Linux Blimp

Get to know networking basics with this tutorial from our archives.

Linux grew up with a networking stack as part of its core, and networking is one of its strongest features. Let’s take a practical look at some of the TCP/IP fundamentals we use every day.

It’s IP Address

I have a peeve. OK, more than one. But for this article just one, and that is using “IP” as a shortcut for “IP address”. They are not the same. IP = Internet Protocol. You’re not managing Internet Protocols, you’re managing Internet Protocol addresses. If you’re creating, managing, and deleting Internet Protocols, then you are an uber guru doing something entirely different.

Yes, OSI Model is Relevant

TCP is short for Transmission Control Protocol. TCP/IP is shorthand for describing the Internet Protocol Suite, which contains multiple networking protocols. You’re familiar with the Open Systems Interconnection (OSI) model, which categorizes networking into seven layers:

• 7. Application layer
• 6. Presentation layer
• 5. Session layer
• 4. Transport layer
• 3. Network layer
• 2. Data link layer
• 1. Physical layer

The application layer includes the network protocols you use every day: SSH, TLS/SSL, HTTP, IMAP, SMTP, DNS, DHCP, streaming media protocols, and tons more.

TCP operates in the transport layer, along with its friend UDP, the User Datagram Protocol. TCP is more complex; it performs error-checking, and it tries very hard to deliver your packets. There is a lot of back-and-forth communication with TCP as it transmits and verifies transmission, and when packets get lost it resends them. UDP is simpler and has less overhead. It sends out datagrams once, and UDP neither knows nor cares if they reach their destination.

TCP is for ensuring that data is transferred completely and in order. If a file transfers with even one byte missing it’s no good. UDP is good for lightweight stateless transfers such NTP and DNS queries, and is efficient for streaming media. If your music or video has a blip or two it doesn’t render the whole stream unusable.

The physical layer refers to your networking hardware: Ethernet and wi-fi interfaces, cabling, switches, whatever gadgets it takes to move your bits and the electricity to operate them.

Ports and Sockets

Linux admins and users have to know about ports and sockets. A network socket is the combination of an IP address and port number. Remember back in the early days of Ubuntu, when the default installation did not include a firewall? No ports were open in the default installation, so there were no entry points for an attacker. “Opening a port” means starting a service, such as an HTTP, IMAP, or SSH server. Then the service opens a listening port to wait for incoming connections. “Opening a port” isn’t quite accurate because it’s really referring to a socket. You can see these with the netstat command. This example displays only listening sockets and the names of their services:

$ sudo netstat -plnt
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN 1583/mysqld
tcp 0 0 127.0.0.1:5901 0.0.0.0:* LISTEN 13951/qemu-system-x
tcp 0 0 192.168.122.1:53 0.0.0.0:* LISTEN 2101/dnsmasq
tcp 0 0 192.168.122.1:80 0.0.0.0:* LISTEN 2001/apache2
tcp 0 0 192.168.122.1:443 0.0.0.0:* LISTEN 2013/apache2
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1200/sshd
tcp6 0 0 :::80 :::* LISTEN 2057/apache2
tcp6 0 0 :::22 :::* LISTEN 1200/sshd
tcp6 0 0 :::443 :::* LISTEN 2057/apache2

This shows that MariaDB (whose executable is mysqld) is listening only on localhost at port 3306, so it does not accept outside connections. Dnsmasq is listening on 192.168.122.1 at port 53, so it is accepting external requests. SSH is wide open for connections on any network interface. As you can see, you have control over exactly what network interfaces, ports, and addresses your services accept connections on.

Apache is listening on two IPv4 and two IPv6 ports, 80 and 443. Port 80 is the standard unencrypted HTTP port, and 443 is for encrypted TLS/SSL sessions. The foreign IPv6 address of :::* is the same as 0.0.0.0:* for IPv4. Those are wildcards accepting all requests from all ports and IP addresses. If there are certain addresses or address ranges you do not want to accept connections from, you can block them with firewall rules.

A network socket is a TCP/IP endpoint, and a TCP/IP connection needs two endpoints. A socket represents a single endpoint, and as our netstat example shows a single service can manage multiple endpoints at one time. A single IP address or network interface can manage multiple connections.

The example also shows the difference between a service and a process. apache2 is the service name, and it is running four processes. sshd is one service with one process listening on two different sockets.

