Category: books

Linux Command Line and Shell Scripting Bible

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bash-bible

This is the third edition of the book and I’ve been well pleased with it. The first part of the book is dedicated to the command line and gaining familiarization with the various commands, file system, navigation, etc. The real meat of the book begins with part 2 where you actually start scripting.

As a software developer by trade, Linux scripting is something that I find myself naturally drawn to. All of the systems I utilize at work aside from my desktop run Red Hat Enterprise Linux so I spend a great deal of time in terminal sessions. Many of the things I do are extremely repetitive and while I can’t (due to security limitations) put custom scripts in every environment I’m slowly working on a library that can help be do those mundane tasks quickly and with reproducible results.

Part 3 covers advanced scripting and the use of tools like sed and awk. Both of these along with regular expressions play a big role in my daily work. I really can’t imagine how difficult it would be for me to evaluate logs and generate reports for executive management without tools like these to make the job significantly easier and faster. I can easily scan massive business logs for key errors and use awk to generate an extract of the critical information I need to review. sed is a great tool when I need to make wholesale changes to configuration files as an example.

Part 4 gets you creating more real-world scripts. You’ll learn how to do things like archive logs. This is a big part of how our system is setup. We only keep a few days’ worth of logs “active” due to their size (we have an extremely high-volume application). Everything else gets compressed and archived to another location. You’ll also learn how to generate reports that can interact with the web, databases, etc.

There are a ton of books on scripting under Linux out there but this is one of my favorites.

# ./cli-book.sh 
I <3 the book 'Linux Command Line and Shell Scripting Bible'

OpenSSL

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openssl

This is a nice (and one of the few) printed resources available on the subject of OpenSSL. It’s a bit dated with a publishing date from 2009 but the general concepts are still the same. You’d certainly do well to read up on the latest versions of the toolkit since there have been a number of security remediations since this book was put out.

I won’t belabor the internals since you can read the table of contents online. I found it to be a good resource for such things as the OpenSSL command line interface, PKI info, and public key algorithms. Again, the latter is dated since it covers topics like Diffie-Hellman which is a weak cipher that most companies are dropping support for in their web tier’s cipher suite.

While you can find the latest info online, I sometimes like to have a physical reference that I can carry around with me. I guess I’m a little old school in this regard but as much as I love my tablet sometimes nothing beats having a real book in your hands.

sed & awk

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sed-awk

One of the tasks I find myself doing a lot these days is reviewing web and application logs. Working in a Windows environment with a product responsible for literally billions of transactions each year it’s difficult if not impossible to do this. A single days’ log can easily exceed the capabilities of many Windows text editors and those that can manage it aren’t as fast as Unix tools.

I don’t have a huge need for sed, the Unix stream editor, but I make extensive use of awk. grep is also another tool that plays an important role in my toolbox. Since awk and grep both make use of regular expressions it was nice to find a chapter dedicated to the subject.

There are three chapters dedicated to sed and four geared towards awk. Each utility also has its own quick-reference guide.

The book hasn’t been updated in some time (pre-2000) but let’s face it, not a whole lot changes with basic Unix functionality. I found the examples to be concise and well-suited to helping me grasp the concepts. The material goes much deeper than what I need for my daily tasks but it’s nice to know that a lot of power is at my fingertips should I need it.

If you’re new to ‘nix system administration or like me and trying to clear off the dust this is a great reference book. Grab a copy!

RHCSA/RHCE Study Guide

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rhcsa

This is my chosen text for my Red Hat cert. I’ve made it through chapter 4 so far and I’ll update this as I make progress. Unfortunately, while it appears to be a good text for the most part I do concur with a number of negative comments from Amazon and other sites.

Things do seem a bit disjointed. I find myself skipping forward and back again trying to set things up. For example, you’re expected to set the virtual machines up before you learn how to set them up. I do like the general layout and the exam and real-world tips that are broken out of the main text. I’m not put off by the issues enough to knock the book.