO.FileSystemWatcher
  2# Get-EventBinding fsw -IncludeUnboundEvents | Connect-Event

New-Event : Create a custom event for insertion into the queue with an optional object payload

New-Event [-EventName] <String> [[-Data] [<PSObject>]] [-QueueName <identifier>] [<CommonParameters>]

Read-Event : Retrieve one or more PSEvent objects representing tracked .NET events that have been raised since the last invocation of this command.

Read-Event [-Wait [<SwitchParameter>]] [-QueueName <identifier>] [-NoFlush <SwitchParameter>] [<CommonParameters>]

Start-KeyHandler : Start generating PSEvent objects for break (cltr+c) and/or keydown events.

Start-KeyHandler [-CaptureCtrlC [<SwitchParameter>]] [-CaptureKeys [<SwitchParameter>]] [<CommonParameters>]

Stop-KeyHandler : Stop generating PSEvent objects for break (ctrl+c) and/or keydown events.

Stop-KeyHandler [<CommonParameters>]

Read some more Syntax Hints for a quick start.

- Oisin Grehan / x0n

UPDATED WIKI: Home

oisin — Wed, 04 Jun 2008 18:19:07 GMT

PSEventing 1.1 Released

Trap and respond to synchronous & asynchronous .NET, COM and WMI events within your powershell scripts with this easy to use suite of cmdlets. Compatible with PowerShell 1.0 and 2.0CTP.

Important

This is intended for PowerShell v1.0 only. PowerShell v2.0 CTP2 has introduced support for eventing with similarly named cmdlets, but with real-time (interrupt-based) event support. See foreground / background swappable downloads in powershell for an advanced example.

New Features

Multiple named queue support and default queue with -QueueName parameter
Better COM support, window message pumping etc.
NoFlush / Peek parameter support for queue reading
read-EventQueue command added for viewing queues and their message counts.

Cmdlet Name Changes

Get-Event -> Read-Event
Connect-Event -> Connect-Event
Disconnect-Event -> Disconnect-Event

64 bit PowerShell Support

How does it work?

Example with FileSystemWatcher

Step 1

1# Add-PSSnapin pseventing
 
2# $fsw = new-object system.io.filesystemwatcher
3# $fsw.Path = "c:\temp"
4# $fsw.EnableRaisingEvents = $true

Step 2

#5 Get-EventBinding fsw -IncludeUnboundEvents | Format-Table -Auto
 
VariableName EventName TypeName          Listening
------------ --------- --------          ---------
fsw          Changed   FileSystemWatcher     False
fsw          Created   FileSystemWatcher     False
fsw          Deleted   FileSystemWatcher     False
fsw          Disposed  FileSystemWatcher     False
fsw          Error     FileSystemWatcher     False
fsw          Renamed   FileSystemWatcher     False

Step 3

5# Connect-Event fsw changed,deleted

Step 4

6# "foo" > c:\temp\bar.txt
7# remove-item c:\temp\bar.txt

Step 5

8# $events = Read-Event
9# $events | Format-Table -Auto
 
Occurred            Source                                  Name    Args
--------            ------                                  ----    ----
5/9/2007 3:31:39 PM System.Management.Automation.PSVariable Changed System.IO.FileSystemEventArgs
5/9/2007 3:31:42 PM System.Management.Automation.PSVariable Deleted System.IO.FileSystemEventArgs

Two events occured since we wired up the listener (or since we last called read-Event since each call drains the queue). Lets have a look at the EventArgs for the first one:

Step 6

10# $events[0].Args | format-table -Auto
 
ChangeType FullPath        Name
---------- --------        ----
   Changed c:\temp\bar.txt bar.txt

And there you have it!

Download the 1.1 release and have a look at the sqlbackup.ps1 example script for more advanced uses.

