WEBVTT 00:01.990 --> 00:06.820 In Lennox, nearly everything you deal with directly is a file. 00:07.270 --> 00:12.970 So and most often these will be text files, for instance, our configuration files. 00:13.270 --> 00:16.580 Um, in Lennox are text file senior. 00:17.280 --> 00:24.850 And so to reconfigure an application, you simply open the configuration file, change the text and 00:24.850 --> 00:27.400 save the file and then restart the application. 00:27.580 --> 00:32.080 So your reconfiguration is complete here. 00:32.320 --> 00:40.540 So now, with so many text files, manipulating text becomes circular in managing Linux and Linux applications. 00:40.840 --> 00:49.180 So in this lecture, actually in this field a several lectures here, you will use several common commands 00:49.180 --> 00:52.990 and techniques for manipulating text in Linux. 00:53.500 --> 01:03.280 For illustrative purposes, I will use files from the world's best network institution detection system 01:03.280 --> 01:04.240 and D. 01:04.240 --> 01:11.410 S Snored, which was first developed by Martin Rules, and it's now owned by Cisco. 01:11.860 --> 01:19.000 So NYDFS are commonly used to detect intrusions by hackers. 01:19.150 --> 01:22.900 So if you want to be a successful hacker, you must be familiar with. 01:23.230 --> 01:34.480 Our ways in I.T. is can um, detect detect attacks and the ways can abuse them to avoid detection. 01:35.200 --> 01:42.490 So let's now I will, uh, learn about, uh, you learn you, uh, the beeping fire. 01:42.510 --> 01:47.980 So, uh, the most basic text this will air command is probably kept here. 01:49.240 --> 02:01.450 So Cat is, uh, to let's use cats to, uh, display this not config file from snort dot con fear, 02:01.450 --> 02:02.650 as you can see here. 02:03.040 --> 02:13.510 So let's in order to open up this file that's right here, cats slash eight CC small snore. 02:13.540 --> 02:17.050 Start Quan Quan, OK. 02:21.020 --> 02:21.530 Actually. 02:29.810 --> 02:32.900 Actually, let's show and them bitcoin for cash. 02:43.500 --> 02:44.510 So you can see this. 02:44.960 --> 02:52.880 Now we printed our this file here, so, um, news can and should be like this here. 02:53.300 --> 03:01.520 So in the following two elections, I will show you an election and next, uh, the next, uh, lecture 03:01.520 --> 03:09.260 to I will show you to hear the detail and heat until, uh, comments, which are two methods for displaying 03:09.260 --> 03:15.230 just part of the finest content in order to, uh, more easily with the key content. 03:15.620 --> 03:17.300 So let's uh, right here. 03:17.510 --> 03:18.870 Heat here. 03:19.640 --> 03:25.880 Uh, it is the SNP s and P that can trigger action here. 03:25.880 --> 03:31.490 As you can see now we are simply looking at heat here and. 03:33.230 --> 03:34.460 Uh, we have. 03:40.670 --> 03:42.680 So now if you. 03:44.380 --> 03:48.130 And I just want to view the beginning of the file here. 03:48.490 --> 03:54.070 You can use the heat command as I used it here, but by default is common. 03:54.070 --> 04:03.070 This is the first ten lines of a fire, so one two three four five six seven eight nine 10 here. 04:03.820 --> 04:06.100 So the, uh, command, for instance. 04:06.910 --> 04:07.810 Uh, here. 04:10.230 --> 04:18.780 For example, just if you want to see the first five lines here, uh, just minus finds the five here. 04:19.140 --> 04:21.990 And then write your file here. 04:22.000 --> 04:26.790 So note in my case is not here, but you can do it in file. 04:28.710 --> 04:29.610 Actually, it's not. 04:30.760 --> 04:31.200 And. 04:32.570 --> 04:36.500 Actually, not as intense as an MP. 04:37.760 --> 04:45.890 As an MP, that can as you can see here, we pour into the first five lines here one two three four 04:45.890 --> 04:46.490 five. 04:47.970 --> 04:57.720 So you should look like that, you see and the article like that, if you if I know right here eight 04:57.720 --> 04:59.070 lines of actual. 