Command Line Archives • Page 51 of 75 • Linux Tips

How To: Extract An .rar File

Today, we’re going to learn how to extract an .rar file in Linux. You don’t see .rar files all that often with Linux, but sometimes they crop up. Today’s article will explain how to extract them.

You may recall .rar files from your Windows days, assuming you have a history with Windows – as many of us Linux users do. You’d probably be most familiar with the application known as ‘WinRAR‘.

While the application is specifically for Windows (there’s a text-based WinRAR for Linux, perhaps a subject for another article), it produces files compressed with the .rar format. The .rar compression is much like any other compression, from .tar.gz to .zip. At some point, you may be faced with opening one while you’re using Linux.

Just because the files are often made with WinRAR doesn’t mean the files will only be opened in Windows. Once in a while, you’ll find something you need that’s in .rar format and you’re using Linux. Well, fear not, you can extract an .rar file easily enough. It’s just a simple terminal command away and you should be all set. While not a skill you’ll need often, it’s one you’ll maybe need and now is a good enough time to learn how.

Extract An .RAR File:

This article requires an open terminal, like many other articles on this site. If you don’t know how to open the terminal, you can do so with your keyboard – just press CTRL + ALT + T and your default terminal should open.

Once you have the terminal open, you’ll need to install an application called ‘unrar’. If you’re using a major distro, it’s likely in your repository – though maybe under the name of ‘unrar-nonfree’. Search your repositories and you’ll find it.

If you’re using Debian/Ubuntu/similar then it’s easy enough – it’s called ‘unrar’ and you install it with:

sudo apt install unrar

1	sudo apt install unrar

With that installed, the next part is really quite easy:

unrar x /path/to/file.rar

1	unrar x /path/to/file.rar

That will extract the contents of the .rar file while preserving paths. If you don’t care about that sort of result, just use the ‘e’ flag like this (and it’ll extract everything to the current directory):

unrar e /path/to/file.rar

1	unrar e /path/to/file.rar

You can also extract password protected content easily enough, just read the man pages with man unrar to learn how. Anything you can do with a GUI you can do with the terminal. You just need to read the man page. This article only covers how to extract an .rar file without any complexity.

Closure:

That’s it. That’s today’s article. The goal was to learn how to extract an .rar file in Linux and now you know how to do so with unrar and the Linux terminal. ‘Snot all that complicated, really.

Thanks for reading! If you want to help, or if the site has helped you, you can donate, register to help, write an article, or buy inexpensive hosting to start your own site. If you scroll down, you can sign up for the newsletter, vote for the article, and comment.

Change Your Hostname

In today’s article, we’re going to learn how to change your hostname in Linux. It’s a pretty easy article to follow along with, so even if you’re a beginner you can follow along. If you’re an advanced user, you probably already know how to do this. If not, you will now.

So, what is your hostname? Basically, it’s the name of your computer (generally speaking). You login as <your_username> to a computer referred to by its <hostname>. So, in this case, I’m currently kgiii@kgiii-lmde. The ‘kgiii-lmde’ is the hostname. When you open your terminal, in all likelihood it shows you the <user>@<hostname> at the start of your regular prompt.

You can do some neat stuff with the hostname. For instance, and depending on the distro, it’s often local or localhost, you can connect to your LAN devices (without knowing the IP address) by connecting to <hostname>.local. This is handy for using SSH around the house, or even for using FTP or whatever.

If you don’t know your hostname, you can use one of the following commands to figure it out:

hostname

hostname

Or you can try:

cat /etc/hostname

1	cat /etc/hostname

There are other ways to show the hostname, but those two should be enough to get you sorted out. Either of them will happily spit out the hostname. Now that you know your hostname, it’s time to learn how to …

Change Your Hostname:

Like so many other articles on this site, this one requires an open terminal to continue. So, just press CTRL + ALT + T and your default terminal should open.

With your terminal open, enter the following command:

sudo hostnamectl set-hostname <new_hostname>

1	sudo hostnamectl set-hostname <new_hostname>

That should permanently change your hostname to the new hostname you chose to use in the command. You can actually change it temporarily, it will not be persistent between reboots, with the hostname command. to do that you’d just sudo hostname <new_hostname> and it’ll change it for the current session only.

To verify that you’ve changed your hostname, run one of the commands listed in the preamble section of this article. (Just type hostname and to verify you know how to change your hostname.)

Anyhow, that’s all there is to it. You really don’t need anything more than that if you want to change your hostname in Linux. Anyone should be able to follow the few directions needed.

