I've recently written about using bash arrays and bash regular expressions, so here's a more useful example of using them to test IP addresses for validity.

iptables is the user-space tool for configuring firewall rules in the Linux kernel. It is actually a part of the larger netfilter framework. Perhaps because iptables is the most visible part of the netfilter framework, the framework is commonly referred to collectively as iptables. iptables has been the Linux firewall solution since the 2.4 kernel.

SOCKS is built in to OpenSSH, so it's a trivial matter to set up a local SOCKS proxy with the -D flag. For example:

Open source has won the present, but what about the future?

Part I of this Deep Dive on containers introduces the idea of kernel control groups, or cgroups, and the way you can isolate, limit and monitor selected userspace applications. Here, I dive a bit deeper and focus on the next step of process isolation—that is, through containers, and more specifically, the Linux Containers (LXC) framework.

Bash brace expansion is used to generate stings at the command line or in a shell script. The syntax for brace expansion consists of either a sequence specification or a comma separated list of items inside curly braces "{}". A sequence consists of a starting and ending item separated by two periods "..".

For Linux users, the command line is a celebrated part of our entire experience. Unlike other popular operating systems, where the command line is a scary proposition for all but the most experienced veterans, in the Linux community, command-line use is encouraged.

Nextcloud could be the first step toward replacing proprietary services like Dropbox and Skype. In its simplest form, the Nextcloud server is "just" a personal, free software alternative to services like Dropbox or iCloud. You can set it up so your files are always accessible via the internet, from wherever you are, and share them with your friends. However, Nextcloud can do so much more.