1 00:00:00,150 --> 00:00:01,230 And we're going to go through 2 00:00:01,230 --> 00:00:03,210 how to manipulate file output. 3 00:00:03,210 --> 00:00:04,200 Typically in Linux, 4 00:00:04,200 --> 00:00:07,710 the standard input is the computer or your mouse. 5 00:00:07,710 --> 00:00:10,398 The standard output is the screen, 6 00:00:10,398 --> 00:00:12,210 but for the command line purposes 7 00:00:12,210 --> 00:00:15,420 it's going to be the display on the CLI. 8 00:00:15,420 --> 00:00:17,490 Now we can change these standard inputs 9 00:00:17,490 --> 00:00:20,610 and outputs using the angle brackets. 10 00:00:20,610 --> 00:00:21,443 For example, 11 00:00:21,443 --> 00:00:22,860 if we're going to use this software 12 00:00:22,860 --> 00:00:24,410 listing that I created earlier, 13 00:00:25,560 --> 00:00:28,260 the standard output is going to be the screen, 14 00:00:28,260 --> 00:00:30,330 the command line interface, 15 00:00:30,330 --> 00:00:35,330 but I can use the same output, and put it in another file. 16 00:00:35,550 --> 00:00:39,060 So we can do software listing one, right. 17 00:00:39,060 --> 00:00:41,190 And the output, we're going to use the right angle bracket. 18 00:00:41,190 --> 00:00:42,023 We want to let it know, hey, 19 00:00:42,023 --> 00:00:45,483 we want to send the output to this test file. 20 00:00:49,830 --> 00:00:52,863 Now, if we look and we see the test file's created, 21 00:00:53,760 --> 00:00:55,410 and we try to view the test file, 22 00:00:56,700 --> 00:00:58,800 we'll see it copy right over for us. 23 00:00:58,800 --> 00:01:02,430 So using the angle bracket to the right, 24 00:01:02,430 --> 00:01:06,090 it replaces what's in that new file, 25 00:01:06,090 --> 00:01:09,000 or creates a file if it doesn't already exist. 26 00:01:09,000 --> 00:01:11,340 Now, if you want to add something to it, 27 00:01:11,340 --> 00:01:12,780 we can use the echo command. 28 00:01:12,780 --> 00:01:14,430 If you want to add specific strings. 29 00:01:14,430 --> 00:01:18,843 So let's say we're going to test. 30 00:01:30,390 --> 00:01:32,370 And now let's do this again. 31 00:01:32,370 --> 00:01:35,040 Now you see it appended the new text 32 00:01:35,040 --> 00:01:36,990 to the bottom of the file. 33 00:01:36,990 --> 00:01:38,640 So it's very important to realize 34 00:01:38,640 --> 00:01:40,500 if you want to add information, 35 00:01:40,500 --> 00:01:43,950 you have to use two angle brackets versus one, 36 00:01:43,950 --> 00:01:45,930 'cause one will replace everything. 37 00:01:45,930 --> 00:01:47,430 So just to use a more clean example, 38 00:01:47,430 --> 00:01:49,120 just say we want to create a file 39 00:01:50,055 --> 00:01:53,790 and we want to have it insert information about the user, 40 00:01:56,340 --> 00:02:00,033 a make of a computer, and the serial number. 41 00:02:02,610 --> 00:02:05,643 And again, we want to add this to, call it testfile2. 42 00:02:09,449 --> 00:02:10,282 Okay. 43 00:02:10,282 --> 00:02:11,116 Now again, 44 00:02:11,116 --> 00:02:15,720 we're going to view this using cat, test, 45 00:02:15,720 --> 00:02:20,673 we did a tab key, and we see it input it to the file. 46 00:02:21,660 --> 00:02:24,300 So again, this operator is very useful. 