WEBVTT 00:02.200 --> 00:06.550 Weaving processes dynamically with top command. 00:07.270 --> 00:13.600 So while the PS command can reveal a lot about what the machine is doing, it provides only a snapshot 00:13.600 --> 00:14.860 of the machine state. 00:14.860 --> 00:18.160 At the moment of the command is executed. 00:19.140 --> 00:22.650 To see more dynamic views of the machine's activity. 00:22.650 --> 00:30.510 We use the top command like this here, so the top command displays a continuously updating by default 00:30.540 --> 00:36.930 every three seconds display of the system processes listed in order of process activity. 00:36.930 --> 00:44.910 So the name top comes from the fact that the top program is used to see top processes on the system. 00:44.910 --> 00:50.010 So the top display consists of two parts a system summary at the top of the display, followed by the 00:50.010 --> 00:55.170 table of processes sorted by CPU activity. 00:55.170 --> 00:59.100 So here the system summary contains a lot of good stuff. 00:59.100 --> 01:00.230 As you can see here. 01:00.240 --> 01:03.570 Let's actually understand what these are. 01:03.810 --> 01:06.180 So here we have top. 01:06.180 --> 01:13.110 So this is the name of the program here and here, as you can see here, we have actually let me get 01:13.110 --> 01:16.380 my marker here so you can see better. 01:17.090 --> 01:17.630 Here. 01:18.260 --> 01:23.810 So here, as you can see here, this is the current time of the day. 01:23.840 --> 01:26.000 This is the current time of the day. 01:26.030 --> 01:26.570 Right. 01:26.660 --> 01:29.830 And we also have the oops. 01:29.840 --> 01:30.590 Let me here. 01:30.590 --> 01:33.910 We also have the OP nine minute here. 01:33.920 --> 01:36.380 Obviously, it says this is a called op time. 01:36.380 --> 01:40.190 So it's the amount of time since the machine was last booted. 01:40.190 --> 01:45.170 So in this example, the system has been up for nine minutes. 01:45.170 --> 01:47.630 And we also have this user here. 01:47.660 --> 01:53.360 This is a there are this means that there are one logged in user. 01:53.360 --> 01:57.440 And as you can see, it's a typhoon here, which is my main user account. 01:57.440 --> 02:01.220 And we also have the load average here. 02:01.220 --> 02:02.180 Load average. 02:02.180 --> 02:09.320 This load average refers to the number of processes that are waiting to run, and that is the number 02:09.320 --> 02:14.180 of processes that are in a runnable state and sharing the CPU. 02:14.180 --> 02:15.980 So three values are shown here. 02:15.980 --> 02:18.980 So each for a different period of time. 02:18.980 --> 02:25.820 And the first is the average of the last sixth here, last 6/62. 02:25.820 --> 02:31.310 So the next here, here, this is the last 60 seconds average of last 60 seconds. 02:31.310 --> 02:35.900 The next is the previous five minutes and the finally here. 02:35.900 --> 02:41.570 So this is and 0.03 is the final of 15 minutes. 02:41.570 --> 02:46.370 So values less than 1.0 indicate that the machine is not busy here. 02:46.380 --> 02:54.110 As you can see here, my machine is not busy right now because our values is less than one in this case, 02:54.110 --> 02:57.380 0.12, 0.10 and 0.3. 02:57.380 --> 03:01.010 And as you can see, it changed to 0.10 right now. 03:02.150 --> 03:04.700 And we also have the tasks. 03:05.150 --> 03:07.300 The tasks here tasks. 03:07.310 --> 03:14.990 So this obviously says that the tasks is summarizes, summarizes the number of processes and their various 03:14.990 --> 03:16.070 process status. 03:16.070 --> 03:19.610 And we also have the CPUs. 03:19.610 --> 03:24.230 And let's actually this task, as you can see, the 192 is total. 03:24.230 --> 03:30.320 One is running 191 is sleeping zero stopped, zero zombie. 03:30.320 --> 03:34.910 And here, as you can see, these are the tasks that I use in my system. 