Linux Resources

Install and Run Python on CentOS 8 - How to do it ?

This article covers how to install python2 and python3 on CentOS 8. By default, python2 and python3 are not installed on CentOS 8. To install both, you need to install all python packages separately according to python versions. Also, you can run python2 and python3 environments on your system. 

The 'alternatives --auto python' command is used to set any python version as the default. 

To run Python in Linux:

A widely used way to run Python code is through an interactive session. 

To start a Python interactive session, just open a command-line or terminal and then type in python, or python3 depending on your Python installation, and then hit Enter .

Python comes preinstalled on most Linux distributions, and is available as a package on all others. 

However there are certain features you might want to use that are not available on your distro's package. 

You can easily compile the latest version of Python from source.

Installing Python 3 on Linux:

1. To see which version of Python 3 you have installed, open a command prompt and run

$ python3 --version

2. If you are using Ubuntu 16.10 or newer, then you can easily install Python 3.6 with the following commands:

$ sudo apt-get update

$ sudo apt-get install python3.6

3. If you're using another version of Ubuntu (e.g. the latest LTS release) or you want to use a more current Python, we recommend using the deadsnakes PPA to install Python 3.8:

$ sudo apt-get install software-properties-common

$ sudo add-apt-repository ppa:deadsnakes/ppa

$ sudo apt-get update

$ sudo apt-get install python3.8

4. If you are using other Linux distribution, chances are you already have Python 3 pre-installed as well. If not, use your distribution's package manager. For example on Fedora, you would use dnf:

$ sudo dnf install python3

To see if pip is installed, open a command prompt and run:

$ command -v pip

Reboot Linux Mint 20 - How to do it ?

This article covers methods to reboot the Linux Mint. If you want to shut down your Linux Mint instead of rebooting, Learn How to Shutdown Linux Mint 20 .

Rebooting is the same as restarting, and close enough to powering off and then turning off your device. The purpose is to close and reopen the operating system. Resetting, on the other hand, means taking the device back to the state in which it left the factory. Resetting wipes all your personal data.

The systemctl command accepts, among many other options, halt (halts disk activity but does not cut power) reboot (halts disk activity and sends a reset signal to the motherboard) and poweroff (halts disk acitivity, and then cut power). These commands are mostly equivalent to starting the target file of the same name.

To reboot Linux:

1. To reboot the Linux system from a terminal session, sign in or "su"/"sudo" to the "root" account.

2. Then type " sudo reboot " to reboot the box.

3. Wait for some time and the Linux server will reboot itself.

To shut down Linux Mint:

Execute the following command:

sudo chmod u+s /sbin/shutdown

You will be prompted for your root password. After that, you're done and can type "exit" to exit out of the Terminal.

Linux Commands to Shutdown and Reboot the System:

1. Linux shutdown / reboot command. On Linux, like all tasks, the shutdown and restart operations can also be done from the command line.

2. "shutdown" command.

3. "reboot" command.

4. "halt" command.

5. "poweroff" command.

6. REISUB - R E I S U B key strokes.

Modify Date, Time, and Timezone in Debian 10 - How to do it ?

This article covers how you can easily change the date, time, and timezone in your Debian system. To change your Debian system's timezone, run the sudo timedatectl set-timezone command followed by the long name of the time zone you want to set

Based on your convenience, you can either choose the command line or the GUI method. If you are using Ubuntu OS, you can visit our post on How to Change the Date, Time, and Timezone in Ubuntu 20.04 LTS .

Using the correct timezone is essential for many systems related tasks and processes. 

For example, the cron daemon uses the system's timezone for executing cron jobs, and the timestamps in the log files are based on the same system's timezone.

On Debian, the system's timezone is set during the install, but it can be easily changed at a later time.

To check the Current Timezone:

timedatectl is a command-line utility that allows you to view and change the system's time and date. It is available on all modern systemd-based Linux systems:

$ timedatectl

To modify Change Time Zone in Debian 10 / Debian 9:

1. Using /etc/localtime File. In this method, we will use /etc/localtime (link to the original time zone file) file to set the timezone for your system.

2. Using timedatectl command. In this method, we will use the timedatectl command to change the time zone in Debian.

Install Chrony on Linux Mint - Easy steps to do it ?

