In the Github profile of this tool, we find the following definition

NetHogs is a small ‘net top’ tool. Instead of breaking the traffic down per protocol or per subnet, like most tools do, it groups bandwidth by process.

Thanks to this tool, we can find out which processes and applications consume the most bandwidth. In administrative situations, it is quite useful to identify network abuses.

Since NetHogs heavily relies on /proc, most features are only available on Linux. NetHogs can be built on Mac OS X and FreeBSD, but it will only show connections, not processes.

So, let’s get started.

Install Nethogs on Ubuntu 20.04

Nethogs is a mature piece of software included in most Linux distributions. And this includes Ubuntu 20.04 and derivatives, so to install it, just run the following command

sudo apt update
sudo apt install nethogs

This way we will be able to use it from the terminal.

Using Nethogs on Ubuntu 20.04

The most common way to use it is simply to run it with root permissions as follows:

sudo nethogs

There you will notice how the set of applications that are using the network are grouped by processes.

It is useful to give the program a refresh rate. This rate is measured in seconds and can be specified with the -d option. For example to indicate that every 5 seconds the monitoring should be refreshed.

sudo nethogs -d 5

Another useful thing to do is to specify which network interface to monitor.

sudo nethogs -d 5 eth1

This way only the network interface eth1 is taken into account, but you can also add more than one.

sudo nethogs -d eth1 eth2

As you can see, it is quite simple to use.

Also, you can install a graphical interface called nethogs-qt for better integration.

Conclusion

These kinds of tools, although simple, can be very useful to see which application consumes a lot of bandwidth. This is useful in a home environment but in a production environment, it can be vital.

Enjoy it.

The post Monitoring your network with Nethogs on Ubuntu 20.04 appeared first on Linux Windows and android Tutorials.

To do it I present you two very simple methods to do it, one consists of using an external program for it. The other method is with a command that normally comes installed on all Linux distributions.

So, let us start.

1. Protect your files using rm-protection

rm-protection is a small program similar to an rm extension that protects your files from accidental deletion. The program can be installed via PIP so there should be no problem with it.

First, you need to install PIP.

If you use Debian, Ubuntu, Linux Mint or derivate:

$ sudo apt install python-pip
$ sudo apt-get install python-setuptools

In case you are using Arch Linux or derivates, you can install it with this command:

:~$ sudo pacman -S pyhton-pip

On CentOS 7 and RHEL:

:~$ su
:~# yum install epel-release
:~# yum install python-pip

Next, install rm-protection.

:~$ sudo -H pip install rm-protection

Next, use the command to protect your file. For example, I have one file called examplerm.txt.

:~$ protect examplerm.txt

Then, the tool will ask your to set a question and answer. If you want to eliminate it, it will ask you a question and you must answer it correctly.

Now, try to remove it.

:~$ rm-p example.txt

You will see this:

As you can see, you have to answer the question. If you don not answer the question correctly, the program will not allow you to remove the file.

However, if you type the answer, then you will remove it.

The script is very good, but not infallible. The root user can delete without knowing the answer to the question, just as if the user knows the answer as well. Use it more than anything to avoid accidents, not to give security to the system.

If you want more security, I recommend to you create a Alias and change rm for rm-p.

2.- Protect your files using the chattr command

The second form is somewhat more drastic than the first and is using the chattr command. It is a command available on almost all Linux distributions.

Its usage is like this:

:~$ chattr [-pRVf] [-+=aAcCdDeijPsStTu] [-v version] files

Do not worry, it is too easy to use it.

For example, I will protect one file called examplechattr.txt.

:~$ sudo chattr +i examplechattr.txt

I’ll explain briefly. Chattr has an operator like + that adds a feature or – that removes it. Option i indicates that the file is immutable, i.e. it cannot be deleted.

Let us try to remove it.

As you can see, even the root user is not allowed to remove the file.

If you want to remove this attribute, you can do so with this command:

:~$ sudo chattr -i examplechattr.txt

Now, you can delete it.

The same way you can protect entire folders. For example:

:~$ sudo chattr -R +i Example/

To revoke it

:~$ sudo chattr -R -i Example/

So, that’s it.

Conclusion

The protection of data and files is an essential task of a sysadmin, for it there are two very simple ways to do it.

Please share this post with your friends.

The post Protect your files from accidental deletion appeared first on Linux Windows and android Tutorials.

Gotop is another terminal based graphical activity monitor, inspired by gtop and vtop, this time written in Go. With this tool, you can visualize the resources that your system consumes in a very friendly way. It is written in Go with many advantages in execution time. It is quite fast and does not consume almost resources.

Some of its main features are:

• It is available for all Linux distributions. As well as for Mac OS and BSD.
• You can customize the color scheme of the application adapting it to your needs.
• It is open source. The program is released under the GNU Affero General Public License.
• You can monitor CPU, Network, RAM, battery level and processes.

And many more.

So, let using Gotop.

1. Upgrade the system

The first step is to update the system so that it has the best possible performance and you will be able to show more accurate data when running Gotop.

