1 00:00:00,210 --> 00:00:01,470 Now a lot of times in Linux, 2 00:00:01,470 --> 00:00:03,360 we're going to have to do operations 3 00:00:03,360 --> 00:00:05,130 on the files that we create 4 00:00:05,130 --> 00:00:07,560 but the most common one is just to view them. 5 00:00:07,560 --> 00:00:11,130 Now, in this example, we're going to use the log file 6 00:00:11,130 --> 00:00:14,010 because we're going to tend to spend a lot of time there. 7 00:00:14,010 --> 00:00:15,930 So we're going to test out two versions 8 00:00:15,930 --> 00:00:19,380 of how to view these, the cat, which stands for concatenate 9 00:00:19,380 --> 00:00:21,510 and the less command. 10 00:00:21,510 --> 00:00:25,170 Now the original use of cat was to join two files 11 00:00:25,170 --> 00:00:27,450 or put the contents on one file into another 12 00:00:27,450 --> 00:00:30,510 but we typically use it to view small files. 13 00:00:30,510 --> 00:00:31,800 So we go see what happens when we use it 14 00:00:31,800 --> 00:00:33,273 with the larger type of file. 15 00:00:43,170 --> 00:00:45,180 Now we say we see a lot of the file, 16 00:00:45,180 --> 00:00:46,560 but we don't see all of it. 17 00:00:46,560 --> 00:00:48,720 Now we can scroll up with a scroll bar 18 00:00:48,720 --> 00:00:50,910 but there's more efficient ways to do this. 19 00:00:50,910 --> 00:00:52,020 This time, we're going to go through this 20 00:00:52,020 --> 00:00:53,403 by using the less command. 21 00:01:00,240 --> 00:01:01,920 Now we see with this display 22 00:01:01,920 --> 00:01:05,640 we can easily put everything on the same screen. 23 00:01:05,640 --> 00:01:08,490 Now to scroll up and down, you can use the up down arrow, 24 00:01:09,780 --> 00:01:11,310 or you can use d, 25 00:01:11,310 --> 00:01:16,310 page up and page down, if you want to use full pages, 26 00:01:17,430 --> 00:01:19,230 space bar also works. 27 00:01:19,230 --> 00:01:20,790 Now you see this command prompt 28 00:01:20,790 --> 00:01:23,193 a colon pretty much at the bottom left. 29 00:01:24,240 --> 00:01:25,770 You can search through this as well. 30 00:01:25,770 --> 00:01:27,040 So do /SELinux 31 00:01:31,140 --> 00:01:33,870 and now we can search this file as well. 32 00:01:33,870 --> 00:01:36,870 So less has a lot more features than cat 33 00:01:36,870 --> 00:01:38,850 and is typically used more. 34 00:01:38,850 --> 00:01:40,830 Now, if we want to go to the next instance 35 00:01:40,830 --> 00:01:43,830 of the particular search results that we use, 36 00:01:43,830 --> 00:01:45,183 I want to use d n. 37 00:01:49,110 --> 00:01:50,890 So I'm just tapping in the n key 38 00:01:53,250 --> 00:01:56,253 to go to the next result. 39 00:01:57,120 --> 00:01:59,910 If I want to go back, I just use the capitalization, 40 00:01:59,910 --> 00:02:00,873 So shift n. 41 00:02:04,800 --> 00:02:06,300 To get out of this can use quit. 42 00:02:06,300 --> 00:02:07,710 I'm going to press the q key. 43 00:02:07,710 --> 00:02:11,700 Now, another thing that we can do is use the head command. 44 00:02:11,700 --> 00:02:14,850 Now head and tail defaults to 10 lines. 45 00:02:14,850 --> 00:02:16,320 So this is very useful, 46 00:02:16,320 --> 00:02:19,560 if we know we only want to see the top portion of a file 47 00:02:19,560 --> 00:02:20,550 typically want to use the head 48 00:02:20,550 --> 00:02:22,050 for something that's repetitive, 49 00:02:22,050 --> 00:02:24,270 so we don't really need to, 50 00:02:24,270 --> 00:02:26,430 it gives us enough information to get the gist 51 00:02:26,430 --> 00:02:27,990 of what we're looking at. 52 00:02:27,990 --> 00:02:30,990 And the tail is usually used for logs 53 00:02:30,990 --> 00:02:33,480 to see the most recent occurrence of something, 54 00:02:33,480 --> 00:02:34,350 'cause that's typically when we're trying to 55 00:02:34,350 --> 00:02:35,220 track something down. 56 00:02:35,220 --> 00:02:37,110 So I'm try this really quick, 57 00:02:37,110 --> 00:02:42,110 I'm going to do head /var/logs/messages 58 00:02:44,607 --> 00:02:46,620 and see it gives us the first 10. 59 00:02:46,620 --> 00:02:48,870 Now we can also set the amount of lines 60 00:02:48,870 --> 00:02:50,370 that we're going to use. 61 00:02:50,370 --> 00:02:51,780 So let's try this, 62 00:02:51,780 --> 00:02:52,730 lets use sudo head, 63 00:02:54,990 --> 00:02:56,340 use the n option, 64 00:02:56,340 --> 00:02:57,790 I'm just going to do five lines. 