1 00:00:01,080 --> 00:00:04,440 Next, I want to move to a set of commands, 2 00:00:04,440 --> 00:00:08,690 and you can install this module from the PowerShell gallery. 3 00:00:08,690 --> 00:00:11,200 I have notes in the demo file on how to do that if 4 00:00:11,200 --> 00:00:12,700 you want to follow along here. 5 00:00:12,700 --> 00:00:16,680 So let's say that you have a completely new command 6 00:00:16,680 --> 00:00:18,670 that you've been assigned, told, hey, 7 00:00:18,670 --> 00:00:22,270 we need you to work with these sets of PowerShell tools, but 8 00:00:22,270 --> 00:00:25,670 you have no idea how to use the tool, so you have to use the 9 00:00:25,670 --> 00:00:32,120 help. My tools that I wrote here, that you can work with, are vegetable commands. 10 00:00:32,120 --> 00:00:34,950 So I have a command called Get‑Vegetable, and we're just 11 00:00:34,950 --> 00:00:39,580 going to look at just the parameters for Get‑Vegetable. And 12 00:00:39,580 --> 00:00:42,510 you can see that it has name, 13 00:00:42,510 --> 00:00:46,740 so it will take a single string, notice there's no square brackets, 14 00:00:46,740 --> 00:00:50,730 the name of vegetable, it's not required, it's positional, 15 00:00:50,730 --> 00:00:55,530 which means I don't have to type ‑name, it takes pipeline input, and it 16 00:00:55,530 --> 00:01:01,020 will accept wildcards, RootOnly is a switch, alright, 17 00:01:01,020 --> 00:01:05,510 so those are really the only parameters for that command. 18 00:01:05,510 --> 00:01:07,920 You know what, let's just run it. It's a get command, you 19 00:01:07,920 --> 00:01:10,800 know, what's the worst that can happen? So let's run 20 00:01:10,800 --> 00:01:14,060 Get‑Vegetable, and there we go. 21 00:01:14,060 --> 00:01:17,960 So I get an object, and the nice thing about this command, these vegetable 22 00:01:17,960 --> 00:01:20,640 commands, is they have nothing to do with technology. 23 00:01:20,640 --> 00:01:25,120 You can just focus on the PowerShell concepts without worrying 24 00:01:25,120 --> 00:01:28,020 about the technology underneath the hood, because you don't need 25 00:01:28,020 --> 00:01:31,140 anything other than the commands and they'll create these kind of 26 00:01:31,140 --> 00:01:33,840 fake vegetable objects for you. 27 00:01:33,840 --> 00:01:34,730 Get‑Vegetable works. 28 00:01:34,730 --> 00:01:36,570 Let's go back and try Get‑Vegetable, let's try that 29 00:01:36,570 --> 00:01:38,390 other parameter, that switch parameter. 30 00:01:38,390 --> 00:01:38,730 Remember, 31 00:01:38,730 --> 00:01:44,850 I don't have to type any values after that, just ‑RootOnly is enough, and the 32 00:01:44,850 --> 00:01:49,030 command is designed to only show me vegetables that belong, that are root 33 00:01:49,030 --> 00:01:51,740 vegetables like carrots and turnips and potatoes, 34 00:01:51,740 --> 00:01:52,930 that sort of thing. 35 00:01:52,930 --> 00:01:59,240 Alright, so the help reinforced and told me how to use the command. 36 00:01:59,240 --> 00:02:03,190 Now I also know that the name parameter is positional, 37 00:02:03,190 --> 00:02:07,370 so I should be able to do Get‑Vegetable carrot, and that value 38 00:02:07,370 --> 00:02:11,680 carrot will be assigned to the name parameter, and sure enough, 39 00:02:11,680 --> 00:02:15,550 that works. Now some commands will have mandatory parameters. Let's 40 00:02:15,550 --> 00:02:18,440 look at help for New‑Vegetable. 41 00:02:18,440 --> 00:02:23,610 Now you can't quite tell it in the syntax there, 42 00:02:23,610 --> 00:02:29,580 so let's just quit this here, and I'm just going to do New‑Vegetable by itself. 43 00:02:29,580 --> 00:02:33,260 I didn't type in anything. PowerShell is saying, 44 00:02:33,260 --> 00:02:40,890 hey, New‑Vegetable has a parameter, ‑name, and it is required, it's mandatory, 45 00:02:40,890 --> 00:02:44,070 so it's prompting me to put in some value. See that 46 00:02:44,070 --> 00:02:47,360 little exclamation point, question mark? 47 00:02:47,360 --> 00:02:54,090 If you type that at the prompt there, 48 00:02:54,090 --> 00:02:56,610 if the command is written with a little help message, 49 00:02:56,610 --> 00:03:00,140 you can get that listed there, and then it'll tell you, hey, 50 00:03:00,140 --> 00:03:01,930 what is the name of the vegetable. 51 00:03:01,930 --> 00:03:06,370 So I'm going to go ahead and create, let's create okra. 52 00:03:06,370 --> 00:03:13,690 Oh, let's make it all proper lowercase here, okra. Okra is green, 53 00:03:13,690 --> 00:03:17,540 and I'm just going to make up a UPC code. 54 00:03:17,540 --> 00:03:20,260 Alright, so now I've created a new vegetable. 