Unix Sockets

Networking is so deeply embedded in Linux that its Unix domain sockets (also called inter-process communications, or IPC) behave like TCP/IP networking. Unix domain sockets are endpoints between processes in your Linux operating system, and they operate only inside the Linux kernel. You can see these with netstat:

$ netstat -lx
Active UNIX domain sockets (only servers)
Proto RefCnt Flags Type State I-Node Path
unix 2 [ ACC ] STREAM LISTENING 988 /var/run/dbus/system_bus_socket
unix 2 [ ACC ] STREAM LISTENING 29730 /run/user/1000/systemd/private
unix 2 [ ACC ] SEQPACKET LISTENING 357 /run/udev/control
unix 2 [ ACC ] STREAM LISTENING 27233 /run/user/1000/keyring/control

It’s rather fascinating how they operate. The SOCK_STREAM socket type behaves like TCP with reliable delivery, and SOCK_DGRAM is similar to UDP, unordered and unreliable, but fast and low-overhead. You’ve heard how everything in Unix is a file? Instead of networking protocols and IP addresses and ports, Unix domain sockets use special files, which you can see in the above example. They have inodes, metadata, and permissions just like the regular files we use every day.

If you want to dig more deeply there are a lot of excellent books. Or, you might start with man tcp and man 2 socket. Next week, we’ll look at network configurations, and whatever happened to IPv6?

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

Source

One of the pieces of software you use daily is a file manager. A good file manager is essential to your work. If you are a Linux user and want to try out file managers other than the default one that comes with your system, below is a list of the best Linux file managers you will find.

What Is a File Manager?

Let’s start with a definition first to make sure we are on the same page. A file manager is a computer application that you can access and manage the files and documents stored on your hard disk. In Windows this application is called Windows Explorer, and in macOS, Finder. In Linux there is no one standardized file manager application for all distributions. These are some of the best Linux File managers.

1. Nautilus

Nautilus, now renamed to GNOME Files, is the standard file manager of the GNOME desktop environment. Since GNOME is a very popular desktop environment, this automatically means Nautilus is also among the most used file managers. One of the key features of Nautilus is that it’s clean and simple to use, while still offering all the basic functionality of a file manager, as well as the ability to browse remote files. This is a file manager suitable for novices and everybody who values minimalism and simplicity. If the default functionality is too limiting for you, you can extend it with the help of plugins.

2. Dolphin

Dolphin File Manager is the KDE counterpart of Nautilus. Similarly to Nautilus, it is intended to be simple to use while also leaving room for customization. Split view and multitabs, as well as dockable panels, are among its core features. You can use Dolphin to browse both local and remote files across the network. For some operations Dolphin offers undo/redo functionality, which is pretty handy for those of us who have (too) quick fingers. If the default functionality of Dolphin is not enough, plugins come to the rescue.

3. Thunar

Thunar might not be as popular as Nautilus or Dolphin, but I personally like it more. It’s the file manager I use on a daily basis. Thunar is the default file manager for the Xfce Desktop Environment, but you can use it with other environments as well. Similarly to Nautilus and Dolphin, Thunar is lightweight, fast, and easy to use. For an old computer, Thunar is probably the best file manager. It is a relatively simple file manager without tons of fancy (and useless) features, but again, it has plugins to extend the default functionality, if this is needed.

4. Nemo

Nemo is a fork of Nautilus, and it’s the default file manager for the Cinnamon desktop environment. One of the special features of Nemo is that it has all the features of Nautilus 3.4 that have been removed in Nautilus 3.6, such as all desktop icons, compact view, etc., and tons of configuration options. Nemo also has useful features, such as open as root, open in terminal, show operation progress when copying/moving files, bookmark management, etc.

5. PCManFM

The last file manager for Linux on this list – PCManFM – has the very ambitious goal to replace Nautilus, Konqueror and Thunar. PCManFM is the standard file manager in LXDE (a distro developed by the same team of developers), and it’s meant to be lightweight, yet fully functional. I don’t have much personal experience with this file manager, but from what I know, I can’t say it’s groundbreaking, breathtaking, etc. It does have the standard features a file manager offers, such as thumbnails, access to remote file systems, multitabs, drag and drop, etc., but I don’t think it has really outstanding features. Still, if you are curious, you can give it a try and see for yourself.

There are many more file managers for Linux I didn’t include because I don’t think they are as good as the ones listed. Some of these managers are Gentoo file manager, Konqueror, Krusader, GNOME Commander, Midnight Commander, etc. If the 5 file managers I reviewed are not what you like, you can give the rest a try, but don’t expect too much from them.

