1 00:00:01,840 --> 00:00:05,190 All of this will be much easier to understand when you see it in action, 2 00:00:05,190 --> 00:00:10,540 so let's head back to PowerShell and look at objects in the pipeline. 3 00:00:10,540 --> 00:00:12,540 Now, if you haven't already done so, 4 00:00:12,540 --> 00:00:14,900 if you want to follow along with these demonstrations, 5 00:00:14,900 --> 00:00:17,760 you'll need the PSTeachingTools module which I talked 6 00:00:17,760 --> 00:00:21,340 about and showed you in the last module, 7 00:00:21,340 --> 00:00:23,690 because I'm going to run Get‑Vegetable. 8 00:00:23,690 --> 00:00:26,940 We're going to demo all of these concepts with my generic 9 00:00:26,940 --> 00:00:30,700 command so that you can focus on the concepts and not get 10 00:00:30,700 --> 00:00:33,240 too caught up on the technology. 11 00:00:33,240 --> 00:00:36,340 So I run Get‑Vegetable and I get a result. 12 00:00:36,340 --> 00:00:38,840 Now, what type of object is that? 13 00:00:38,840 --> 00:00:43,940 Well, let's rerun Get‑Vegetable and pipe it to Get‑Member. 14 00:00:43,940 --> 00:00:50,440 So there you can see the TypeName is PSTeachingTools.PSVegetable object, 15 00:00:50,440 --> 00:00:54,560 and you can see the methods and the properties. 16 00:00:54,560 --> 00:00:54,670 Now, 17 00:00:54,670 --> 00:00:59,510 some of the methods that PowerShell will display like Equals and GetHashCode, 18 00:00:59,510 --> 00:01:02,740 PowerShell adds to all objects, 19 00:01:02,740 --> 00:01:06,640 and that the more you look at this you'll start recognizing those things. 20 00:01:06,640 --> 00:01:09,970 The methods that are unique to these object types, 21 00:01:09,970 --> 00:01:14,500 in this case my PSVegetable object, are things like Peel and Prepare, 22 00:01:14,500 --> 00:01:17,290 and then you can see the properties like Color, 23 00:01:17,290 --> 00:01:19,340 CookedState, Count. 24 00:01:19,340 --> 00:01:21,060 You can limit the results. 25 00:01:21,060 --> 00:01:22,990 This isn't too bad because it's a small object, 26 00:01:22,990 --> 00:01:26,940 but let's do Get‑Vegetable, pipe it again to Get‑Member, 27 00:01:26,940 --> 00:01:28,850 and this time I'm going to tell it, hey, 28 00:01:28,850 --> 00:01:31,640 only show me the properties. 29 00:01:31,640 --> 00:01:33,330 When you get to stuff like process objects, 30 00:01:33,330 --> 00:01:33,980 for example, 31 00:01:33,980 --> 00:01:38,170 you'll want to limit the results so you're not scrolling back and forth. 32 00:01:38,170 --> 00:01:44,240 So there we go, there are just the properties of my object, a little bit easier. 33 00:01:44,240 --> 00:01:50,690 So, let's run Get‑Vegetable, and let's just do corn. 34 00:01:50,690 --> 00:01:54,040 Now, look at that output. 35 00:01:54,040 --> 00:01:57,000 So the output, you see UPC, Count, Name, 36 00:01:57,000 --> 00:01:58,020 State, and Color, 37 00:01:58,020 --> 00:02:02,980 but you don't necessarily see all of those property names in the 38 00:02:02,980 --> 00:02:05,110 list there that you see with the properties, 39 00:02:05,110 --> 00:02:05,900 right? 40 00:02:05,900 --> 00:02:08,510 For example, there's no IsPeeled. 41 00:02:08,510 --> 00:02:13,840 That's part of the object, but it's not part of the default display. 42 00:02:13,840 --> 00:02:17,140 We're going to do more with properties in the next module. 43 00:02:17,140 --> 00:02:18,610 Let's look at methods now. 44 00:02:18,610 --> 00:02:21,040 So, again, we'll go back to Get‑Vegetable, 45 00:02:21,040 --> 00:02:25,500 pipe to Get‑Member, and this time we'll tell it only show me Methods, 46 00:02:25,500 --> 00:02:31,240 Peel, Prepare, those are the methods of this particular object. 