65 00:03:02,790 --> 00:03:05,390 So now we see that we only get the first five lines. 66 00:03:06,450 --> 00:03:08,150 Let's try the same thing for tail. 67 00:03:15,420 --> 00:03:17,580 So we get the bottom 10 there, 68 00:03:17,580 --> 00:03:19,831 clear the screen to make it a little easier for us. 69 00:03:19,831 --> 00:03:21,390 Let me try this one more time, 70 00:03:21,390 --> 00:03:25,743 and we only want the first bottom five lines. 71 00:03:28,890 --> 00:03:30,210 Okay, we can see how that works. 72 00:03:30,210 --> 00:03:33,540 Next, I'm going to walk you through the process of moving files 73 00:03:33,540 --> 00:03:35,730 from one location to another, 74 00:03:35,730 --> 00:03:37,200 how to create a directory 75 00:03:37,200 --> 00:03:39,570 as well as remove an existing directory. 76 00:03:39,570 --> 00:03:43,110 So on this example, we're going to look at the options folder. 77 00:03:43,110 --> 00:03:44,710 So let's view this really quick, 78 00:03:45,810 --> 00:03:49,683 list up options go to linuxplus. 79 00:03:50,820 --> 00:03:52,620 Now I have five different 80 00:03:52,620 --> 00:03:55,410 acceptable use policy files in here. 81 00:03:55,410 --> 00:03:57,300 And so we're going to copy these over 82 00:03:57,300 --> 00:04:00,570 into our home directory folder. 83 00:04:00,570 --> 00:04:02,190 So we're going to use the copy command 84 00:04:02,190 --> 00:04:05,763 along with the r option that's for recursively. 85 00:04:06,884 --> 00:04:08,250 And then remember we're going to use this tab 86 00:04:08,250 --> 00:04:10,710 to make sure we're getting things together. 87 00:04:10,710 --> 00:04:11,543 All right. 88 00:04:11,543 --> 00:04:13,260 So we want to copy everything 89 00:04:13,260 --> 00:04:14,648 in the linuxplus folder, 90 00:04:14,648 --> 00:04:17,850 again that's what the recursively option is for. 91 00:04:17,850 --> 00:04:20,220 We can just use the tilde symbol here 92 00:04:20,220 --> 00:04:21,899 and create its own directory, 93 00:04:21,899 --> 00:04:23,430 in our home directory, 94 00:04:23,430 --> 00:04:26,760 we should now see a folder called linuxplus. 95 00:04:26,760 --> 00:04:29,040 So we're already presently in our home directory 96 00:04:29,040 --> 00:04:30,060 'cause you can see the tilde symbol 97 00:04:30,060 --> 00:04:31,410 at the end of the prompt. 98 00:04:31,410 --> 00:04:33,110 So we go ahead and list things out 99 00:04:34,110 --> 00:04:38,760 and now you see the linuxplus about four files down 100 00:04:38,760 --> 00:04:41,010 that directory was copied over. 101 00:04:41,010 --> 00:04:43,170 So we can list that out, see what's in there. 102 00:04:43,170 --> 00:04:45,240 Remember it's relative path, 103 00:04:45,240 --> 00:04:47,800 we don't need to put the forward slash 104 00:04:49,290 --> 00:04:51,810 and we can see successfully copied every file that was 105 00:04:51,810 --> 00:04:54,988 in the options linuxplus into our home directory 106 00:04:54,988 --> 00:04:56,940 and named it linuxplus as well. 107 00:04:56,940 --> 00:04:58,110 It's going to automatically just use 108 00:04:58,110 --> 00:04:59,288 the same naming convention 109 00:04:59,288 --> 00:05:03,570 that was used prior when using the copy command. 110 00:05:03,570 --> 00:05:04,860 So we're going to make a new directory, 111 00:05:04,860 --> 00:05:06,310 we're going to name it policies. 112 00:05:09,270 --> 00:05:10,440 Make sure that it got created, 113 00:05:10,440 --> 00:05:11,670 Okay, we see that there. 114 00:05:11,670 --> 00:05:13,920 So we're want to see into the linuxplus folder, 115 00:05:15,570 --> 00:05:17,370 and then again, let's list this out. 116 00:05:18,510 --> 00:05:20,310 It's clear, so we're going to move the 117 00:05:20,310 --> 00:05:22,143 acceptable use policy V1, 118 00:05:24,060 --> 00:05:25,980 we're going to move it to the policies folder. 119 00:05:25,980 --> 00:05:29,700 So the two dots mean we're going to go back 120 00:05:29,700 --> 00:05:30,570 to the parent directory, 121 00:05:30,570 --> 00:05:32,280 which is going to be our home folder, 122 00:05:32,280 --> 00:05:34,980 that's where the policies folder live. 123 00:05:34,980 --> 00:05:37,330 We're going to do the same thing with version two. 124 00:05:40,230 --> 00:05:45,230 Okay, so we list cd into the policies folder 125 00:05:48,750 --> 00:05:50,610 and list everything out. 126 00:05:50,610 --> 00:05:52,710 Okay, we see that was successfully moved over. 127 00:05:52,710 --> 00:05:55,740 Now with the move command, is different from the copy, 128 00:05:55,740 --> 00:05:59,670 It doesn't keep the existing object in place, 129 00:05:59,670 --> 00:06:02,580 it actually deletes it from this current location 130 00:06:02,580 --> 00:06:05,970 and creates it in this destination. 