WEBVTT 00:00.410 --> 00:01.782 Hello and welcome to command 00:02.240 --> 00:04.249 line BASIX, this budget will cover 00:04.250 --> 00:05.660 common Linux tools. 00:05.690 --> 00:07.339 I'm Christopher Haler and let's get 00:07.340 --> 00:08.340 started. 00:09.110 --> 00:10.580 So our learning objectives for 00:11.000 --> 00:12.289 this module is we're going to learn 00:12.290 --> 00:13.290 how to read files. 00:13.490 --> 00:15.199 We're going to learn how to copy 00:15.200 --> 00:16.719 files, understand how to delete 00:17.420 --> 00:19.489 files and understand how to search 00:19.490 --> 00:20.419 through files. 00:20.420 --> 00:21.949 So these are going to be very common 00:21.950 --> 00:23.780 tasks. You're going to be able to 00:24.350 --> 00:25.399 you're going to have to be able to 00:25.400 --> 00:26.919 do on Linux if you are pursuing 00:27.530 --> 00:29.600 a career in computer science, 00:29.900 --> 00:31.760 in penetration testing, 00:32.030 --> 00:33.189 in ethical hacking. 00:33.410 --> 00:34.849 So it's very important that you 00:34.850 --> 00:36.349 understand these concepts and know 00:36.350 --> 00:37.350 how to apply them. 00:38.600 --> 00:40.021 All right. Presentment, which 00:40.250 --> 00:41.671 command is the best to search 00:42.290 --> 00:43.290 through text? 00:43.820 --> 00:45.290 Is it A strings, 00:45.950 --> 00:46.950 B, text C 00:48.200 --> 00:49.200 grippe D and 00:50.210 --> 00:51.210 grippe. 00:52.310 --> 00:53.682 If you said C grippe, you're 00:54.320 --> 00:55.219 correct. 00:55.220 --> 00:57.409 So the grep command, 00:57.410 --> 00:58.939 as I've stated earlier in this 00:58.940 --> 01:01.039 course, it is a regular 01:01.040 --> 01:03.049 expression searching tool 01:03.050 --> 01:05.089 and it is very powerful 01:05.090 --> 01:06.099 and very effective. 01:07.220 --> 01:09.439 The Strings Command, while 01:09.680 --> 01:11.509 it will bring up a text 01:11.510 --> 01:13.640 file, it searches through 01:13.940 --> 01:15.919 ASCII strings in a text 01:15.920 --> 01:17.145 file and it's not exactly 01:18.320 --> 01:20.239 very search oriented. 01:20.240 --> 01:21.709 As much as printing 01:23.600 --> 01:25.180 different characters out. 01:25.700 --> 01:27.589 The text file is not 01:27.590 --> 01:29.409 for searching and the anger 01:29.480 --> 01:31.369 file is for network rep 01:31.370 --> 01:33.134 and it is searching through a packet 01:33.470 --> 01:34.470 capture file. 01:35.000 --> 01:36.225 So not exactly for a text 01:36.920 --> 01:37.920 file. 01:39.170 --> 01:40.549 All right. So we are going to learn 01:40.550 --> 01:41.599 how to read a text file. 01:41.870 --> 01:43.250 We get a few different options. 01:43.580 --> 01:44.903 We have the cat command and 01:45.470 --> 01:46.969 now this is a very common command 01:46.970 --> 01:48.739 that you're going to use a lot in 01:48.740 --> 01:49.760 your Linux career. 01:50.150 --> 01:51.469 And it actually stands for 01:51.500 --> 01:52.500 CONCATENATE. 01:52.550 --> 01:53.579 And what it is, is it 01:54.650 --> 01:56.509 spits out all of the text 01:56.510 --> 01:58.519 of a file and you can actually 01:58.520 --> 02:00.349 use it on two or three 02:00.350 --> 02:01.849 files at once and it will 02:01.850 --> 02:03.349 automatically add those files 02:03.350 --> 02:05.119 together and spit them all out as 02:05.120 --> 02:06.120 one contiguous 02:06.950 --> 02:08.469 set of text. 02:09.169 --> 02:11.239 And we also have the more command, 02:11.660 --> 02:13.789 which is similar to CAT, 02:13.790 --> 02:15.529 except you can't really combine 02:15.950 --> 02:17.379 different text files together. 02:17.630 --> 02:19.099 It will just spit out a 02:20.870 --> 02:22.580 text of a text file 02:23.060 --> 02:24.979 and then you have the less command. 