55 00:03:20,260 --> 00:03:26,340 I had the required parameter, but I was able to handle that just fine. 56 00:03:26,340 --> 00:03:28,670 If we go back and look at help for New‑Vegetable 57 00:03:28,670 --> 00:03:31,170 and look at that name parameter, sure enough, 58 00:03:31,170 --> 00:03:33,280 you can see that it is required. 59 00:03:33,280 --> 00:03:37,440 It's positional, so you don't have to specify the name parameter. 60 00:03:37,440 --> 00:03:44,500 There is no default value, and it doesn't accept wildcards. 61 00:03:44,500 --> 00:03:49,430 Let's look at one more example with my vegetable commands and parameters. 62 00:03:49,430 --> 00:03:53,140 Let's look at Set‑Vegetable. 63 00:03:53,140 --> 00:03:53,440 Alright, 64 00:03:53,440 --> 00:03:58,230 so you can see here there are two parameter sets to use this, 65 00:03:58,230 --> 00:04:01,050 one that allows you to do an input object, 66 00:04:01,050 --> 00:04:03,050 which means, generally when you see that, 67 00:04:03,050 --> 00:04:05,610 that means something is going to be piped into the command. 68 00:04:05,610 --> 00:04:10,320 Or you can specify modifying vegetables by parameters, you can see 69 00:04:10,320 --> 00:04:14,140 there's ‑name and parameters for changing the cooking state and 70 00:04:14,140 --> 00:04:17,430 the number of vegetables and whatnot. 71 00:04:17,430 --> 00:04:21,760 So let's just run help for Set‑Vegetable and look at 72 00:04:21,760 --> 00:04:24,420 all the parameters in more detail. 73 00:04:24,420 --> 00:04:27,780 So CookingState, you can see a little description there. 74 00:04:27,780 --> 00:04:29,190 You can see it's not required. 75 00:04:29,190 --> 00:04:30,400 It's named, which means, 76 00:04:30,400 --> 00:04:36,320 if I want to use that parameter I have to type ‑CookingState, count, 77 00:04:36,320 --> 00:04:39,320 input object, and so on, so you can look at those in 78 00:04:39,320 --> 00:04:42,400 a little more detail on your own. 79 00:04:42,400 --> 00:04:48,280 Let's go ahead and run Set‑Vegetable, and let's modify corn, and let's grill 80 00:04:48,280 --> 00:04:51,900 it, because I love grilled corn. And we'll use ‑passthru, 81 00:04:51,900 --> 00:04:57,110 which tells PowerShell, hey, show me the object that was written to 82 00:04:57,110 --> 00:05:01,230 the pipeline, and there is my updated object, 83 00:05:01,230 --> 00:05:04,370 which I can verify again by running Get‑Vegetable using the 84 00:05:04,370 --> 00:05:10,680 positional parameter corn, and there we go, so that all works. Even 85 00:05:10,680 --> 00:05:14,060 though I had no idea, and you have no idea how to use these commands, 86 00:05:14,060 --> 00:05:16,400 by taking the time to read the help, 87 00:05:16,400 --> 00:05:23,050 It will tell you what you can expect and how you can use the command. 88 00:05:23,050 --> 00:05:26,030 I know we're just getting started with PowerShell, but at least let me 89 00:05:26,030 --> 00:05:31,070 give you a taste of this idea of pipeline and object in the pipeline, 90 00:05:31,070 --> 00:05:35,120 because I want to make sure you can kind of understand what this looks 91 00:05:35,120 --> 00:05:38,800 like in terms of the help documentation. 92 00:05:38,800 --> 00:05:42,170 So if I look at my vegetable command and look at the name parameter 93 00:05:42,170 --> 00:05:47,700 again for Get‑Vegetable, we see, just to reiterate here, 94 00:05:47,700 --> 00:05:49,710 this will accept pipeline input, 95 00:05:49,710 --> 00:05:54,910 meaning I can send stuff into this command and it will take it by 96 00:05:54,910 --> 00:05:59,790 value or by property name. By value, again, means if I see 97 00:05:59,790 --> 00:06:02,740 something, a thing like a string or a word, 98 00:06:02,740 --> 00:06:07,780 I'm going to assume that must be the name of a vegetable. By property name 99 00:06:07,780 --> 00:06:14,390 means if I see an object, and if the object coming in has a name property, or 100 00:06:14,390 --> 00:06:20,030 to be clearer, a property called name, I will then take that value from the 101 00:06:20,030 --> 00:06:24,940 object and assign it to the name parameter, because the name parameter matches 102 00:06:24,940 --> 00:06:27,100 the name property on the object. 103 00:06:27,100 --> 00:06:28,630 Those two things go together, 104 00:06:28,630 --> 00:06:34,040 and so the values just kind of get piped and passed on through. 