How To: Show All Environment Variables

Today’s article is going to show you how to show all your environment variables in Linux. There are quite a few and some of them can be quite useful. If you don’t know what an environment variable is, we’ll cover that briefly as well.

So, what is an environment variable? It’s a static name for a dynamic value. In other words the system has information that varies, but using an environment variable will point to the dynamic information as though it was static.

As an example, we can use ‘echo $PWD‘ in the terminal and it will output the present working directory. If you change the directory and run that command again, it will output the new present working directory. You can do things like ‘echo $SHELL’ and it will tell you the shell you’re using, even if you’ve changed from the default shell. Things like that are the point of having environment variables.

These things really shine when used for things like scripting. They’re useful when you’re not certain of the architecture they’ll be used on and still want the script to work predictably wherever it is used. You’ll also see environment variables put to work in programming. They’re pretty handy, as I said!

If you’d like to see an example, read my article about clearing EXIF data for privacy’s sake. Scroll down to find the alias example I included and you’ll see the $PWD environment variable at work. See? It’s pretty easy and effective. So, let’s see a few ways to show all environment variables.

Show All Environment Variables:

Like most articles, you’re gonna need an open terminal. You can do that with your keyboard, by pressing CTRL + ALT + T and your default terminal should open.

Now that you have your terminal open, we’ll start with the first way to show all the environment variables:

You can also use:

You can also use the following command, but I don’t recommend doing so. It’s here for the sake of completeness and the command will output a lot of gibberish that’s really of no value to the average user.

Now that you know how to show them, here are a few handy examples that further demonstrate what an environment variable does.

Show home with:

Find the system language with:

Or find the desktop environment in use with:

Those are just a few of the environment variables available to you as a Linux user. If you make use of these on a regular basis, please leave a comment explaining how you use them.

Closure:

Yup… Another article. Another step closer to the anniversary of this site. I still have some content to move over from the original site, but writing completely new stuff is pretty fun. Seriously, it’s pretty fun. Please feel encouraged to write an article or two, considering I normally take the whole month of January off!

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.

 

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How To: Mount An .iso In Linux

Today’s article will teach you how to mount an .iso in Linux, a task undertaken seldom but worth knowing. This isn’t something I use often but it’s something you may want. It promises to be a quick and easy article, so read on!

I’m pretty sure the ‘unmount’ is incorrect English and that it’d be ‘dismount’ if you had mounted something like a horse or gym equipment. But, when I look around the web I see ‘unmount’ used with greater frequency. So, I’ll be saying ‘unmount’, even though that seems wrong.

Why would you want to mount an .iso? Well, there’s software that’s meant to be run from CD/DVD. You could burn your .iso to optical media or you can just mount the .iso and use it from there. Rather than wasting time burning the disk, you might just as well mount it.

You might want to verify that the image works before you burn a copy or upload it to share it. You might want to make edits to an .iso image and mounting the .iso will help with that, as you’d obviously unmount the image between changes.

So, you have a few reasons as to why you might want to mount an .iso. This article will explain how. It might not be a skill you need to day, but it’s one you may want eventually. We might as well get it written down now.

Mount An .iso In Linux:

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.

The first command you need to run is to set up the mount’s directory:

With that done, you can navigate to the directory where your .iso is stored or just use the full path. Your command should look a little something like this:

When you’ve done that, the .iso should be mounted and remain mounted until you unmount it or reboot. This is not a permanent mount, so you’ll not have any permanent changes to your system because of this. For permanency, you’d need fstab.

By the way, just cd /mnt/iso to navigate to your newly mounted iso and that should work just fine. If you want to unmount the .iso on your own, you’d just use this command:

You can verify that you mounted and unmounted it with the lsblk. The output from that command should first show the .iso mounted and then show it when it’s unmounted.

Closure:

That’s about it. There’s not much more to say about how you mount an .iso in Linux. It’s a pretty simple activity and one easy to master. In my case, I just do it so infrequently that I never actually remember all the commands. So, it ended up in my notes – which means it turned into an article.

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.

