WEBVTT 00:00.550 --> 00:01.990 Hello, my name is Typhoon. 00:01.990 --> 00:07.750 And in this lecture of our course, you will learn about lot of things about Linux command line. 00:07.750 --> 00:09.070 So let's get started. 00:22.400 --> 00:28.790 When you work in the Windows, Mac OS and most other operating systems, you probably spend your time 00:28.790 --> 00:34.490 running applications like web browsers, word processors, spreadsheets and games. 00:34.520 --> 00:41.730 A typical application is packed with features everything that designers or their users will need. 00:41.750 --> 00:44.360 So most applications are self-sufficient. 00:44.630 --> 00:53.330 They don't rely on other applications, so you might copy and paste between applications from time to 00:53.330 --> 00:56.660 time, but for the most part they are separate. 00:56.780 --> 01:01.130 But the Linux command line is different. 01:01.160 --> 01:07.640 Instead of big applications with tons of features, Linux supplies thousands of small commands with 01:07.640 --> 01:08.960 very few features. 01:08.990 --> 01:11.150 The command cat, for example. 01:11.150 --> 01:15.500 Cat the for example, the print files on the screen. 01:15.500 --> 01:16.220 That's about it. 01:16.220 --> 01:23.840 So the less files, less here, less command lists, the file in a directory, MV renames files and 01:23.840 --> 01:24.320 so on. 01:24.320 --> 01:28.580 So each command has a simple, fairly well-defined purpose. 01:28.610 --> 01:30.990 What if you need to do something more complicated? 01:31.010 --> 01:31.550 Don't worry. 01:31.700 --> 01:40.400 So Linux makes it easy to combine commands so their individual features work together as accomplish 01:40.400 --> 01:40.930 your goal. 01:40.940 --> 01:45.740 So this way of working yields a very different mindset about computing. 01:45.770 --> 01:52.790 Instead of asking which application should I launch to achieve some results, the question becomes which 01:52.790 --> 01:55.940 command should I combine? 01:56.120 --> 02:02.300 In this lecture, you will learn about how to arrange and run commands in different combinations. 02:02.300 --> 02:05.420 To do what you need to keep things simple. 02:05.420 --> 02:13.070 I will introduce just six Linux commands and their most basic uses so you can focus on the more complex 02:13.070 --> 02:18.680 and interesting part about that, combining them with a huge learning curve. 02:18.710 --> 02:26.640 So it's a bit like learning to cook with six ingredients or learning carpentry with just a hammer and 02:26.640 --> 02:26.960 saw. 02:26.970 --> 02:31.050 So you will combine commands using pipes. 02:31.380 --> 02:34.230 And here this is a pipe here in Linux. 02:34.230 --> 02:42.840 So this is the Linux feature that connects the output of one command to the output of another. 02:42.840 --> 02:46.290 So let me open my driver here. 02:46.320 --> 02:49.500 Jiffy Yeah, Grommet NP here. 02:49.500 --> 02:50.250 So. 02:51.170 --> 02:52.790 It takes one here. 02:52.790 --> 02:55.030 So if you have here. 02:55.040 --> 02:55.450 Yeah. 02:55.460 --> 02:56.240 Toggle painting. 02:56.240 --> 02:56.770 Yeah. 02:56.780 --> 02:59.480 If you have one here, for example, this is our one result. 02:59.480 --> 03:04.850 If you make pipe between them like this, this will take here and put it here. 03:05.390 --> 03:06.350 So. 03:07.690 --> 03:10.390 We will example will be practical for daily use. 03:10.390 --> 03:16.300 So while others are just toy examples to demonstrate an important feature. 03:16.390 --> 03:22.900 So let's get started with input output and pipes in Linux here. 03:23.260 --> 03:24.550 Uh, yes, actually. 03:24.550 --> 03:27.660 How can we clear screen shift and home? 03:27.670 --> 03:29.440 Yes, clear screen here. 03:29.470 --> 03:34.360 So most linux commands read input from keyboard. 03:35.360 --> 03:37.950 Write output to the screen or both. 03:37.970 --> 03:41.330 So Linux has fancy names for the reading and writing. 