WEBVTT 00:00.050 --> 00:01.640 Let's start to use the terminal. 00:01.640 --> 00:06.350 And in this video we are also going to focus on navigation and the file system. 00:06.350 --> 00:08.990 So first of all how to open a terminal. 00:08.990 --> 00:11.030 Well you have the terminal icon on the top here. 00:11.030 --> 00:14.360 You can just click and it's going to open a terminal okay. 00:14.390 --> 00:17.240 And then you can close it and open it again. 00:17.240 --> 00:21.260 You can also click on the menu and go to accessories. 00:21.260 --> 00:25.070 And here you will find as well the same terminal. 00:25.070 --> 00:28.220 And note that you can open several terminal windows okay. 00:28.250 --> 00:30.650 You can have as many as you want. 00:31.700 --> 00:33.770 Now you can leave it like this. 00:33.770 --> 00:37.850 There is just one thing I'm going to do so that you can actually read my screen. 00:37.850 --> 00:39.590 It's going to be better for the course. 00:39.590 --> 00:43.100 I'm going to right click here and go to preferences. 00:43.100 --> 00:45.560 And I'm going to increase the size. 00:45.560 --> 00:50.570 So the font size I'm going to go from 10 to 18. 00:50.720 --> 00:52.490 Now you can just choose any value you want. 00:52.520 --> 00:57.440 Just make sure it's readable but not too big so that you can fit a lot of stuff on the screen. 00:57.470 --> 00:57.710 Okay. 00:57.740 --> 01:00.500 So I'm going to select that okay. 01:00.500 --> 01:02.820 And let's just open a new one. 01:04.020 --> 01:04.320 All right. 01:04.320 --> 01:06.780 So with this, you should be able to read easily. 01:06.810 --> 01:08.400 Now we are on the terminal. 01:08.400 --> 01:15.240 And to explain to you what we're going to do in the terminal, I'm going to open a file manager on the 01:15.240 --> 01:16.260 side. 01:16.290 --> 01:19.860 So first let's have a look at this file manager here. 01:19.860 --> 01:26.040 If I open the file manager we are in a folder named slash home slash Pi. 01:26.040 --> 01:31.530 And you can see we have the documents folder in this documents folder we have created our Python programs. 01:31.530 --> 01:36.510 So if I go back here you can see that pi is kind of your user directory. 01:36.510 --> 01:41.970 So if you have several users on the Raspberry Pi, several users on a computer, basically you have 01:41.970 --> 01:43.680 different user directories. 01:43.680 --> 01:51.720 And how it works in basically most Unix systems is you have you can see you have a root here slash. 01:51.720 --> 01:55.140 So that's what we call the root of the file system. 01:55.140 --> 01:59.700 And under this slash you have a lot of different folders. 01:59.700 --> 02:07.650 So all of those folders are used for what the basic command lines, network system configuration, etc. 02:07.650 --> 02:09.840 but we're not going to go too much into this. 02:09.840 --> 02:15.660 But in this root folder you also have a home directory. 02:15.690 --> 02:15.930 Okay. 02:15.960 --> 02:20.790 And in that home directory you have basically a directory for each user. 02:20.790 --> 02:21.990 So we only have one user. 02:21.990 --> 02:22.920 It's called pi. 02:22.950 --> 02:25.710 If I go there I am in my home directory. 02:25.710 --> 02:30.330 That's your user main directory where you're going to put most of your files. 02:30.360 --> 02:32.130 Now why do I talk about this. 02:32.130 --> 02:38.100 So let's go back to the terminal and let's see one first comment to just know where you are. 02:38.130 --> 02:45.300 This command is p w d okay so p w d you can just write this and then you press enter. 02:45.300 --> 02:51.270 And this is going to give you the current path of where you are currently in the terminal. 02:51.270 --> 02:57.600 And you can see we just open the terminal I do PWD and I see slash home slash Pi. 02:57.600 --> 03:00.120 And this is exactly what we have here. 03:00.120 --> 03:03.160 So this is our home directory with the user of pi. 03:03.160 --> 03:07.540 And basically we are at the same place in the terminal. 