47 00:02:31,240 --> 00:02:31,480 Now, 48 00:02:31,480 --> 00:02:34,960 we don't have to rely on these methods in order to 49 00:02:34,960 --> 00:02:39,170 manipulate the object, look for commands, and in 50 00:02:39,170 --> 00:02:41,610 PowerShell's case with my vegetable commands, 51 00:02:41,610 --> 00:02:44,580 if there's a Get, well, there is a corresponding Set. 52 00:02:44,580 --> 00:02:46,490 Not always, but often there is. 53 00:02:46,490 --> 00:02:49,450 So, I can try, hey, I could use get command and say, 54 00:02:49,450 --> 00:02:52,050 hey, is there a Set‑Vegetable, or just look for help, 55 00:02:52,050 --> 00:02:55,940 and sure enough there is a Set‑Vegetable cmdlet, 56 00:02:55,940 --> 00:03:00,140 and you can see the parameters there on how to use it. 57 00:03:00,140 --> 00:03:01,600 So let's go ahead and use it. 58 00:03:01,600 --> 00:03:04,440 Let's do Set‑Vegetable, 59 00:03:04,440 --> 00:03:09,410 and we'll use the name for corn, we'll set the cookingstate to grilled, 60 00:03:09,410 --> 00:03:14,160 and because this has ‑Whatif, and we talked about this a little bit last time, 61 00:03:14,160 --> 00:03:15,950 let's do ‑Whatif. 62 00:03:15,950 --> 00:03:20,150 So ‑Whatif tells PowerShell, I'm not going to make the change, 63 00:03:20,150 --> 00:03:23,540 but this is what I would have done if you let me do it, and it would have 64 00:03:23,540 --> 00:03:29,940 set the cookingstate to grilled on the vegetable corn. 65 00:03:29,940 --> 00:03:32,740 So I'm going to retype this command, 66 00:03:32,740 --> 00:03:37,340 and let's go ahead and actually do it without ‑Whatif. 67 00:03:37,340 --> 00:03:38,370 Did it change? 68 00:03:38,370 --> 00:03:39,640 Well, I don't know. 69 00:03:39,640 --> 00:03:40,650 I didn't get a result. 70 00:03:40,650 --> 00:03:42,940 Why did I not get a result? 71 00:03:42,940 --> 00:03:46,240 Well, if you look back up in the help, see that ‑Passthru? 72 00:03:46,240 --> 00:03:48,110 Yeah, if you see that, 73 00:03:48,110 --> 00:03:51,290 that's your clue this command is not going to write an 74 00:03:51,290 --> 00:03:54,140 object to the pipeline by default. 75 00:03:54,140 --> 00:03:58,720 I need to use ‑Passthru if I want to force it to show me 76 00:03:58,720 --> 00:04:01,940 the object that it is working with. 77 00:04:01,940 --> 00:04:04,110 And we can try this again here. 78 00:04:04,110 --> 00:04:05,740 Let's do Get‑Vegetable, 79 00:04:05,740 --> 00:04:08,650 and now you can see that it actually did change the state, 80 00:04:08,650 --> 00:04:11,740 because now it is showing up as Grilled. 81 00:04:11,740 --> 00:04:14,640 And if we look at help for Set‑Vegetable, 82 00:04:14,640 --> 00:04:17,090 and we can see there is a ‑Passthru parameter, 83 00:04:17,090 --> 00:04:21,410 and it tells you there in the help, Write object to the pipeline. 84 00:04:21,410 --> 00:04:22,360 Let's try this here. 85 00:04:22,360 --> 00:04:25,640 Let's do Get‑Vegetable, and let's just get the root vegetables. 86 00:04:25,640 --> 00:04:29,050 We're going to pipe all of those vegetables to Set‑Vegetable, 87 00:04:29,050 --> 00:04:33,890 and change the CookingState to Roasted, we're going to change the Count to 5, 88 00:04:33,890 --> 00:04:37,540 and now I'll use ‑Passthru. 89 00:04:37,540 --> 00:04:38,350 See the difference? 90 00:04:38,350 --> 00:04:43,100 So now ‑Passthru gives me the object that Set‑Vegetable worked on, 91 00:04:43,100 --> 00:04:45,770 and you can see that it changed the Count and it 92 00:04:45,770 --> 00:04:49,240 changed the CookingState of that object. 93 00:04:49,240 --> 00:04:52,960 There's no scripting there, I just told PowerShell get these things, 94 00:04:52,960 --> 00:04:56,040 do this with it, show me the results. 95 00:04:56,040 --> 00:04:58,810 No scripting, PowerShell did that all at once. 96 00:04:58,810 --> 00:05:02,940 I did it for, you know, four objects here. 97 00:05:02,940 --> 00:05:04,280 It could have been 4,000. 98 00:05:04,280 --> 00:05:05,530 It's the same command. 99 00:05:05,530 --> 00:05:07,420 This is what I'm talking about when I get excited 100 00:05:07,420 --> 00:05:10,850 about PowerShell managing at scale. 