Category Archives: Tutoriale Linux

GeckoLinux Brings Flexibility and Choice to openSUSE | Linux.com


I’ve been a fan of SUSE and openSUSE for a long time. I’ve always wanted to call myself an openSUSE user, but things seemed to get in the way—mostly Elementary OS. But every time an openSUSE spin is released, I take notice. Most recently, I was made aware of GeckoLinux—a unique take (offering both Static and Rolling releases) that offers a few options that openSUSE does not. Consider this list of features:

  • Live DVD / USB image

  • Editions for the following desktops: Cinnamon, XFCE, GNOME, Plasma, Mate, Budgie, LXQt, Barebones

  • Plenty of pre-installed open source desktop programs and proprietary media codecs

  • Beautiful font rendering configured out of the box

  • Advanced Power Management (TLP) pre-installed

  • Large amount of software available in the preconfigured repositories (preferring packages from the Packman repo—when available)

  • Based on openSUSE (with no repackaging or modification of packages)

  • Desktop programs can be uninstalled, along with all of their dependencies (whereas openSUSE’s patterns often cause uninstalled packages to be re-installed automatically)

  • Does not force the installation of additional recommended packages, after initial installation (whereas openSUSE pre-installs patterns that automatically installs recommended package dependencies the first time the package manager is used)

The choice of desktops alone makes for an intriguing proposition. Keeping a cleaner, lighter system is also something that would appeal to many users—especially in light of laptops running smaller, more efficient solid state drives.

Let’s dig into GeckoLinux and see if it might be your next Linux distribution.

Installation

I don’t want to say too much about the installation—as installing Linux has become such a no-brainer these days. I will say that GeckoLinux has streamlined the process to an impressive level. The installation of GeckoLinux took about three minutes total (granted I am running it as a virtual machine on a beast of a host—so resources were not an issue). The difference between installing GeckoLinux and openSUSE Tumbleweed was significant. Whereas GeckoLinux installed in single digits, openSUSE took more 10 minutes to install. Relatively speaking, that’s still not long. But we’re picking at nits here, so that amount of time should be noted.

The only hiccup to the installation was the live distro asking for a password for the live user. The live username is linux and the password is, as you probably already guessed, linux. That same password is also the same used for admin tasks (such as running the installer).

You will also note, there are two icons on the desktop—one to install the OS and another to install language packs. Run the OS installer. Once the installation is complete—and you’ve booted into your desktop—you can then run the Language installer (if you need the Language packs—Figure 1).

After the Language installer finished, you can then remove the installer icon from the desktop by right-clicking it and selecting Move to Trash.

Those fonts

The developer claims beautiful font rendering out of the box. In fact, the developer makes this very statement:

GeckoLinux comes preconfigured with what many would consider to be good font rendering, whereas many users find openSUSE’s default font configuration to be less than desirable.

Take a glance at Figure 2. Here you see a side by side comparison of openSUSE (on the left) and GeckLinux (on the right). The difference is very subtle, but GeckoLinux does, in fact, best openSUSE out of the box. It’s cleaner and easier to read. The developer claims are dead on. Although openSUSE does a very good job of rendering fonts out of the box, GeckoLinux improves on that enough to make a difference. In fact, I’d say it’s some of the cleanest (out of the box) looking fonts I’ve seen on a Linux distribution.

I’ve worked with distributions that don’t render fonts well. After hours of writing, those fonts tend to put a strain on my eyes. For anyone that spends a good amount of time staring at words, well-rendered fonts can make the difference between having eye strain or not. The openSUSE font rendering is just slightly blurrier than that of GeckoLinux. That matters.

Installed applications

GeckoLinux does exactly what it claims—installs just what you need. After a complete installation (no post-install upgrading), GeckoLinux comes in at 1.5GB installed. On the other hand, openSUSE’s post-install footprint is 4.3GB.  In defense of openSUSE, it does install things like GNOME Games, Evolution, GIMP, and more—so much of that space is taken up with added software and dependencies. But if you’re looking for a lighter weight take on openSUSE, GeckoLinux is your OS.

GeckoLinux does come pre-installed with a couple of nice additions—namely the Clementine Audio player (a favorite of mine), Thunderbird (instead of Evolution), PulseAudio Volume Control (a must for audio power users), Qt Configuration, GParted, Pidgen, and VLC.

If you’re a developer, you won’t find much in the way of development tools on GeckoLinux. But that’s no different than openSUSE (even the make command is missing on both). Naturally, all the developer tools you need (to work on Linux) are available to install (either from the command line or from with YaST2).

Performance

Between openSUSE and GeckoLinux, there is very little noticeable difference in performance. Opening Firefox on both resulted in maybe a second or two variation (in favor of GeckoLinux). It should be noted, however, that the installed Firefox on both was quite out of date (52 on GeckoLinux and 53 on openSUSE). Even after a full upgrade on both platforms, Firefox was still listed at release 52 on GeckoLinux, whereas openSUSE did pick up Firefox 57. After downloading the Firefox Quantum package on GeckoLinux, the application opened immediately—completely blowing away both out of the box experiences on openSUSE and GeckLinux. So the first thing you will want to do is get Firefox upgraded to 57.

