Retrieving File Permissions in Octal Mode Using the Command Line

Retrieving File Permissions in Octal Mode Using the Command Line

File permissions on a Linux system can be represented in either symbolic mode or octal mode. Using octal mode to represent file permissions is a little more succinct, since we can usually list all relevant file permissions with just three numbers. These numbers represent the owner, group, and other user permissions for any file or directory on Linux. In this tutorial, you will see how to get a listing of file permissions in octal mode representation on the Linux command line.

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how to manage groups on Linux

How to manage groups on Linux

Groups are an essential part of how discretionary access control (DAC) is implemented on Linux and, in general, on any Unix-based operating system. The creation, modification, and removal of groups are relatively straightforward operations which can be carried out using some utilities installed by default.

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Introduction to Linux capabilities

On Linux, traditionally, a process could either run as root, and so have limitless access to the system, or as a non-root user, subject to a set of restrictions. Since version 2.2 of the kernel, capabilities were introduced as a way to grant permissions in a more granular way.

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How to check open ports on Raspberry Pi

How to check open ports on Raspberry Pi

Raspberry Pi devices are commonly used to host a variety of lightweight services as they can do so very affordably. A simple example would be a web server, which handles user requests whenever someone navigates to a website. In order to make sure these services are accessible either on the local network or over the internet, we must make sure that the corresponding ports are open. Checking for open ports is also an essential security task that all administrators should perform in order to make sure that their Raspberry Pi only has the ports open that are necessary.

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Redhat Disable Firewall - start, stop, enable, disable

Redhat Disable Firewall – start, stop, enable, disable

firewalld is the default firewall on Red Hat Enterprise Linux, and it’s enabled by default, but it’s possible to disable the firewall on Redhat, and you’ll also see how to check firewall status in Linux. Normally, there should not be a need to disable the firewall, but it may be quite handy for testing purposes or other scenarios. In this tutorial, you’ll see how to check the status of firewalld, enable or disable the service from starting automatically upon system boot, and how to stop or start the firewalld service in RHEL.

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Set Kali root password and enable root login

Set Kali root password and enable root login

In order to enable root login for Kali Linux, we must set the the root password manually. In past versions of Kali Linux, users were able to log in directly to the root account by default. On more recent versions, this has been disabled. The reasoning behind this change should be obvious, but if you’re a Kali user, you probably know your way around a Linux system by now, and there’s not much risk in letting you use the root account to log in.

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How to enable/disable firewall on Raspberry Pi

How to enable/disable firewall on Raspberry Pi

The firewall on a Raspberry Pi will, by default, block incoming connections to certain ports. This is a security feature, but may cause problems if you try to configure an SSH server on your Raspberry Pi, host a website, or otherwise host some service that needs to accept incoming connections. The usual answer to this problem is to configure the firewall to accept the connections on the particular ports that you need to open. Another alternative is to disable the firewall completely.

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Checking Your Raspberry Pi's OS Version

Checking Your Raspberry Pi’s OS Version

Being aware of your current Raspberry Pi OS version will help you know when it is time to update. It is important to know the version of your Raspberry Pi system, as new versions are released based on Debian’s release schedule, and new updates are issued all the time. Staying up to date will keep your Raspberry Pi secure and ensure that you have the newest software available. All Raspberry Pi models can run the same operating system, so updates are universal across all devices.

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List of best hex editors on Linux

List of best hex editors on Linux

Hex editors allow users to edit a binary file after it has already been compiled. Ordinarily, you should make changes to a program by editing the source code and compiling it into an executable file. But if you do not have access to the source code, it is still possible to change various bytes of data of the compiled file, in the hopes that your edit will yield the desired results. This is a hacky solution that can be used for both honest and nefarious purposes.

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How to ZIP file with password on Linux

How to ZIP file with password on Linux

If you have one or more files that you need to send to a friend or store for a long time, compressing the files into a .zip archive is a good way to save on space and combine all files into a single object. If you need to keep the file contents private, for fear that they could be intercepted by the wrong party, or that someone could try to access them on your own system, then it is possible to add a password to your zip file. In this tutorial, you will learn how to zip files and add a password to your zip archive on a Linux system.

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