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‘sudo apt remove’ vs ‘sudo apt purge’

Today’s article is going to cover ‘sudo apt remove’ vs ‘sudo apt purge’ and will be a different format than some articles. It’s a brief article meant to answer a specific question. It’s nothing more, and nothing less.

The question would be, “What’s the difference between sudo apt remove and sudo apt purge?” It’s a perfectly fine question, thanks. This article will answer it.

It does open up an idea. If you have any questions, you can always just “Ask KGIII” a question. For example, the question prompting this article might be, “What’s the difference between sudo apt autoremove vs sudo apt purge?” It’s a perfectly legitimate question, and a good example, of the kinds of questions I’d welcome.

So, for fun, we can pretend someone asked this question! 

If you don’t ask me any questions, I may just have to pretend you did and write my own questions and answers all by myself! However, this is the kind of question I’d be looking for. Leave a comment with a question, thanks!

If you lie about your email address to ask a question, that’s fine – just don’t also opt to subscribe to responses. It results in some ‘spammy’ domain behavior and I’d like to avoid that. Use  @example.com, if you want. It should work but there is no example.com of note so bouncing emails won’t be a problem. On the other hand, others can attest to the fact that I’ve sent zero spam messages.

‘sudo apt remove’ vs ‘sudo apt purge’:

In this case, both of these commands are used to remove software from your system. These commands are valid in distros like Debian or Ubuntu, systems that use APT as the package management system. If you want to remove software, the commands would look like one of the following:

With both of these commands, you’ll remove software. It will not only remove the software, it’ll mark the software as uninstalled in your database of installed applications. This means you can opt to install the software again.

But, there is a difference. When you use sudo apt remove <package_name>, you just remove the software itself. When you use sudo apt purge <package_name>, it not only removes the package, it also removes the configuration files.

In theory, you can do ‘apt remove’ and then re-install the application at a later date while keeping the pre-existing, pre-removal configuration. The regular ‘apt remove’ doesn’t touch configuration files, it only removes those things that were listed as files in the packages manifest and created during the installation process.

So, when you run ‘apt remove’ you’re removing it from your system. When you run ‘apt purge’ you’re making sure (ideally) no traces of it remain. I say “ideally” because it’s not as cut and dry as one might think. Package management isn’t all that smart and things like MySQL will leave behind a user, and other package installs will do similar. 

As a bonus, if you’ve seriously messed up an application’s configuration then you can purge it and have a clean slate, with (ideally) no previous configuration files left over. Of course, if you just use ‘apt remove’ then your configuration files may still exist. If you want to maybe install the application again, and you were happy with the say it was configured, you should use ‘apt remove’. Otherwise, use ‘apt purge’.

If you, like me, are curious as to how the purge command really works (it’s not all that intelligent) then click here to learn how the purge command works. The answer is well-written and, more importantly, is correct (inasmuch as I understand). It’s well worth reading, for a better understanding. As I mentioned elsewhere, the package manager isn’t really all that intelligent – but it is what it is and it’s much easier than doing it all yourself!

Closure:

And there you have it. You have another article! This one is kinda like a pretend person asked a question and I answered the question in the form of an article. I’d like to do that sort of thing every couple of weeks, but it’d require someone to actually ask me questions.

I don’t mind if they’re questions I have to research. I think it’d be an interesting new aspect to the site. We can call it ‘Reader Questions’ and maybe give out a prize of some type if your question is chosen. I mean, you shouldn’t need a prize but it might motivate a few of you. Leave a ‘Reader Question’ as a comment on this post and we’ll see how it goes! If it looks like it might work, I’ll add it as a new category.

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.

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How To: Update OpenSUSE Tumbleweed From The Terminal

It’s time for an article that describes how to update openSUSE from the terminal. After all, I’ve done so for Ubuntu and Fedora. I might as well do one for openSUSE. It seems like a good thing to do.

While most of this site is aimed at bringing you up to speed, making Linux easier, it’s also biased towards desktop Linux users. Well, today’s distro isn’t really all that popular in the desktop sphere, it’s more a server distro. There is a desktop version, and it’s a pretty great distroy.

So, to avoid confusion, “SLES” stands for SUSE Linux Enterprise Server. It is a paid product with an excellent pedigree and a great reputation in the community. openSUSE is the community edition of that software. openSUSE is mostly used on the desktop, as a workstation distro.