Included Cmdlets

All cmdlets have -? help support, and you can also get more information via get-help about_pseventing

Connect-Event : Start tracking one or more event(s) for one or more variable(s)

Connect-Event [-VariableName] <String> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [-QueueName <identifier>] [<CommonParameters>]
Connect-Event [-Variable] <PSVariable> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [-QueueName <identifier>] <CommonParameters>]

Disconnect-Event : Stop tracking one or more event(s) for one or more variable(s)

Disconnect-Event [-VariableName] <String> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [<CommonParameters>]
Disconnect-Event [-Variable] <PSVariable> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] <CommonParameters>]

Get-EventBinding : Retrieve event binding information for variables

Get-EventBinding [[-Variable] [<PSVariable[]>]] [-IncludeUnboundEvents [<SwitchParameter>]] [<CommonParameters>]
Get-EventBinding [[-VariableName] [<String[]>]] [-IncludeUnboundEvents [<SwitchParameter>]] [<CommonParameters>]

Hint : bind or unbind all events at once for a variable

  1# $fsw = New-Object System.IO.FileSystemWatcher
  2# Get-EventBinding fsw -IncludeUnboundEvents | Connect-Event

New-Event : Create a custom event for insertion into the queue with an optional object payload

New-Event [-EventName] <String> [[-Data] [<PSObject>]] [-QueueName <identifier>] [<CommonParameters>]

Read-Event : Retrieve one or more PSEvent objects representing tracked .NET events that have been raised since the last invocation of this command.

Read-Event [-Wait [<SwitchParameter>]] [-QueueName <identifier>] [-NoFlush <SwitchParameter>] [<CommonParameters>]

Start-KeyHandler : Start generating PSEvent objects for break (cltr+c) and/or keydown events.

Start-KeyHandler [-CaptureCtrlC [<SwitchParameter>]] [-CaptureKeys [<SwitchParameter>]] [<CommonParameters>]

Stop-KeyHandler : Stop generating PSEvent objects for break (ctrl+c) and/or keydown events.

Stop-KeyHandler [<CommonParameters>]

Read some more Syntax Hints for a quick start.

- Oisin Grehan / x0n

UPDATED RELEASE: PSEventing 1.1 (Jun 04, 2008)

Wed, 04 Jun 2008 18:16:55 GMT

UPDATED WIKI: Home

oisin — Wed, 04 Jun 2008 17:54:27 GMT

PSEventing 1.1 Released

Trap and respond to synchronous & asynchronous .NET, COM and WMI events within your powershell scripts with this easy to use suite of cmdlets. Compatible with PowerShell 1.0 and 2.0CTP.

Important

This is intended for PowerShell v1.0 only. PowerShell v2.0 CTP2 has introduced support for eventing with similarly named cmdlets, but with real-time (interrupt-based) event support.

New Features

Multiple named queue support and default queue with -QueueName parameter
Better COM support, window message pumping etc.
NoFlush / Peek parameter support for queue reading
read-EventQueue command added for viewing queues and their message counts.

Cmdlet Name Changes

Get-Event -> Read-Event
Connect-Event -> Connect-Event
Disconnect-Event -> Disconnect-Event

64 bit PowerShell Support

How does it work?

Example with FileSystemWatcher

Step 1

1# Add-PSSnapin pseventing
 
2# $fsw = new-object system.io.filesystemwatcher
3# $fsw.Path = "c:\temp"
4# $fsw.EnableRaisingEvents = $true

Step 2

#5 Get-EventBinding fsw -IncludeUnboundEvents | Format-Table -Auto
 
VariableName EventName TypeName          Listening
------------ --------- --------          ---------
fsw          Changed   FileSystemWatcher     False
fsw          Created   FileSystemWatcher     False
fsw          Deleted   FileSystemWatcher     False
fsw          Disposed  FileSystemWatcher     False
fsw          Error     FileSystemWatcher     False
fsw          Renamed   FileSystemWatcher     False

Step 3

5# Connect-Event fsw changed,deleted

Step 4

6# "foo" > c:\temp\bar.txt
7# remove-item c:\temp\bar.txt

Step 5

8# $events = Read-Event
9# $events | Format-Table -Auto
 
Occurred            Source                                  Name    Args
--------            ------                                  ----    ----
5/9/2007 3:31:39 PM System.Management.Automation.PSVariable Changed System.IO.FileSystemEventArgs
5/9/2007 3:31:42 PM System.Management.Automation.PSVariable Deleted System.IO.FileSystemEventArgs

Two events occured since we wired up the listener (or since we last called read-Event since each call drains the queue). Lets have a look at the EventArgs for the first one:

Step 6

10# $events[0].Args | format-table -Auto
 
ChangeType FullPath        Name
---------- --------        ----
   Changed c:\temp\bar.txt bar.txt

And there you have it!