Is this article useful?

Source

GUPnP AV i an open source and completely free library software designed as part of the GUPnP framework, providing users with a collection of helpers for building audio and video applications using GUPnP.

What is GUPnP?

GUPnP is an object-oriented and open source framework designed especially for creating UPnP devices and control points, written in C using libsoup and GObject. The GUPnP API is intended to be easy to use, flexible and efficient.

The GUPnP framework was initially created because of developer’s frustrations with the libupnp library and its mess of threads. Therefore, GUPnP is entirely single-threaded, it integrates with the GLib main loop, it’s asynchronous, and offers the same set of features as libupnp.

Getting started with GUPnP AV

Installing the GUPnP AV project on a GNU/Linux computer is the easiest of tasks, as you will have to first download the latest version of the software from Softpedia or via its official website (see the homepage link at the end of the article), and save it on your PC, preferably somewhere on your Home folder.

Use an archive manager utility to extract the contents of the source package, open a terminal emulator application and navigate to the location of the extracted archive files (e.g. cd /home/softpedia/gupnp-av-0.12.7), where you will run the ‘./configure && make’ command to configure/optimize and compile the project.

Please note that you should first install the GUPnP program before attempting to install this tool. After a successful compilation, you can install GUPnP AV system wide and make it available to all users on your machine by running the ‘sudo make install’ command as a privileged user or the ‘make install’ command as root.

Under the hood

Taking a look under the hood of the GUPnP AV program, we can notice that it has been written in the Vala and C programming languages. It is currently supported on 32-bit and 64-bit computer platforms.

Object-oriented framework UPnP devices GUPnP framework Object-oriented Framework A/V UPnP

Source

According to The Information, Instagram has suffered a serious security leak of its own that could’ve exposed user’s passwords. While Facebook recently had a much more serious problem linked to its “View As” tool that was being actively exploited by… someone, the Instagram issue is linked to its tool that allows users to download a copy of their data. Facebook notified affected Instagram users that when they utilized the feature, it sent their password in plaintext in the URL. For some reason, these passwords were also stored on Facebook’s servers, however the notification said that data has been deleted and the tool was updated so it won’t happen now.

Read this full article at Engadget

Source

We never meant to make that widely public which is why we made a public FAQ for it

Microsoft was, and maybe still is, considering injecting targeted adverts into the Windows 10 Mail app.

The ads would appear at the top of inboxes of folks using the client without a paid-for Office 365 subscription, and the advertising would be tailored to their interests. Revenues from the banners were hoped to help keep Microsoft afloat, which banked just $16bn in profit in its latest financial year.

According to Aggiornamenti Lumia on Friday, folks using Windows Insider fast-track builds of Mail and Calendar, specifically version 11605.11029.20059.0, may have seen the ads in among their messages, depending on their location. Users in Brazil, Canada, Australia, and India were chosen as guinea pigs for this experiment.

Bad news: Mail for #Windows10 is getting ads for non-office 365 subscribers! https://t.co/xDELzAClJq pic.twitter.com/gXkQXab5Wr

— Aggiornamenti Lumia (@ALumia_Italia) November 16, 2018

A now-deleted FAQ on the Office.com website about the “feature” explained the advertising space would be sold off to help Microsoft “provide, support, and improve some of our products,” just like Gmail and Yahoo! Mail display ads.

Also, the advertising is targeted, by monitoring what you get up to with apps and web browsing, and using demographic information you disclose:

You can also close an ad banner by clicking on its trash can icon, or get rid of them completely by coughing up cash:

Here’s where reality is thrown into a spin, literally. Microsoft PR supremo Frank Shaw said a few hours ago, after the ads were spotted:

This was an experimental feature that was never intended to be tested broadly and it is being turned off.

Never intended to be tested broadly, and was shut down immediately, yet until it was clocked, had an official FAQ for it on Office.com, which was also hastily nuked from orbit, and was rolled out in highly populated nations. Talk about hand caught in the cookie jar.

And there’s no denying they will ever come back; just that they’re going away for now at least from Mail and Calendar. It may be that the ads appeared outside the intended sandbox of Brazil, India, etc, or even outside the Windows Insider program, forcing Microsoft to pull the plug.

Still, it sounds to us as though it was intended to be tested relatively broadly.