03:07.570 --> 03:12.460 Now the second command we're going to see is L s with LZ. 03:12.490 --> 03:18.400 You can list everything that's well right here in this folder where you are right now. 03:18.400 --> 03:21.130 So I just type LZ and I press enter. 03:21.190 --> 03:22.690 And you can see I have. 03:22.690 --> 03:30.070 So if you have stuff like this in bold and kind of blue purple bold, it means it's a directory, okay. 03:30.100 --> 03:32.320 If it's in white it's going to be a file. 03:32.350 --> 03:38.050 And so here we have the list of all directories inside this pi folder. 03:38.050 --> 03:41.950 And you can see this is exactly what we have on the file manager. 03:41.950 --> 03:45.880 So that's what I told you that basically the file manager and the terminal is the same thing. 03:45.880 --> 03:50.590 We are navigating inside the same thing the same folders. 03:50.590 --> 03:57.010 And so for example let's say I create a new file here in my file manager I do right click new file. 03:57.040 --> 03:58.720 I will name it ABC. 03:59.020 --> 04:00.940 I press enter okay. 04:00.970 --> 04:02.800 So I have a new file name ABC. 04:03.130 --> 04:05.510 I just one note is in Linux. 04:05.540 --> 04:11.870 While any Unix system you don't need to add an extension to a file, you can have a file with any extension 04:11.870 --> 04:13.550 or no extension at all. 04:13.550 --> 04:14.810 Everything is valid. 04:14.810 --> 04:15.560 So great! 04:15.560 --> 04:16.910 I have my new file here. 04:16.940 --> 04:24.680 Now if I do l s in the terminal, you can see that while we have the new file a, b, c. 04:24.950 --> 04:25.250 All right. 04:25.280 --> 04:27.950 So if there is something new here what is the same. 04:28.040 --> 04:29.750 There is something in your home directory. 04:29.750 --> 04:31.400 You're going to see it with ls. 04:31.400 --> 04:37.070 And now if I remove this so I can do move to wastebasket. 04:38.300 --> 04:41.870 If I remove that file and I do ls again. 04:41.870 --> 04:45.050 And note that to do ls again I don't need to type the command. 04:45.080 --> 04:48.680 Even if it's just two characters, I can use the up arrow. 04:48.710 --> 04:48.860 Okay. 04:48.890 --> 04:51.590 If I use the up arrow, I'm going to come back to the previous command. 04:51.590 --> 04:55.940 So I run LS again and you can see now the ABC is gone. 04:55.940 --> 04:56.360 Great. 04:56.360 --> 05:01.700 So now you can already know where you are in the terminal and see what's inside where you are. 05:01.700 --> 05:05.450 But there is something missing is how to go to a place. 05:05.480 --> 05:05.690 Okay. 05:05.720 --> 05:08.030 How to navigate to some place. 05:08.060 --> 05:10.190 And for this you have another command. 05:10.220 --> 05:10.370 Okay. 05:10.370 --> 05:15.710 So here in this lesson we will see three commands PWD, LRS and CD. 05:15.740 --> 05:19.520 With CD you can navigate to a directory. 05:19.520 --> 05:22.880 And for example let's say I want to navigate to documents. 05:22.880 --> 05:25.670 I just do CD and then space. 05:25.670 --> 05:27.830 And then I put the name documents. 05:27.890 --> 05:30.020 So make sure it's exactly the same. 05:30.260 --> 05:32.990 I press enter and now you can see. 05:33.020 --> 05:35.720 Well first of all here we see something. 05:35.720 --> 05:40.250 You see already that we are in documents actually you see this. 05:40.250 --> 05:43.220 You see tilde slash document. 05:43.250 --> 05:49.820 So if I do PWD, we are in fact in slash home slash pi slash documents. 05:49.820 --> 05:53.480 So when you see tilde it basically means home directory. 05:53.510 --> 05:57.920 It also means slash home slash whatever user you have. 05:57.950 --> 05:58.310 Okay. 05:58.310 --> 06:04.040 So if you do tilde slash documents it means you are in the documents folder inside the home directory. 06:04.040 --> 06:05.850 So that's the complete path here. 06:05.850 --> 06:09.990 And if I do ls well, I have a test folder that I have created myself. 06:09.990 --> 06:12.000 But then we have our Python programs. 