1 00:00:06,580 --> 00:00:09,169 The main command for creating users is useradd. 2 00:00:10,250 --> 00:00:15,089 If you're on Ubuntu, it's important to use userad m because on Ubuntu users do not get 3 00:00:15,089 --> 00:00:19,929 a home directory by default. And really you want your users to have a home directory. 4 00:00:20,589 --> 00:00:23,850 So don't forget the m option on Ubuntu. 5 00:00:24,870 --> 00:00:30,550 You will also find that alternative commands are available instead of useradd. There's also add user. 6 00:00:31,530 --> 00:00:37,310 But I would advise you focus on one command. Why would you want to learn about different commands to do the exact same thing? 7 00:00:38,670 --> 00:00:44,825 When users are created default settings from the file etc login.devs are applied and if login.devs 8 00:00:44,825 --> 00:00:50,980 file is an important file, you should consider changing settings in it before creating the users. 9 00:00:51,619 --> 00:00:57,750 And that is because once you have changed settings, they won't be applied for existing users. 10 00:00:59,000 --> 00:01:05,069 You can also use userad D to get an overview of currently effective default settings. 11 00:01:05,799 --> 00:01:07,439 Let me show you how to use all of this. 12 00:01:09,620 --> 00:01:15,420 Let's start with the sudo useradd d where we can see some of the default settings. 13 00:01:16,420 --> 00:01:19,980 So what are these default settings? So that is actually funny. Group is 100. 14 00:01:21,340 --> 00:01:27,359 That is not true Shell has been bashed. That is true. Skel is etc skelled that is also true. 15 00:01:28,180 --> 00:01:31,865 This etc skel is a sk directory and the contents of 16 00:01:31,865 --> 00:01:35,550 the skeleton directory will be copied into the user home directory. 17 00:01:36,150 --> 00:01:39,965 Much more important than the output of user AT 18 00:01:39,965 --> 00:01:43,780 D is the contents of this file etclogin devs. 19 00:01:45,760 --> 00:01:48,040 There you will find login definitions. 20 00:01:48,700 --> 00:01:52,900 Notice that many items in the file show as not supported. 21 00:01:53,439 --> 00:01:59,115 That is because behind user configuration there's a more advanced system with the name pam. As spam 22 00:01:59,115 --> 00:02:04,790 is taking care of things, then the functionality is taken out of the etc login devs. 23 00:02:05,290 --> 00:02:09,569 So as you can see there's a lot of not supported. But if you scroll 24 00:02:09,569 --> 00:02:13,849 down a little bit right here we do see some parameters that are important. 25 00:02:14,509 --> 00:02:19,289 Pass max days. That is definitely a value that you want to change. 26 00:02:19,810 --> 00:02:25,905 Because if a user password is set, then the user password according to this value 27 00:02:25,905 --> 00:02:32,000 is valid for 99,999 days. For your information, that is that's about 272 years. 28 00:02:32,560 --> 00:02:33,599 I think that's too much. 29 00:02:34,150 --> 00:02:38,909 So change that to 99 to make it a little bit more secure. 30 00:02:39,930 --> 00:02:45,615 There are other parameters as well, like the userid max and the gid max 31 00:02:45,615 --> 00:02:51,300 and min which is identifying where user IDs and group IDs should be starting. 32 00:02:51,819 --> 00:02:54,240 Let's not do that right now. Let's just keep it as it is. 33 00:02:54,780 --> 00:03:00,435 And add a user. User add Anna and oh boy, does that make sense. Of course 34 00:03:00,435 --> 00:03:06,090 that makes sense, because we want to add a user and that requires super user privileges. 35 00:03:07,069 --> 00:03:14,050 Now this creates user Anna and if any relevant values were changed in the etc login.dev they will be applied as well. 36 00:03:14,810 --> 00:03:19,909 Honestly, I didn't change any relevant values, but I can show you sudo 37 00:03:19,909 --> 00:03:25,009 passwd anna and then I'm going to enter the new password twice. 38 00:03:25,509 --> 00:03:29,814 And now I'm going to use sudo till minus 55 on 39 00:03:29,814 --> 00:03:34,120 etc shadow. That's the file where user passwords are stored. 40 00:03:34,740 --> 00:03:38,439 Now what do we see? We see for lynda there is 41 00:03:38,439 --> 00:03:42,139 a value of 99,999. For Anna there's a value of 99. 42 00:03:43,539 --> 00:03:48,659 This is the maximum password validity that I just changed in etc login.devs.