101 00:05:10,850 --> 00:05:15,840 Let's try one more example here with the PowerShell pipeline. 102 00:05:15,840 --> 00:05:21,240 I have a text file in my work folder called services.txt. 103 00:05:21,240 --> 00:05:23,710 It's just a list of services. 104 00:05:23,710 --> 00:05:26,990 Now I'm going to create an audit trail. 105 00:05:26,990 --> 00:05:33,630 I want to get the services, restart them, and save the results to a text file. 106 00:05:33,630 --> 00:05:37,920 In order to show you how this all works, let's break it down into simple steps. 107 00:05:37,920 --> 00:05:41,870 So Get‑Service has a Name parameter, which we have seen. 108 00:05:41,870 --> 00:05:47,140 And we can look at help here and see that it does accept pipeline input. 109 00:05:47,140 --> 00:05:47,530 Good. 110 00:05:47,530 --> 00:05:52,110 And I can test this very easily, just take a simple service like Lanmanserver, 111 00:05:52,110 --> 00:05:57,030 pipe to Get‑Service, and sure enough, it works. 112 00:05:57,030 --> 00:06:00,940 What I want you to do as I walk through this process is see if 113 00:06:00,940 --> 00:06:04,550 you can visualize what PowerShell is doing. 114 00:06:04,550 --> 00:06:06,450 Really important skill, I think, 115 00:06:06,450 --> 00:06:10,940 that will make PowerShell easier if you can do it. 116 00:06:10,940 --> 00:06:14,340 So we're going to do Get‑Content, the command I just ran. 117 00:06:14,340 --> 00:06:15,800 So I'm going to get the content. 118 00:06:15,800 --> 00:06:17,810 You already saw what it's going to do, right? 119 00:06:17,810 --> 00:06:21,110 It's going to give me a list of service names. 120 00:06:21,110 --> 00:06:24,690 I'm then going to pipe that, and when this happens, 121 00:06:24,690 --> 00:06:28,280 by the way, when you get that little double arrow there, 122 00:06:28,280 --> 00:06:30,580 that's PowerShell's way of telling you, hey, 123 00:06:30,580 --> 00:06:32,420 there must be more to the command, 124 00:06:32,420 --> 00:06:34,850 because I can't figure out what you want me to do. 125 00:06:34,850 --> 00:06:38,710 So if you're running a command and you aren't expecting to see this, 126 00:06:38,710 --> 00:06:40,260 you're thinking, hey, how come you're not running, 127 00:06:40,260 --> 00:06:45,530 you probably forgot closing curly brace or parenthesis or some piece of 128 00:06:45,530 --> 00:06:49,460 punctuation PowerShell doesn't understand what you are doing. 129 00:06:49,460 --> 00:06:50,140 In my case, 130 00:06:50,140 --> 00:06:55,010 I intentionally wanted to start each command on its own line to 131 00:06:55,010 --> 00:06:58,660 try to reinforce what the pipeline is doing. 132 00:06:58,660 --> 00:07:00,340 So we're going to get the content, 133 00:07:00,340 --> 00:07:02,550 we're then going to pipe it to another command, 134 00:07:02,550 --> 00:07:03,940 Get‑Service. 135 00:07:03,940 --> 00:07:06,240 We already know what that's going to do, right? 136 00:07:06,240 --> 00:07:12,140 It's going to take his output and pipe it to another command. 137 00:07:12,140 --> 00:07:16,840 We're going to pipe to Restart‑Service, and I'm using ‑Passthru. 138 00:07:16,840 --> 00:07:18,450 That's your clue, remember, 139 00:07:18,450 --> 00:07:21,560 that that command does not write objects to the pipeline. 140 00:07:21,560 --> 00:07:26,650 But I need objects to the pipeline, because if I don't use ‑Passthru, 141 00:07:26,650 --> 00:07:30,790 this next line where I'm going to create the file won't do anything. 142 00:07:30,790 --> 00:07:32,460 It'll create an empty file. 143 00:07:32,460 --> 00:07:38,510 Using ‑Passthru tells PowerShell, take the service objects that you restarted, 144 00:07:38,510 --> 00:07:41,130 send them onto the pipeline, and in this case, 145 00:07:41,130 --> 00:07:46,140 send them to Out‑File, which does its thing and creates the text file. 146 00:07:46,140 --> 00:07:51,580 PowerShell is doing its thing, I got no errors, so it must have worked. 