02:25.790 --> 02:27.169 Now, this is kind of a play on words 02:27.170 --> 02:28.849 where less is more, 02:29.570 --> 02:31.759 the less command is much more useful 02:31.760 --> 02:33.181 than the more command because 02:33.800 --> 02:35.839 you can actually scroll up and down 02:36.500 --> 02:38.270 instead of just moving 02:38.420 --> 02:39.988 the screen by screen by with the 02:40.280 --> 02:41.280 more command. 02:41.570 --> 02:43.187 So let's give you a demonstration 02:43.880 --> 02:45.610 of these tools real quick. 02:46.100 --> 02:47.100 So I am in my home 02:47.960 --> 02:49.550 directory right now as 02:49.790 --> 02:51.349 displayed by the till day here. 02:51.860 --> 02:53.240 So I'm going to use the 02:53.840 --> 02:55.759 command and see 02:55.760 --> 02:57.319 what is in my folder here. 02:58.010 --> 02:59.719 Right. Desktop documents, downloads. 02:59.990 --> 03:01.159 I want to go to my desktop. 03:01.160 --> 03:03.229 So CD and 03:03.410 --> 03:05.539 Capital D e, 03:05.730 --> 03:07.759 I'm going to put the tab key 03:07.970 --> 03:09.199 and it's going to fill that out for 03:09.200 --> 03:10.200 me. 03:10.220 --> 03:11.886 All right. Now let's see what's in 03:12.080 --> 03:13.080 our desktop. 03:13.970 --> 03:15.048 And I want to get into 03:15.830 --> 03:16.699 documents. 03:16.700 --> 03:18.800 So CD Capital D 03:19.370 --> 03:20.370 documents. 03:20.570 --> 03:22.520 And now if you don't know already 03:23.000 --> 03:24.979 Linux is case sensitive. 03:25.310 --> 03:27.199 So if I were to do a 03:27.200 --> 03:28.200 lowercase D 03:29.270 --> 03:30.838 and then push tab, nothing would 03:31.220 --> 03:32.592 come up because there are no 03:32.780 --> 03:33.780 matches. 03:34.140 --> 03:35.630 However, with the capital D, 03:36.200 --> 03:37.278 it finds it hard we're 03:38.060 --> 03:40.039 going to go in there and s 03:40.610 --> 03:41.933 all right. So now I have to 03:42.500 --> 03:44.479 text files in here and I'm 03:44.480 --> 03:46.520 going to do cat on 03:46.760 --> 03:47.760 words. 03:48.980 --> 03:50.839 All right. So I had a bunch of 03:51.110 --> 03:52.430 different Latin words here 03:53.420 --> 03:55.309 and now I can scroll up because 03:55.310 --> 03:56.682 I have this scroll bar on my 03:57.110 --> 03:58.069 terminal here. 03:58.070 --> 03:59.736 If I didn't have this scrollbar or 04:00.050 --> 04:02.230 if I was in a SEAL, I only 04:02.250 --> 04:04.129 Linux distribution, then 04:04.130 --> 04:05.659 I wouldn't be able to see past this 04:05.660 --> 04:06.660 top row here. 04:07.340 --> 04:08.761 And it can be difficult to do 04:09.350 --> 04:10.610 that if 04:11.900 --> 04:12.900 you can't scroll. 04:13.310 --> 04:15.379 So the cat command is great 04:15.380 --> 04:16.790 for spitting out information. 04:17.390 --> 04:19.489 And let me demonstrate really 04:19.490 --> 04:21.156 quick how we can combine two files 04:21.589 --> 04:22.639 together. So we're going to two 04:22.640 --> 04:23.640 words that text and 04:24.680 --> 04:26.449 then longer file dot text 04:27.800 --> 04:28.800 enter. All right. 04:29.210 --> 04:30.210 So check it out. 04:30.740 --> 04:31.769 These are both of the 04:32.750 --> 04:33.709 text files. 04:33.710 --> 04:35.689 Just spitting out one after another 04:36.410 --> 04:37.410 concatenated. 04:38.450 --> 04:39.289 All right. 04:39.290 --> 04:41.029 Now, like I was saying, if I have a 04:41.030 --> 04:43.130 Seelie only distribution, 04:43.610 --> 04:45.529 then what I do is the more 04:45.530 --> 04:47.419 command and then 04:48.140 --> 04:49.140 longer file. 04:49.820 --> 04:51.379 And as you can see in the bottom 04:51.380 --> 04:53.389 left, right here, it tells 04:53.390 --> 04:55.339 us how far we are in the file and 04:55.340 --> 04:57.055 it lets us read from the first line 04:57.230 --> 04:58.230 up here. 04:58.460 --> 04:59.369 So in order. 