WEBVTT 00:00.910 --> 00:05.350 The word command has three different meanings in Linux. 00:05.350 --> 00:12.130 So the first is a command is just a program here, just let's change my mouse. 00:12.130 --> 00:12.610 Yeah. 00:12.850 --> 00:15.990 Command is just a program pro. 00:19.560 --> 00:21.540 So command is a just a program. 00:21.540 --> 00:31.740 So this is an executable program named and executed by a single word such as the LZ here, LZ, or a 00:31.740 --> 00:35.550 similar feature built into the shell, such as the CD here. 00:35.550 --> 00:40.590 Actually, let's see, LZ, see the cat? 00:42.520 --> 00:44.770 And goes like that. 00:44.860 --> 00:49.410 So we also the command is also can be a similar command. 00:49.420 --> 00:52.060 So this is a program name or a shell built in. 00:52.060 --> 00:53.830 Actually, the simple here. 00:53.830 --> 00:54.700 Simple. 00:58.270 --> 00:59.080 Simple. 00:59.080 --> 01:07.720 So this is a shell built in or optional, followed by an argument such as Here the simple command is 01:07.720 --> 01:09.130 like L. 01:09.130 --> 01:12.790 S and here it calls the L here. 01:12.790 --> 01:16.510 And after that the, for example, home. 01:19.640 --> 01:22.400 So this is a simple command. 01:22.400 --> 01:27.590 And we also have a combined command combined. 01:32.100 --> 01:33.480 Combined command. 01:33.510 --> 01:38.010 So this is a several simple commands treated as a unit in combined. 01:38.040 --> 01:38.550 Command here. 01:38.550 --> 01:40.590 So let's actually write something like that. 01:40.590 --> 01:42.360 So we have L. 01:44.060 --> 01:45.800 Else here. 01:46.130 --> 01:49.490 So after that, it's L and. 01:50.480 --> 01:52.080 That's been here or home? 01:52.100 --> 01:52.850 Home. 01:54.790 --> 02:00.780 And after that, we have we are using the pipeline here and then we are writing less. 02:00.790 --> 02:03.210 For example, this is a combined command. 02:03.220 --> 02:12.460 So why I'm telling combined is that, for example, here we are using a program, so we are using program 02:12.460 --> 02:12.880 here. 02:12.880 --> 02:15.160 So LS is a program. 02:15.670 --> 02:17.530 This is a program. 02:18.350 --> 02:24.650 Also the less here is also program, but less. 02:24.680 --> 02:26.960 Home is a simple command. 02:26.960 --> 02:29.450 So this is a simple command. 02:29.660 --> 02:30.740 Simple. 02:33.370 --> 02:34.680 So command here. 02:34.690 --> 02:39.160 So also these two are the. 02:39.860 --> 02:40.810 What I said. 02:40.820 --> 02:43.040 The program program. 02:46.880 --> 02:53.210 But here the all of these are a combined command. 02:53.320 --> 02:54.920 So actually, let's delete that. 02:55.250 --> 03:00.110 Yeah, all of these are a combined command. 03:00.110 --> 03:04.430 So here it is, the combined. 03:08.490 --> 03:11.340 This is all of this code here. 03:11.430 --> 03:15.150 The comment here is a combined comment. 03:15.150 --> 03:20.150 So, um, in this course I will use the word command in all these ways. 03:20.160 --> 03:24.330 So usually the surrounding context will make clear which one I mean. 03:24.330 --> 03:31.320 But if not, I will use one of one of the more specific terms in our next lectures here.