Download the 1.1 release and have a look at the sqlbackup.ps1 example script for more advanced uses.

Included Cmdlets

All cmdlets have -? help support, and you can also get more information via get-help about_pseventing

Connect-Event : Start tracking one or more event(s) for one or more variable(s)

Connect-Event [-VariableName] <String> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [-QueueName <identifier>] [<CommonParameters>]
Connect-Event [-Variable] <PSVariable> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [-QueueName <identifier>] <CommonParameters>]

Disconnect-Event : Stop tracking one or more event(s) for one or more variable(s)

Disconnect-Event [-VariableName] <String> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] [<CommonParameters>]
Disconnect-Event [-Variable] <PSVariable> [-EventName] <String[]> [-CaseSensitive [<SwitchParameter>]] <CommonParameters>]

Get-EventBinding : Retrieve event binding information for variables

Get-EventBinding [[-Variable] [<PSVariable[]>]] [-IncludeUnboundEvents [<SwitchParameter>]] [<CommonParameters>]
Get-EventBinding [[-VariableName] [<String[]>]] [-IncludeUnboundEvents [<SwitchParameter>]] [<CommonParameters>]

Hint : bind or unbind all events at once for a variable

  1# $fsw = New-Object System.IO.FileSystemWatcher
  2# Get-EventBinding fsw -IncludeUnboundEvents | Connect-Event

New-Event : Create a custom event for insertion into the queue with an optional object payload

New-Event [-EventName] <String> [[-Data] [<PSObject>]] [-QueueName <identifier>] [<CommonParameters>]

Read-Event : Retrieve one or more PSEvent objects representing tracked .NET events that have been raised since the last invocation of this command.

Read-Event [-Wait [<SwitchParameter>]] [-QueueName <identifier>] [-NoFlush <SwitchParameter>] [<CommonParameters>]

Start-KeyHandler : Start generating PSEvent objects for break (cltr+c) and/or keydown events.

Start-KeyHandler [-CaptureCtrlC [<SwitchParameter>]] [-CaptureKeys [<SwitchParameter>]] [<CommonParameters>]

Stop-KeyHandler : Stop generating PSEvent objects for break (ctrl+c) and/or keydown events.

Stop-KeyHandler [<CommonParameters>]

Read some more Syntax Hints for a quick start.

- Oisin Grehan / x0n

UPDATED RELEASE: PSEventing 1.1 (Jun 04, 2008)

Wed, 04 Jun 2008 17:41:07 GMT

CLOSED ISSUE: sometimes get-event (now read-event) -wait returns immediately with no events

oisin — Wed, 04 Jun 2008 17:34:37 GMT

sometimes read-event -wait returns immediately with no events - seems to be related to using ctrl+c to break out; a subsequent call immediately returns, but additional calls behave as normal. Probably not resetting my exit flag. doh.

CLOSED FEATURE: add -noflush to read-event (previously get-event) cmdlet

oisin — Wed, 04 Jun 2008 17:34:36 GMT

currently a read flushes the queue; this would allow a "peek" of the default queue (or specific named queue) without emptying it.

Source code checked in

oisin — Wed, 04 Jun 2008 17:34:35 GMT

COMMENTED ISSUE: sometimes get-event (now read-event) -wait returns immediately with no events

oisin — Wed, 04 Jun 2008 17:33:18 GMT

conditions for repro:

ps> start-keyhandler -capturectrl
ps> read-event -wait
... hit ctrlc - returns ctrlc event ...
ps> read-event -wait
(returns immediately with no event!)
ps> read-event -wait
(waits correctly)

CLOSED ISSUE: Unable to bind to EventHandler events

oisin — Wed, 04 Jun 2008 17:07:05 GMT

The snapin cannot handle events with EventHandler<T> generic delegates.
Comments: fixed in 1.1

UPDATED RELEASE: PSEventing 1.1

Wed, 04 Jun 2008 17:05:57 GMT

_New Features_

* Multiple named queue support + default queue
* Better COM support
* NoFlush / Peek support for queue reading
* Get-EventQueue command added

_Changes_

* Get-Event -> Read-Event
* Connect-EventListener -> Connect-Event
* Disconnect-EventListener -> Disconnect-Event

Source code checked in

oisin — Wed, 04 Jun 2008 17:01:15 GMT

1.1 Release; added WiX 3.0 installer project.