06:12.030 --> 06:12.270 Okay. 06:12.300 --> 06:17.370 So just like if I would go here, I would open this file manager and go to documents. 06:17.550 --> 06:19.290 And I have my Python programs. 06:19.290 --> 06:23.070 So I can go in there and see all the Python code so I can do the same. 06:23.100 --> 06:34.080 I do CD Python programs and I am in, so I can do PWD to verify that. 06:34.470 --> 06:34.890 All right. 06:34.890 --> 06:39.210 And I can do LS and I see all my files. 06:39.240 --> 06:39.420 Okay. 06:39.450 --> 06:41.160 Just like you see all the files here. 06:41.160 --> 06:45.780 So you can see you can navigate in the terminal with just some comments. 06:45.780 --> 06:51.900 So the CD command you can navigate the same way you would navigate by clicking on stuff here on the 06:51.900 --> 06:52.740 file manager. 06:52.770 --> 06:56.490 Now what if you want to go back for example I want to go back to the parent folder. 06:56.490 --> 06:57.570 How to do this. 06:57.570 --> 07:01.920 You can do CD and then so space and then dot dot. 07:01.950 --> 07:04.740 If you do two dots it means the previous directory. 07:04.740 --> 07:08.860 So if I press enter, you see, I am back in my documents. 07:08.890 --> 07:12.220 Now, if I want to go back again, I can do it again. 07:12.250 --> 07:13.690 CD dot dot. 07:13.690 --> 07:18.850 And actually I just run the command before so I can use the up arrow and press enter. 07:18.850 --> 07:20.950 And I am back to my home directory. 07:20.950 --> 07:25.960 And you can combine also different folders at the same time with the CD command okay. 07:25.990 --> 07:28.900 You don't need to do a CD command for every new folder. 07:28.900 --> 07:35.110 For example, if I want to go back to this folder, I can write document and Python programs directly. 07:35.110 --> 07:38.500 And there is one more thing is it's called auto completion. 07:38.500 --> 07:40.780 So for example I write doc. 07:40.900 --> 07:46.000 So I start with doc and I press tab and you can see I have documents. 07:46.000 --> 07:47.950 And then I put Python. 07:47.950 --> 07:51.280 So I start the name and then I press tab. 07:51.280 --> 07:53.920 And I have the name that's automatically completed. 07:53.920 --> 07:55.390 So I can press enter. 07:55.390 --> 07:58.690 And you see we are back to this Python program folder. 07:58.690 --> 08:04.960 So here with just one command you see we do something that we need two clicks here. 08:04.960 --> 08:08.950 So we need to do double click here and a double click here on the file manager. 08:08.950 --> 08:10.930 And we just use one command here. 08:10.930 --> 08:12.700 And I can do the same to go back. 08:12.700 --> 08:18.640 If I want to go back to my home directory I can do CD and then dot dot dot dot I press enter. 08:18.640 --> 08:22.840 And I am back here now just to make sure you understand the autocompletion. 08:22.840 --> 08:25.960 So here if I do ls I'm in my home directory. 08:25.960 --> 08:34.660 Let's say I want to go to my documents folder so I can do CD and then d o c for example, and I press 08:34.690 --> 08:37.630 tab and you see documents is auto completed. 08:37.660 --> 08:38.110 Great. 08:38.140 --> 08:44.650 Now what you can notice is that there are two folders that start with D and O. 08:44.650 --> 08:47.050 So let's say I just put D and o. 08:47.080 --> 08:49.540 Now I press tab once nothing happens. 08:49.540 --> 08:54.460 If I press tab a second time, you see that now I have documents and downloads. 08:54.460 --> 08:56.320 Those are suggestions. 08:56.320 --> 08:58.540 So the auto completion will work. 08:58.780 --> 09:01.150 So the auto completion will work. 09:01.150 --> 09:07.700 If there is only one possibility to finish what you're typing here we have two possibilities, so the 09:07.700 --> 09:09.680 terminal cannot choose for you. 09:09.710 --> 09:11.000 You need to give enough. 09:11.150 --> 09:12.920 Enough data, enough information. 