WEBVTT 00:01.320 --> 00:06.160 Now, you may think that the program is completed, but I have to tell you that it is not completed. 00:06.160 --> 00:08.960 Still, there is things, ways that we can improve it. 00:09.800 --> 00:11.440 How to see. 00:11.480 --> 00:18.120 Here we are having the interface and also the Mac address inside the script, inside the program. 00:18.120 --> 00:26.560 Whenever a user want to change a mac address to a mac address or change the interface, they need to 00:26.560 --> 00:29.120 open the program, it is not very good. 00:29.120 --> 00:32.480 Okay, so how can we fix this? 00:32.480 --> 00:37.240 It is better to ask the user to enter interface and enter the Mac address. 00:37.760 --> 00:42.240 So interface is equal to input and list. 00:42.920 --> 00:45.840 And here ask for interface okay. 00:48.400 --> 00:49.800 This is going to be the interface. 00:49.800 --> 00:53.600 And this port it is going to be the Mac address. 00:53.840 --> 00:58.360 So input and let's say new Mac. 00:59.960 --> 01:07.560 And now it is I think better let's go for this and execute this. 01:10.450 --> 01:10.890 Okay. 01:10.890 --> 01:13.490 What is the interface you want to change? 01:13.730 --> 01:15.850 It is ETH zero. 01:16.250 --> 01:17.730 And what is the new Mac address? 01:17.730 --> 01:20.650 0011 okay. 01:20.690 --> 01:21.410 One one. 01:22.770 --> 01:23.250 Sorry. 01:24.890 --> 01:28.010 Interface is ETH zero. 01:28.050 --> 01:40.450 Hit enter now 1100 okay 2233 and four four and five five hit enter. 01:40.890 --> 01:47.130 Now you see that changing Mac address to this one okay. 01:47.170 --> 01:48.890 Cannot assign request address. 01:48.890 --> 01:49.690 No problem. 01:49.930 --> 01:55.370 Now let's use ifconfig and see if it is changed or not okay. 01:56.490 --> 02:00.570 And here you see that it is not changed. 02:01.170 --> 02:03.210 Let's come back here okay. 02:03.890 --> 02:06.010 And see why it is not changed. 02:12.650 --> 02:13.010 Okay. 02:13.050 --> 02:15.290 It looks it is Okay. 02:15.330 --> 02:16.890 It has no error here. 02:17.530 --> 02:18.850 We have no problem. 02:19.170 --> 02:21.290 Let's go and execute that again. 02:21.770 --> 02:24.610 Let's see what is problem. 02:24.650 --> 02:24.930 Okay. 02:24.930 --> 02:28.890 Let me clear this for not clear. 02:30.330 --> 02:30.770 Okay. 02:30.770 --> 02:32.250 We have eth0. 02:32.370 --> 02:32.730 Okay. 02:33.130 --> 02:36.090 So now you see that this is the Mac address okay. 02:36.930 --> 02:39.050 And zero zero okay. 02:39.370 --> 02:45.410 112233 and four four. 02:45.450 --> 02:48.490 This time again I'm going to change it back to five five. 02:48.530 --> 02:49.130 Hit enter. 02:49.890 --> 02:55.210 And you see that it is changing Mac address for eth0 to this Mac address. 02:55.250 --> 02:58.250 It is what we executed or it is what we give. 02:58.290 --> 02:59.370 Okay. 02:59.410 --> 03:04.410 And now if I use ifconfig you see that it is changed okay. 03:04.450 --> 03:06.290 I don't know what was the problem. 03:06.330 --> 03:08.170 Cannot assign requested address. 03:08.210 --> 03:09.010 Oh my God. 03:09.050 --> 03:14.130 It is something that I give is the problem with problem is with giving. 03:14.130 --> 03:17.210 This Mac address is not something that we can assign. 03:17.250 --> 03:17.650 Okay. 03:18.690 --> 03:21.130 And here we used. 03:21.130 --> 03:21.420 Um. 03:23.740 --> 03:25.060 Input function okay. 03:26.340 --> 03:34.020 To ask the user to enter interface and new Mac address, and then we can use it that there is still 03:34.020 --> 03:34.900 a problem. 03:34.940 --> 03:35.340 Okay. 03:35.540 --> 03:36.540 Let me show you. 03:39.180 --> 03:39.580 Now. 03:43.660 --> 03:44.020 Okay. 03:44.500 --> 03:47.860 The user it is asking the user to enter the interface. 03:47.980 --> 03:53.300 He is entering the ETH zero and then this semicolon. 03:53.300 --> 03:55.980 And then for example LSE again semicolon. 03:55.980 --> 03:59.780 And then hit enter new Mac address something okay. 04:00.740 --> 04:08.140 And you see here we have changing Mac address to this. 04:08.260 --> 04:10.340 And then we have eth0. 04:11.060 --> 04:14.620 And again we have ETH zero okay. 04:14.620 --> 04:16.980 We have Mac changer dot pi. 04:17.580 --> 04:20.380 And then this thing not found. 04:20.380 --> 04:22.740 And then we have three times this one. 04:22.740 --> 04:23.980 Why is that. 04:25.500 --> 04:25.980 Okay. 04:25.980 --> 04:26.580 Come on. 04:29.220 --> 04:30.460 And what is that? 04:30.940 --> 04:31.700 What happened? 04:32.540 --> 04:34.620 It is called hijacking. 04:34.620 --> 04:35.020 Okay. 04:35.900 --> 04:38.780 In programming language, it is called hijacking. 04:39.220 --> 04:41.820 While we use this semicolon. 04:41.860 --> 04:42.100 Okay. 04:42.140 --> 04:48.100 And then use another command that means first it will execute this one and then it will execute this 04:48.100 --> 04:48.500 one. 04:48.500 --> 04:49.620 So it is one problem. 04:49.620 --> 04:50.980 One big problem. 04:50.980 --> 04:58.980 Whenever the user is going to use our program, he could hijack your program and use and execute another 04:58.980 --> 05:00.980 command beside what we give. 05:00.980 --> 05:03.060 So we need to solve this problem okay. 05:03.060 --> 05:10.620 We can solve it very easily by just uh, by just adding here, okay. 05:11.420 --> 05:14.620 Not just giving all this as a string, okay. 05:16.020 --> 05:18.380 By giving them into a list. 05:18.420 --> 05:18.860 Okay. 05:19.260 --> 05:20.900 By putting them into a list. 05:21.180 --> 05:28.500 So while the user is checking, it will come and check if a thing that the user enter if that exists 05:28.540 --> 05:30.300 in a list, so it will execute. 05:30.300 --> 05:33.060 If not then it will not be executed. 05:33.180 --> 05:35.620 So let's go and see that in the next lecture.