04:59.370 --> 05:01.339 To move and read 05:01.340 --> 05:03.199 more of it, we can push 05:03.200 --> 05:04.817 the anarchy and that will go down 05:04.970 --> 05:06.170 one line at a time, 05:07.400 --> 05:09.109 or if we push the spacebar, 05:09.590 --> 05:11.660 it'll go down a full page at a time 05:12.680 --> 05:14.029 so we can take our time reading 05:14.030 --> 05:15.199 through everything and we're not 05:15.200 --> 05:16.200 going to miss anything. 05:16.790 --> 05:18.920 Now, the 05:19.040 --> 05:20.959 kind of limitation with more is 05:20.960 --> 05:22.759 that as soon as you go down a line, 05:22.760 --> 05:23.810 you can't go back up. 05:24.680 --> 05:26.690 So this is where less 05:26.810 --> 05:27.980 is more comes in. 05:29.510 --> 05:31.059 So now we can go down. 05:31.670 --> 05:33.559 I'm pushing down Iraq right now 05:33.830 --> 05:34.920 and go back up. 05:34.940 --> 05:36.490 I am pushing up Iraqi 05:37.100 --> 05:38.929 and some distributions allow 05:38.930 --> 05:40.694 you to scroll with your scrollbar on 05:40.730 --> 05:41.730 your mouse. 05:41.930 --> 05:43.489 And as soon as you are done, you 05:43.490 --> 05:45.319 just push this little button here 05:46.160 --> 05:47.160 and we are done. 05:47.360 --> 05:49.070 So very useful to keep the mind. 05:50.450 --> 05:51.450 All right, 05:52.790 --> 05:54.589 moving on, so we got a copy and move 05:54.590 --> 05:55.619 files, so copying, we 05:56.510 --> 05:58.759 have a copy command and 05:58.760 --> 06:00.660 we can also use the tech R 06:00.680 --> 06:02.003 or excuse me, Dasch are for 06:02.270 --> 06:04.279 recursively copying and 06:04.280 --> 06:06.199 then move is M.V. 06:06.200 --> 06:07.009 Command. 06:07.010 --> 06:08.899 And we can also use this to rename 06:08.900 --> 06:10.920 files in a in a special way. 06:11.360 --> 06:12.634 So let me take you a quick 06:13.100 --> 06:14.420 demonstration of that. 06:15.320 --> 06:17.169 So let's take a look in our folder. 06:17.180 --> 06:18.439 We have words here. 06:18.470 --> 06:19.929 I am going to do Sepi 06:20.480 --> 06:22.429 words and 06:22.430 --> 06:24.499 I want to put it into my 06:24.890 --> 06:26.060 desktop folder. 06:28.050 --> 06:29.429 And if you leave it blank, it will 06:29.430 --> 06:31.529 just copy the existing 06:31.530 --> 06:33.089 file name and place it into that 06:33.090 --> 06:34.090 directory. 06:34.230 --> 06:36.089 And now we can see here I have 06:36.090 --> 06:37.769 the words file that was copied 06:38.160 --> 06:39.569 into this directory. 06:40.500 --> 06:41.500 Now I'm going to delete it. 06:41.550 --> 06:42.550 I don't want it there. 06:43.680 --> 06:45.630 All right. Now for the Move Command. 06:46.200 --> 06:48.149 I'm going to do the same command 06:48.150 --> 06:49.150 here, 06:50.250 --> 06:51.439 slash desktop. 06:53.280 --> 06:54.280 And there 06:55.290 --> 06:56.549 we go. We have the words command 06:56.550 --> 06:57.550 back on my desktop. 06:58.320 --> 07:00.209 And if we look in here in 07:00.210 --> 07:02.279 the documents folder, the words 07:02.280 --> 07:03.509 is no longer in there. 07:05.130 --> 07:07.019 It's gone because it was moved. 07:07.410 --> 07:08.790 So I want to move 07:10.290 --> 07:11.300 this back. 07:11.670 --> 07:13.019 I can just drag and drop. 07:16.340 --> 07:17.908 And check it out, we're back and 07:18.080 --> 07:19.649 what's neat about the move command 07:19.670 --> 07:21.529 is we can also kind of rename 07:21.530 --> 07:23.480 files by moving 07:23.510 --> 07:25.519 them since it 07:26.450 --> 07:27.940 doesn't keep a copy of the 07:28.280 --> 07:29.280 the existing file. 07:29.930 --> 07:32.179 So let's take a look, move words, 07:32.300 --> 07:33.427 and I'm going to rename 07:34.250 --> 07:36.350 it to new name 07:36.680 --> 07:37.680 