05:00.840 --> 05:02.400 Here it lines. 05:05.620 --> 05:06.040 Here. 05:07.450 --> 05:07.730 Oops! 05:10.890 --> 05:12.570 It's an excellent yes. 05:13.930 --> 05:20.430 Hate crimes, for example, as you can see here, I printed eight lines of our. 05:22.000 --> 05:25.540 Configuration file here and here. 05:27.510 --> 05:28.100 I'm sorry. 05:31.350 --> 05:33.240 Let's change this resolution here. 05:33.450 --> 05:36.540 A resolution here. 05:40.830 --> 05:41.250 Yes. 05:42.930 --> 05:44.340 This configuration here. 05:48.770 --> 05:49.130 So. 05:50.530 --> 05:53.050 Notice here we have. 05:54.120 --> 05:54.770 Tatel. 05:56.070 --> 05:59.400 Uh, come on the spill tail, commander spill here. 05:59.640 --> 06:03.330 So the tail command is similar to the hit command. 06:04.850 --> 06:05.390 But. 06:08.820 --> 06:12.270 But it's used to weave the last lines of a file. 06:12.840 --> 06:17.340 So let's use this tail comb one this well here again. 06:18.040 --> 06:18.660 Uh, here. 06:20.720 --> 06:21.410 Tell. 06:22.570 --> 06:24.040 Here it is. 06:24.310 --> 06:27.940 It's an empire, it's MP that configuration here. 06:28.460 --> 06:33.460 Uh, but uh, so for example, it's as you can see, we're, uh, printed. 06:33.820 --> 06:39.970 These are all files here because we don't mentioned any, um, any. 06:43.810 --> 06:52.420 Last lions here, for example, if they try like that, for example, uh, minus five, this tail command 06:52.430 --> 07:02.860 will show us the last file of last five lines of our, uh, configuration file or any text file here. 07:03.880 --> 07:08.630 So, uh, we have then numbering the lines call months as well. 07:08.650 --> 07:15.190 So sometimes, especially with very long files, we may want the file to display line or line numbers 07:15.790 --> 07:16.300 signs. 07:16.600 --> 07:21.700 This is an empty configuration, has not many lines here. 07:22.060 --> 07:25.270 I will try another file here. 07:25.270 --> 07:31.540 For example, it's found in the file um, file, for example. 07:32.020 --> 07:33.400 Let's use. 07:35.090 --> 07:37.050 Somebody here, some. 07:38.810 --> 07:42.650 And SMB dot com, I think this moment, OK? 07:42.740 --> 07:46.670 As you can see, there is a swarming alliance, so. 07:48.260 --> 07:49.050 Mm hmm. 07:50.070 --> 07:58.530 We may want to file display and nine line numbers because it's so many lines here with some configuration 07:58.530 --> 07:59.220 file here. 07:59.790 --> 08:01.110 So let's. 08:03.030 --> 08:10.000 So this makes it easier to arrest and change and come back to the same place within the file, so to 08:10.020 --> 08:12.630 display a file with nine numbers. 08:13.380 --> 08:21.390 We chose the NFL, yes and l, uh, comments or simply enter the A comment here, et cetera. 08:22.260 --> 08:23.630 It is here. 08:23.640 --> 08:26.040 Um uh, what it was. 08:26.040 --> 08:27.150 It was humble, right? 08:29.360 --> 08:32.050 Yes, Samba Samba SMB configuration. 08:32.900 --> 08:35.190 Uh, Samba SMB. 08:35.480 --> 08:39.080 Com Fair, as you can see here, we printed a line like that. 08:39.620 --> 08:44.540 Uh, line last line is one hundred eight and nine line here. 08:45.080 --> 08:50.490 And as you can see here, we have so many lines here. 08:56.650 --> 08:56.980 Yes. 09:06.830 --> 09:10.220 So let's filter our files with. 09:11.840 --> 09:12.950 Com month here. 09:13.490 --> 09:21.710 So the command and grip is probably the most widely used takes manipulation command, so it lets you 09:21.710 --> 09:24.380 filter the content of a file for display. 