In any case, Redmond is or was mulling extracting revenue from people one way or another, either via Office subs or advertising, which is to be expected. It should be no surprise, just like knowing Facebook puts its own interests and profits ahead of its addicts should be no great shock. Redmond has been squeezing little adverts into its operating system for a few years now.

Injecting adverts into a desktop email client may be a little too much for Microsoft’s traditional users and loyalists to swallow, though. ®

Source

Mark Shuttleworth has announced that Ubuntu 18.04 will be supported for ten years. Long Term Support releases of Ubuntu usually enjoy just five years of support, so this doubling is highly significant.

Shuttleworth — the founder of Canonical and Ubuntu — made the announcement at the OpenStack Summit in Berlin, and the change is a tactical maneuver that will help Ubuntu better compete against the likes of Red Hat/IBM. It is also an acknowledgement that many industries are working on projects that will not see the light of day for many years, and they need the reassurance of ongoing support from their Linux distro. Ubuntu can now offer this.

See also:

• deepin 15.8 Linux distribution available for download — replace Windows 10 now!
• Linux on DeX Beta can turn your Samsung Galaxy smartphone or tablet into an Ubuntu desktop
• Microsoft is porting Sysinternals utilities to Linux, starting with ProcDump

Ubuntu 18.04 was released in April of this year, and the new announcement means that it will be supported until 2028. It is a significant and important change for developers working in various fields including hardware, IoT and the cloud, but it is not known whether a similar support cycle will be adopted for future LTS releases.

As reported by ZDNet, Mark Shuttleworth said:

I’m delighted to announce that Ubuntu 18.04 will be supported for a full 10 years. In part because of the very long time horizons in some of industries like financial services and telecommunications but also from IoT where manufacturing lines for example are being deployed that will be in production for at least a decade.

While the support cycle for future releases is not yet known, Shuttleworth said that support for Ubuntu 16.04 — which was due to come to an end in April of 2021 — will also be extended.

Source

Rygel is an open source project that provides users with both a command-line and graphical application that implements a lightweight UPnP media server. It has been tailored for users of the GNOME desktop environment.

Features at a glance

It allows Linux users to easily share video, picture and music files to any UPnP compatible device, locally or remote. For example, you can access the files from your PC or laptop with another computer, smart TV, gaming console, tablet, smartphone or media center devices.

In other words, with Rygel you will be able to browse and play media stored on a computer through a PlayStation or Xbox console, easily search and play media using a laptop, phone or smart TV, as well as to redirect sound output to DLNA speakers.

Command-line options

On the other hand, the command-line, which is the most important part of the program, empowers users to disable media transcoding, disallow upload and deletion of files, set a specific network interface and port, and set the path of a certain engine or plugin.

Additionally, it can be used to disable a certain plugin, set plugin titles and options, disable UPnP for a streaming-only operation, force the program to use a specific configuration file instead of the default user configuration, shutdown remote Rygel reference, and use comma-separated list of domain:level pairs for logging.

Under the hood

Being written in the Vala programming language, the application provides users with a GTK+ graphical user interface, accessible with the rygel-preferences command, that allows them to share media through the DLNA (Digital Living Network Alliance) protocol, add or remove dedicated media folders, and add or remove network interfaces.

The application is based on the GUPnP framework and supports pluggable media providers. It is the most lightweight and easy to use UPnP media server for Linux-based operating systems. But if you want more, you should try XBMC or Plex Media Server.

Source

Nagios is one of the most popular open source monitoring system. Nagios keeps an inventory of your entire IT infrastructure and ensures your networks, servers, applications, services, and processes are up and running.

In case of failure or suboptimal performance Nagios will send notification alerts via various methods.

This tutorial will guide you through the steps required to install and configure the latest version of Nagios Core on Ubuntu 18.04.

An older version of Nagios (version 3) is available in the Ubuntu software repository and can be easily installed with apt install nagios3.

Prerequisites

Before continuing with this tutorial, make sure you are logged in as a user with sudo privileges.

Update your Ubuntu system and install the following packages which are necessary to download and compile the Nagios main application and Nagios plugins:

sudo apt update && sudo apt upgrade
sudo apt install autoconf gcc libc6 make wget unzip apache2 php libapache2-mod-php7.2 libgd-dev
sudo apt install libmcrypt-dev libssl-dev bc gawk dc build-essential libnet-snmp-perl gettext

Installing Nagios on Ubuntu

The following steps describes how to install the latest version of Nagios Core from source.

