Archive

Archive for the ‘Microsoft’ Category

PowerShell: Recreating SQL*Plus ‘ed’ Command

Aside from PowerShell, I spend a bit of time day-to-day in Oracle’s SQL*Plus.  I’m slowly replacing my dependency on SQL*Plus with PowerShell scripts, functions, and such, but there are some core things that it’s just easier to bring up a console and hack out.

One thing I really love about SQL*Plus is the ‘ed’ command.  The ‘ed’ command dumps your last statement into a temp file, then opens it in Notepad.  Make your changes in Notepad, save, and rerun (in SQL*Plus, it’s a single slash and then Enter), and the frustration of lengthy command line editing is solved.

So, this is a work in progress—my attempt to simulate the same process in PowerShell.

Example Situation

Let’s say, for example, we have a long command we have been hacking away at, but are getting tired of arrowing back and forth on:

$count = 0; sq mydb “select id from reports” | % { $count++ }; $count

(Yes, yes, it’s not ‘very long’, but that’s why this is called an example!)

So, a simple row counter.

The ‘ed’ Command

To recreate the ‘ed’ experience, I need two things:

  • Access to the command line history via get-history.
  • A temporary file.

touch c:\temp.tmp

get-history | ?{ $_.commandline -ne “ex” } |

? { $_.commandline -ne “ed” } |

select commandline -last 1 |

%{ $_.CommandLine} > c:\temp.tmp

np c:\temp.tmp

Stepping through the code:

  1. Create a temporary file.  I used c:\temp.tmp, but you could get a bit fancier and use the systems $TEMP directory or something.
  2. Get-History.  This returns an ascending list of your command history in PowerShell by ID and CommandLine.  We want to ignore any calls to our ‘ed’ or ‘ex’ functions and grab the “last 1”—then insert it into our temp file.
  3. Finally, open up the temp file in NotePad (np is an alias on my PowerShell profile for NotePad2).

So now that I have my ed command, let’s try it out after I’ve already ran my simple row counter.

Last Command in NotePad2

Cool.  We can now make changes to this and SAVE the temp file.  The next step would be to jump back to PowerShell and execute the updated command.

The ‘ex’ Command

Since the slash has special meaning in a PowerShell window, I simply named this script ‘ex’ instead.  Ex… execute… surely I can’t forget that, right?

get-content c:\temp.tmp |

% {

$_

invoke-expression $_

}

The ‘ex’ command is pretty simple.

  1. Get the content of our temporary file from get-content.
  2. For each line (since get-content returns an array of lines), print out the line as text and then invoke (run) it using invoke-expression.

Invoke-Expression takes a string as a command (from our text file) and returns the results.  For more information on Invoke-Expression, check out MSDN.

Wrapping It Up

Now that we have our two commands—ed and ex—we’re ready for those “oh, this is short and easy” commands that turn into multi-page monsters—without fighting tabs and arrow keys.

As I said, this is a work-in-progress.  I’ll update the post as new/better ideas come up. :)

PowerShell : TGIF Reminder

November 6, 2009 David Longnecker 1 comment

Jeff Hicks’ TGIF post yesterday was a fun way to learn a bit of PowerShell (casting, working with dates, etc) and also add something valuable to your professional toolbelt—knowing when to go home. :)

I tweaked the date output a bit to be more human readable, but also moved it from just a function to part of my UI.  I mean, I should ALWAYS know how close I am to quittin’ time, right? Especially as we joke around our office during our ‘payless weeks’.

# Determines if today is the end of friday! (fun function)
function get-tgif {
 $now=Get-Date
 # If it’s Saturday or Sunday then Stop! It’s the weekend!
 if ([int]$now.DayOfWeek -eq 6 -or [int]$now.DayOfWeek -eq 7)
 {
  ”Weekend!”
 }
 else {
  # Determine when the next quittin’ time is…
  [datetime]$TGIF=”{0:MM/dd/yyyy} 4:30:00 PM” -f `
   (($now.AddDays( 5 – [int]$now.DayOfWeek)) )
  
  # Must be Friday, but after quittin’ time, GO HOME!
  if ((get-date) -ge $TGIF) {
   ”TGIF has started without you!”
  }
  else {
   # Awww, still at work–how long until
   # it’s time to go to the pub?
   $diff = $($tgif – (get-date))
   ”TGIF: $($diff.Days)d $($diff.Hours)h $($diff.Minutes)m”
  }
 }
}

NOTE: My “end time” is set to 4:30PM, not 5:00PM—since that’s when I escape.  Change as necessary. ;)

The code comments explain most of it.  As you can see, I added in one more check—let me know when it’s simply the weekend.  I also removed the Write-Host calls, since I simply want to return a String from the function.  I could use the function, as necessary, with formatting, and add it to other scripts and such.  For example:

Write-Host $(get-tgif) -fore red

The next step was tapping into the $Host variable.  Since I use Console2, my PowerShell window is a tab rather than the whole window.  Console2 is aware of PowerShell’s $Host.UI methods and adheres to the changes.