If you’re hoping for a significant performance increase over openSUSE, look elsewhere. If you’re accustomed to the performance of openSUSE (it not being the sprightliest of platforms), you’ll feel right at home with GeckoLinux.

The conclusion

If you’re looking for an excuse to venture back into the realm of openSUSE, GeckoLinux might be a good reason. It’s slightly better looking, lighter weight, and with similar performance. It’s not perfect and, chances are, it won’t steal you away from your distribution of choice, but GeckoLinux is a solid entry in the realm of Linux desktops.

Learn more about Linux through the free “Introduction to Linux” course from The Linux Foundation and edX.

How to Test Website Loading Speed in Linux Terminal | Linux.com


A website response time can have a great impact on user experience, and if you are a web developer, or simply a server administrator who is particularly responsible for organizing the pieces together, then you have to make it a point that users don’t feel frustrated while accessing your site – so there is really “need for speed”.

This guide will show you how to test a website response time from the Linux command line. Here, we will show how to check the time in seconds, it takes:

  • to perform name resolution.
  • for TCP connection to the server.
  • for the file transfer to begin.
  • for the first byte to be transferred.
  • for the complete operation.

Read more at Tecmint

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8 Holiday Projects with Raspberry Pi and Arduino | Linux.com


The best way to celebrate the coldest, darkest time of year is to build fun Raspberry Pi and Arduino projects. These projects will light up the gloomiest gloom, fill your days with fun and your heart with joy, and all without draining your pocketbook. You can control lights and music, build a retro gaming console, build a cool weather station, build a photo frame, or just learn the basics and fiddle around randomly.

MicroPython on Arduino Smart Holiday Lights

When you want a versatile lighting project that you can tailor in all kinds of way, such as size, shape, animations, and colors, try MicroPython Smart Holiday Lights. It’s an advanced project that is great for learning a whole lot of cool stuff, like MicroPython, LED strip lights, and ESP8266 devices. ESP8266 is a 32-bit microcontroller with an embedded TCP stack, and ESP8266 boards are usually very small. This makes them a bit challenging to work with, which is a perfect reason to treat yourself to a good-quality lighted magnifier LED lamp. The small size also makes them quite versatile for easy embedding in all manner of objects.

Some examples of ESP8266 boards are the SparkFun ESP8266 Thing and Adafruit Feather HUZZAH.

Arduino Blinky Lights for Beginners

If you need something more basic to get started, try An Arduino Project: How To Make Flashy Christmas Lights Ornaments. This uses an Arduino Uno (Figure 1), a breadboard, and a pile of LEDs and resistors. The article links to a UK vendor for the parts, but any Arduino supplier has what you need. Breadboards are the bee’s knees for fast testing and learning, no soldering necessary.

Adafruit.com is cram-full of great beginning tutorials; you might like Breadboards for Beginners.

Easy Controllable Light Strings for Arduino

5 Minute Christmas Neopixel Led Strip has minimal soldering, and gets right into the programming. (Remember, any soldered connections can also be made on a breadboard.) The xtmas_neopixel sketch is complete with 33 animations, which you can study and modify.

The parts links in are all for overseas vendors, but you can easily find them at any Arduino supplier.

Arduino Lights and Music

Christmas Lights to Music Using Arduino is a first-rate tutorial with loads of pictures and product links. Use it to control larger light projects, such as a great gob of lawn decorations. It is based on the Arduino Duemilanove, which has been superseded and improved by the Uno R3. The Uno R3 is a super-nice board with a reset button, USB interface chip, and a fuse.

This project uses a component you don’t often see in these projects, a solid-state relay board. SSRs are for projects that require a lot of high-speed switching, and they comes in many sizes, so you tailor it to your project.

It also uses an FM transmitter and landscape cables. When you successfully put all the pieces together you’ll have a flexible controller you can adapt for all kinds of scenarios.

Retro Gaming with Raspberry Pi

Holiday projects aren’t limited to lights and music. How about some classic gaming? Retro Gaming with Raspberry Pi builds a classic arcade game machine. It’s a fairly complicated project, but as always the Adafruit instructions are clear and complete, with extensive guidance on which hardware to use, such as game controllers, joysticks, and arcade buttons. Before you spend any money, you can download various emulators and test them first on your PC.

Raspberry Weather

What’s the weather doing? You could look outside. Or you could build a Raspberry Weather station. This collects weather data over time and displays it in graphs on your web site. It’s a medium-complex project, but the tutorial is thorough and details all the steps, including how to set up a web site on WordPress.org to display your weather data.

Raspberry Pi Photo Frame

The Raspberry Pi Photo Frame is a good project for beginners. Your photos are stored on an SD card, and the screen is the Raspberry Pi 7″ touch screen. You could use a smaller screen and hang it on your Christmas tree.

How to Make a Raspberry Pi Media Panel is a more complex project that powers a full-sized screen and adds a music server.

Learn more about Linux through the free “Introduction to Linux” course from The Linux Foundation and edX.

