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[No audio]

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File Maintenance Commands. In this lesson, we will cover

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a few of the commands that are used to

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maintain or keep or change your files.

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Some of the commands are listed here.

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The first one is the copy command,

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cp, which copies one file to another.

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The second one is to remove a file which is, rm.

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The third one is move,

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this command is used to move the location of a file

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from one location to another or to rename a file.

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So it does two things or it serves two purpose.

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Then we have mkdir which is to make directory and then

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rmdir to remove a directory or there's another way to remove

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a directory by typing rm -r or hyphen r.

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Then we have change group which is the ownership

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of a file at the group level, and then

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we have change ownership which is the ownership of

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the file at the user level.

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Some of the commands we have already covered and some

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of the commands we will be covering in this lesson.

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So let's go to our Linux machine and go over these

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commands one by one,

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[No audio]

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and let's log into our machine.

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We already have the last screen open.

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Let's clear this out.

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Where are we?

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We are in etc.

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When you type cd, and hit enter, and then pwd,

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now you are back in your home directory.

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Clear the page,so this way you will start fresh.

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Now the first command that

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we will be learning is cp.

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Again cp is a copy command.

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You could find out by hitting man and cp.

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This will tell you cp copy files and directories.

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So the way you could do it in Windows is you

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right click on a file and you get the option of

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copy and then you go to another file, another directory or

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another location and then right click and do the paste. In Linux,

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this is how it works.

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We will, let's look at our listing.

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We have all these files.

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So now we will copy the file called george

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and we will name it to a different name,

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let's say another character of the show

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david, and you hit enter.

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So this will tell you that cp space source which

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is the george, and the destination which is the david.

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You hit enter, then you do ls -ltr.

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The tr option will give you the newest

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file created at the bottom, hit enter.

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So the david file is created. If you also notice,

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the george file is still there, and it created a

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file, copied the file george and renamed it david.

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We could also add something to the file

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as let's say echo

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[No audio]

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david puddy,

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[No audio]

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is Eliane's boy friend

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[No audio]

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and then we'll output to david, and hit enter.

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And how do you verify it?

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You do cat david.

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You will see the contents in there.

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That's what you do the copy for, you could

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also do, is you copy david, and then you

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can copy it not at this location where you

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are, you could copy it some other location.

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Let's say we wanted to copy into tmp location.

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So it is going to copy it.

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It's now going to remove that file.

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It will copy it to the tmp directory.

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Hit enter, do ls -ltr.

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You'll see it has the david

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copy, the original copy here.

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Now we will go to /tmp, and then we will

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do ls -ltr at the bottom to see the file is there.

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See the same file that we copied

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but it's in a different location,

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and it is owned by me,

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owned by the same group as myself,

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and it has same number of bytes.

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You could do cat and david to

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see what's inside of the file.

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So which directory you are in?

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We are in tmp directory.

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If you want to go back to

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our home directly, just simply type cd,

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hit enter, pwd, and you are

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back in your home directory, ls -ltr.

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And that's where you have your

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all the files. That's about the copy.

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You could practice that copy command by

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copying different files or different names,

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whichever names that you like.

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The next command we're going to learn is remove.

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Let's create another file touch,

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and we will create a new file in homer, bard, marge,

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lisa, and we call another file apoho.

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apoho is another character of Simpsons family.

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So we'll create this file called apoho.

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And we will do ls -ltr,

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and you'll see it created a file apoho.

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If you want to append a file or add

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something to that file, what do we do?

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We do echo, apoho is an indian character in the show.

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Right. So I'll put that to where, apoho.

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How do you verify that, apoho, apoho an indian character in the show.

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That's how you do it. Now you want to remove this file. Now,

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after certain times you don't need it.

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So what you do, you do rm apoho, simply

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as that, hit enter, and it's gone. Let's try,

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let's make sure it's gone or not. Yes.

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See there is no such file apoho in our directory,

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because we removed it.

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We could also remove a directory,

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but we'll cover that when it's turns going to come.

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The next command we have to learn is move.

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Now move command,

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actually move the file from one location

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to another and also rename the file.

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How does it work? Let's call lex, in Superman

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there is this character,

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of course it's a villain character, lex. So let's see,

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we have the lex.

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Yes, we have there.

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We wanted to rename that to luther.

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So lex, last name was luther. So let's try,

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we wanted to change to Luther. So how do we do it?

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We do mv lex, and this is of course the source,

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and what's the destination name you want to give it to,

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luther, luther.

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This is going to rename this

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file within the same directory.

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Hit enter, ls -ltr,

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and here you see luther.

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So this is how you rename it.

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If you wanted to rename any

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other file, you could do that,

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or you wanted to create a

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different file, you could do that.

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Let's say we have this file called david,

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and we want to change to the last name

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of course, which is mv david to puddy.

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So that's his last name.

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So we are moving david to the name puddy.

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Let's ls -ltr.

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It changed the name from david to puddy,

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but it kept the content of that file, which was if

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you do cat, you'll see david puddy is Eliane's boy friend.

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So it just changed the name.

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It didn't change the content.

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Next one, by the way, also to change the location

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is if you wanted to move puddy from this location

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to a different location, let's say to tmp, it will

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move that file to a different location tmp.

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Now let's see do we still have that file?

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No, we don't. Where did it go?

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We moved it to tmp.

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So how do we know it moved to tmp?

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You do cd into tmp, ls -ltr.

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See, this is the puddy file that you created.

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Now let's move puddy back to our home directory.

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And what is our home directory?

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You guys should know that home,

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your username, and hit enter.

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It should bring you back to your home directory.

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When you do cd, hit enter,

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it will bring you back to your home directory.

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Do ls -ltr, and your puddy file is back.

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Next one is make directory.

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It's simply we will make mkdir gameofthrone, one of the biggest show,

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how's that. We created this,

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this is how the new directory is created mkdir.

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Now let's try command which is remove directory.

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So remove directory,

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if you want to delete one of

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these directories from your home directory,

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let's say I wanted to remove gameofthrone directory.

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You just simply type rmdir gameofthrone,

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and it is gone.

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This is one way to remove it. Another way to remove it,

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in order for us to remove it, let's recreate it again,

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hit up arrow key, and you will

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get back to the same command.

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mdir gameofthrone, the directory is created.

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Another way to remove it is rm -r gameofthrone, and it is gone.

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[No audio]

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All right. Next command we have change group.

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Changing group is changing the ownership of the file,

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changing the ownership of a group of a file.

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And the last command is changing

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the ownership of a file.

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So if I wanted to change the ownership of file

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puddy and I wanted to change it to group called

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root, so we will do chgrp root puddy.

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It says, Operation not permitted. Why?

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Because who we are, we are ourselves.

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And who can make these changes?

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If I wanted to assign something to

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root, I have to be root.

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So let's become root.

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[No audio]

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Once you're root, let's go back to our home directory.

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[No audio]

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And now what we'll is do chgrp root puddy.

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And this time it worked, because we have all

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permissions in the world we could think of.

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Now, next command change ownership to root of puddy.

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This will change the ownership of the

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file name puddy to root as well.

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Now, if you wanted to do both commands at once

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so chown, you could do, iafzal:iafzal puddy.

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So what this command will do, it will change the ownership

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as well as group ownership of the file name puddy.

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Hit enter, ls -ltr, and there you go.

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You got your file back with the

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original permission or original ownership permission.

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So these are the file maintenance command.

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Once again the recap, cp, rm, mv, mkdir,

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rmdir, chgrp, chown.

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[No audio]