To add get-tgif to my prompt’s window title:

$windowTitle = “(” + $(get-tgif) + “) “
$host.ui.rawui.WindowTitle = $windowTitle

Easy enough.  Now my window title looks like (ignore the path in there for now):

TGIF countdown in WindowTitle

But that only sets it when you log in… and I want to update it (and keep that path updated as I traverse through directories).  To do that add a function called ‘prompt’ to your PowerShell Profile.  Prompt is processed every time the “PS>” is generated and allows you a great deal of customization.  See the post here for further details on how I’ve customized my prompt to handle Git repositories.

So, move those two lines into our prompt function, and our TGIF timer now updates every time our prompt changes… keeping it pretty close to real time as you work.

function prompt {
 $windowTitle = “(” + $(get-tgif) + “) ” + $(get-location).ToString()
 $host.ui.rawui.WindowTitle = $windowTitle

[…]

}

This could be tweaked to any type of countdown.  I’m sure a few of those around the office would have fun adding retirement countdowns, etc. ;)

Happy TGIF!

PowerShell : Add Recursive Directories to PATH

As I continue to go script crazy (a bit) with PowerShell, I’ve noticed that my general scripts directory has grown quite a bit and is becoming a bit unmanagable.  Being a lover of neat and tidy, I wanted to separate ‘common’ scripts from ‘server-based’ and ‘task’ scripts.

Sounds easy enough, but that breaks part of my PowerShell profile—the part where I add the scripts directory to the path.  Moving those files out of that directory, even if they’re in subdirectories, would take them out of the path and I’d lose my [a..b]-{tab} goodness.

So, how to add the recursive structure to PATH?

It’s easy!

In my Profile, $scripts is a variable that contains a path to my ‘standard’ scripts directory based on whatever computer I’m currently logged into.

From there, simply use the built-in features of PowerShell.

gci $scripts |

                ? { $_.psIsContainer } |

                % { [System.Environment]::SetEnvironmentVariable(“PATH”,

                                $Env:Path + “;” + $_.FullName, “Process”) }

Verbatim: for each child object in $scripts that is a container, append the full name to PATH.

Exactly what I wanted and works like a champ.  Now I can move my scripts around, create new directories, the works—and each time I restart my console, it’ll detect the new directories and simply work—exactly like a shell should.

Categories: Microsoft, PowerShell

PowerShell – Easy Line Numbers using Cat (Get-Content)

October 8, 2009 David Longnecker 1 comment

I often cat out code pages from the prompt when I simply want to see what’s inside or look for a method.  Cat, of course, is an alias to PowerShell’s get-content cmdlet, but cat brings me back to days in Unix and makes me feel better. :)

One thing that was a bit of a trouble was looking for a specific line of code.

For example: Looking through the debug logs, I see an error occuring at line 40 of some file.  That’s great, but who wants to count lines?  Instead, we open up Visual Studio and look.  Well, that’s a hassle too.

Here’s a quick script that does a simple line count with the line in the file.

param ([string] $filename)
$counter = 0;
$content = get-content $filename |
 % { $counter++; write-host “$counter`t| $_” }

Since the result of get-content becomes an enumerable line-by-line list, it’s easy to iterate through and increment a counter.

To call it, just call the method with the file name.  For mine, I called it cat-code.ps1, though I’ll probably set an alias to ‘cc’ or something later on.

.\cat-code.ps1 psake_default.ps1

Code Cat example.

From here, you could add in a check to the $Host.UI.RawUI and handle the overflows a bit better, but that’s for another day!

Automating Extracts Using External .SQL Files and PowerShell

September 29, 2009 David Longnecker Leave a comment

Rather than rely on a system task, I wanted to be able to kick off an export of one of our SQL databases on the fly, have it generate a CSV, then email the CSV to one of our developers.

Sounds like a task for PowerShell!

Why PowerShell? Well, frankly, because moving jobs around and such on our mixed-mash of SQL versions and servers is a bit annoying and I wanted to see if it worked.