147 00:07:51,580 --> 00:07:55,740 And if I look at the content of my restart.txt, 148 00:07:55,740 --> 00:08:00,290 there are the service objects that Restart‑Service wrote to the pipeline, 149 00:08:00,290 --> 00:08:03,240 which I captured with Out‑File. 150 00:08:03,240 --> 00:08:05,760 When you're learning and working with PowerShell 151 00:08:05,760 --> 00:08:09,590 and just kind of getting started, don't try to write, 152 00:08:09,590 --> 00:08:11,840 you know, this entire command that I just showed you. 153 00:08:11,840 --> 00:08:13,520 Don't try to write it all at once. 154 00:08:13,520 --> 00:08:16,460 That's what I was saying, you may think you know what you're doing, 155 00:08:16,460 --> 00:08:19,420 but a lot of beginners, there's a lot you're learning, 156 00:08:19,420 --> 00:08:21,890 and so if it doesn't work, you wont know, 157 00:08:21,890 --> 00:08:24,440 okay, which part of the command didn't work? 158 00:08:24,440 --> 00:08:26,140 Do the first part. 159 00:08:26,140 --> 00:08:27,190 Good, it works. 160 00:08:27,190 --> 00:08:28,540 Pipe onto the next part. 161 00:08:28,540 --> 00:08:29,510 Good, that worked. 162 00:08:29,510 --> 00:08:30,720 Then pipe onto the next part. 163 00:08:30,720 --> 00:08:32,640 Good, that works. 164 00:08:32,640 --> 00:08:37,780 As you slowly build experience, you'll be able to do more and more faster, 165 00:08:37,780 --> 00:08:40,410 but don't push yourself from the beginning. 166 00:08:40,410 --> 00:08:45,040 Try to visualize, what is PowerShell trying to do? 167 00:08:45,040 --> 00:08:48,070 Let me point out that PowerShell doesn't mean you have to write 168 00:08:48,070 --> 00:08:50,410 everything in a single pipeline expression, 169 00:08:50,410 --> 00:08:53,600 but taking advantage of the pipeline means that you can get a lot 170 00:08:53,600 --> 00:08:56,920 done with less work than the way we used to have to script with 171 00:08:56,920 --> 00:08:59,150 tools like VBScript or batch files. 172 00:08:59,150 --> 00:08:59,490 Of course, 173 00:08:59,490 --> 00:09:03,300 the best way that you can understand all of this is to try it yourself. 174 00:09:03,300 --> 00:09:05,540 If you make a mistake, pause, 175 00:09:05,540 --> 00:09:08,580 take a moment to read the error message, it most likely will tell you 176 00:09:08,580 --> 00:09:11,540 what to do to fix the problem, and then try again. 177 00:09:11,540 --> 00:09:15,050 I also encourage you to visualize or verbalize what 178 00:09:15,050 --> 00:09:17,430 you're trying to have PowerShell do. 179 00:09:17,430 --> 00:09:22,150 Often, when you say it out loud, it becomes easier to figure out what to do, 180 00:09:22,150 --> 00:09:23,950 and once you say it out loud, 181 00:09:23,950 --> 00:09:26,840 then it becomes easier to figure out what commands to use. 182 00:09:26,840 --> 00:09:29,320 And don't be afraid to reread help and examples. 183 00:09:29,320 --> 00:09:32,810 You need to get in the habit of reading and rereading help, 184 00:09:32,810 --> 00:09:35,540 even for commands that you think you understand. 185 00:09:35,540 --> 00:09:37,770 PowerShell is still under active development, 186 00:09:37,770 --> 00:09:40,840 and I really don't expect that to change any time soon. 187 00:09:40,840 --> 00:09:43,520 You're going to see new releases a few times a year, 188 00:09:43,520 --> 00:09:46,910 and the PowerShell team might introduce a new cmdlet or parameter, 189 00:09:46,910 --> 00:09:49,810 or they might update help with new examples. 190 00:09:49,810 --> 00:09:52,640 And don't forget the about help topic. 191 00:09:52,640 --> 00:09:55,720 Staying on top of the help will go a long way in helping you get the 192 00:09:55,720 --> 00:10:04,000 most out of working with objects in the pipeline. In the next module, we'll take this concept another step, so I'll see you there.