09:25.250 --> 09:33.830 If, for instance, you want to see all lines that include word, for example, read on here or parts 09:33.830 --> 09:34.220 here. 09:35.440 --> 09:37.600 Uh, like that path here. 09:38.260 --> 09:38.860 Um. 09:41.790 --> 09:49.380 Uh, in your, uh, this SMB file configuration file, you called use camp and asked to display only 09:49.710 --> 10:00.240 to files like that, for example, cat ethicists, some with some assembly that configuration and one 10:00.390 --> 10:07.440 line pipe here and then grab, uh, grippier read uh, what it was. 10:07.440 --> 10:10.530 Uh, read only use it. 10:10.620 --> 10:12.450 Only read. 10:13.540 --> 10:18.880 As you can see here, we printed out all our red files here. 10:19.300 --> 10:31.690 So this command will first be, um, assembly configuration file and then using the pipe here to send 10:31.690 --> 10:35.800 it to grab, and which we will take the file as an input. 10:36.220 --> 10:40.600 So now look for license plate occurrences of the word read. 10:41.590 --> 10:45.430 And display only to lions here, as you can see here. 10:46.330 --> 10:54.520 So the grape command is very powerful and essential command for working in Linux because it can save 10:54.520 --> 11:00.190 you hearts of searching for every occurrence of a volt or command in file. 11:01.360 --> 11:01.780 So. 11:05.540 --> 11:14.180 Well, let's say you want to display the fine lines immediately before a line that says Step six to 11:14.180 --> 11:18.230 configure polygons using the LEDs for comment you just earned. 11:18.560 --> 11:21.080 So how have you how will you do it? 11:23.050 --> 11:23.470 So. 11:25.260 --> 11:25.820 And. 11:30.050 --> 11:37.760 So there are many options to this commander to, as we have discussed, so you can learn more commands 11:37.760 --> 11:48.230 by using the built in Linux men, for example, mentale here will show the health file of tail comb 11:48.290 --> 11:54.980 mounted as you can see here, or, uh, just press X and then enter to quit here. 11:56.960 --> 11:57.410 Yeah. 11:58.810 --> 12:02.920 Uh, our uh, you can press Q Command to create here. 12:03.250 --> 12:10.360 What example, man can't, as you can see here, we're showing, uh, health file of cat combattere 12:10.360 --> 12:12.220 or non amputee. 12:12.460 --> 12:15.940 So a man is, uh, helpful comment here. 12:16.000 --> 12:23.980 Uh, actually actually, it's application here, so it will help you to show the health files of, uh, 12:24.070 --> 12:24.550 your. 12:26.460 --> 12:27.600 Application of common. 12:27.990 --> 12:34.950 So there are many ways to solve this challenge, and he and I show you each line stretching to do it 12:34.950 --> 12:44.580 in one way and your find another method here so we can do it like that and how it is there some bar 12:45.200 --> 12:54.140 assembly that can fish and pipe here and grip right here. 12:54.210 --> 13:00.570 As you can see here, we bring that this here which so we can see that the line here in the. 13:04.870 --> 13:08.380 We pretend like that here, as you can see, or with lines. 13:09.780 --> 13:10.470 No. 13:11.950 --> 13:20.240 So as you can see here, we have, um, challenges done with Intel and grab command. 13:20.260 --> 13:27.580 As you can see here we have um, we used nail command, which is similar to Cat, but it solves the 13:27.580 --> 13:35.260 lines of numbers or in one hundred eighty two, uh, line we have read only yes, one hundred seventy 13:35.260 --> 13:35.710 four. 13:35.710 --> 13:39.160 We have read only here, as you can see here. 13:39.460 --> 13:42.860 So I will of, uh, video here and I'm waiting. 13:42.860 --> 13:43.840 Go in next picture.