1 00:00:00,910 --> 00:00:05,350 The word command has three different meanings in Linux. 2 00:00:05,350 --> 00:00:12,130 So the first is a command is just a program here, just let's change my mouse. 3 00:00:12,130 --> 00:00:12,610 Yeah. 4 00:00:12,850 --> 00:00:15,990 Command is just a program pro. 5 00:00:19,560 --> 00:00:21,540 So command is a just a program. 6 00:00:21,540 --> 00:00:31,740 So this is an executable program named and executed by a single word such as the LZ here, LZ, or a 7 00:00:31,740 --> 00:00:35,550 similar feature built into the shell, such as the CD here. 8 00:00:35,550 --> 00:00:40,590 Actually, let's see, LZ, see the cat? 9 00:00:42,520 --> 00:00:44,770 And goes like that. 10 00:00:44,860 --> 00:00:49,410 So we also the command is also can be a similar command. 11 00:00:49,420 --> 00:00:52,060 So this is a program name or a shell built in. 12 00:00:52,060 --> 00:00:53,830 Actually, the simple here. 13 00:00:53,830 --> 00:00:54,700 Simple. 14 00:00:58,270 --> 00:00:59,080 Simple. 15 00:00:59,080 --> 00:01:07,720 So this is a shell built in or optional, followed by an argument such as Here the simple command is 16 00:01:07,720 --> 00:01:09,130 like L. 17 00:01:09,130 --> 00:01:12,790 S and here it calls the L here. 18 00:01:12,790 --> 00:01:16,510 And after that the, for example, home. 19 00:01:19,640 --> 00:01:22,400 So this is a simple command. 20 00:01:22,400 --> 00:01:27,590 And we also have a combined command combined. 21 00:01:32,100 --> 00:01:33,480 Combined command. 22 00:01:33,510 --> 00:01:38,010 So this is a several simple commands treated as a unit in combined. 23 00:01:38,040 --> 00:01:38,550 Command here. 24 00:01:38,550 --> 00:01:40,590 So let's actually write something like that. 25 00:01:40,590 --> 00:01:42,360 So we have L. 26 00:01:44,060 --> 00:01:45,800 Else here. 27 00:01:46,130 --> 00:01:49,490 So after that, it's L and. 28 00:01:50,480 --> 00:01:52,080 That's been here or home? 29 00:01:52,100 --> 00:01:52,850 Home. 30 00:01:54,790 --> 00:02:00,780 And after that, we have we are using the pipeline here and then we are writing less. 31 00:02:00,790 --> 00:02:03,210 For example, this is a combined command. 32 00:02:03,220 --> 00:02:12,460 So why I'm telling combined is that, for example, here we are using a program, so we are using program 33 00:02:12,460 --> 00:02:12,880 here. 34 00:02:12,880 --> 00:02:15,160 So LS is a program. 35 00:02:15,670 --> 00:02:17,530 This is a program. 36 00:02:18,350 --> 00:02:24,650 Also the less here is also program, but less. 37 00:02:24,680 --> 00:02:26,960 Home is a simple command. 38 00:02:26,960 --> 00:02:29,450 So this is a simple command. 39 00:02:29,660 --> 00:02:30,740 Simple. 40 00:02:33,370 --> 00:02:34,680 So command here. 41 00:02:34,690 --> 00:02:39,160 So also these two are the. 42 00:02:39,860 --> 00:02:40,810 What I said. 43 00:02:40,820 --> 00:02:43,040 The program program. 44 00:02:46,880 --> 00:02:53,210 But here the all of these are a combined command. 45 00:02:53,320 --> 00:02:54,920 So actually, let's delete that. 46 00:02:55,250 --> 00:03:00,110 Yeah, all of these are a combined command. 47 00:03:00,110 --> 00:03:04,430 So here it is, the combined. 48 00:03:08,490 --> 00:03:11,340 This is all of this code here. 49 00:03:11,430 --> 00:03:15,150 The comment here is a combined comment. 50 00:03:15,150 --> 00:03:20,150 So, um, in this course I will use the word command in all these ways. 51 00:03:20,160 --> 00:03:24,330 So usually the surrounding context will make clear which one I mean. 52 00:03:24,330 --> 00:03:31,320 But if not, I will use one of one of the more specific terms in our next lectures here.