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[Intro Music]

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We have just successfully created

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new user using another command

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called 'adduser'. And this command

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is much more convenient for use as

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'useradd' command, because it has

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interactive prompts, and you're able

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to set the Working Directory

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password and other settings just in

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one command. Great. Now let me

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demonstrate you how to change

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ownership for a specific file or

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directory. And let me create a new

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file in home directory for this

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'bogdan' user, but under 'root' user

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account. Let's go back to root

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session, 'exit', and here now I'm

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logged in as root user. And now

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let's create a new file in the '/home/bogdan'.

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Let's use the

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touch command 'touch /home

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/bogdan', and here will be

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filename 2.txt. File was created.

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Let's now list contents of the '/home

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/bogdan' directory. Let's add here

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'-la' options. And now I see new

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file 2.txt. But username and

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group are set to root because I

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have just created this file as a

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root user. Now let's change to

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'bogdan' user. 'su -bogdan'. Let's

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clear terminal. And let's list

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contents of home directory here

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under 'bogdan' user. And now I

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still see here this 2.txt file

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that we have just created as root

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user. And in those columns, you'll

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see this information root and root.

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Now let's try to modify this file

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2.txt under bogdan's

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account. Let's use Nano editor, and

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type 2.txt as argument. And

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here you will see that file 2.txt

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is unwriteable, and that is due

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to ownership issue. Owner of this

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file is 'root'. And of course, when

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you have a look at those

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permissions, you'll see that only

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owner of this file is able to write

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this file, here you see this 'w'. Other

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users that are members of this

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'root' group or other groups are not

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able to write this file. That's why

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we are not able to modify it. And

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in order to solve this problem,

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you're able to either change

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permissions, or change ownership of

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this file. This file is located in

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the home directory for bogdan

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user. And logically it's better to

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change ownership of this file,

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because again, this file is located

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in the home directory for 'bogdan'

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user. Let's do that. For that

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you need to use command 'chown', this

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one. Let's first have a look at

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help options for this command.

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Let's scroll a bit up to the beginning

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of this output, and you'll see that

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this command is used for change of

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the owner and or group for a

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specific file or files. And you'll

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see that first you need to

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specify options, if any.

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Afterwards, you need to specify new

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owner optionally, and new group

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optionally, and afterwards comes

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file or files. Let's try that in action.

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Let's clear terminal, and type

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chown. Next comes user name, we

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want to change ownership of the

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file to, it will be 'bogdan'; and

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next comes file name, 2.txt. Let's

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try to enter this command here

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under bogdan's account, Enter. And

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of course I see here error,

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Operation not permitted. Could you

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guess what is the reason for this

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error? Why I am not able to change

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ownership of this file under

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Bogdan's account?

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[Clock Ticking]

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You are right, answer is very simple. We are not

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able to modify this file under any

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other accounts except only root

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account. That's why I need to perform

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this action on the root account, and

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afterwards go back to bogdan's

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account, and then I will be able to

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modify this file as owner of this

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file. All right, let's go back to

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'root' account, exit, and let's type

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the same command 'chown bogdan',

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but now I need to enter a full path

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to this 2.txt file because now

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I'm the home directory for root

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user. So I am typing here

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'/home/bogdan/2.txt'.

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And now let's verify whether

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ownership was changed. 'ls -

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la /home/bogdan'. And yes, I see that

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now owner of this file 2.txt

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is 'bogdan', but group remained

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unchanged, it is still 'root', and

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that's probably not what you have

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expected. If you want to change

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group as well, you need to slightly

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modify this command. Let's go back

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to this command 'chown bogdan',

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and here after ':' you need to

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specify group name. It will be

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'bogdan'. Let's press Enter. And

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now let's verify whether something

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was changed here or not. And yes,

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now I see User and Group equal to

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'bogdan', my username.

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Let's now go back to 'bogdan' user

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'su -bogdan', and let's have

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a look at contents of home

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directory. And now I see correct

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ownership of this file, 2.txt.