47 00:02:24,300 --> 00:02:27,480 You don't always have to use a text editor like VIM or Nano, 48 00:02:27,480 --> 00:02:29,400 what you can do is type directly 49 00:02:29,400 --> 00:02:31,350 on the screen it's something quick, 50 00:02:31,350 --> 00:02:34,440 use the right angle bracket operator 51 00:02:34,440 --> 00:02:36,000 or the double one if you want to append it. 52 00:02:36,000 --> 00:02:36,833 Remember, 53 00:02:36,833 --> 00:02:39,630 a single right bracket operator is going to erase 54 00:02:39,630 --> 00:02:42,330 the contents of a file and replace them with your own. 55 00:02:44,160 --> 00:02:45,393 So let's test this out. 56 00:02:51,570 --> 00:02:56,223 Same thing, USER1, MAKE1, serial number one. 57 00:02:58,410 --> 00:03:00,960 Now when we look at the contents of this file 58 00:03:00,960 --> 00:03:03,003 we'll see that it's replaced. 59 00:03:04,290 --> 00:03:05,540 But if we want to add it, 60 00:03:09,030 --> 00:03:14,030 operator, do it again, now added it. 61 00:03:14,100 --> 00:03:14,933 Again, 62 00:03:14,933 --> 00:03:17,070 that's just another example to further demonstrate 63 00:03:17,070 --> 00:03:20,460 the use of the right angle bracket operator. 64 00:03:20,460 --> 00:03:23,280 Now, next we're going to use the translate command. 65 00:03:23,280 --> 00:03:25,470 Now this command is going to be used to translate 66 00:03:25,470 --> 00:03:27,270 one character to another, 67 00:03:27,270 --> 00:03:31,320 and we're going to use it with the left angle bracket operator. 68 00:03:31,320 --> 00:03:32,153 Okay? 69 00:03:32,153 --> 00:03:33,720 So we're going to just, again, 70 00:03:33,720 --> 00:03:35,820 we're going to look at our test file in here. 71 00:03:37,470 --> 00:03:38,343 Let's see here. 72 00:03:40,320 --> 00:03:41,373 Do test file two. 73 00:03:43,230 --> 00:03:44,063 Okay. 74 00:03:44,063 --> 00:03:45,750 So we see we have this information in there. 75 00:03:45,750 --> 00:03:47,340 So just say we wanted to change 76 00:03:47,340 --> 00:03:50,100 all the Us to lowercase Us. 77 00:03:50,100 --> 00:03:52,683 So we're going to do, translate here, 78 00:03:54,300 --> 00:03:58,260 and the first character's going to be one to be replaced. 79 00:03:58,260 --> 00:03:59,640 So all uppercase Us, 80 00:03:59,640 --> 00:04:02,250 and we'll change it to lowercase Us. 81 00:04:02,250 --> 00:04:05,287 And we're going to do that for our testfile2.txt. 82 00:04:09,450 --> 00:04:12,660 And we can see that now it output the result 83 00:04:12,660 --> 00:04:15,993 showing that the users now have a lowercase Us. 84 00:04:17,940 --> 00:04:19,230 So again, we can do the same thing. 85 00:04:19,230 --> 00:04:23,043 Just to make it a little weird for the uppercase Ms, 86 00:04:24,180 --> 00:04:25,630 change those to lowercase Ms. 87 00:04:27,480 --> 00:04:28,313 And again, 88 00:04:28,313 --> 00:04:29,670 these files are usually used to change things 89 00:04:29,670 --> 00:04:31,350 from lowercase to uppercase. 90 00:04:31,350 --> 00:04:33,810 But again, you see, this is just showing the output, 91 00:04:33,810 --> 00:04:35,100 and it's not actually changing 92 00:04:35,100 --> 00:04:38,730 the content of the test file itself. 93 00:04:38,730 --> 00:04:41,250 Now just say sticking to this same example that we did, 94 00:04:41,250 --> 00:04:44,850 want to change the output and put it in another file. 95 00:04:44,850 --> 00:04:46,530 We can do that same thing. 96 00:04:46,530 --> 00:04:50,640 So again, we want to translate the Us, 97 00:04:50,640 --> 00:04:53,103 or the uppercase Us, to lowercase Us. 98 00:04:54,108 --> 00:04:57,483 And the file we want to use is testfile, 99 00:05:01,170 --> 00:05:04,380 and we want to put it in another file. 100 00:05:04,380 --> 00:05:06,033 We're going to name this testfile3. 