1 00:00:01,040 --> 00:00:01,570 Next, 2 00:00:01,570 --> 00:00:05,100 let's turn our attention to running commands. As I 3 00:00:05,100 --> 00:00:06,540 showed you in the slides, really, 4 00:00:06,540 --> 00:00:09,340 all you need to do is once you know the command is just type 5 00:00:09,340 --> 00:00:12,910 it out and hit Enter. And I can, in this case, get all the 6 00:00:12,910 --> 00:00:16,100 processes on my computer. Now, 7 00:00:16,100 --> 00:00:20,550 in order to demonstrate some of these commands and the concepts and techniques, 8 00:00:20,550 --> 00:00:24,650 I'm going to use a command called Get‑Vegetable. 9 00:00:24,650 --> 00:00:26,480 Now, this is a command that I wrote, 10 00:00:26,480 --> 00:00:30,400 and it is part of a module called PS Teaching Tools, 11 00:00:30,400 --> 00:00:34,230 which you can install from the PowerShell gallery in the download 12 00:00:34,230 --> 00:00:36,840 materials. There's notes on how you can do that. 13 00:00:36,840 --> 00:00:43,740 I find that using a non‑technical example, like vegetable, sometimes 14 00:00:43,740 --> 00:00:48,880 helps a great deal in letting you focus on the techniques and concepts 15 00:00:48,880 --> 00:00:52,740 without getting hung up on the underlying technology, so you're not 16 00:00:52,740 --> 00:00:58,870 looking at services or user accounts or processes. We're just taking 17 00:00:58,870 --> 00:01:02,610 something generic and focusing on the concept. Because once you apply 18 00:01:02,610 --> 00:01:03,200 the concept, 19 00:01:03,200 --> 00:01:05,860 it doesn't matter whether we're applying it to vegetables, this 20 00:01:05,860 --> 00:01:09,120 fake object that I'm creating, or services. 21 00:01:09,120 --> 00:01:12,010 The concepts apply across PowerShell. 22 00:01:12,010 --> 00:01:13,410 Get some noun, 23 00:01:13,410 --> 00:01:17,100 so we get a verb, get, and a singular version of the thing we 24 00:01:17,100 --> 00:01:20,240 want to imagine, in this case, vegetables. 25 00:01:20,240 --> 00:01:20,710 There we go. 26 00:01:20,710 --> 00:01:25,320 So there's my default output. So I can do Get‑Vegetable, and I can 27 00:01:25,320 --> 00:01:28,930 also look for help on how to run this command. 28 00:01:28,930 --> 00:01:32,980 So you can see there are just a couple of parameters there, name, and 29 00:01:32,980 --> 00:01:39,260 whether it's a root only. So I could Get‑Vegetable ‑name corn. 30 00:01:39,260 --> 00:01:41,680 Remember, parameters, dash, the name of the 31 00:01:41,680 --> 00:01:48,080 parameter, a space, and then the value, and they were just the corn vegetables. 32 00:01:48,080 --> 00:01:51,140 Now that RootOnly parameter that you see up there, 33 00:01:51,140 --> 00:01:52,930 notice there's no value after that. 34 00:01:52,930 --> 00:01:55,040 That means it is a switch. 35 00:01:55,040 --> 00:01:58,790 I only have to use that parameter in order, in a 36 00:01:58,790 --> 00:02:00,780 sense, to turn that on in the command. 37 00:02:00,780 --> 00:02:03,990 You don't have to worry about what it's doing under the hood; the 38 00:02:03,990 --> 00:02:06,120 help will tell you. And in this case, it will say, 39 00:02:06,120 --> 00:02:10,440 hey, only show me vegetables that are classified as root vegetables. 40 00:02:10,440 --> 00:02:14,120 So if I run that here, and sure enough, 41 00:02:14,120 --> 00:02:21,400 those as far as I know are root vegetables. All commands have the verbose 42 00:02:21,400 --> 00:02:24,660 parameter because that's one of the common parameters. 43 00:02:24,660 --> 00:02:25,480 However, 44 00:02:25,480 --> 00:02:28,400 that parameter won't do anything unless the command has 45 00:02:28,400 --> 00:02:30,360 been coded to do something with it. 46 00:02:30,360 --> 00:02:34,580 So in my case, Get‑Verbose shows me a command that 47 00:02:34,580 --> 00:02:38,140 found 17 items, it's processing, and then it's ending. 48 00:02:38,140 --> 00:02:42,640 Not every command will do that; you won't know until you try. 49 00:02:42,640 --> 00:02:47,150 So now that we understand kind of the concepts from that generic command, 50 00:02:47,150 --> 00:02:50,340 let's go into PowerShell and try the same things. 51 00:02:50,340 --> 00:02:55,060 So let's use Get‑Service and let's find all of the services that 52 00:02:55,060 --> 00:03:00,280 start with win, and I'll use verbose just to show you that in 53 00:03:00,280 --> 00:03:01,800 this case it doesn't do anything. 54 00:03:01,800 --> 00:03:07,440 It doesn't hurt anything, but it also doesn't give me any added value. 55 00:03:07,440 --> 00:03:12,140 Now, some parameters, as I mentioned, in PowerShell are positional. 56 00:03:12,140 --> 00:03:16,730 If I do Get‑Service win*, PowerShell assumes that whatever I 57 00:03:16,730 --> 00:03:22,440 put immediately after the cmdlet name, I must mean the name parameter. 58 00:03:22,440 --> 00:03:23,180 And sure enough, 59 00:03:23,180 --> 00:03:27,760 that's what happens. Now you can see this in the help, if I do 60 00:03:27,760 --> 00:03:32,480 Help on Get‑Service and look at that name parameter, you can 61 00:03:32,480 --> 00:03:36,940 see there that it is not required, which means it's not mandatory, 62 00:03:36,940 --> 00:03:41,650 and it has a position of 0, meaning it's the first position. 