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And of course, because now I'm

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owner of this file, I am able to

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write this file, modify it. Let's

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try to modify it, 'nano 2.txt',

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'Modified file'. Let's save

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changes, 'Ctrl + x', Yes, Enter, and

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now file was successfully changed.

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Let's have a look at contents of

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this file, 'cat 2.txt'; and yes,

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I see here contents 'Modified file'.

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That's how you're able to modify

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ownership for a specific file. In

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the same way, you're able to modify

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ownership for a specific directory.

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Let's quickly do that. And let's

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create new directory here in

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home folder for bogdan user,

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and let's do that again as 'root'

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user. Let's go back to root account

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and here let's create a new folder

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in '/home/bogdan'; and let's name

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it 'tmp'. And now if I list the

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contents of '/home/bogdan', I will

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see this new folder here and the

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owner is root and group is root as

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well. And let's create a new file

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in this 'tmp' folder. Let's actually

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'cd' to this tmp folder. I'll copy

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this folder name like so. And let's

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'touch 3.txt', and 4.txt.

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I'll create two new files here

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in 'tmp' folder. Here they are. And

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of course owner of those files is

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root. Alright, let's now try to

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modify ownership for entire folder,

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'tmp' folder. Let's 'cd' to home

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directory for root user, and let's

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enter 'chown'; next comes 'bogdan

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:bogdan'; and here

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will be path to this 'tmp' folder,

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'/home/bogdan', and

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here will be 'tmp' like so. Let's

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press Enter. And now let's list

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contents of the '/home/bogdan';

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and I'll see the owner of 'tmp'

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folder was changed to 'bogdan'. But

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if I have a look at contents of the

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'tmp' folder, I'll still see owner

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'root' for both files, 3.txt

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and 4.txt; and that means

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that I have just adjusted owner

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only of the folder, directory 'tmp';

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and ownership of any included files

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or subdirectories wasn't changed.

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If you want to change also owner of

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the inner files, you need to use

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additional options. Let's have a

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look at the help for 'chown' command.

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'chown --help', and scroll a bit

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up, and you'll find here option

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'-R', or '--recursive';

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and with this option in

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place, you'll be able to modify

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ownership of all inner files and

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directories. Let's try to use this

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option. Let's clear terminal and

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type 'chown'; next comes option this

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'-R', capital 'R'; next we will type

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username and the group name we

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want to change ownership to. And

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here will be path to folder we want

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to change ownership. Here will be

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'/home/bogdan/tmp', like so. Let's

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press Enter. And now let's verify

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whether file's ownership in this

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'tmp' folder was changed or

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not? Let me copy this path and 'ls

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-la', and paste copied path. And

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now I see the owner for those files

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3.txt, and 4.txt was

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correctly changed to 'bogdan'. And

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of course, if I go back to bogdan's

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account, 'su - bogdan', and

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verify contents of home

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directory, and list files and

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folders in 'tmp' folder, I'll see

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correct ownership everywhere. And

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that means that now I'm able to

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modify those files, 3.txt

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or 4.txt. Let's try that

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quickly. 'nano tmp/3.txt'.

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Here I'm using relative path

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without any slashes. Or I'm

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actually able to use such

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syntax tilde, '~'; and here will be

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'/'; it means that I am accessing

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specific file inside of the home

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directory of this user. Let's press

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Enter, and here add 'Hello', save

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changes, Yes, Enter, and now let's

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read the contents of this file 'tmp/

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3.txt', and I see those

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contents here. That's how we have

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successfully changed the ownership

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for entire directory and all

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inner files and directories.

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Great. That's all for this lecture.

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And now you understand how to

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change ownership for specific file,

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files, or directories. Next, let's

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talk about permissions. And I'll

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explain you how to modify

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permissions. And I'll actually

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demonstrate to you first how to

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create executable script in Linux.

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And we will create a very basic

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simple script that will simply

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print 'Hello world' to the terminal

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I'll see you in the next lecture,

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guys. Bye-Bye.

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[no audio]