So, to start off, I have a file, call it export_data.sql that contains all of the logic of my SQL query and the format I require.

I’ll also be using the Microsoft SQL query script I discussed in this blog post.

The tricky part is reading in the .sql file as a single “entity”—not the array of rows that get-content usually provides.  Thankfully, there is an easy way to do it.

@(gc ‘export_data.sql’ -readcount 0)

According to the PowerShell documentation, the readcount parameter serves two purposes: one is to set the number of lines to read at a time, the second (when set to zero) is to pull in all of the lines at once.  Great, that’s exactly what we need.

From there, it’s simply feeding our query to the sql-query function I wrote and exporting to CSV.  Nice enough, CSV exports are built-in to PowerShell!

The final command looks something like this:

@(gc ‘export_data.sql’ -readcount 0) | 
   % { sql-query server db $_ } |
   export-csv dump.csv

I could then add another field to mail the csv using the built-in command Send-MailMessage.

<3 PowerShell.

ASP.NET Development Server From ‘Here’ in PowerShell

September 9, 2009 David Longnecker Leave a comment

Long title… almost longer than the code.

I used to have an old registry setting that started up the ASP.NET Development Server from the current path; however, since I rarely open up Explorer—and then opening up FireFox was even more painful—I needed a script.

What does it do?

The script starts up the ASP.NET Development server with a random port (so you can run multiples…) at your current location.  It then activates your machine’s DEFAULT BROWSER and browses to the site.  FireFox user?  No problem.  Works like a champ!

The Script (Full Code)

$path = resolve-path .
$rand = New-Object system.random
$port = $rand.next(2048,10240)
$path_to_devserver = “C:\\Program Files (x86)\\Common Files\\microsoft shared\\DevServer\\9.0\\Webdev.WebServer.exe”

& $path_to_devserver /port:$port /path:$path
(new-object -com shell.application).ShellExecute(“http:\\localhost:$port”)

The $path_to_devserver can be updated—depending on 64–bit vs. 32–bit machines.  Simple, easy, and to the point.  Now, no more fumbling around to launch a quick web application!

Ramping up with PSake

September 8, 2009 David Longnecker Leave a comment

I’ve been tetering back and forth with PSake and my trusty NAnt scripts for quite a while now.  For those not familiar with PSake, it’s build automation that makes you drunk—but in a good way. ;)   You can read James Kovacs’ original post here or check out the repository here for the latest bits.

I originally looked at rake scripts (after exposure working with Fluent NHibernate) as PowerShell is loathed in our organization—or was.  That mindset is slowly changing (being able to show people how to crank out what was originally scoped at a week in two lines of PowerShell script helps out); so I’m using PSake as further motivation.

My prior PSake scripts were a bit tame.  Launch msbuild, copy a few files.  With the latest release of xUnit 1.5 hitting the wires over the weekend (and a much needed x86 version for my poor, cranky Oracle libraries), I decided to bite the bullet and dig in to PSake.

I had two goals:

  1. Build a reliable framework “default.ps1” file that I could drop into almost any project and configure with little or no effort.
  2. Compile, test, and rollout updates from a single PSake command task.

I borrowed the basic layout from Ayende’s Rhino Mocks PSake; however, I couldn’t get msbuild to run correctly simply by calling it.

Here’s what I ended up with for our internal core library.  The core library, isn’t so much a “utilities” container, but just as it sounds—the framework all of our applications are built on to keep connections to our various applications (HR, student systems, data warehouses, etc) consistant as well as hold our base FNH conventions.

CODE: Full code available on CodePaste.NET

Properties

The properties area holds all of the configuration for the PSake script.  For me, it’s common to configure $solution_name, $libraries_to_merge, and $libraries_to_copy.  With our naming standards, the $test_library should be left unchanged.  I also added in the tester information so we could change from XUnit to MBUnit (if Hell froze over or something)).

properties {

 

  # ****************  CONFIGURE ****************

       $solution_name =           “Framework”

       $test_library =            “$solution_name.Test.dll”

 

       $libraries_to_merge =      “antlr3.runtime.dll”, `

                                  “ajaxcontroltoolkit.dll”, `

                                  “Castle.DynamicProxy2.dll”, `

                                  “Castle.Core.dll”, `

                                  “FluentNHibernate.dll”, `

                                  “log4net.dll”, `

                                  “system.linq.dynamic.dll”, `

                                  “xunit.dll”, `

                                  “nhibernate.caches.syscache2.dll”, `

                                  “cssfriendly.dll”, `

                                  “iesi.collections.dll”, `

                                  “nhibernate.bytecode.castle.dll”, `

                                  “oracle.dataaccess.dll”

      

       $libraries_to_copy =       “system.data.sqlite.dll”

 

       $tester_directory = “j:\shared_libraries\xunit\msbuild”

       $tester_executable = “xunit.console.x86.exe”

       $tools_directory =         “$tools”

       $base_directory  =         resolve-path .

