Author: Admin

Understanding Linux Permissions

Linux is a multiuser operating system. In a multiuser environment, it is necessary to ensure that a user cannot access or modify files or directories that they arent supposed to. File permissions provide a protection mechanism for controlling access to files and directories.

Linux’s file security model is based on that of Unix. Each file or directory can be accessed or modified by the user who created it, or a group of users who have been given permission to do so. Permissions can also be defined for other users that do not belong to either of these two categories.

In this guide, we will go over how file permissions work in Linux for beginners. We’ll cover how you can view the permissions associated with files and directories and also how you can change them.

Source: Understanding Linux Permissions (Linux Academy)

How to Clear the Google Chrome DNS Cache

Flushing your DNS cache can help to fix host connection problems you may experience when accessing some web pages. To get a better Internet access performance, Google built a caching system, not only for site content but DNS as well. So yes, Google Chrome does have a built-in internal DNS caching system – a hidden feature that allows users to manually clear out the Chrome DNS host cache from within the browser itself.

Flushing out the Chrome DNS cache can prove useful, especially when you have changed the DNS settings. If clearing out the DNS cache from the operating system level does not fix the host connection problems, clearing up Chrome’s own DNS cache should do the trick.

This article will show you step by step how to clear the Chrome DNS cache.

Source: How to Clear the Google Chrome DNS Cache – Make Tech Easier

freezetab: A powerful alternative to bookmarks in the Chrome browser

Freezetab helps you save your tabs and keep them organized.

Features:

★ Tab Groups

Every time you save a bookmark the browser forces you to pick a folder to put the bookmark in. You often don’t have a folder name in mind, so all of your tabs end up in one giant unorganized folder. Freezetab doesn’t force you to create a new folder every time you save a tab. Instead it groups your tabs based on when you saved them, which keeps your tabs organized without any extra effort.

★ Websites

Wouldn’t it be nice if you could view a breakdown of all your saved tabs based on the websites the tabs are from? Freezetab allows you to accomplish this in just a single click.

★ Tab Calendar

Imagine you saved a tab on a certain day, but you don’t remember the title or name of the website. With Freezetab’s calendar you can click on a day to view a searchable list of every tab you saved that day.

★ Sharing

With Freezetab sharing tabs is incredibly easy. Just click share in any folder or tab group and a text box will appear with all your links.

★ Search

Unlike the browser’s bookmarking system, Freezetab starts searching as soon as you start typing. The search results update every time you type a character into the search box. Freezetab’s search is incredibly accurate. It searches based on the title of the website, the name of the website, and even the titles of your tab groups.

★ Save Tabs

Browsers only give you two options for saving tabs: the current tab, or every tab. Freezetab allows you to save all tabs, the current tab, everything except the current tab, everything to the right or left of the current tab, or specific tabs. And after you’ve saved your tabs, Freezetab asks if you’d like to close the saved tabs to get them out of the way.

★ Quick Save

Sometimes you just need to quickly save some tabs without all the extra hassle. Freezetab has a quick save feature that saves all your tabs, and then closes them. You can change the default action in the settings.

★ Sorting

Freezetab offers six different ways of sorting your tab groups. You can sort from A-Z, Z-A, oldest to newest, newest to oldest, least to greatest, and greatest to least. You can also search for a tab group by name using the search box.

★ Close Tabs

Browsers offer a few different options for closing tabs. You can close the entire window, the current tab, everything to the right of the current tab, and everything except the current tab. Freezetab adds two additional options: you can close everything to the left of the current tab, or specific tabs. Closing specific tabs can be really useful when you have so many tabs open that the browser doesn’t display their titles.

★ Folders

Browsers have only one way of organizing your saved tabs: dragging and dropping from one folder to another. Before you can organize tabs with folders, you need to find the tabs you’re trying to organize. Freezetab allows you to sort your tabs based on the title or name of the website, the date you saved them, and a variety of other ways. After you’ve found the tabs you’re looking for, you can drag and drop them into folders.

★ Stars

Sometimes you need to quickly mark a tab or tab group as important. Freezetab has a star feature that does exactly this.

Link: Freezetab

OpenSnitch: The Little Snitch application like firewall tool for Linux

OpenSnitch (forked version) screenshot

EDIT: The original developer apparently has abandoned OpenSnitch, however there is a forked version that as of 2021 is still being actively developed. In addition, there is a newer project by a completely different developer called eBPFSnitch. For more information on the forked version, see OpenSnitch Linux Application Firewall Fork With Improvements And Bug Fixes (LinuxUprising)

Continue reading “OpenSnitch: The Little Snitch application like firewall tool for Linux” →

The Ultimate Firefox Privacy & Security Guide

Online privacy and security are constantly under assault. It seems like every day there’s a new threat to your personal information. Choosing and configuring the right web browser goes a long way in protecting yourself. Right now Firefox is the best option for that. It’s open source, gives you tons of options for control, and has all of the privacy and security add-ons you’ll need.

This guide is as complete as it can be at the time of writing. These are ever-evolving topics, and threats continue to change. Regardless, this guide will give you a good basis to protect yourself from common threats.

Source: The Ultimate Firefox Privacy & Security Guide – Make Tech Easier

Raspberry Pi Pushbutton Shutdown/Startup

This is extracted from a single post by user RonR in a thread about FreePBX for the Raspberry Pi on DSLReports. I though it might be useful to many Raspberry Pi users:

Raspberry Pi Pushbutton Shutdown/Startup

The attached script will install shutdown and startup capability using a SPST NO momentary pushbutton
switch connected to GPIO header pins 5 and 6. Pressing the button on a running system will initiate
a graceful shutdown (shutdown -h now). Once shut down, pressing the button will restart the system.

1. Copy install and gpio-shutdown.dtbo to the Raspberry Pi.

2. Make the install script executable:

$ chmod +x install

3. Run the install script:

$ sudo ./install

4. Reboot

For additional info, see:

http://www.stderr.nl/Blog/Hardware/RaspberryPi/PowerButton.html

The script can be downloaded from RonR’s original post or directly from https://www.dslreports.com/r0/download/2324182~6a03744946c51bfa4876b6ecd8d4528c/PushButton.zip

How to Pass Arguments to a Bash-Script

You can write a bash script such that it receives arguments specified when the script is called from the command line. This method is used when a script has to perform a slightly different function depending on the values of input parameters (the arguments).

For example, you may have a script called “stats.sh” that performs a particular operation on a file, such as counting its words. If you want to be able to use that script on many files, it is best to pass the file name as an argument, so that you can use the same script for all the files to be processed.

Source: How to Pass Arguments to a Bash-Script (Lifewire)