Closure:

There you have it, another article. To think, we’re over 200 articles now. This is just one more among many, and this one is easy enough to follow. If you ever wanted to change your hostname, now you know…

Turn Your Ubuntu Into A Wireless Hotspot

Have you ever wanted to use your Linux computer as a wireless hotspot? It’s actually pretty easy. Today’s article will get you started and it really isn’t all that difficult. We will actually be cribbing a bit of this article from the software’s homepage, but while some more, rather important, information added.

For many years, I used my own router that I had configured on my own hardware. It was built on Linux. The preceding version actually ran on BSD, but that’s not important for a site called Linux-Tips. Today, you can get a NUC or Pi for dirt cheap and so making a new router is back on my list of things to do. In other words, it’s a fun project that won’t take a lot of money to get into.

All of the varied software and hardware components are already there to make your own router, but I want to enable wireless connectivity. a wireless hotspot, and that’s what we’re going to look at today. The tool we’re going to use is called ‘linux-wifi-hotspot‘ That’s is a great tool, complete with GUI if wanted, written by lakinduakash. It has only been around for a few years, but it’s spoken of very highly – and it just works and works well.

At least it worked the last time I used it. This article is from the old site and I’m just moving it to this site. I actually haven’t bothered much with my own router for the past year or so. So, this information is a bit dated.

Turn Your Ubuntu Into A Wireless Hotspot:

The software is easy enough to install. If you’re using Debian/Ubuntu, just add the PPA and install the software. To add the PPA, you just run:

sudo add-apt-repository ppa:lakinduakash/lwh

1	sudo add-apt-repository ppa:lakinduakash/lwh

On a modern Ubuntu, you shouldn’t need to do this, but you might want to go ahead and run a quick update with:

sudo apt update

1	sudo apt update

Then you can install the software, starting to get your system into a workable wireless hotspot. To do that, it’s just:

sudo apt install linux-wifi-hotspot

1	sudo apt install linux-wifi-hotspot

If you want, you can visit the link above (in the preamble), click on releases, and download the .deb file for the current release and just install it with gdebi. In this case, I’d suggest installing with the PPA – just to make sure

Then, you can go ahead and start it. You can also go ahead and make it start at boot, which would be prudent if you intended to use this to make your own router. It’s really self-explanatory and without specific questions for using it, I’m just going to refer you to the man page and the information at the project page.

Caveats:

But, before you can even do all of this, you need to know that your wireless adapter actually supports doing this. To find out, you need to know if your wireless adapter supports “AP” mode. AP obviously meaning ‘Access Point’.

To check this, you need to run the following command:

iw list | grep AP

1	iw list \| grep AP

The project page is noticeably silent with this, but it’s a necessary step. See, you need to know if your hardware actually supports it before you even bother trying. Come to think of it, I probably should have put this closer to the top of the page! Ah well…

Anyhow, the output should contain one or both of the following lines:

Device supports AP scan.

And/Or:

Driver supports full state transitions for AP/GO clients.

So long as you see one or both of those, you should be all set to proceed. If you don’t see either of them, there’s no software solution and you’ll need to get hardware that supports AP mode. In many cases, that’ll mean doing a bunch of research and may even mean contacting the vendor or OEM.

Nobody appears to have compiled a list of hardware that supports AP mode and I don’t think I’ve ever bought wireless adapters that explicitly stated they do on the box. As near as I can tell, more modern adapters support it just fine, so you’ll probably be alright. Online specs are more thorough than what’s printed on the outside of the box, so maybe searching is okay.

Closure:

Alright, there’s your article for the day. I have no idea if you want to make a wireless hotspot for your Linux box, but now you know how. It’s pretty self-explanatory, and you shouldn’t have any questions. If you do, you know where to find me – or to find others who can help you – at Linux.org.

Change Ownership Of Files And Folders

Today, we’ll be covering how to change ownership of files and folders. This is a pretty basic task and one every Linux user should know. This needn’t be terribly complicated, so this article will explain all you really need to know about changing ownership of files and folders.

When dealing with file management, permissions are important. It’s a security matter and a usability matter. You can assign various file and folder permissions, such as read and write permissions, a subject for a different article. However, files and folders all should have owners – owners who can do anything they want with the file or folder.

Curiously, your account should not always be the owner. While maybe not all that intuitive, you shouldn’t have ownership of all the files. This is why you have to use elevated permissions to perform certain tasks. This is to keep things segmented and secure.