       $thirdparty_directory =    “$base_directory\thirdparty”

       $build_directory =         “$base_directory\build”

       $solution_file =           “$base_directory\$solution_name.sln”

       $release_directory =       “$base_directory\release”

}

Clean and easy enough.  You’ll notice that $libraries_to_merge and $libraries_to_copy are implied string arrays.  That works out well since string arrays end up as params when passed to commands… and our $libraries_to_copy can be iterated over later in the code.

Tasks – Default

task default -depends Release

The default task (if just running ‘psake’ without parameters) runs Release.  Easy enough.

Tasks – Clean

task Clean {

  remove-item -force -recurse $build_directory -ErrorAction SilentlyContinue | Out-Null

  remove-item -force -recurse $release_directory -ErrorAction SilentlyContinue | Out-Null

}

Clean up those build and release directories.

Tasks – Init

task Init -depends Clean {

    new-item $release_directory -itemType directory | Out-Null

    new-item $build_directory -itemType directory | Out-Null

    cp $tester_directory\*.* $build_directory

}

Restore those build and release directories that we cleaned up; then copy in our unit testing framework so we can run our tests (if necessary).

Tasks – Compile

task Compile -depends Init {

       # from http://poshcode.org/1050 (first lines to get latest versions)

       [System.Reflection.Assembly]::Load(‘Microsoft.Build.Utilities.v3.5, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’) | Out-Null

       $msbuild = [Microsoft.Build.Utilities.ToolLocationHelper]::GetPathToDotNetFrameworkFile(“msbuild.exe”, “VersionLatest”)

      

       # adding double slash for directories with spaces. Stupid MSBuild.

       &$msbuild /verbosity:minimal /p:Configuration=”Release” /p:Platform=”Any CPU” /p:OutDir=”$build_directory”\\ “$solution_file”

}

Compile is a bit tricky.  As noted in the code, I ended up using a SharePoint example from PoSH code to get MSBuild to behave.  The standard exec methodology provided by PSake kept ignoring my parameters.  Maybe someone has an good reason.. but this works.

You also see that my OutDir has TWO slashes.  It seems that directories with spaces require the second.  I’m sure this will somehow bite me later on, but it seems to be working for now. ;)

Tasks – Test

task Test -depends Compile {

  $origin_directory = pwd

  cd $build_directory

  exec .\$tester_executable “$build_directory\$test_library”

  cd $origin_directory       

}

I want to thank Ayende for the idea to dump the origin directory into a parameter—brilliant.  This one is pretty simple—just calls the tester and tests.

Tasks – Merge

task Merge {

       $origin_directory = pwd

       cd $build_directory

      

       remove-item “$solution_name.merge.dll” -erroraction SilentlyContinue

       rename-item “$solution_name.dll” “$solution_name.merge.dll”

      

       & $tools\ilmerge\ilmerge.exe /out:”$solution_name.dll” /t:library /xmldocs /log:”$solution_name.merge.log” `

              “$solution_name.merge.dll” $libraries_to_merge

                          

       if ($lastExitCode -ne 0) {

              throw “Error: Failed to merge assemblies!”

       }

       cd $origin_directory

}

Merge calls ILMerge and wraps all of my libraries into one.  Do I need to do this?  Nah, but for the framework, I prefer to keep everything together.  I don’t want to be chasing mis-versioned libraries around.  Again, since $libraries_to_merge is a string array, it passes each “string” as a separate parameter—which is exactly what ILMerge wants to see.

I also have ILMerge generate and keep a log of what it did—just to have.  Since the build directory gets blown away between builds (and isn’t replicated to source control), then no harm.  Space is mostly free. ;)

Tasks – Build & Release

task Build -depends Compile, Merge {

       # When I REALLY don’t want to test…

}

 

task Release -depends Test, Merge {

       copy-item $build_directory\$solution_name.dll $release_directory

       copy-item $build_directory\$solution_name.xml $release_directory

      

       # copy libraries that cannot be merged

       % { $libraries_to_copy } | %{ copy-item (join-path $build_directory $_) $release_directory }

      

}

Build provides just that—building with no testing and no copying to the release directory.  This is more for testing out the scripts, but useful in some cases.