Over the years, I’ve tried openSUSE here and there and found it to be functional, stable, and easy enough to figure out. There’s a lovely rolling-release version of openSUSE that’s called ‘Tumbleweed’. If you have a hankering to try openSUSE, go for it and give Tumbleweed a shot!

A shout-out to a Linux.org user: Gecko Linux is based on openSUSE.

Oddly, it’s often harder to write the intro than it is to write the meat of the article. It can even take more time to write the intro than it takes to write the rest of the article. This article is likely to be one of those. 

Ah well… On to the article!

Update openSUSE From The Terminal:

You’ll need an open terminal. 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.

First, you need to refresh the database of what software you have vs what software is available. Obviously this means comparing version numbers. This is a necessary step, otherwise it’d be updating blindly and that’d make no sense! So, the command you’re looking for is:

That will run its course and take some time. On a rolling release, you can expect quite a lot of updates to be available. When it is finished, and you’re ready to do the updates, you can just enter:

That’s actually all there is to it, at the base level. There’s still more, as there always is. There’s always more! If you have run the refresh command and want to see what upgrades are available, you can do that with this command:

But, that’s about all you’re going to need to know. Like always, check the man page. It’s not terribly difficult to update openSUSE, anyhow. It’s straight forward in both the terminal and GUI. My personal preference is to use the terminal.

Closure:

Woohoo! There you have it! Here’s another article and this one is showing you how to update openSUSE in the terminal. It’s not terribly difficult, but it’s worth knowing. Not too many people use openSUSE and even the best of us might be unfamiliar and need a hint.

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.

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How To: Determine Your Desktop Environment

Today’s article will help you determine your desktop environment. Often abbreviated as “DE”, your desktop can be any number of choices – including none at all. This should be a relatively short and easy article. If you don’t know, the desktop environment is a bunch of software that provides the GUI system you use to navigate, load files, and manage your computer.

Once in a while, an article should get back to the basics. This is one of those articles. When someone poses a question and you need to know their desktop environment, you can just tell them that you need that information and link to an article like this one.

As such, it’s not exhaustive nor is it expected to be all that deep. There are a number of ways to get your desktop information. For a more universal approach, these ways will all be through the terminal. In most other situations, you can use the GUI and figure it out. For example, you might use HardInfo and get the data that way. Not everyone will have that installed, so we can just do it though the terminal.

Determine Your Desktop Environment:

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.

Now that you have your terminal open, you can try either ‘neofetch‘ or ‘screenfetch‘. Both of them will happily spit out the information you need. The screenfetch may be better here, as it also gives the version of your desktop environment – from what I can tell. Both are easy to install and may already be installed.

Here’s an example of the relevant output from running screenfetch in the terminal:

screenfetch displaying desktop environment information
See? It’s right there! Easy enough!

You can also do the same thing with running neofetch in your terminal. Once again, it looks something like this:

neofetch showing desktop environment
Once again, it’s nice and easy! Tada!

Now, there’s some chance you just want to determine your desktop environment and don’t need or want any additional information. You can do that. It’s not hard, it’s not hard at all. In fact, both are environment variables that you can easily get to echo as stdout.

You can also use:

Both of those will tell you the desktop environment that you’re using. See:

using echo to view the desktop environment
See? You can use either one effectively and efficiently.

As suggested by @wizardfromoz, of Linux.org fame, I completely forgot to include my beloved inxi. The inxi system information tool is increasingly installed by default, but the link will show you how to install it. It’s a great tool, providing a ton of information, that’s used frequently for support questions.

To use inxi to determine your desktop environment, you can just run:

That’s an uppercase S and it’ll look something like this:

inxi showing the desktop environment
See? It’s even included in the inxi output! inxi does it all!

And there you have it, a few different ways to determine your desktop environment from the terminal. You should probably just know this information, but newer users may not know and may need help in finding this information. 

Closure:

So, there’s another one… Yet another article, said and done. This one is pretty easy and aimed at rank beginners, but it’s not without use. It may even save some time as people might actually search before asking questions! Well, they could… 

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.

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