This article covers how to #install Chrony on Linux Mint 20. Once it will be installed on your system, its daemon will silently work in the background to synchronize your system's clock with the #NTP server. 

However, if you do not want Chrony to perform this job any longer, then you can simply uninstall it as well.

Chrony is a flexible implementation of the Network Time Protocol (NTP). 

It is used to synchronize the system clock from different NTP servers, reference clocks or via manual input.

Chrony comes with two programs:

1. chronyc – command line interface for chrony

2. chronyd – daemon that can be started at boot time

How to Install #Chrony in #Linux :

On some systems, chrony may be installed by default. Still if the package is missing, you can easily install it. 

You can install chrony Using your default package manager tool on your respective Linux distributions using following command:

# yum -y install chrony    [On CentOS/RHEL]

# apt install chrony       [On Debian/Ubuntu]

# dnf -y install chrony    [On Fedora 22+]

To check the status of chronyd use the following command:

# systemctl status chronyd      [On SystemD]

# /etc/init.d/chronyd status    [On Init]

If you want to enable chrony daemon upon boot, you can use the following command:

# systemctl enable chronyd       [On SystemD]

# chkconfig --add chronyd        [On Init]

How to Check Chrony Synchronization in Linux ?

To check if chrony is actually synchronized, we will use it's command line program chronyc, which has the tracking option which will provide relevant information:

# chronyc tracking

To check information about chrony’s sources, you can issue the following command:

# chronyc sources

Install and Use TermRecord on CentOS 8 - Do it now

This article Covers how to install the TermRecord application on CentOS 8. The TermRecord application allows you to better enjoy the recorded #Terminal content. 

TermRecord is a simple, open source, terminal session recorder with easy-to-share self-contained HTML output.

#TermRecord Stores these files as your own notes, email them to collaborators, use them as instructional examples, or whatever you wish.

TermRecord consumes output from the script command with timing information and can create a self-contained HTML file which replays the recorded session without needing to load anything from the web. 

These term sessions can be emailed and viewed on practically any device (including iPads etc.). 

The end user only needs a modern browser.

Features of TermRecord includes:

1. User friendly.

2. Detects the terminal size.

3. Nest sessions.

4. Cross-platform HTML-based output.

5. Stores the output as either JSON, embeddable JavaScript, or a static HTML file.

6. Written in Python.

To install on TermRecord #CentOS:

1. First of all, connect to your server via SSH and make sure that all of your system software is up to date. 

Run the following command to update the package list and upgrade all of your system software to the latest version available:

$ sudo yum update -y

2. Install Pip. 

Add the EPEL Repository:

$sudo yum install epel-release

Install pip:

$ sudo yum install python-pip

Once the installation has completed, you can verify that it was successful by using the following command:

$pip -V

3. Install TermRecord

Install TermRecord using the Python package manager (pip):

$sudo pip install TermRecord

How to use TermRecord on CentOS system ?

Taking a video of the terminal with TermRecord is rather simple, just run the following command (be attentive to capital letters):

TermRecord -o record.html

Note: We specify the output file in which the video will be recorded using the -o option. the .html format is the default format.

For more complex operations check out TermRecord --help

Assign Multiple IP Addresses to Single NIC in Debian 10 - How to do it ?

This article covers how to assign and remove multiple IP addresses to and from a single NIC. Based on your preferences, you can either assign the multiple IP addresses temporarily or permanently.

There's no simple command that you can run to determine whether the IP address on a Linux system is assigned by DHCP or static. 

If it changes when the system restarts, it's clearly dynamically assigned, but even a dynamic address has some resistance to change. 

The best way is to look at the configuration file.

To add a static route in Linux:

1. Use the route command with the –p option to add a persistent route: # route -p add default ip-address.

2. Use the route command with the –name option to add a persistent route by specifying a name rather than destination and gateway: # route -p add destination-address gateway-address -name name.

What is ip route command in Linux?

ip route is used to manipulate entries in the kernel routing tables. 

Route types: 

1. unicast - the route entry describes real paths to the destinations covered by the route prefix. 

2. unreachable - these destinations are unreachable. 

Packets are discarded and the ICMP message host unreachable is generated.

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