1 00:00:00,710 --> 00:00:01,380 Hello, everyone. 2 00:00:01,950 --> 00:00:05,910 And this is listen, I'm going to talk about the special permissions clinics. 3 00:00:06,210 --> 00:00:08,370 We have three special permissions bits. 4 00:00:08,670 --> 00:00:12,720 We have the city was an I.D. We have the Citigroup I.D. and have the sticky bit. 5 00:00:13,530 --> 00:00:15,020 We sit at the special machine. 6 00:00:15,180 --> 00:00:21,930 It's unacceptable file or a batch file or a directory in order to change the seating of these files 7 00:00:22,050 --> 00:00:22,750 or directories. 8 00:00:23,250 --> 00:00:31,020 So the reason is to allow the users to work on dispatch files or directories without asking the route 9 00:00:31,020 --> 00:00:34,440 user or the admin for any help to enter their password. 10 00:00:34,890 --> 00:00:41,470 So I don't wait to ask the route user or even the admin to give them their password in order to change 11 00:00:41,490 --> 00:00:48,830 the sitting and apply the city's I.D. or the Citigroup I.D. or just keep it on the bushfires or agentic 12 00:00:48,870 --> 00:00:49,170 trees. 13 00:00:50,490 --> 00:00:55,890 Let's see, the VAT is here for each of these special permissions. 14 00:00:55,950 --> 00:00:59,730 So we have the sit user I.D. bit, the VAT, it's number four. 15 00:01:00,270 --> 00:01:08,090 And as you remember in the previous session when we talked about the four digits of the you mask. 16 00:01:08,430 --> 00:01:11,490 So the phrase digit is is set for what? 17 00:01:11,910 --> 00:01:13,680 For this special permission. 18 00:01:13,710 --> 00:01:16,590 So for the city I.D., we have the value for. 19 00:01:16,710 --> 00:01:21,540 We bought them before the permissions of the user group and others. 20 00:01:22,590 --> 00:01:24,990 The value here for the city was already is a number for. 21 00:01:25,530 --> 00:01:28,310 So for the Citigroup I.D., the value here is a number two. 22 00:01:28,650 --> 00:01:33,660 And we put it at the beginning of the you mask of the file or the directory. 23 00:01:34,080 --> 00:01:36,450 The sticky bit and a value is number one. 24 00:01:36,940 --> 00:01:42,330 We would it at the beginning of of the you mask it here. 25 00:01:42,690 --> 00:01:44,970 So what is the site user I.D.? 26 00:01:45,020 --> 00:01:51,480 So the city was Aidi grants and ordering user to run unacceptable fired or a Basche fine and programs 27 00:01:51,510 --> 00:01:52,170 as an owner. 28 00:01:52,830 --> 00:01:59,980 And here is the command if you would like to assign site user I.D. to us to our bushfire. 29 00:02:00,390 --> 00:02:02,100 So we are under command. 30 00:02:02,100 --> 00:02:05,390 Change what then you plus s. 31 00:02:05,880 --> 00:02:10,740 So do you represent the user and s is you represent a city user I.D.. 32 00:02:11,070 --> 00:02:12,060 This is the fine name. 33 00:02:12,600 --> 00:02:18,020 There is to know common command and lennix that pass WD. 34 00:02:18,340 --> 00:02:22,890 So do they still commands like we run them as an owner. 35 00:02:22,920 --> 00:02:27,210 So we didn't need any permission from the route to run those comments. 36 00:02:27,420 --> 00:02:33,330 So if we can see here for in this example, if we are under commanded us that shell slash band slash 37 00:02:33,570 --> 00:02:35,430 massively d we can see here. 38 00:02:35,520 --> 00:02:37,230 S beside what. 39 00:02:37,480 --> 00:02:40,470 Beside the permission of the user here. 40 00:02:40,890 --> 00:02:42,420 And the same thing for the pseudo. 41 00:02:42,870 --> 00:02:50,970 So it's you we see also s beside the the user permissions here. 42 00:02:52,950 --> 00:02:57,030 Go here to the next set example here we have a bash script. 43 00:02:57,240 --> 00:03:05,580 And here in this special script we would like to assign a user set user I need to do to the file. 44 00:03:06,000 --> 00:03:07,440 What we do, we're under command. 45 00:03:07,590 --> 00:03:09,510 Change more the U. 46 00:03:09,600 --> 00:03:10,430 Plus S. 47 00:03:10,830 --> 00:03:11,850 And this is the fine. 48 00:03:12,400 --> 00:03:20,070 There's a very important point we have to put into consideration when we want to sit or assign a city 49 00:03:20,070 --> 00:03:22,040 user I.D. to define Schill. 50 00:03:22,680 --> 00:03:24,540 There is some security reasons. 51 00:03:24,570 --> 00:03:29,460 And Lennix, for example, imagine that we want to run a very important Basche script. 52 00:03:29,860 --> 00:03:30,210 Fine. 53 00:03:30,390 --> 00:03:34,790 In our system, that can change the seating on the configuration of the corner. 54 00:03:34,830 --> 00:03:41,790 And the system with the system will do the system for sure will ignore the city user I.D.. 55 00:03:41,910 --> 00:03:43,590 So this is for security reasons. 56 00:03:43,620 --> 00:03:45,570 We have to put this into consideration. 