03:34.910 --> 03:38.000 And we also have the CPU. 03:38.000 --> 03:39.710 So this is the CPU. 03:40.010 --> 03:46.760 This row describes the character of the activities that the CPU is performing here. 03:46.760 --> 03:53.180 So now I will explain what these tabs and information that the CPU tab provides us. 03:53.600 --> 04:01.820 The firstly here, as you can see here, us that written here, so the US that written here means that 04:01.920 --> 04:09.240 here in this case it's 0.6, 0.6% of the CPU is being used for user process here. 04:09.240 --> 04:13.200 As you can see, 0.5, 0.3 and so on. 04:13.200 --> 04:15.930 And we also have see here. 04:15.930 --> 04:21.270 So this is and right now is 0.8, 0.3 here. 04:21.270 --> 04:25.980 So this is the present of the CPU is being used for system kernel. 04:25.980 --> 04:27.840 So it's a kernel. 04:29.090 --> 04:29.930 Colonel. 04:31.240 --> 04:34.870 And we also have an AI here. 04:34.870 --> 04:37.120 So 0.0 an AI. 04:37.600 --> 04:45.700 So this 0.0 in this percent of the CPU is being used by nice, low priority processes. 04:45.700 --> 04:51.130 So as you learned the what's the nice and low, what's you in previous lecture actually you learned 04:51.130 --> 04:56.140 about high priority priority and low priority processes in previous lecture. 04:56.140 --> 05:04.780 So in this case it's my CPU is used, its powers 0.0% for low priority process processes. 05:04.780 --> 05:07.510 And we also have this here. 05:07.510 --> 05:14.710 In this case, it's a 97.3 ID, this is the percent of the CPU is in idle mode. 05:14.740 --> 05:19.480 Like you turn on your car and it's just an idle mode. 05:19.480 --> 05:22.390 It doesn't do or go to anywhere. 05:22.390 --> 05:30.250 And we also have one point 0VA it's now probably 0.0 and here it's going to be 1.0. 05:30.250 --> 05:34.760 So this is a present of the CPU is waiting for input output. 05:34.790 --> 05:42.410 You also learned what the input output is in previous lectures and we also have mem mem. 05:42.410 --> 05:49.040 So this is a obviously this shows how physical ram, random how physical random access memory is being 05:49.040 --> 05:50.240 used here. 05:50.240 --> 05:55.400 This is A93 thousand 914 total. 05:56.150 --> 06:00.950 2,658.93. 06:01.850 --> 06:07.430 1004 15 used and 477. 06:08.190 --> 06:10.110 Miss buffered and chats. 06:10.260 --> 06:15.060 And we also have the swap tab here, swap information here. 06:15.060 --> 06:21.570 This this swap shows how swap space or virtual memory is being used. 06:21.570 --> 06:30.300 In this case, the total swap memory is 1024, which is one gigabyte and not used here. 06:30.300 --> 06:32.430 As you can see, total is right here. 06:32.430 --> 06:34.710 And this all of them is free. 06:34.710 --> 06:39.210 So 0.0 is used right now and avail mem here. 06:39.210 --> 06:42.810 So the top program accepts a number of keyword commands. 06:42.810 --> 06:47.870 So the most interesting are the h h command here. 06:47.880 --> 06:48.930 H keyword here. 06:48.930 --> 06:54.870 Let's actually try that h here, as you can see here with h command. 06:55.880 --> 07:02.310 Uh, this display, this command displays the help screen and Q command here. 07:02.360 --> 07:06.450 Q, Q keyboard When you press the key. 07:06.660 --> 07:14.340 Q keyboard Q key in your keyboard, you will get this you will get here, as you can see here. 07:14.340 --> 07:18.750 Now, we could from the top command here and let's try it. 07:19.750 --> 07:22.000 Age again and toggle the forest view. 07:22.000 --> 07:23.740 And here we. 07:27.270 --> 07:27.600 Here. 07:27.930 --> 07:35.520 We here, as you can see here, we have several commands that we will use in next lectures here. 07:35.880 --> 07:36.690 So. 07:40.500 --> 07:41.250 And so. 07:42.520 --> 07:47.740 Uh, both major desktop environments provide graphical applications that display information similar 07:47.740 --> 07:53.830 to top in much the same way that task manager in Windows Works and the top is better than the graphical 07:53.830 --> 07:58.900 versions because it is faster and it consumes far fewer system resources. 07:58.900 --> 08:04.390 After all, our system monitor program shouldn't be the source of the system slowdown that we are trying 08:04.390 --> 08:05.260 to track. 08:05.260 --> 08:09.640 So in next lecture you will learn how to control the processes in Linux. 08:09.640 --> 08:11.470 So I'm waiting you in next lecture.