A few days ago Boe Prox posted some very nifty PowerShell modules for using the title bar as a ticker for RSS feeds like the weather. I thought this was an awesome idea and an easy way to take advantage of what would otherwise be unused screen space. I was especially intrigued with his use of timer objects and event subscriptions to manage the updating.

Naturally I decided to run with this. My main goal was to take Boe’s fundamental idea and turn it into something more re-usable or extensible. My result is a module called ConsoleTitle.

The overall premise is pretty simple, define a global variable $PSConsoleTitle and use a timer to periodically update the console title bar with this value. During the refresh interval you can run whatever code you like, however you like, to provide a new value to the variable. In the module I’ve included two sample commands, Get-SystemStat and Get-Inspiration. The former uses WMI to gather system information from the local computer.

The other command defines an array of slogans, sayings and suggestions and randomly selects one to use as the title bar text.

The module includes a few commands for working with timer objects. You can use New-Timer in your own scripts. Here’s the function.

And here’s how you might use it.

Think of the module as a framework or SDK for building your own solutions. The module also includes an about topic. I hope you’ll download ConsoleTitleand let me know what you think.

Recently I was tracking down a bug in script for a client. The problem turned out to be a simple typo. I could have easily avoided that by using Set-StrictMode, which I do now, but that’s not what this is about. What I realized I wanted was a way to look at all the for “words” in a script. If I could look at them sorted, then typos would jump out. At least in theory.

My plan was to get the content of a text file or script, use a regular expression pattern to identify all the “words” and then get a sorted and unique list. Here’s what I came up with.

The function uses Get-Content to retrieve the content (what else?!) of the specified file. At the beginning of the function I defined a regular expression object to find “words”.

This is an intentionally broad pattern that searches for anything not a space. The \b element indicates a word boundary. Because this is a REGEX object, I can do a bit more than using a basic -match operator. Instead I’ll use the Matches() method which will return a collection of match objects. I can pipe these to Select-Object retrieving just the Value property. I also use the -Unique parameter to filter out duplicates. Finally the values are sorted.

The matches and filtering are NOT case-sensitive, which is fine for me. With the list I can see where I might have used write-host instead of Write-Host and go back to clean up my code. Let me show you how this works. Here’s a demo script.

The script has some case inconsistencies as well as a typo. I’ve dot sourced the function in my PowerShell session. Here’s what I end up with.

For best results, you need to make sure there are spaces around commands that use the = sign. But now I can scan through the list and pick out potential problems. Sure, Set-StrictMode would help with variable typos but if I had errors in say comment based help, that wouldn’t help. Maybe you’ll find this useful in your scripting work, maybe not. But I hope you learned a few things about working with REGEX objects and unique properties.

Download Get-ContentWords and enjoy.

This past weekend I did an online presentation for a friend of mine who teaches for ITT in Omaha, Nebraska. He wanted me to do a brief talk about what PowerShell is and show how to use it, especially for managing Active Directory. I probably went much longer than I needed but everyone seemed to get a lot out of it. The session was recorded via WebEx. I then transcoded the recording so I could get it up on YouTube. That’s why the screen layout is a little funky and the audio is far from perfect. Still, I hope you find it useful. The presentation has a some slides but is primarily demo, including using the Microsoft Active Directory cmdlets.

You can also download my presentation and a zip filewith my demo scripts.

If you are ready to learn more check out some of the books and training videos in the side bar. Or bring me in to run a private PowerShell class for your organization. Good Luck and Enjoy!

Today’s Friday Fun is a continuation of my exploration of ways to use Start-Job. A few weeks ago I wrote about using Start-Job to create “scheduled” tasks. I realized I could take this further and turn this into a sort of alarm clock. The goal is to execute at command at a given time, but I wanted to make it easy to specify the time. What I have so far is a function called New-Alarm. I have some other ideas and hope to expand this into a module, but for now I thought I’d toss this out to you and get some feedback.

The function includes full help.

To use the function you specify a command string to execute at a given time. The default’s are to run Notepad in 5 minutes. You can either specify an exact time.

Or X number of seconds, minutes or hours.

The first command defines a command string, $s. This creates a temporary file, writes some text to it, displays it with Notepad and then deletes it. The second command creates a new alarm that will invoke the expression in 15 minutes.

For now, the command is passed as text. This is so that I can create an internal scriptblock. I use a Do loop to compare the current time to the alarm time. When the time is right, the command string is executed using Invoke-Expression.

I also add some metadata to the script block which gets written as the job’s result.

Finally, the alarm function allows for an initialization command, like you might use with Start-Job. This permits you to run commands such as importing modules or dot sourcing scripts. I have a function that displays a VB style message box. Here’s how I might use it as an alarm job.

In 5 minutes the alarm will go off and I’ll get this.

Remember, the function is creating new jobs with the Start-Job cmdlet. Which means I can get job results.

What do you think? As I said, I have a few more ideas and there are certainly a few tweaks I can make even to this code. I’ve added my Get-MessageBox function in case you want to toy with that. Download AlarmScripts.zip and let me know what you think.