57 00:03:46,350 --> 00:03:48,130 Let's move on to the Citigroup by. 58 00:03:48,570 --> 00:03:50,130 So what is the Citigroup I.D.? 59 00:03:50,230 --> 00:04:00,440 A similar concept of the switch, user I.D. however we apply or we assign the CIT Group I.D. to the 60 00:04:00,440 --> 00:04:02,910 five and the level of the group. 61 00:04:03,720 --> 00:04:06,450 See here, for example, the difference here. 62 00:04:07,410 --> 00:04:12,810 We in the previous example for the CIT user I.D., we use you. 63 00:04:12,870 --> 00:04:16,500 But here for the Citigroup I.D., we we use sheet. 64 00:04:16,589 --> 00:04:21,800 So to change what we don't discriminate, change more dingy plus s then define a name. 65 00:04:22,610 --> 00:04:32,560 There is a very common file that we can use, for example, in Linux as as as a group here. 66 00:04:32,850 --> 00:04:37,800 If we're ENDESA commanded a special slash use user slash band and. 67 00:04:37,860 --> 00:04:38,250 Right. 68 00:04:38,730 --> 00:04:46,300 And we can see here, this is beside what when we assigned Citigroup idee is beside the user, the group 69 00:04:46,300 --> 00:04:48,830 permission that the user permission and the same thing. 70 00:04:48,840 --> 00:04:52,680 There is another common file also called command. 71 00:04:54,150 --> 00:04:59,850 Well, command, this is also has a set group I.D. school here to the example here we. 72 00:05:00,040 --> 00:05:02,030 An example for the set grew by D. 73 00:05:02,750 --> 00:05:03,950 So something changed much. 74 00:05:04,340 --> 00:05:04,640 G. 75 00:05:04,670 --> 00:05:11,120 Plus s and we have a text file here or four on it and you see it an example. 76 00:05:11,150 --> 00:05:15,980 We don't have a set group idea for this text file. 77 00:05:16,510 --> 00:05:22,850 When we change and we assign a set group by D to the file on we are under any special to define. 78 00:05:22,970 --> 00:05:27,410 We can see s here beside the group permissions. 79 00:05:28,790 --> 00:05:30,290 There's also a very important point. 80 00:05:30,290 --> 00:05:34,950 We have to be very careful when we run either to C to use I.D. or a ruling by the system. 81 00:05:35,030 --> 00:05:41,660 It might harm ungifted unauthorized users, but if it is used to access the system around bushfires 82 00:05:41,710 --> 00:05:42,660 and axes to put, fine. 83 00:05:42,730 --> 00:05:45,740 So we have to be very careful when we use these two permissions. 84 00:05:46,520 --> 00:05:48,500 Let's move on to the sticky bit. 85 00:05:48,860 --> 00:05:50,730 So what is this to keep it sticky? 86 00:05:50,800 --> 00:05:59,030 It prevents anyone on the system to remove and modify fine except owner route users who can remove and 87 00:05:59,030 --> 00:06:00,380 modify the fire. 88 00:06:00,680 --> 00:06:05,060 So we run the same command to change mode all bloustein in the fire name. 89 00:06:05,750 --> 00:06:12,620 So he is a very calm on a very important, you know, a very important fight in our Linnik system is 90 00:06:12,680 --> 00:06:13,490 a slash temp. 91 00:06:13,700 --> 00:06:14,540 So this. 92 00:06:15,880 --> 00:06:22,060 Directory, we can not delete it because it has a sticky bit, as we can see here. 93 00:06:22,180 --> 00:06:23,190 It has a sticky bit. 94 00:06:23,530 --> 00:06:26,200 Nobody can remove this file. 95 00:06:27,250 --> 00:06:29,390 Here's an example if we'd like. 96 00:06:29,500 --> 00:06:33,160 We have a directory here on or would like to assign us to keep it to a historic tree. 97 00:06:33,230 --> 00:06:35,320 So change mode or plasty. 98 00:06:35,860 --> 00:06:37,480 And you can see here when we are on it. 99 00:06:38,020 --> 00:06:41,200 He had before we assigned a sticky bit to the directory. 100 00:06:41,320 --> 00:06:46,080 We don't have any stickybeak permission beside the other here. 101 00:06:46,480 --> 00:06:53,630 And when we assign it and we run the list, Desh Deja Edik tree, we can see here the T litter is beside. 102 00:06:53,680 --> 00:06:55,540 The other permissions. 103 00:06:55,960 --> 00:06:58,600 So Jordi kab on what we said. 104 00:06:59,500 --> 00:07:03,100 Very important for the site user I.D.. 105 00:07:03,370 --> 00:07:09,930 We when we assigned a security jersey, it comes with the user I.D. We assign it to the user permission 106 00:07:09,930 --> 00:07:10,170 here. 107 00:07:10,570 --> 00:07:18,040 When we are center set Grube I.D., we assign it to the crew permission here and decide here, as we 108 00:07:18,040 --> 00:07:21,430 can see here from the ah greet w x. 109 00:07:21,580 --> 00:07:23,260 So read, write, execute one. 110 00:07:23,290 --> 00:07:24,970 We assign a sticky bit. 111 00:07:25,300 --> 00:07:31,660 We assigned the stickybeak to the other at the end of of the permissions. 112 00:07:33,010 --> 00:07:34,120 That concludes our session. 113 00:07:34,240 --> 00:07:34,630 Thank you. 114 00:07:34,720 --> 00:07:36,460 And see you in the next lesson.