09:12.920 --> 09:18.380 So here, for example, if I want to go to downloads I will put d o w and I can press tab. 09:18.380 --> 09:21.800 If I want to go to document I need to at least put a C. 09:21.830 --> 09:25.160 Now for example, if I press tab here, I press tab twice. 09:25.160 --> 09:28.340 You see that I have two different folders. 09:28.340 --> 09:31.190 This one starts with P and this one starts with t. 09:31.190 --> 09:34.610 So if I just put p I should be able to press tab again. 09:34.610 --> 09:35.780 And then I press enter. 09:35.780 --> 09:37.970 And we are in the directory. 09:37.970 --> 09:39.530 And this can go very fast. 09:39.530 --> 09:42.470 You see for example I do CD dot dot dot dot. 09:42.470 --> 09:45.740 And then I do CD doc tab tab. 09:45.740 --> 09:48.290 And you can see that it goes very fast. 09:48.290 --> 09:49.730 So this of course with practice. 09:49.730 --> 09:52.310 But the more you practice the faster you will become. 09:52.310 --> 09:57.470 And then you can really navigate super fast in different places of your file system. 09:57.470 --> 10:02.180 Now what if you type CD just like that CD and nothing else? 10:02.630 --> 10:07.770 What you can see is that if you type CD, you will come back to your home Directory. 10:07.770 --> 10:11.520 So if I click on the home button here, for example go to home folder. 10:11.520 --> 10:15.000 We go to slash home slash pi okay. 10:15.030 --> 10:22.200 So from anywhere if I'm in downloads and I do CD, I come back here from anywhere in the file system, 10:22.200 --> 10:25.050 I do CD and I come back to the home directory. 10:25.080 --> 10:25.470 All right. 10:25.470 --> 10:30.540 So you have seen how to go to a directory with the what we call the relative path. 10:30.540 --> 10:35.700 So depending on where you are for example here the relative path is to go here and say we are in this 10:35.700 --> 10:36.330 home directory. 10:36.360 --> 10:38.970 We go there, then we are here, we go there. 10:39.000 --> 10:41.100 This is relative to where you are. 10:41.160 --> 10:44.550 You also have seen just the CD command to go back to the home directory. 10:44.550 --> 10:47.670 And you can use CD with an absolute path. 10:47.670 --> 10:55.530 So the absolute means that you will start from a slash if you start CD, and then with a slash, it 10:55.530 --> 10:58.800 means you are starting from the root of the file system. 10:58.800 --> 11:05.460 So for example, how to go to the home directory and then to the documents folder, I will need to do 11:05.490 --> 11:11.940 slash home Slash pi slash documents. 11:12.360 --> 11:12.840 Okay. 11:12.870 --> 11:15.330 And I can do the same thing with auto completion. 11:15.330 --> 11:17.520 I can do home like this. 11:17.520 --> 11:24.780 And then I just put P on nothing because there is just one user and then doc documents. 11:24.810 --> 11:25.080 Okay. 11:25.110 --> 11:31.800 So sometimes using the absolute path is going to be important, especially if you need to write a path 11:31.800 --> 11:34.710 inside a Python file inside a Python script. 11:34.710 --> 11:40.350 And you don't necessarily know where your Python script is going to be executed, then at least with 11:40.380 --> 11:43.680 an absolute path, you know exactly where you go, okay. 11:43.710 --> 11:49.380 Because if you run CD documents and Python program like this, it means you are already in the home 11:49.380 --> 11:50.100 directory. 11:50.130 --> 11:50.370 Okay. 11:50.400 --> 11:53.310 If I run this command from anywhere else, it's not going to work. 11:53.310 --> 11:58.500 But if I run this from anywhere, it's going to work because it's going to use the absolute path, okay? 11:58.530 --> 12:02.370 Which always starts at the beginning of the file system. 12:02.370 --> 12:03.840 So here it works. 12:03.870 --> 12:04.260 All right. 12:04.260 --> 12:08.640 And to finish with the CD, well there are different ways you can go to the same place. 12:08.640 --> 12:10.390 For example, let's say I want to go. 12:10.390 --> 12:13.840 So here in my home directory I want to go to my downloads folder. 12:13.840 --> 12:18.940 And let's say I am here in my documents folder or even in my Python programs folder. 