1. Downloading Nagios

We are going to download Nagios source in the /usr/src directory which is the common location to place source files, change to the directory with:

Download the latest version of Nagios from the project Github repository using the following wget command:

sudo wget https://github.com/NagiosEnterprises/nagioscore/archive/nagios-4.4.2.tar.gz

When the download is complete extract the tar file with:

sudo tar zxf nagios-*.tar.gz

Before continuing with the next steps, make sure you change to the Nagios source directory by typing:

2. Compiling Nagios

To start the build process run the configure script which will perform a number of checks to make sure all of the dependencies on your system are present:

sudo ./configure –with-httpd-conf=/etc/apache2/sites-enabled

Upon successful completion, the following message will be printed on your screen:

*** Configuration summary for nagios 4.4.2 2018-08-16 ***:

General Options:
————————-
Nagios executable: nagios
Nagios user/group: nagios,nagios
Command user/group: nagios,nagios
Event Broker: yes
Install $: /usr/local/nagios
Install $: /usr/local/nagios/include/nagios
Lock file: /run/nagios.lock
Check result directory: /usr/local/nagios/var/spool/checkresults
Init directory: /lib/systemd/system
Apache conf.d directory: /etc/apache2/sites-enabled
Mail program: /bin/mail
Host OS: linux-gnu
IOBroker Method: epoll

Web Interface Options:
————————
HTML URL: http://localhost/nagios/
CGI URL: http://localhost/nagios/cgi-bin/
Traceroute (used by WAP):

Review the options above for accuracy. If they look okay,
type ‘make all’ to compile the main program and CGIs.

You can now start the compilation process using the make command:

The compilation may take some time, depending on your system. Once the build process is completed, you will be presented with the following message:

3. Creating Nagios User And Group

The following command will create a new system nagios user and group:

sudo make install-groups-users

Add the Apache www-data user to the nagios group:

sudo usermod -a -G nagios www-data

4. Install Nagios Binaries

Perform the following command to install Nagios binary files, CGIs, and HTML files:

You should see the following output:

*** Main program, CGIs and HTML files installed ***

5. Creating External Command Directory

Nagios can process commands from external applications. Create the external command directory and set the proper permissions by typing:

sudo make install-commandmode*** External command directory configured ***

6. Install Nagios Configuration Files

Install the sample Nagios configuration files with:

*** Config files installed ***

Remember, these are *SAMPLE* config files. You’ll need to read
the documentation for more information on how to actually define
services, hosts, etc. to fit your particular needs.

7. Install Apache Configuration Files

The command below will install the Apache web server configuration files:

sudo make install-webconf*** Nagios/Apache conf file installed ***

Make sure Apache rewrite and cgi modules are enabled:

sudo a2enmod rewrite
sudo a2enmod cgi

8. Creating User Account

To be able to access the Nagios web interface you’ll need to create an admin user called nagiosadmin

Using the following htpasswd command to create a user called nagiosadmin

sudo htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin

You will be prompted to enter and confirm the user’s password.

New password:
Re-type new password:
Adding password for user nagiosadmin

Restart the Apache service for changes to take effect:

sudo systemctl restart apache2

9. Configuring Firewall

The firewall will secure your server against unwanted traffic.

If you don’t have a firewall configured on your server, you can check our guide about how to setup a firewall with ufw on ubuntu

Open the Apache ports by typing run:

Installing Nagios Plugins

Switch back to the /usr/src directory and ownload the latest version of the Nagios Plugins from the project Github repository:

cd /usr/src/
sudo wget -O nagios-plugins.tar.gz https://github.com/nagios-plugins/nagios-plugins/archive/release-2.2.1.tar.gz

Once the download is complete extract the tar file by typing:

sudo tar zxf nagios-plugins.tar.gz

Change to the plugins source directory and compile by typing:

cd nagios-plugins-release-2.2.1

Run the following commands one by one to compile and install the Nagions plugins:

sudo ./tools/setup
sudo ./configure
sudo make
sudo make install

Starting Nagios

Now that both Nagios and its plugins are installed, start the Nagios service with the following command:

sudo systemctl start nagios

To verify that Nagios is running, check the service status with the following command:

sudo systemctl status nagios

The output should look something like bellow indicating that Nagios service is active and running.