txt 07:39.050 --> 07:40.050 and do a listing 07:40.970 --> 07:42.829 and check it out where we have 07:42.830 --> 07:44.959 our new name, that text file here. 07:46.910 --> 07:48.169 All right, so these are very useful 07:48.170 --> 07:50.089 commands and now deleting 07:50.090 --> 07:51.090 files, so the 07:52.070 --> 07:53.869 R.M. command, this is used for 07:53.870 --> 07:54.870 removing files and 07:55.760 --> 07:57.709 if you are logged in as the root 07:57.710 --> 07:58.710 user and you use 07:59.570 --> 08:01.040 the dash F 08:01.430 --> 08:02.753 for forcing it, it will not 08:03.410 --> 08:04.410 ask you twice. 08:04.820 --> 08:06.949 It will start deleting and 08:06.950 --> 08:08.119 it won't look back. 08:08.130 --> 08:09.769 So you have to be very careful. 08:10.640 --> 08:11.869 So let me give you a quick 08:11.870 --> 08:13.069 demonstration of this. 08:13.380 --> 08:14.605 I'm going to copy our new 08:15.230 --> 08:16.230 name, that text 08:17.480 --> 08:19.339 file and give 08:19.340 --> 08:20.730 it four words, that text. 08:21.650 --> 08:22.939 And let's 08:23.540 --> 08:24.540 not forget that we 08:25.580 --> 08:26.899 have both for our files. 08:26.910 --> 08:27.910 They are the same. 08:28.040 --> 08:29.118 So let's say I want to 08:29.930 --> 08:31.430 remove a new 08:32.090 --> 08:33.450 name, that texte 08:34.909 --> 08:36.440 listing, and it's going 08:37.010 --> 08:38.010 good. 08:39.159 --> 08:40.159 All right, 08:41.409 --> 08:43.173 now, searching through text, we have 08:43.360 --> 08:45.299 the command, so 08:45.320 --> 08:46.809 grep is one of the most powerful 08:46.810 --> 08:47.860 tools we can use. 08:48.130 --> 08:49.600 It is pattern based search and 08:50.110 --> 08:51.489 it works well when typed to other 08:51.490 --> 08:52.490 commands. 08:52.780 --> 08:54.789 So inside of this 08:54.790 --> 08:55.819 longer file, I have a 08:56.620 --> 08:57.929 secret word in there. 08:58.420 --> 08:59.988 So in order to find it, it's use 09:00.220 --> 09:02.440 grip secret 09:02.770 --> 09:04.269 because this is what we're searching 09:04.270 --> 09:06.039 for and then into 09:06.100 --> 09:07.100 a longer file. 09:09.160 --> 09:10.069 And there we go. 09:10.070 --> 09:11.650 It's highlighted. That's our secret. 09:12.220 --> 09:13.529 Here is the secret. 09:14.500 --> 09:15.879 So it's very useful to search 09:15.880 --> 09:17.790 through a large amount of text. 09:17.800 --> 09:19.419 It's very fast. But what it does to. 09:21.390 --> 09:23.007 All right. Post assessment, is it 09:23.070 --> 09:25.109 possible to concatenate multiple 09:25.110 --> 09:26.110 files, no, only 09:27.090 --> 09:28.090 one file at a time? 09:28.470 --> 09:30.119 Yes, but only two files? 09:30.510 --> 09:32.759 No. You need to use the more command 09:33.090 --> 09:34.315 or yes, there is no limit 09:34.950 --> 09:36.020 to the amount of files. 09:37.260 --> 09:38.681 The answer is D Yes, there is 09:39.210 --> 09:40.820 no limit to the amount of files. 09:41.250 --> 09:42.867 So what's great about the command 09:43.380 --> 09:45.209 is that you can combine 09:45.210 --> 09:46.739 a whole bunch of different files 09:46.740 --> 09:47.699 together. 09:47.700 --> 09:50.250 That way you can type them into 09:50.520 --> 09:51.959 grep and search through. 09:52.120 --> 09:54.029 It's very useful so you 09:54.360 --> 09:55.949 become more comfortable with it as 09:55.950 --> 09:57.330 you use the command line. 09:58.620 --> 10:00.089 All right. So in this video, we 10:00.090 --> 10:01.560 learned how to read files, how 10:01.950 --> 10:03.175 to copy files, understand 10:03.840 --> 10:05.506 how to delete files and understood 10:06.150 --> 10:07.739 how to search through files with 10:07.740 --> 10:09.210 grep. And I hope to see you in 10:09.570 --> 10:10.289 the next video.