101 00:05:11,490 --> 00:05:14,670 Now we'll see the output is changed, 102 00:05:14,670 --> 00:05:19,143 and "saves" because it is sent to another file. 103 00:05:23,490 --> 00:05:24,323 Okay. 104 00:05:25,500 --> 00:05:28,986 Again, you'll see the contents of the first file, 105 00:05:28,986 --> 00:05:31,950 testfile2 remains the same. 106 00:05:31,950 --> 00:05:34,260 But we can change that information 107 00:05:34,260 --> 00:05:36,993 and send it to be saved to another file. 108 00:05:38,460 --> 00:05:39,390 So again, once we read it, 109 00:05:39,390 --> 00:05:40,830 if you're looking at the command 110 00:05:40,830 --> 00:05:42,181 we're reading it from left to right, 111 00:05:42,181 --> 00:05:44,070 so we're going to translate the uppercase Us 112 00:05:44,070 --> 00:05:47,223 to lowercase Us in the text file number two, 113 00:05:48,060 --> 00:05:50,463 and send it to test file number three. 114 00:05:51,930 --> 00:05:54,180 So next one I'll work on another file that I created, 115 00:05:54,180 --> 00:05:57,750 this computer lists of users, operating system, 116 00:05:57,750 --> 00:05:59,250 and the make of the computers. 117 00:06:00,210 --> 00:06:02,190 What we're going to do is, I want to sort them really quick. 118 00:06:02,190 --> 00:06:03,870 We're just going to show the output, 119 00:06:03,870 --> 00:06:05,640 and see how we can change the standard 120 00:06:05,640 --> 00:06:07,440 input and output with these as well. 121 00:06:09,420 --> 00:06:10,253 Okay. 122 00:06:10,253 --> 00:06:12,330 So we see that on the first column 123 00:06:12,330 --> 00:06:15,090 it sorted the object in alphabetical order. 124 00:06:15,090 --> 00:06:18,476 Now, again, we see that the header was included, 125 00:06:18,476 --> 00:06:20,550 but we're going to use another example 126 00:06:20,550 --> 00:06:22,620 where the header is not included. 127 00:06:22,620 --> 00:06:24,360 So the name will stay at the top, 128 00:06:24,360 --> 00:06:27,450 and it will sort all the actual fields below. 129 00:06:27,450 --> 00:06:28,920 Now, to do that, 130 00:06:28,920 --> 00:06:31,350 we're going to use the piping command. 131 00:06:31,350 --> 00:06:33,360 So what that does is it redirects 132 00:06:33,360 --> 00:06:37,560 the output from one into another. 133 00:06:37,560 --> 00:06:42,560 So we're going to use the tail, use -n, 134 00:06:42,810 --> 00:06:45,183 so the number of lines, plus three. 135 00:06:46,380 --> 00:06:48,090 So we're going to specify this. 136 00:06:48,090 --> 00:06:51,060 And we're going to use the computer text file. 137 00:06:51,060 --> 00:06:54,633 So that output, we're going to sort that output. 138 00:06:55,770 --> 00:06:56,970 On the first column, 139 00:06:56,970 --> 00:06:59,320 so prior we have the name title 140 00:07:00,330 --> 00:07:02,610 associated with the fields below, 141 00:07:02,610 --> 00:07:04,680 but now it's no longer there. 142 00:07:04,680 --> 00:07:06,630 So again, reading that command from left to right, 143 00:07:06,630 --> 00:07:09,960 you'll see that we're only going to see the bottom 10, 144 00:07:09,960 --> 00:07:11,160 and we're not really concerned about that 145 00:07:11,160 --> 00:07:13,590 because we have less than 10 in here. 146 00:07:13,590 --> 00:07:17,100 The number of lines is going to be the top three, right? 147 00:07:17,100 --> 00:07:20,520 So that means we're going to include line three and below only. 148 00:07:20,520 --> 00:07:23,643 So again, if we were just to capture this out, 149 00:07:24,630 --> 00:07:27,240 we'll see the number of lines 150 00:07:27,240 --> 00:07:29,820 'cause I think it's very useful to see that, 151 00:07:29,820 --> 00:07:31,773 and then run the sort again. 