Remember, Linux is designed to be a multi-user operating system. That’s not just human users, but different processes and applications may also be associated with users. For example, look at all the users on your system by running the following command in your terminal emulator:

getent passwd

1	getent passwd

You can also see all the groups on your system with this command:

getent group

1	getent group

Obviously, if a user is a member of a group they share permissions with that group. Files also only have one owner and one associated group, of course. So, if you want two people to have control over a file, one way to do that would be to make sure they’re both members of the same group. There’s all sorts of creative things you can do with permissions. This article will be covering just one aspect, it’ll be about how you can …

Change Ownership Of Files And Folders:

Like oh so many of these articles, this one requires an open terminal. You can do so using only your keyboard – just press CTRL + ALT + T and your default terminal should open.

Go right ahead and stay in your home directory. You can check the various files and their permissions with the following:

ll

The output of that command will show you the user and group, with the two being listed in that order as in the image below:

ll listing user and groups — See? I even gave you handy arrows. The order is owner:group, to repeat myself.

To change the owner, the format is:

sudo chown <new_owner> /path/to/file/or/folder

1	sudo chown <new_owner> /path/to/file/or/folder

To change the group, the format is:

sudo chgrp <new_group> /path/to/file/or/folder

1	sudo chgrp <new_group> /path/to/file/or/folder

If you want to recursively take ownership, you need the -R flag. For that, you’d want something that looks a bit like this:

sudo chgrp -R <new_group> /path/to/file/or/folder/*

1	sudo chgrp -R <new_group> /path/to/file/or/folder/*

You can actually just use chown to change both the owner and group at the same time. You’ll most often do this with your own user and group, so I’ll show the command that way:

sudo chown kgiii:kgiii /path/to/file/or/folder/

1	sudo chown kgiii:kgiii /path/to/file/or/folder/

As you can guess, the -R flag will work there and an asterisk will cover all the files and folders within that directory. Obviously, this applies to folders and not to files.

Closure:

There you have it. You have yet another article and this one has hopefully taught you how to change ownership of files and folders. It may not be one of the most interesting articles, but it’s a skill you’ll eventually want to have and another tool for your Linux toolbox.

How To: Show Hidden Files And Folders

Today, you’ll read an article that tells you how to show hidden files and folders (in Linux, of course). This is something everyone should know. This is a basic skill that you’re almost certain to need if you make the decision to use Linux.

Fortunately, it’s pretty easy to show hidden files and folders. You’ll see…

First, I should probably explain what hidden files and folders are. They’re files and folders that start with a period. So .foo.txt is a hidden file and .bar could be a hidden directory. One should remember that Linux is, by design, a multi-user system. With that in mind, having hidden files makes sense – if you don’t want those files to be accidentally (or maliciously) edited.

Any files or folders that begins with a period will be a hidden file. If you’re new to Linux, you might want to leave them hidden until you’re a bit more comfortable working with system files. Or not… It’s your system, you do what you want with it.

In a GUI file manager, you can usually figure out how to show hidden files and folders pretty easily. Sadly, it’s not universal in a GUI. Look in the right click menu, under the “View” option, or in the application’s preferences. It’s also often ALT + H and I want to say I’ve even seen it be ALT + F4. Look around, you’ll find it.

This article is more about showing those hidden files and folders in the terminal. It’s a really easy command and won’t take too long to explain it to you. So, enough preamble, let’s begin.

Show Hidden Files And Folders:

We’ll stay right in the default directory, your home directory. If you’re not currently in your home folder, you can get there with:

cd ~/

cd ~/

Your home folder should have all sorts of hidden files and folders. First, let’s see your home directory without showing the hidden files and folders:

ls

Unless you’re in the habit of storing files in your home directory, you should have a fairly tidy list of folders and files that you’re likely already familiar with.

Now, let’s try again – this time showing hidden files and folders:

ls -a

ls -a

Or, you can get a more easy to read output with this command (and you get more information with it):

ls -la

ls -la

If you want to see it in action, you can try this command:

touch .foo.txt

1	touch .foo.txt

Now, if you use the ls command you won’t see that file. If you use the ls -a command you’ll see the hidden file that you created called .foo.txt. This of works with directories, as they too can be hidden.

Yup, that’s it. That’s today’s article. See? I told you it was easy.

Closure:

Indeed, it is an easy article – and one most of my readers will already know. This one is aimed squarely at the new user who has yet to learn how to show hidden files and folders. It’s a pretty important skill to learn, and it’s also important to know which ones you probably shouldn’t edit. So, judicious use is important.