63 00:03:41,650 --> 00:03:44,680 If it was required, it would be named. 64 00:03:44,680 --> 00:03:45,850 Let me show you that. 65 00:03:45,850 --> 00:03:51,240 Let's look at another parameter, requiredServices. 66 00:03:51,240 --> 00:03:52,750 There you can see that position. 67 00:03:52,750 --> 00:03:54,300 See, it says named. 68 00:03:54,300 --> 00:03:59,080 So if I wanted to use this parameter, I actually have to type it out. 69 00:03:59,080 --> 00:04:03,640 And in this case, I kind of have to type it out anyway because it is a switch. 70 00:04:03,640 --> 00:04:07,340 So I can do get service bits, so bits is the value for 71 00:04:07,340 --> 00:04:10,340 the name parameter which is positional. 72 00:04:10,340 --> 00:04:12,180 So I don't have to type ‑name, 73 00:04:12,180 --> 00:04:17,160 but I do need to type ‑RequiredServices if I want to use that parameter. 74 00:04:17,160 --> 00:04:22,940 So this is showing me all the required services that bits needs. 75 00:04:22,940 --> 00:04:23,530 All right, 76 00:04:23,530 --> 00:04:27,760 let's look at processes, just because there's some interesting 77 00:04:27,760 --> 00:04:31,040 things here to show you in terms of parameters. 78 00:04:31,040 --> 00:04:32,790 So I do help Get‑Process. 79 00:04:32,790 --> 00:04:36,340 You can see there are a number of ways that I can get 80 00:04:36,340 --> 00:04:41,840 a process, by name or process ID. 81 00:04:41,840 --> 00:04:45,660 So I'm going to try get‑process. $pid is a built‑in 82 00:04:45,660 --> 00:04:50,400 variable that shows you the current process ID of your 83 00:04:50,400 --> 00:04:53,590 PowerShell session. And that failed. 84 00:04:53,590 --> 00:04:55,790 But I see there there's Get‑Process, 85 00:04:55,790 --> 00:04:59,880 and I should be able to give it the Id. How come that didn't work? Well, 86 00:04:59,880 --> 00:05:02,720 if we come back here and look at help on get‑process 87 00:05:02,720 --> 00:05:07,270 and look at that Id parameter, you can see its position. 88 00:05:07,270 --> 00:05:08,200 It's named. 89 00:05:08,200 --> 00:05:11,080 I have to specify and tell PowerShell, hey, 90 00:05:11,080 --> 00:05:14,330 you need to use the Id parameter so that it knows what 91 00:05:14,330 --> 00:05:19,040 that value $pid what it goes to. 92 00:05:19,040 --> 00:05:23,760 So if I rerun the command and use ‑id and give it the value, now 93 00:05:23,760 --> 00:05:26,120 that works, and that's what I am expecting. 94 00:05:26,120 --> 00:05:29,990 So you have to be in the habit of reading the help so that you 95 00:05:29,990 --> 00:05:32,960 totally can understand what PowerShell is doing, 96 00:05:32,960 --> 00:05:37,140 why things work, or, more importantly, why things sometimes don't work. 97 00:05:37,140 --> 00:05:41,710 Look here then now at some mandatory parameters. If I run 98 00:05:41,710 --> 00:05:47,040 Get‑CimInstance and just stop it by itself, 99 00:05:47,040 --> 00:05:49,010 I get prompted, because it says, hey, 100 00:05:49,010 --> 00:05:53,510 there needs to be a ClassName for this command. 101 00:05:53,510 --> 00:05:58,140 I need to know what types of CimInstance information do you want me to get. 102 00:05:58,140 --> 00:06:01,380 So I'm just going to hit Enter just to get the error message, hey, 103 00:06:01,380 --> 00:06:06,140 you have to give me something. Okay, and let's go back and look at help. 104 00:06:06,140 --> 00:06:09,040 And I used wildcards here because I want to show you a couple things here. 105 00:06:09,040 --> 00:06:12,560 The ClassName is required and it's positional, 106 00:06:12,560 --> 00:06:12,900 which means, 107 00:06:12,900 --> 00:06:18,070 right, I don't have to specify, I don't have to type the ‑ClassName 108 00:06:18,070 --> 00:06:23,860 parameter. ComputerName, if we scroll down here, is not required, 109 00:06:23,860 --> 00:06:28,310 but it is a named parameter. So if I want to use it, 110 00:06:28,310 --> 00:06:31,740 I have to include the parameter name. 111 00:06:31,740 --> 00:06:36,740 So let's kind of put these things together here. Let's do Get‑CimInstance 112 00:06:36,740 --> 00:06:42,340 and get the win32_operating system for the localhost. 113 00:06:42,340 --> 00:06:46,670 And I'm going to throw in verbose output just because to show you, this 114 00:06:46,670 --> 00:06:50,610 particular cmdlet does have verbose output, and it will give you some 115 00:06:50,610 --> 00:06:54,740 additional information which may be of value to you. 116 00:06:54,740 --> 00:06:55,410 So there we go. 117 00:06:55,410 --> 00:07:02,040 So the ClassName is positional, no parameter name, but ComputerName is 118 00:07:02,040 --> 00:07:06,240 required. I have to specify that parameter if I want to do it. 119 00:07:06,240 --> 00:07:10,640 If I just ran that command without ‑ComputerName and just put in localhost, 120 00:07:10,640 --> 00:07:14,890 PowerShell would not know what parameter that belongs to. 121 00:07:14,890 --> 00:07:27,000 And I probably would be getting an error. Help again. That is the answer to figuring out why things work or why things won't work.