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Before we wrap up,

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there is one more area I want to touch on because it can

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affect how you run commands in PowerShell.

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This will especially become important when you start writing

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your own PowerShell scripts and functions.

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Now, PowerShell by itself is nothing more than an engine, like a car engine.

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It needs to be inserted into a vehicle in order to really use it.

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In our case, PowerShell has to be hosted in an application.

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Now you don't have to worry about this other than understand that

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there is a difference between the host and PowerShell.

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When you run a PowerShell command, it writes objects to the PowerShell pipeline.

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This is what allows you to do a lot of work from a

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Command Prompt with minimal effort.

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For the most part,

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this is how you should be working with PowerShell; objects in the pipeline.

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However, you can also interact directly with the hosting application.

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There are commands in PowerShell that let you write to and read from the host.

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It is the writing part that trips up a lot of beginners.

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You can only work with objects that are written to the PowerShell pipeline.

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If you write to the host, all you can do is read and

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write whatever is on the screen.

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And this will be much easier to see in a demonstration.

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I need to make sure you understand about the PowerShell host.

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Understand why commands in the pipeline are really important.

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Make sure you understand the ins and outs of using write‑host.

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And since we're at it,

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I might as well show you read‑host, although this is something

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that you probably really won't get into until you start doing

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your own PowerShell scripting.

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All right,

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so let me show you what I'm talking about between the host and PowerShell.

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And when I say PowerShell,

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what I'm really talking about is the PowerShell pipeline.

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This is something that trips up a lot of PowerShell beginners.

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So I'm going to look at a built‑in variable called $host.

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So you can see that I'm running in the ConsoleHost, and

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that also shows you the version.

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And I'm going to do a couple things here.

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They'll all look the same.

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So I'm just going to type the string "apple," and PowerShell shows me apple.

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I'm going to use a cmdlet called Write‑Output,

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and I'll do the same thing with Write‑Host.

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Now, as far as you can tell, it looks like they all did the same thing.

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And if all you're doing is just reading what's on the screen, yeah,

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maybe it really doesn't matter, but it will matter.

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So I'm going to take that string "apple" and pipe it to Get‑Member,

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which is a command that I'm going to cover in the next module.

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So this shows me that "apple" is a string object and Get‑Member shows

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me all of the methods and properties of that object.

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This works because something was written to the pipeline

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for Get‑Member to know what to do with.

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Let's take write‑output, repeat the process. Again, I get

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an object written to the pipeline that Get‑Member can

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consume and do something with.

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Now let's try with Write‑Host.

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I see the string there apple, but I also now get an error message.

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You must specify an object to the Get‑Member cmdlet,

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and this is the big distinction.

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Write‑Host does exactly what the name is implying.

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It's writing to the hosting application.

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It's not writing output to the pipeline.

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It's not writing to PowerShell.

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Now, this can be sometimes useful, by the way,

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so don't don't get the idea that Write‑Host is totally bad.

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If we look at help for Write‑Hosts,

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you'll see that there are some options there where you can specify formatting

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for colors of the whatever it is that you want to write.

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So if I wanted to, I could write a message to the console saying,

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just kind of silly here, "A is for Apple," but display it in a red

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color. When I see that, I now know that that output is not part of

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my script or not part of the command, it's written directly to the host.

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Now here's where it kind of gets interesting now that I think about it.

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We now have all this capability of doing ANSI formatting, so you could

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actually write an ANSI‑colored string to the pipeline.

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It would be displayed in color, but would also be written to the pipeline.

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So my little idea of only using color with Write‑Host may or may not be useful,

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but it is an option there.

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The difference that you have to keep in mind is you can only deal

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with objects that you have written to the pipeline using

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Write‑Output, what you really don't need, just let PowerShell do its

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thing, and then consume those objects.

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Using Write‑Host is telling PowerShell, take whatever this is

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and just display it to me so I can look at it.

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I really can't do anything else with it.

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All right, so here's something else.

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I'm going to create a variable called "Jeff." Most of the

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time, that's really all you need to do.

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Just define the variable,

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assign it a value, and you're ready to go, and you can use it.

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I can just do $Name and it shows me the name of the variable.

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You can, however,

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use the hosting capabilities to prompt using Read‑Host for a

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value. So I could say Read‑Host and give it a prompt, hey, "Enter

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a service name." And let's put in bits.

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So now $name is the name of a service,

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and if I do Get‑Service, or using the alias gsv, and my

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variable, I can see that is working.

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This also works, this Read‑Host for credentials, or should I say secure strings.

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So I can say, hey, enter a credential for the password for the username.

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Now, put something in. Now that Get‑Credential, by the way,

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all it's doing is allowing you to input a credential.

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I have no idea if that password I put in was correct or not.

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I won't know until I use that.

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But you can see, though, that it masked the password and I now

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have a credential object that I could use with other commands

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that might take a credential object.

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I'm not going to demo anything like that right now.

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You probably really aren't going to use Read‑Host until you start scripting,

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but I wanted you to see that it is available if you were doing something

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interactively and you kind of wanted to be prompted or take advantage of that.

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I've gone through a lot of demo in this module.

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If you felt a little lost,

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that's okay, and actually to be expected. Download the demo files and

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try some of the commands in PowerShell yourself.

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Now,

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I know some people get worked up and feel a little bit

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nervous about working at a Command Prompt.

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Relax.

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You're not going to break anything.

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I'm trusting you're trying everything out here in a

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non‑critical desktop. Using PowerShell to get your job

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done is a simple three‑step process.

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First, find the command you think you need to use.

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Read the help and examples. And then lastly, run the command from the prompt.

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Don't worry about scripting right now.

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Focus on running commands from the PowerShell prompt.

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So that's it for now.

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I suggest you take a quick break,

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stretch your legs, and then come on back to learn more about putting PowerShell to work.