105 00:06:34,040 --> 00:06:37,800 So, let me show you this, now that you can kind of see that the help says, 106 00:06:37,800 --> 00:06:37,980 hey, 107 00:06:37,980 --> 00:06:43,280 this should work. So I should be able to get content on a list of vegetables 108 00:06:43,280 --> 00:06:49,010 that I have in my work folder and pipe them to Get‑Vegetable. PowerShell under 109 00:06:49,010 --> 00:06:51,430 the hood is going to go through that list and say, 110 00:06:51,430 --> 00:06:54,890 hey, I see the first value is carrot, 111 00:06:54,890 --> 00:06:57,930 so I'm going to assign that to the name parameter. 112 00:06:57,930 --> 00:07:01,320 I'll do that again for broccoli and then cauliflower, 113 00:07:01,320 --> 00:07:04,910 and so Get‑Vegetable gives me the results that I am expecting 114 00:07:04,910 --> 00:07:10,960 from reading in that list of vegetables from the text file. To 115 00:07:10,960 --> 00:07:16,140 make sure you really understand this, let's try something that's going to fail. 116 00:07:16,140 --> 00:07:21,480 So I'm just going to get a list of shares in a text file I have here, 117 00:07:21,480 --> 00:07:26,570 and I'm just going to save this to a variable $list so I don't have to rerun 118 00:07:26,570 --> 00:07:30,820 the Get‑Content, and just so you can see what is in $list. 119 00:07:30,820 --> 00:07:31,230 Alright, 120 00:07:31,230 --> 00:07:36,830 so I'm looking for shares on my computer called work, scripts, and reports. 121 00:07:36,830 --> 00:07:41,440 Now I have this command Get‑SMBshare, and we can look at help real quickly. 122 00:07:41,440 --> 00:07:48,050 You can see that there is a Name parameter. So I'm not even going to dig too 123 00:07:48,050 --> 00:07:50,730 far into it, let's just say I glanced at the help and go, 124 00:07:50,730 --> 00:07:57,370 okay, I should be able to maybe pipe $list to Get‑SMBshare, 125 00:07:57,370 --> 00:08:02,700 and I should be able to get all the shares that match those names in that list. 126 00:08:02,700 --> 00:08:04,050 No I don't. 127 00:08:04,050 --> 00:08:07,260 I get a bunch of error messages. Now, just so you know, 128 00:08:07,260 --> 00:08:12,360 I changed the color of the background error message so that 129 00:08:12,360 --> 00:08:15,230 it would be easier to see on the screen. 130 00:08:15,230 --> 00:08:18,020 Get‑SMBshare is giving me errors that says, 131 00:08:18,020 --> 00:08:18,740 hey, 132 00:08:18,740 --> 00:08:23,530 the input object cannot be mapped or bound to the parameters of any command, 133 00:08:23,530 --> 00:08:27,100 and I get that three times because it's trying to do that for each thing 134 00:08:27,100 --> 00:08:30,340 that is getting piped in. And I may be thinking, 135 00:08:30,340 --> 00:08:31,840 well, why doesn't that work? 136 00:08:31,840 --> 00:08:36,440 I mean, it worked for Get‑Vegetable, why doesn't it work for Get‑SMBshare? 137 00:08:36,440 --> 00:08:38,580 This is why you need to read the help. 138 00:08:38,580 --> 00:08:42,520 So I go back now and look at the Name parameter. 139 00:08:42,520 --> 00:08:48,180 You can see that it will take names as a collection of strings, 140 00:08:48,180 --> 00:08:52,090 but it does not accept pipeline input by value, 141 00:08:52,090 --> 00:08:53,550 which is what I was trying to do. 142 00:08:53,550 --> 00:08:56,720 It will take it by property names. 143 00:08:56,720 --> 00:09:03,010 So what that means is if I were to do import csv, and if I have a CSV file that 144 00:09:03,010 --> 00:09:10,970 has the names of the shares, then that I can pipe into Get‑SMBshare and that 145 00:09:10,970 --> 00:09:15,100 works, and I get an error for reports because that share does not exist on the 146 00:09:15,100 --> 00:09:19,360 computer, and that's kind of what I want to see here anyway. You can take a 147 00:09:19,360 --> 00:09:25,910 look at data.csv if you want to see how that file is structured. Import csv is 148 00:09:25,910 --> 00:09:29,550 reading the CSV file and creating an object with the header names as the 149 00:09:29,550 --> 00:09:30,940 property names. 150 00:09:30,940 --> 00:09:33,660 There is a property called Name, 151 00:09:33,660 --> 00:09:39,150 so PowerShell says, hey, this command can take input by property name, and 152 00:09:39,150 --> 00:09:43,620 so I'll take that name property of the incoming object, assign it to the 153 00:09:43,620 --> 00:09:47,240 parameter value, and then the magic happens. 154 00:09:47,240 --> 00:09:49,680 That is the power of the pipeline, 155 00:09:49,680 --> 00:09:53,180 and you may need to refer to the PowerShell help to understand 156 00:09:53,180 --> 00:09:57,490 why it may or may not be working in your work or the things 157 00:09:57,490 --> 00:10:03,000 that you are trying to get done. So with that, let's go back to the slides and wrap up this lesson.