1 00:00:00,260 --> 00:00:04,674 You in this video, I'll 2 00:00:04,674 --> 00:00:09,089 tell you about Linux permissions. 3 00:00:10,429 --> 00:00:13,099 Now, permissions come in three different sets. 4 00:00:13,660 --> 00:00:18,244 There are basic permissions. These are the most important, so make sure you understand 5 00:00:18,244 --> 00:00:22,829 them. There's also advanced permissions and access control lists. They are not as important. 6 00:00:23,989 --> 00:00:30,140 The base permissions determine what the user can do on a file and you can set them on files. 7 00:00:30,940 --> 00:00:33,060 Or even better, on directories. 8 00:00:34,240 --> 00:00:37,719 There is the read permission with the octal value of 4. 9 00:00:38,369 --> 00:00:44,515 An octal value is a value that consists of 3 bits and you can address from 0 up to 7 10 00:00:44,515 --> 00:00:50,659 and these octal values are used to work with the permissions in the CHMOT command as we will see later. 11 00:00:51,179 --> 00:00:52,700 And read has the octal value of 4. 12 00:00:53,789 --> 00:00:58,759 The meaning on files is that if you have read, you can read contents. Basically you can open the file. 13 00:00:59,399 --> 00:01:03,280 On directories, you can list the contents of directories with the LS command. 14 00:01:03,880 --> 00:01:10,450 Then there is write which allows you to modify file contents, and on directories it allows you to add and remove files. 15 00:01:11,390 --> 00:01:17,465 And there is execute with the octal value of one, which is required on files if you want to 16 00:01:17,465 --> 00:01:23,540 run the file, if it contains executable code. And on directories it allows you to change into the directory. 17 00:01:24,280 --> 00:01:25,400 Using the cd. 18 00:01:26,390 --> 00:01:29,230 Execute on directories may sound a little bit odd. 19 00:01:30,129 --> 00:01:35,894 The only thing to remember is that on directories you always need execute without execute. You can't do anything 20 00:01:35,894 --> 00:01:41,659 on a directory, so just read on a directory doesn't work. Make sure you have read and execute. 21 00:01:42,459 --> 00:01:44,840 In the next video I'll show you how to work with these.