152 00:07:33,720 --> 00:07:36,210 We can see that it started with line three. 153 00:07:36,210 --> 00:07:38,190 So you see John is included 154 00:07:38,190 --> 00:07:41,010 in this result, and it went down. 155 00:07:41,010 --> 00:07:44,133 And we sorted everything with column one. 156 00:07:45,090 --> 00:07:47,220 Next we're going to use the T command. 157 00:07:47,220 --> 00:07:52,140 Now the T command simply does an output redirect 158 00:07:52,140 --> 00:07:56,640 to a file or directory, but also displays it on the screen. 159 00:07:56,640 --> 00:07:57,960 So you could have both. 160 00:07:57,960 --> 00:08:02,820 And you can see what is being sent to the particular file. 161 00:08:02,820 --> 00:08:05,160 So earlier when we used the echo command, 162 00:08:05,160 --> 00:08:08,400 it didn't show us what it actually sent to the file, 163 00:08:08,400 --> 00:08:09,450 but with the T command, 164 00:08:09,450 --> 00:08:11,820 it's going to show us what it sent to the file. 165 00:08:11,820 --> 00:08:13,980 So for this example we're just going to show 166 00:08:13,980 --> 00:08:16,173 the list of files in this folder. 167 00:08:17,400 --> 00:08:20,823 And we're going to just want to copy that list in this folder, 168 00:08:21,690 --> 00:08:25,530 and we're going to send it to another folder 169 00:08:25,530 --> 00:08:29,757 that we're going to name, backup directory. 170 00:08:34,980 --> 00:08:35,909 Now it's letting us know, 171 00:08:35,909 --> 00:08:40,909 we sent the list from this directory to backup directory, 172 00:08:41,190 --> 00:08:43,500 and this is what it looks like. 173 00:08:43,500 --> 00:08:47,373 So if we do a cat, backup directory, 174 00:08:48,240 --> 00:08:51,840 we see the display starting from here. 175 00:08:51,840 --> 00:08:52,673 So again, 176 00:08:52,673 --> 00:08:55,650 it does nothing more than just show us at the same time, 177 00:08:55,650 --> 00:08:58,702 it redirects it to a particular file. 178 00:08:58,702 --> 00:08:59,580 And the last thing I'm going to go over 179 00:08:59,580 --> 00:09:03,663 is how to pipe grep and cut, and use those together. 180 00:09:04,530 --> 00:09:06,480 So we're going to check our secure file 181 00:09:06,480 --> 00:09:08,580 and that pretty much stores all 182 00:09:08,580 --> 00:09:10,920 of our authentication attempts. 183 00:09:10,920 --> 00:09:12,180 So we're going to pull out some 184 00:09:12,180 --> 00:09:15,120 of the information after we've searched through the file 185 00:09:15,120 --> 00:09:18,420 for a particular type of error that we're looking for. 186 00:09:18,420 --> 00:09:22,890 So we're going to find a password check fail, 187 00:09:22,890 --> 00:09:24,480 and then we're going to condense the information, 188 00:09:24,480 --> 00:09:25,590 'cause we don't need everything 189 00:09:25,590 --> 00:09:27,303 that's going to be presented to us. 190 00:09:28,530 --> 00:09:31,953 So for example, we're going to look at the file, 191 00:09:35,340 --> 00:09:37,800 and we see that it gets us a lot of information, 192 00:09:37,800 --> 00:09:39,780 and some of them might be unnecessary 193 00:09:39,780 --> 00:09:41,820 for what we're looking for, 194 00:09:41,820 --> 00:09:43,740 so we're going to condense that. 195 00:09:43,740 --> 00:09:44,675 So the first thing we want to do is, 196 00:09:44,675 --> 00:09:46,110 we're going to do sudo, we're going to grep, 197 00:09:46,110 --> 00:09:46,950 we're going to search through this. 198 00:09:46,950 --> 00:09:51,003 We want to look for password check, the fail. 199 00:09:54,630 --> 00:09:56,943 We'll look in the var/log/secure, 200 00:10:03,120 --> 00:10:05,280 and we see it returns only the instances 201 00:10:05,280 --> 00:10:07,023 of a failed password attempt. 