How to Write a Custom Nagios Check Plugin | Linux.com


Even though Nagios Exchange has thousands of available plugins to freely download, sometimes the status needed to be checked is very specific for your scenario.

Considerations

It is assumed that:

  • You have Nagios installed and running (You can follow this Tutorial if not).
  • You know the basics on Nagios administration.

Nagios server in this example is hosted on 192.168.0.150 and an example client is hosted on IP 192.168.0.200

Read more at HowToForge

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How to Manage Users with Groups in Linux | Linux.com


When you administer a Linux machine that houses multiple users, there might be times when you need to take more control over those users than the basic user tools offer. This idea comes to the fore especially when you need to manage permissions for certain users. Say, for example, you have a directory that needs to be accessed with read/write permissions by one group of users and only read permissions for another group. With Linux, this is entirely possible. To make this happen, however, you must first understand how to work with users, via groups and access control lists (ACLs).

We’ll start from the beginning with users and work our way to the more complex ACLs. Everything you need to make this happen will be included in your Linux distribution of choice. We won’t touch on the basics of users, as the focus on this article is about groups.

For the purpose of this piece, I’m going to assume the following:

You need to create two users with usernames:

You need to create two groups:

Olivia needs to be a member of the group editors, while nathan needs to be a member of the group readers. The group readers needs to only have read permission to the directory /DATA, whereas the group editors needs to have both read and write permission to the /DATA directory. This, of course, is very minimal, but it will give you the basic information you need to expand the tasks to fit your much larger needs.

I’ll be demonstrating on the Ubuntu 16.04 Server platform. The commands will be universal—the only difference would be if your distribution of choice doesn’t make use of sudo. If this is the case, you’ll have to first su to the root user to issue the commands that require sudo in the demonstrations.

Creating the users

The first thing we need to do is create the two users for our experiment. User creation is handled with the useradd command. Instead of just simply creating the users we need to create them both with their own home directories and then give them passwords.

The first thing we do is create the users. To do this, issue the commands:

sudo useradd -m olivia

sudo useradd -m nathan

We have now created our users. If you look in the /home directory, you’ll find their respective homes (because we used the -m option, which creates a home directory).

Next each user must have a password. To add passwords into the mix, you’d issue the following commands:

sudo passwd olivia

sudo passwd nathan

When you run each command, you will be prompted to enter (and verify) a new password for each user.

That’s it, your users are created.

Creating groups and adding users

Now we’re going to create the groups readers and editors and then add users to them. The commands to create our groups are:

addgroup readers

addgroup editors

That’s it. If you issue the command less /etc/group, you’ll see our newly created groups listed (Figure 1).

With our groups created, we need to add our users. We’ll add user nathan to group readers with the command:

sudo usermod -a -G readers nathan

We’ll add the user olivia to the group editors with the command:

sudo usermod -a -G editors olivia

Now we’re ready to start managing the users with groups.

Giving groups permissions to directories

Let’s say you have the directory /READERS and you need to allow all members of the readers group access to that directory. First, change the group of the folder with the command:

sudo chown -R :readers /READERS 

Next, remove write permission from the group with the command:

sudo chmod -R g-w /READERS

Now we remove the others x bit from the /READERS directory (to prevent any user not in the readers group from accessing any file within) with the command:

sudo chmod -R o-x /READERS

At this point, only the owner of the directory (root) and the members of the readers group can access any file within /READERS.

Let’s say you have the directory /EDITORS and you need to give members of the editors group read and write permission to its contents. To do that, the following command would be necessary:

sudo chown -R :editors /EDITORS

sudo chmod -R g+w /EDITORS

sudo chmod -R o-x /EDITORS

At this point, any member of the editors group can access and modify files within. All others (minus root) have no access to the files and folders within /EDITORS.

The problem with using this method is you can only add one group to a directory at a time. This is where access control lists come in handy.

Using access control lists

Now, let’s get tricky. Say you have a single folder—/DATAand you want to give members of the readers group read permission and members of the group editors read/write permissions. To do that, you must take advantage of the setfacl command. The setfacl command sets file access control lists for files and folders.

The structure of this command looks like this:

setfacl OPTION X:NAME:Y /DIRECTORY

Where OPTION is the available options, X is either u (for user) or g (for group), NAME is the name of the user or group, and DIRECTORY is the directory to be used. We’ll be using the option -m for modify. So our command to add the group reader for read access to the /DATA directory would look like this:

sudo setfacl -m g:readers:rx -R /DATA

Now any member of the readers group can read the files contained within /DATA, but they cannot modify them.

To give members of the editors group read/write permissions (while retaining read permissions for the readers group), we’d issue the command;

sudo setfacl -m g:editors:rwx -R /DATA 

The above command would give any member of the editors group both read and write permission, while retaining the read-only permissions to the readers group.

All the control you need

And there you have it. You can now add members to groups and control those groups’ access to various directories with all the power and flexibility you need. To read more about the above tools, issue the commands:

  • man usradd

  • man addgroup

  • man usermod

  • man sefacl

  • man chown

  • man chmod

Learn more about Linux through the free “Introduction to Linux” course from The Linux Foundation and edX.