I call this the unofficial bash strict mode. This causes bash to behave in a way that makes many classes of subtle bugs impossible. You’ll spend much less time debugging, and also avoid having unexpected complications in production.
Source: Use the Unofficial Bash Strict Mode (Unless You Looove Debugging) (aaron maxwell)
Use iptables to create a VPN killswitch to protect against data leaks.
If you’re connected to a VPN, you need a killswitch. No, it’s not as metal as it sounds. It’s just a mechanism that stops your Internet connection when you’re disconnected from the VPN. It protects you from inadvertently leaking sensitive information onto the Internet when the VPN connection drops.
Source: How To Create A VPN Killswitch Using Iptables on Linux – LinuxConfig.org
The ls command is used to list directory contents and the results can be sorted upon several criteria such as by date, alphabetical order of filenames, modification time, access time, version and file size.
In this article, I will show you how to sort files by date using ls command in Linux.
Source: Guide to Sort Files by Date Using LS Commandline in Linux (LinOxide)