Unix as a Second Language

By Sandra Henry-Stocker

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Advice for everyday Unix systems administration and some clever ways to approach more challenging problems.

Showing memory usage in Linux by process and user

There are several commands for checking up on memory usage in a Linux system, and here are some of the better ones.

Setting up passwordless Linux logins using public/private keys

Using a set of public/private keys to allow you to log into a remote Linux system or run commands using ssh without a password can be very convenient, but setup is just tad tricky. Here's how and a script to help.

Locking and unlocking accounts on Linux systems

There are times when locking a Linux user account is necessary and times when you need to reverse that action. Here are commands for managing account access and what's behind them.

Generating numeric sequences with the Linux seq command

The Linux seq command can generate lists of numbers and at lightning speed. It's easy to use and flexible, too.

Unix is turning 50. What does that mean?

Unix time, also known as 'epoch time,' is the number of seconds that have passed since Jan 1, 1970. As Unix turns 50, let's take a look at what worries kernel developers.

How to tell if you’re using a bash builtin in Linux

A built-in is a Linux command that's part of whatever shell you're using. Can you tell what commands are built-ins and which are not?

7 ways to remember Linux commands

Linux commands run from the nearly obvious to the very complicated, but there are many ways that you can easily remember and use even the most obscure commands.

Breaking Linux files into pieces with the split command

Some simple Linux commands allow you to break files into pieces and reassemble them as needed. In this post, we'll look at the split command and some of its more useful options.

Counting down the days in Linux using bash

Need to know how many days there are before some important event? Let bash and the date command help with that!

Displaying dates and times your way in Linux

The Linux date command provides more options for displaying dates and times than you can shake a stick at (without hurting your wrist anyway). Here are some of the more useful choices.

The many faces of awk

The awk command provides a lot more than simply selecting fields from input strings, including pulling out columns of data, printing simple text evaluating content – even doing math.

Cleaning up with apt-get

Most of us with Debian-based systems use apt-get routinely to install packages and upgrades, but how often do we pull out the cleaning tools? Let's check out some of the tool's options for cleaning up after itself.

Red Hat Responds to Zombieload v2

Red Hat calls for updating Linux software to address Intel processor flaws that can lead to data-theft exploits

Red Hat announces RHEL 8.1 with predictable release cadence

Red Hat has just released Red Hat Enterprise Linux 8.1, first to follow the predictable release cadence promised at Red Hat Summit 2019

Looping your way through bash

There are many ways to loop through data in a bash script and on the command line. Which way is best depends on what you're trying to do.

Viewing network bandwidth usage with bmon

Introducing bmon, a monitoring and debugging tool that captures network statistics and makes them easily digestible.

Using multitail on Linux

Multitail allows you to watch multiple files as they are being updated -- like a split-window tail -f display. Let's check out how you can use it to monitor system activity and your files.

Viewing files and processes as trees on Linux

A look at three Linux commands - ps, pstree and tree - for viewing files and processes in a tree-like format.

How the Linux screen tool can save your tasks – and your sanity – if SSH is interrupted

The Linux screen command can be a life-saver when you need to ensure long-running tasks don't get killed when an SSH session is interrupted. Here's how to use it.