202 00:10:12,330 --> 00:10:13,230 All right. 203 00:10:13,230 --> 00:10:14,790 Now, we don't need all this information, 204 00:10:14,790 --> 00:10:17,310 so what we're going to do is cut some of this. 205 00:10:17,310 --> 00:10:19,980 And so that's where we're going to use the cut command. 206 00:10:19,980 --> 00:10:22,230 And so I'm going to show what it does by itself. 207 00:10:22,230 --> 00:10:27,230 Going to sudo cut, var/log/secure. 208 00:10:30,510 --> 00:10:32,580 And this D is the delimiter that we're going to use. 209 00:10:32,580 --> 00:10:35,670 So the delimiter that we're going to use is a space. 210 00:10:35,670 --> 00:10:39,180 Delimiter meaning just something that separates fields, 211 00:10:39,180 --> 00:10:40,500 or just say in the English language, 212 00:10:40,500 --> 00:10:42,240 a space separates words. 213 00:10:42,240 --> 00:10:43,920 So for this search that we're going to 214 00:10:43,920 --> 00:10:45,840 use the delimiter, it's going to be the space. 215 00:10:45,840 --> 00:10:47,700 So pretty much what's going to let us indicate 216 00:10:47,700 --> 00:10:51,453 is which fields that we want to specify for the result. 217 00:10:52,890 --> 00:10:53,820 So in this example, 218 00:10:53,820 --> 00:10:57,660 we're going to specify fields five through 12. 219 00:10:57,660 --> 00:10:59,550 And the fields again, 220 00:10:59,550 --> 00:11:01,893 are associated with the spaces in between. 221 00:11:03,840 --> 00:11:07,200 So now I cut off some of the beginning, and most of the end. 222 00:11:07,200 --> 00:11:09,903 So we see that it's a better look for us. 223 00:11:11,640 --> 00:11:13,800 Now let's combine those together. 224 00:11:13,800 --> 00:11:16,002 So we're going to make a smaller output. 225 00:11:16,002 --> 00:11:19,680 So we're going to do, sudo grep, new password, 226 00:11:19,680 --> 00:11:21,900 again, that's what we're looking for. 227 00:11:21,900 --> 00:11:24,803 Check failed for our log secure file. 228 00:11:30,870 --> 00:11:33,330 Now again, now we're going to pipe this. 229 00:11:33,330 --> 00:11:37,530 So pretty much send that information to the cut command, 230 00:11:37,530 --> 00:11:40,743 and the cut command is going to look for spaces, 231 00:11:42,420 --> 00:11:47,420 and is going to use fields five through 12 for the return. 232 00:11:51,180 --> 00:11:52,013 Now look at that, 233 00:11:52,013 --> 00:11:56,040 a much more clean output for exactly what we're looking for. 234 00:11:56,040 --> 00:11:59,220 All right, we went over how to use the echo command, 235 00:11:59,220 --> 00:12:01,620 and use the right bracket angle operator 236 00:12:01,620 --> 00:12:03,630 to send information to a file. 237 00:12:03,630 --> 00:12:05,760 The left angle bracket operator to send 238 00:12:05,760 --> 00:12:07,980 that input to another command. 239 00:12:07,980 --> 00:12:09,810 We also went through how to translate 240 00:12:09,810 --> 00:12:12,510 a few files using the uppercase lowercase. 241 00:12:12,510 --> 00:12:15,120 And how to condense information using the cut. 242 00:12:15,120 --> 00:12:17,760 And how to show our redirection, 243 00:12:17,760 --> 00:12:19,830 the output that is being sent 244 00:12:19,830 --> 00:12:22,290 to the file using the T command. 245 00:12:22,290 --> 00:12:24,090 And I'll see you in the next lesson.