03:41.330 --> 03:42.410 For example. 03:42.800 --> 03:43.760 STD in. 03:43.880 --> 03:45.560 STD in here. 03:45.560 --> 03:47.810 So this is actually not a comment, but just I want to talk. 03:47.870 --> 03:48.740 About this. 03:48.740 --> 03:54.500 So this STD in is standard input or standard in so this is a stream. 03:54.530 --> 03:58.970 Of input that Linux reads from your keyboard. 03:58.970 --> 04:05.750 So when you type any comments at the prompt, you are displaying data on STD in. 04:05.840 --> 04:12.920 And we also have the STD out pronounced as the standard output or standard out. 04:12.950 --> 04:16.970 So this is the stream of the output that Linux writes to your display. 04:16.970 --> 04:25.010 So when you run the command, for example, to print file names, the result appears on STD out. 04:25.010 --> 04:33.170 So now this comes the cool part here so you can connect the STD out of one command to the STD in of 04:33.170 --> 04:33.650 another. 04:33.750 --> 04:35.790 So the first command feeds the second. 04:35.790 --> 04:39.870 So let's begin with the familiar LSL command here. 04:39.870 --> 04:43.140 So LSL and been here, for example. 04:43.590 --> 04:48.900 So as you can see here, the directory contains far more files. 04:48.900 --> 04:54.240 For example, if you have directory contains the file more files than your display has lines. 04:54.240 --> 04:58.110 So the output quickly scrolls off the screen here. 04:58.110 --> 05:04.720 As you can see, it's a it's a shame that the LHS can't print the information on screen and full at 05:04.720 --> 05:05.130 the time. 05:05.130 --> 05:13.860 So pausing until you press a key to continue here so like this or for example, s m home oops, home. 05:13.860 --> 05:16.710 And as you can see here, we got this. 05:16.830 --> 05:17.700 So. 05:19.300 --> 05:27.670 Asexual also used a less here for example my file and as you can see we don't have a my file so the 05:27.670 --> 05:34.420 last command displays a file on a screenful at a time so you can connect this to your commands because 05:34.810 --> 05:39.160 writes the stdout and less can read from the stdin. 05:39.160 --> 05:42.970 So for example ls ls l here? 05:42.970 --> 05:44.500 So let's clear? 05:44.530 --> 05:45.220 Yeah. 05:45.430 --> 05:53.580 LS l here bin And this is a pipe here, so use a pipe to send the output from L. 05:53.590 --> 05:55.840 S to bin here. 05:55.840 --> 05:57.610 So not like this here. 05:57.610 --> 06:05.530 So use a pipe to send output from ls to the input of less here. 06:05.530 --> 06:08.770 So in this case the less is going to be less. 06:08.770 --> 06:10.360 And just add. 06:10.360 --> 06:15.460 And as you can see here, we got an a screen here like this oops. 06:15.610 --> 06:16.230 Here. 06:16.480 --> 06:16.930 So it. 06:16.930 --> 06:17.500 Yeah. 06:19.820 --> 06:20.180 Here. 06:21.130 --> 06:22.150 As you can see here. 06:22.150 --> 06:27.250 So the combined command displays the directory contents one screenful at a time here. 06:27.250 --> 06:28.630 So the vertical. 06:29.460 --> 06:33.810 But here vertical path that we've written here. 06:35.570 --> 06:36.400 Yes. 06:36.410 --> 06:40.220 Uh, here, press return to quick here. 06:40.220 --> 06:44.690 Or for example, let's lsl home like this. 06:44.690 --> 06:48.440 And as you can see here, we've written like the output here. 06:50.360 --> 06:50.990 Like this. 06:52.060 --> 06:55.360 So first commands is stdout to the next command. 06:55.750 --> 06:59.330 And so any command line containing pipe is called. 06:59.350 --> 07:00.250 Pipeline. 07:00.250 --> 07:03.610 So commands generally are not aware that they are part of a pipeline. 07:03.610 --> 07:11.530 So unless believes it's writing to the display when the expected output has been redirected to less 07:11.530 --> 07:17.410 here so and less believes it's reading from the keyboard when it's actually reading from the output 07:17.410 --> 07:19.150 of a less.