The Import-CSV cmdlet in PowerShell is incredibly useful. You can take any CSV file and pump objects to the pipeline. The cmdlet uses the CSV header as properties for the custom object.

But there is a downside: all of the properties are strings.

The means some tasks such sorting or filtering will fail. But there are ways to get around this limitation. One way is to use an expression to cast a property to a different type. For example, I want to sort my test data on the Date property, but it needs to be a [DateTime] object to sort properly. Here’s how:

My output object properties are all still strings. All I did was cast the Date property in the Sort expression. Here’s an example using filtering.

These examples are only producing results. More likely I want to import the CSV file as typed objects. Assuming you know in advance the property names and what types you want to use, here’s how you could achieve this.

I imported my CSV file and piped it to Select-Object, using hash tables to redefine the properties with appropriate types. Import-CSV writes a PSCustomObject to the pipeline anyway so using Select-Object has no effect other than giving me typed properties.

Now I can use $data objects anyway I want.

I’m working on something that takes this idea to the next level but it isn’t quite ready for prime time. But I hope this will help manage imported objects a bit more efficiently and let you really take advantage of the PowerShell pipeline.

Today’s Friday Fun comes out of a short exchange I had yesterday with Hal Rottenberg on Google Plus. We were playing around with piping a PowerShell command to Clip.exe which dumps the output to the Windows Clipboard. I got to thinking about taking this a step further based on my needs as a writer. Often I’d like to see the results of a command and then copy and paste the results into whatever I’m working on. In other words, I need to TEE the output to two places.

PowerShell has a cmdlet called Tee-Object that follows this principal. The default behavior is to write output to the pipeline AND send it to a text file.

I’ll see the results and save them to a text file. I can also use this cmdlet to save results to a variable.

One approach I came up with to incorporate with Clip.exe was this:

I don’t get the results immediately to the screen; they are saved to the variable. But at the same time output has been directed to the Windows Clipboard. That could be useful. But you know me, I always have to tinker a bit more and I ended up with a function called Out-Tee.

This simple function takes a PowerShell expression and writes the results to the console using Write-Host and also to the clipboard. The default output will use the current console foreground color. But you can specify any other color that you would use with Write-Host. I even added some alias properties so you can use -foregroundcolor or -fg.

With this function I can see the result and have it dumped to the clipboard. Because the default text color is the same as my session, I don’t see any difference when using Out-Tee.

Or if I want to pretty it up, I can add a little color.

Of course, the clipboard is just text. But now I have something easier to use to save output to the clipboard so I can paste it into my documents, assuming I like the output I see on the screen. The one caveat is that this function only works with successful commands. Errors, warnings, or verbose statements won’t get dumped to the clipboard. I can think of some ways around that which I might try in a future version. But for my immediate needs this works just fine.

Download Out-Tee and give it a try.

I’ve had a few comments and emails lately about my post and script on converting text to objects. I decided the function needed a little more lovin’ so today I have an updated version, complete with comment based help.

Check out the original article to understand the basics. The major change here is the SplitCount parameter. Often you might end up with a line of text like this:

LinkDate : 11/20/2010 4:30:42 AM

The function needs to split the string into an array on the colon. But when you do that, the time stamp will “break”. The answer is to tell the Split operator how many strings to create. The default of 0 will split into all strings.

If I try that with the time stamp string you see the problem.

But now I can specify the number of strings and I get what I need.

The new version of the function incorporates this. I also received a comment about including a skip feature. I kicked that idea around for awhile, but decided in the end that PowerShell already had a mechanism for skipping lines. I wanted to keep my function limited to a single purpose. So if your text output includes a number of lines you want to skip, before you begin converting text to object, use something like this:

The script file with the function, will also create an alias of cto. I hope you’ll download Convert-TexttoObject.-v1.5 and let me know what you think.

I love how easy it is to manage computers with Windows PowerShell. It is a great reporting tool, but often I find people getting locked into one approach. I’m a big believer in flexibility and re-use and using objects in the pipeline wherever I can. So I put together a PowerShell script that I can run every morning on my computer and get a quick summary about what is happening, or perhaps not happening. My script, MorningReport.ps1, relies on WMI to gather a variety of system information. By default it connects to the local host, but I’ve provided a computername parameter. I’m assuming current credentials are good enough for any remote system, but you can always add support for alternate credentials, assuming I don’t in some future version.

By default the script writes a custom object to the pipeline that contains all of the other WMI information like disk utilization, service status, and event logs. But I wanted flexibility and ease of use, so the script also supports parameters of -Text and -HTML. The former creates nicely formatted text suitable for printing or saving to a file. The latter creates HTML code from the original objects. I rely heavily on creating HTML fragments with ConvertTo-HTML and then assembling everything at the end. The script writes the HTML code to the pipeline so if you want to save results to a file, simply pipe to Out-File. I did this because there may be times when you want the “raw” HTML code. You might want to save the HTML and create an HTML mail message with Send-MailMessage. Or maybe further tweak the HTML before saving it to a file. Again, I didn’t want to lock myself in. Here’s the main part of the script.