Release copies the library and the xml documentation out ot the release directory.  It then iterates through the string array of “other” libraries (non-manged code libraries that can’t be merged, etc) and copies them as well.

 

 

 

Querying Oracle using PowerShell

September 1, 2009 David Longnecker 4 comments

Yesterday, I wrote up a quick bit of code to query out our SQL Servers.  Initially, I wanted a speedy way to hit, parse, and report back log4net logs in our “server status” scripts.

Well, never one to leave something alone, I started tinkering with Oracle support.  In our enterprise, most of our key systems sit on Oracle and there are SEVERAL opportunities for quick data retrieval routines that could help out in daily work.

Plus, doing an Oracle query in PowerShell beats five minute process of cranking up Oracle SQL Developer for a simple, single query. :)

CODE: The full source of this is available here on codepaste.net.

param (
    [string]$server = “.”,
    [string]$instance = $(throw “a database name is required”),
    [string]$query
)

[System.Reflection.Assembly]::LoadWithPartialName(“System.Data.OracleClient”) | out-null
$connection = new-object system.data.oracleclient.oracleconnection( `
    “Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=$server)(PORT=1521)) `
    (CONNECT_DATA=(SERVICE_NAME=$instance)));User Id=USER_ID;Password=PASSWORD;”);

$set = new-object system.data.dataset   

$adapter = new-object system.data.oracleclient.oracledataadapter ($query, $connection)
$adapter.Fill($set)

$table = new-object system.data.datatable
$table = $set.Tables[0]

#return table
$table

I chose to use the OracleClient library for simplicity sake.  I could have used ODP.Net; however, that’d make my scripts FAR less portable.  Since OracleClient isn’t loaded by default in PowerShell, this script loads it.  In addition, I chose to use the TNS-less connection string as I don’t typically keep a ‘tnsnames.ora’ file on my computer.  This further adds to the portability of the script.

Past that and the change from SqlClient to OracleClient, the rest of the code is the same from the prior example.

Dealing With Empty Strings and Nulls

One thing that I did run across that differed between Oracle and Microsoft SQL revolved around how empty strings were dealt with when parsing using PowerShell.

Example:

oq “SELECT * FROM Schools”

ID  NAME        PRINCIPAL_EMAIL_ADDRESS

  —-        ———————–

100 School

102 School

112 School      user3@domain.net

140 School      user1@domain.net

etc.

Now, what if I wanted to just see the schools missing a principal_email_address?  I’d just rewrite my SQL query, right?  Yeah, probably, but for the sake of argument and perhaps some scripting.

oq “SELECT * FROM Schools” | ? { $_.principal_email_address -eq “”}

No results.

What? Why not?  I see two in my last query.  Unfortunately, dealing with “nulls” and empty strings can get a bit tricky when pulling from database data.  With Microsoft SQL, a text-based column (varchar, ntext, etc) seems to handle -eq “” just fine, but Oracle is less than pleased.  @ShayLevy suggested -eq [string]::Empty but that didn’t pull through either. 

From a prior experiment, I also tried -eq $null and was greeted with something very different—it returned all results. Meh.

Randomly, I tried -like $null and it worked. Well, that’s interesting.  So the value isn’t empty in Oracle, but it is “like” a null.  After a bit more digging, I discovered that the real value is -eq [DBNull]::Value.

oq “SELECT * FROM Schools” | ? { $_.principal_email_address -eq [DBNull]::Value }

ID  NAME        PRINCIPAL_EMAIL_ADDRESS

  —-        ———————–

100 School
102 School

It makes sense… but more testing is required to see which is more reliable for a wide variety of data types.  I like the concept of “like null” to simulate “string empty or null”.  Further testing required. :)

 

Querying SQL Server using PowerShell

The great thing about PowerShell is direct access to objects.  For my apps, database connectivity is happily handled by NHibernate; however, that doesn’t mean we can’t take advantage of good old System.Data.SqlClient for our PowerShell scripting.