So, in Debian, Ubuntu, and derivates:

:~$ sudo apt update && sudo apt upgrade

For CentOS 7 and RHEL:

:~$ sudo yum update

If you are using Fedora 28, 29:

:~$ sudo dnf update

Finally, if you are using OpenSUSE, you can update the system with this command:

:~$ sudo zypper up

Once you have updated the system, you can move on.

2. Installing and using Gotop

Now it is time for installation. To do this, first, you have to download the binaries from the download section of the project website.

At the time of writing this post, the latest stable version of Gotop is 2.0 which introduces new features such as the ability to monitor the battery of a laptop.

So, download it.

:~$ wget -c https://github.com/cjbassi/gotop/releases/download/2.0.0/gotop_2.0.0_linux_amd64.tgz

Of course, if you do not have wget installed, you have to do it.

For Debian, Ubuntu, Linux Mint and derivates:

:~$ sudo apt install wget

In case, you are using CentOS 7 and RHEL:

:~$ yum install wget

For Fedora 29:

:~$ sudo dnf install wget

Finally, if you are using OpenSUSE:

:~$ sudo zypper in wget

However, wget is a main component of the system. It is likely installed by default.

Next, decompress the file.

:~$ tar -xvzf gotop_2.0.0_linux_amd64.tgz

Now, run it.

:~$ ./gotop

To exit, press CTRL + C.

If you want more options, you can show the help.

:~$ ./gotop --help

So, you can change the color schemes. For example:

:~$ ./gotop --color=monokai

Or, enable the averages.

:~$ ./gotop -a

Conclusion

It is always good to have tools to monitor the state of our system. Now we have another tool that will help us with the task in a simple and friendly.

The post Using Gotop a graphical system monitor appeared first on Linux Windows and android Tutorials.

There are very simple commands to use and others not so simple, for now we will focus on two very simple but useful commands when performing tasks in the terminal, especially if you are a system administrator, the ZCAT and CAT commands.

First we go with zcat!!

Actually both commands are simple and similar to use, first we will deal with zcat.

zcat is a command for unix systems such as GNU/LINUX that allows us to view the contents of compressed files from the command line.

Its use from the terminal is simple and uses this syntax:

zcat [OPTION]… [FILE]…

Using the help of zcat in the terminal we visualize the available options:

Its use is simple. First we will create 4.txt files and then we will compress them for our example.

:~$ mkdir zcat_command
:~$ cd zcat_command
:~$ touch r{1..3}.txt
:~$ nano r1.txt // we add some text
:~$ gzip r1.txt r2.txt r3.txt

the result of this is the creation of 3 compressed text files with extension.txt.gz

Now we’re ready to go.

• Display the contents of a compressed text file with gz

:~$ zcat r1.txt.gz

• Displaying the contents of multiple files at the same time

We can display the contents of several files at once:

:~$ zcat file1 file2
:~$ zcat r1.txt.gz r2.txt.gz

We will get the contents of each file successively:

• Enabling pagination

To enable pagination we can do it with less or more

:~$ zcat file | more
:~$ zcat file | less
:~$ zcat r1.txt.gz | more
:~$ zcat r1.txt.gz | less

• Force Mode

By default zcat only works with.gz compressed files but it can be used with uncompressed files by forcing them to run.

:~$ zcat -f file
:~$ nano t1.txt // add hello
:~$ zcat -f t1.txt

• Showing compressed file properties

It is also possible to show the properties of a file by using the option -l

:~$ zcat -l file.gz
:~$ zcat -l r1.txt.gz

Now it’s cat’s turn

The cat command is very similar in its use and functionality to zcat, but this time we will work with uncompressed text files. But it also serves to concatenate the output of several files by the standard output of the terminal. We will also have a new feature, which is that cat allows us to concatenate text files to be displayed in a single output by the terminal.

First we’ll examine the help the command gives us from your terminal:

We will examine several examples to demonstrate how to use this command:

• Display the contents of a text file

This is the most basic way to use the cat command:

:~$ cat path_of_the_file
:~$ cat file1

• Display the contents of multiple files

It is also possible to display several files at once, for this purpose:

:~$ cat path_of_the_file1 path_of_the_file2 ...
:~$ cat file1.txt file2.txt

• Identify Specific File Content

If, as in the previous example, we need to show the contents of several files, it is very useful to identify when one line is finished and the other starts. Using the -e option we can do that, because at the end of the line’s content display it places the $ sign

:~$ cat -e file1.txt file2.txt

• Add Number of Lines in Output

However, showing the lines that a file has is very easy and its use is highly recommended to better examine the file.

:~$ cat -n file1.txt

• Copy Contents of One file to Another

cat comes from “concatenate” so we can pass the content from one file to another.

:~$ cat file1.txt > file2.txt
:~$ cat file2.txt

With this > cat operator, it reads the contents of the first file and overwrites the second file.

• Combine or Append the Content of One File to Another

Now if we want to “combine” the contents of one file with another we must use the >> operator.

:~$ cat file1.txt >> file2.txt
:~$ cat file2.txt

As you can see cat reads the content of the first file and combines it with the second one.

As a result, we can say that these very similar commands in their use are of great help to get a taste for the terminal of any Unix system, or in this case, of GNU/LINUX. Both are simple to use, and their usefulness is very diverse according to what we need.

Try using these and other commands, please share this article through your social networks.

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