12:18.940 --> 12:26.710 What I can do is I can use the relative path so I can do CD, dot, dot slash, dot dot, and actually 12:26.710 --> 12:27.640 I can do another slash. 12:27.640 --> 12:32.620 So here with this I will go back to the home directory and then downloads. 12:32.620 --> 12:34.840 And I can use the auto completion okay. 12:34.840 --> 12:37.810 So I go back one folder two folders and then downloads. 12:38.020 --> 12:39.100 And I am there. 12:39.100 --> 12:40.450 So that's one way to do it. 12:40.450 --> 12:46.660 Another way to do it is actually so I often do that if the folder is close to the home directory, I 12:46.660 --> 12:47.350 just do CD. 12:47.380 --> 12:49.210 First I go to the home directory. 12:49.210 --> 12:53.890 So from anywhere to the home directory and then CD downloads. 12:53.890 --> 12:56.050 So it takes two commands instead of one. 12:56.050 --> 13:01.180 But sometimes it's much faster because you are sure that with this you come back to the home directory 13:01.180 --> 13:03.280 and then you can easily find the folder. 13:03.280 --> 13:12.320 And finally, if we use the absolute path, I can do CD slash home slash pie. 13:12.350 --> 13:17.660 I'm in my home directory and then slash downloads, and we're going to get to the same place. 13:17.660 --> 13:20.600 So you can see we've three different ways here. 13:20.600 --> 13:22.700 We can go to the same place. 13:22.730 --> 13:23.300 Great. 13:23.300 --> 13:24.800 And let's go back to the home directory. 13:24.800 --> 13:26.750 So to go back to the home directory we do CD. 13:27.110 --> 13:31.550 One last thing I'm going to come back to the LS command. 13:31.580 --> 13:32.090 Okay. 13:32.090 --> 13:39.200 If you do LS and then dash a you will see that we see actually more files. 13:39.200 --> 13:41.210 And you see files with a dot. 13:41.210 --> 13:44.240 So files with a dot and also folders with a dot. 13:44.270 --> 13:45.710 And what are those files. 13:45.710 --> 13:48.680 Well those files are hidden files. 13:48.680 --> 13:50.810 So there is nothing really special about them. 13:50.810 --> 13:56.360 Hidden just means that well you don't see them when you just type ls or from the file manager. 13:56.360 --> 13:57.410 That's just about it. 13:57.410 --> 13:59.660 And how to make a file or folder hidden. 13:59.660 --> 14:01.760 You just add a dot in front of it. 14:01.760 --> 14:07.130 Now if you do the dash A with ls, you can see all the hidden files and folders. 14:07.130 --> 14:08.930 And we're going to come back to this in this course. 14:08.930 --> 14:11.480 Actually it's the same in the file manager. 14:11.480 --> 14:16.130 If you go to view, you can click on Show Hidden Files. 14:16.130 --> 14:18.590 And you see we have well we have the same files. 14:18.590 --> 14:21.830 It's just that by default it's going to be unchecked. 14:21.830 --> 14:23.600 And you can do the same thing on windows. 14:23.600 --> 14:26.990 And basically I think almost any operating system. 14:27.020 --> 14:27.530 All right. 14:27.530 --> 14:34.130 So in this lesson you have discovered the terminal and you saw how to navigate in the terminal. 14:34.130 --> 14:37.970 So we have seen three commands PWD, CD and LS. 14:37.970 --> 14:40.370 And with those three commands you can know where you are. 14:40.370 --> 14:45.860 And you can navigate to anywhere in the terminal the same way you would do with a file manager. 14:45.860 --> 14:51.530 And you have also understood a bit more how the file system works here on Unix system. 14:51.530 --> 14:57.170 And what's great about what you learned here is that this knowledge is the same for different OSes based 14:57.170 --> 14:58.220 on Unix. 14:58.250 --> 15:02.210 If, for example, one day you need to work on ubuntu, you may have heard about this. 15:02.210 --> 15:05.900 Well, if you need to work on that, you also going to use the same commands. 15:05.900 --> 15:11.570 So what you learned here is going to be useful for anything you do with any Unix system.