CODE: The full source of this is available here on codepaste.net.

param (
    [string]$server = “.”,
    [string]$instance = $(throw “a database name is required”),
    [string]$query
)

$connection = new-object system.data.sqlclient.sqlconnection( `
    “Data Source=$server;Initial Catalog=$instance;Integrated Security=SSPI;”);
   
$adapter = new-object system.data.sqlclient.sqldataadapter ($query, $connection)
$set = new-object system.data.dataset

$adapter.Fill($set)

$table = new-object system.data.datatable
$table = $set.Tables[0]

#return table
$table

Not too long or challenging—it’s mostly working to instantiate a quick SQL connection and pass in your query.  I even considered plugging in a check on the $query parameter to ensure it began with SELECT to ensure I wouldn’t do accidental damage to a system. Maybe I’m just paranoid. ;)

What this little snippet allows me to do is quickly add log4net checking into some of my server monitoring PowerShell scripts.

query sqlServer myDatabase “Select count(id), logger from logs group by logger” | format-table -autosize

Notice I didn’t include the format-table command in my main query script.  Why?  I wanted to keep the flexibility to select, group, and parse the information returned by my query.  Unfortunately, it seems that the format commands break that if they’re ran before a manipulation keyword.  Adding in “ft –a” isn’t difficult in a pinch.

WebStorageHandler[1]

Quick and easy…

Other uses:

  • Customer calls up with a question about data—save time and do a quick query rather than waiting for Management Studio to wind up.
  • Keep tabs on database statistics, jobs, etc.
  • and more…

Digging into the Event Log with PowerShell

There are a few of our applications that haven’t been converted over to log4net logging so their events still land in the good ol’ Windows Event Log.  That’s fine and was fairly easy to browse, sort, and filter using the new tools in Windows Server 2008.

I’ve found a bit better tool, however, over the past few hours for digging into the logs on short notice and searching—obviously, PowerShell.

Full source for this can be found here.

I wanted to be able to quickly query out:

  • the time – to look at trending,
  • the user – trending, and filtering if I have them on the phone,
  • the URL – shows both the application and the page the problem is occuring on,
  • the type – the exception type for quick filtering,
  • the exception – the core of the issue,
  • the details – lengthy, but can be ever so helpful even showing the line number of the code in question.

param ([string]$computerName = (gc env:computername))

function GetExceptionType($type, $logEvent)
{
 if ($type -ne "Error") { $logEvent.ReplacementStrings[17] }
 else {
        $rx = [regex]"Exception:.([0-9a-zA-Z].+)"
        $matches = $rx.match($logEvent.ReplacementStrings[0])
        $matches.Groups[1].Value
 }
}

function GetException($type, $logEvent)
{
 if ($type -ne "Error") { $logEvent.ReplacementStrings[18] }
 else {
        $rx = [regex]"Message:.([0-9a-zA-Z].+)"
        $matches = $rx.match($logEvent.ReplacementStrings[0])
        $matches.Groups[1].Value
 }
}

get-eventlog -log application -ComputerName $computerName |
    ? { $_.Source -eq "ASP.NET 2.0.50727.0" } |
    ? { $_.EntryType -ne "Information" } |
    select `
  Index, EntryType, TimeGenerated, `
  @{Name="User"; Expression={$_.ReplacementStrings[22]}}, `
  @{Name="Url"; Expression={truncate-string $_.ReplacementStrings[19] 60 }}, `
  @{Name="Type"; Expression={GetExceptionType $_.EntryType $_ }}, `
  @{Name="Exception"; Expression={GetException $_.EntryType $_ }}, `
  @{Name="Details"; Expression={$_.ReplacementStrings[29]}}

The code itself is probably pretty overworked and, I hope, can be refined as time goes on.

The two helper functions, GetExceptionType and GetException, exist because (it seems) that Warnings and Information store their information in one location and Errors store their information in one HUGE blob of text that needs to be parsed.  Those helpers provide that switch logic.

The get-eventlog logic itself is pretty straightforward:

  1. Open up the ‘Application’ EventLog on the specified computer,
  2. Filter only “ASP.NET 2.0.50727.0” sourced events,
  3. Exclude “Information” type events,
  4. Select 3 columns and generate 5 columns from expressions.

The great advantage is I can then take this file and “pipe” it into other commands.

get-aspnet-events webserver1 | select user, url, type | format-table -auto

User               Url                               Type
----               ---                               ----
domain\dlongnecker http://domain.net/Create.aspx     PreconditionException
domain\dlongnecker http://domain.net/Create.aspx     PreconditionException
domain\dlongnecker http://domain.net/View.aspx       PostconditionException
domain\dlongnecker http://domain.net/View.aspx       AssertionException

or

get-aspnet-events webserver1 | ? { $_.user -like “*dlongnecker” }

The possibilities are great—and a real time saver than hitting each server and looking through the GUI tool.

The code also includes a helper method I created for truncating strings available here via codepaste.  If there’s built-in truncating, I’d love to know about it.