* nagios.service – Nagios Core 4.4.2
Loaded: loaded (/lib/systemd/system/nagios.service; enabled; vendor preset: enabled)
Active: active (running) since Fri 2018-11-16 14:54:21 PST; 1s ago
Docs: https://www.nagios.org/documentation
Process: 18294 ExecStopPost=/bin/rm -f /usr/local/nagios/var/rw/nagios.cmd (code=exited, status=0/SUCCESS)
Process: 18293 ExecStop=/bin/kill -s TERM $ (code=exited, status=0/SUCCESS)
Process: 18315 ExecStart=/usr/local/nagios/bin/nagios -d /usr/local/nagios/etc/nagios.cfg (code=exited, status=0/SUCCESS)
Process: 18313 ExecStartPre=/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg (code=exited, status=0/SUCCESS)
Main PID: 18325 (nagios)
Tasks: 6 (limit: 2319)
CGroup: /system.slice/nagios.service

Accessing the Nagios Web Interface

To access the Nagios web interface open your favorite browser and type your server’s domain name or public IP address followed by /nagios:

http(s)://your_domain_or_ip_address/nagios

Enter the nagiosadmin user login credentials and you will be redirected to the default Nagios home page as shown on the image below:

Conclusion

You have successfully installed the latest Nagios version from source on your Ubuntu system.

You should now check the Nagios Documentation and learn more about how to configure and use Nagios.

If you hit a problem or have a feedback, leave a comment below.

Source

Whenever you login into your computer, you’re presented with a screen asking your credential to verify that it’s you. After you enter the password, you’re in your world. Each time you log in, you have to go through this process again and again. Doesn’t it feel boring to look at the face of that same, plain screen? I bet you’re pretty tired of the system’s default login screen. Well, let’s add a splash of color! Having an awesome background would really rejuvenate your desktop experience, don’t you agree? Ubuntu is the most popular Linux distro for general users, no doubt. However, over the course of its lifetime, there’s that same, BORING login screen appearing. It’s time to change that.

Ubuntu shifted from Unity to GNOME desktop environment and GDM as login agent. By default, Ubuntu allows you to modify your desktop wallpaper and lock screen background. However, there’s no direct option available for changing the login screen background. We’ll have to dig our way through various system tweaks.

At first, make sure that you have your background image ready.

Now, fire up a terminal and run the following commands –

sudo cp ~/Desktop/mybackground.png /usr/share/backgrounds

Or, you can also use the file manager to do the task.

xhost +local: && sudo nautilus /usr/share/backgrounds/

Now, you have to edit the CSS file that defines the login background.

Xhost +local: && sudo gedit /etc/alternatives/gdm3.css

Now, find out the following section –

Change the “background” entry –

#lockDialogGroup {
background: url(file:///usr/share/backgrounds/mybackground.png);
background-repeat: no-repeat;
background-size: cover;
background-position: center; }

Save the file.

Enjoying the effect

After everything is complete, restart your system.

Voila! Enjoy the most amazing login screen backgrounds of your entire life!

Source

Gedit is an open source text editor application for Linux-based operating systems. It is mostly used under the GNOME desktop environment, but you can also install it on other open source window managers.

It is more than a simple text editor, as it can be used by developers as a programmers’ editor. The software provides users with an uncluttered user interface that can be used by novices and expert users alike.

Recognizes numerous programming languages

Gedit features full support for internationalized text (UTF-8), configurable syntax highlighting for various languages, such as C, C++, Java, XML, HTML, Python, Perl, undo and redo functions, as well as the ability to load files from remote locations.

Talking about supported programming languages, the application automatically detects the syntax of a certain file, but it also allows users to choose one from the statusbar or the Highlights Mode entry of the View menu.

Features at a glance

Its main features include spell checking support with automatic highlighting of misspelled words, advanced document statistic functionality that displays the total number of lines, words, bytes, as well as characters, with or without spaces, in the entire document or the current selection.

Among other features we can mention file reverting, print and print preview support, clipboard support (cut, copy, paste), search and replace, go to specific line, auto indentation, text wrapping, line numbers, right margin, current line highlighting, bracket matching, file backup, and configurable colors and fonts.

Supported OSes and availability

While the application is distributed only as a source archive that can be configured, compiled and installed on any Linux flavor, users can find and install Gedit straight from the default software repositories of their distribution.

With a complete online user manual, Gedit can be easily used by programmers to successfully write and edit code. Besides Linux, the application also supports the Mac OS X and Microsoft Windows operating systems.

Source