131 00:06:05,970 --> 00:06:09,820 So if we list out the linuxplus 132 00:06:12,120 --> 00:06:14,820 and we see we moved the acceptable use policy 133 00:06:14,820 --> 00:06:16,890 version one and version two. 134 00:06:16,890 --> 00:06:19,830 So again, the move command removes the current object 135 00:06:19,830 --> 00:06:23,100 from its source and puts it a destination. 136 00:06:23,100 --> 00:06:25,298 Any copy keeps the object in place, 137 00:06:25,298 --> 00:06:27,370 but just makes a replica of itself 138 00:06:27,370 --> 00:06:30,150 in the destinated location. 139 00:06:30,150 --> 00:06:33,450 Now we're going to go through and create placeholder files. 140 00:06:33,450 --> 00:06:35,790 So we're going to use the touch command. 141 00:06:35,790 --> 00:06:38,733 'Cause remember this one allows us to create a file, 142 00:06:39,630 --> 00:06:43,203 we'll just name it aup under score, we call it new.text. 143 00:06:46,828 --> 00:06:48,278 We can create a few of those. 144 00:06:53,910 --> 00:06:57,180 Okay, so list this up. 145 00:06:57,180 --> 00:06:59,520 We can see those were added. 146 00:06:59,520 --> 00:07:00,720 Okay if we use the concatenate 147 00:07:00,720 --> 00:07:05,460 we'll see that they they're empty, 148 00:07:05,460 --> 00:07:06,910 there's nothing in those, so. 149 00:07:07,744 --> 00:07:09,540 Or again, we can list it out, 150 00:07:09,540 --> 00:07:11,820 we just see zero bytes on them. 151 00:07:11,820 --> 00:07:13,830 Okay, now what we're going to do next 152 00:07:13,830 --> 00:07:16,080 is we're going to try to remove this linuxplus folder 153 00:07:16,080 --> 00:07:17,880 'cause we no longer need it. 154 00:07:17,880 --> 00:07:19,800 We brought it over just as a placeholder 155 00:07:19,800 --> 00:07:22,200 and then we wanted to put everything to our policies folder. 156 00:07:22,200 --> 00:07:24,030 So let's go back to that. 157 00:07:24,030 --> 00:07:29,030 So going to cd, going to go parent directory, linuxplus, 158 00:07:29,820 --> 00:07:31,950 all right so we're going to see that those 159 00:07:31,950 --> 00:07:33,960 three files are still remaining, 160 00:07:33,960 --> 00:07:36,270 and we're going to try to remove this directory. 161 00:07:36,270 --> 00:07:40,320 Okay, so now there's a remove directory command 162 00:07:40,320 --> 00:07:43,920 but it's only useful and only able enable us be used, 163 00:07:43,920 --> 00:07:46,050 if the current directory you are in 164 00:07:46,050 --> 00:07:48,480 or trying to target is empty. 165 00:07:48,480 --> 00:07:52,203 So we're just going to test it out really quick to see. 166 00:07:53,970 --> 00:07:58,970 So let's say tilde, that means our home directory, 167 00:07:59,100 --> 00:08:00,147 do linuxplus. 168 00:08:03,660 --> 00:08:04,830 And if you look at the error 169 00:08:04,830 --> 00:08:08,400 it says failed to remove because directory is not empty. 170 00:08:08,400 --> 00:08:09,330 So in order to do that, 171 00:08:09,330 --> 00:08:10,380 we're going to have to use the remove 172 00:08:10,380 --> 00:08:12,273 with the recursive option, 173 00:08:13,200 --> 00:08:17,913 tilde, linuxplus, and we see that it went through. 174 00:08:18,810 --> 00:08:21,540 So if we go through back to our home directory 175 00:08:21,540 --> 00:08:22,650 and we list it out, 176 00:08:22,650 --> 00:08:26,943 we should see the linuxplus folder is now gone. 177 00:08:29,520 --> 00:08:32,340 So we're going to do a clean example of just showing how 178 00:08:32,340 --> 00:08:33,960 if you make a directory, that's empty, 179 00:08:33,960 --> 00:08:38,960 going to call it test directory, list this out, 180 00:08:40,409 --> 00:08:45,000 we see the test directory about three from the bottom there, 181 00:08:45,000 --> 00:08:47,513 and now we're going to use the remove directory command. 182 00:08:50,460 --> 00:08:52,683 Again list it out, see it's gone. 183 00:08:53,580 --> 00:08:55,050 So that sums up this walkthrough, 184 00:08:55,050 --> 00:08:57,063 and I will see you in the next lesson.