As you can see, it is a lengthy script, but I’ve tried to include a fair amount of internal comments and documentation, so I won’t repeat it here, but I will touch on a few key points.

First, I’m embedding a style sheet directly in any HTML output so any files I create can stand alone. You could certainly modify the relevant sections and use the -CSSUri parameter with ConvertTo-HTML. Next, I use a combination of Test-Connection and Try/Catch to handle computers that are offline or I can’t access. This speeds up the script and makes it nicer for the script user. Assuming all is good, I create a number of variables that hold the WMI information I am interested in.

After everything is collected, then I can write output using an If/ElseIf statement depending on what parameters were passed. If no parameters were specified then a custom object is assembled and written to the pipeline.

But perhaps you’d like to see this in action. Here’s a sample HTML SampleReport. In this report, there are no recent errors or warnings in the Application event log.

Or if you have a few minutes, here’s a short clip of the script in action.

I hope you find this a useful jumping off point for your own script, although I think I’ve already worked out information you are most likely interested in. Download MorningReport.ps1 and try it out for yourself.

I use scriptblocks quite a bit in my PowerShell work, often saved as variables. These are handy for commands you want to run again, but don’t necessarily need to turn into permanent functions.

Now in PowerShell I can invoke the scriptblock.

Ok then. I have a number of these defined. I decided I wanted an easy way to identify them when I run Get-Variable. For example, if I remembered all the variable names I could just do this:

But needless to say that’s asking too much. When I first looked at this problem I went down the path of trying to parse values I saw with Get-Variable to identify potential script blocks. Then I realized this was a rookie mistake. PowerShell is all about the objects. Now a variable is also an object with a value property. This value could be a string, and integer or a pscredential. So my task then was to identify each value type.

Every object in PowerShell has a built in method called GetType().

This is actually another object with a Name property.

Aha! Let’s look at this with my variable.

This is a one-line shortcut that gets the Value property of the Freec variable and then runs the GetType() method followed by retrieving just the Name property. This is promising. Here’s one way I can use this:

As you can see there is still an issue with variables with no values.

I’ll just add another condition to my Where expression.

Success!

These are in fact all of the scriptblocks in my current session. But now I can take this a step further and look at my other variables and their type.

Or I might try grouping.

I wanted to filter out empty values so I’m only keeping objects that have a defined type in my grouped output.

The bottom line is never forget about the object!

Here’s a technique you might want to use for ad hoc troubleshooting or reporting. Even though it is possible to set up scheduled tasks to run PowerShell commands or scripts, it is cumbersome and time consuming. PowerShell v3 offers a great alternative, but I’ll cover that another day. Suppose I want to do something every 15 minutes such as check the status of a service. Instead of going through the effort of creating a scheduled task, I’ll create a PowerShell job.

If I setup a job, it will run in my PowerShell session for as long as it needs to run or until I close my PowerShell session. Thus the trick is to keep the job running which easy to accomplish with a simple While loop.

This will loop indefinitely because True is always True. In an interactive session, I can break out of this using Ctrl+C or insert code to break out if some condition is met. If I use this loop in my Start-Job command, the command will run indefinitely until the job terminates. I can always kill the job with the Stop-Job cmdlet. Although I suppose you should be careful with the code you put in the While loop as part of job because if you use Stop-Job, there’s no way of knowing what code might be executing at the time. But for my use of this technique I’m keeping it simple and quick.

The other part is the timing interval. This is easily accomplished using the Start-Sleep cmdlet and specifying a value in milliseconds, or more typically, seconds. Depending on your task you could also take advantage of eventing, but that too is a bit complicated to setup and tear down. So, now the main part of my While loop looks like this:

My code will run every 900 seconds (15 minutes). Here’s a longer example that I put in a script.

I could have put all of that into a script block and created the job, or I could use the script.

The job will write the service status information to a local text file every 10 minutes. When I’m done I can simply my PowerShell session or run Stop-Job. Here’s where it can really get interesting: how about running this “scheduled task” ON a remote computer? There are two approaches. It depends on where you want the job to live. I could keep the job on my computer:

The job object is on my (local) computer, even though the task is running on the remote computer. The other approach is to put the job ON the remote computer. This is a little trickier since I have to get the code I want to run ON the remote computer. I could copy the script over. Or I might try something like this:

First I want to convert my script into a scriptblock by stripping out the comments and inserting a semi colon at the end of each line. Then I can create a scriptblock from this text on the remote computer.

I can pass this text as a parameter with invoke-command to setup a job on the remote computer. I recommend using a PSSession in case you want to go back later and stop the job.

The job is created on the remote session and runs indefinitely.

As I mentioned there are probably several ways you could do this. When I am finished I can either terminate the PSSession or stop the remote job.

So the next time you need some scheduled PowerShell, at least on a temporary basis, take a look at Start-Job.