Click here to close now.


Linux Containers Authors: Elizabeth White, Pat Romanski, Flint Brenton, Liz McMillan, David Dodd

Related Topics: Linux Containers

Linux Containers: Article

Book Rookery: Wicked Cool Shell Scripts

101 different, fun, and useful shell scripts

In this installment of the Book Rookery, Martin C. Brown speaks with Dave Taylor, author of Wicked Cool Shell Scripts, about all the fun things you can do with shell scripts, whether you're running Linux, Mac OS X, or even a mainstream Unix system.

Can you tell us more about the book and what's inside?

For years I've picked up different programming books and lamented that they weren't fun or interesting. In the shell scripting world, it's even worse, with book after book talking about how to use an "if" statement, but none containing fun, hip, edgy, and even kind of wacky shell scripts that demonstrate all sorts of useful constructs and capabilities, but focus on being interesting. That's exactly what I've done with my book, though. I skip all the how-to and instructional material - after all, there's tons of stuff online nowadays anyway - and jump straight into the content, into listing and explaining 101 different, fun, and useful shell scripts.

What's your favorite script in the book?

Well, I had the most fun figuring out how to get the hangman game (#100) to work in as few lines as possible. A flashback to my early programming life when "toss in more RAM" wasn't the solution to a bloated app! In terms of scripts I use every day, the Mac OS X "titleterm" script (#96) is just part of my everyday activity, and I really like the concepts embodied in the bestcompress script (#38) too.

What's the biggest challenge about using shell scripts?

At the end of the day, shell scripts can only be so sophisticated. My rule of thumb is that if the script is growing to be more than 200 lines or so, it's probably time to migrate to a more sophisticated programming environment. For me, it's just about always a switch into C, but I'm an old-time Unix guy so C is second nature to me.

Shell scripts? Why wouldn't people use Perl?

Perl is a viable option, but what I think is really great about shell scripts is that everyone who uses Unix, Linux, or the terminal in Mac OS X already has 90% of the skills and expertise needed to begin creating their own shell scripts. Further, every line you type into a shell script can be easily tested at a command line, so I'll often start out a script by building a longer and longer pipe of commands, then eventually just copy and paste the entire command sequence into a file and poof a new script is born.

There are lots of different Unix-related books - including a number that you've written - and shell script books. Why another one?

Yes, I admit, I've written Teach Yourself Unix in 24 Hours, Teach Yourself Unix System Administration in 24 Hours, and Unix: Man or Beast?. No, wait. Only the first two titles. Sorry.

More seriously, there are lots of books on Unix and Unix-related topics, but they almost all focus on being either dry reference works (five lines and a table of flags for all 1,600 commands included with your OS, yawn) or on step-by-step tutorials (both of my books fall into this category, the "12,158 simple steps to becoming a Unix expert" style), but there are way too few books that are fun and entertaining, choosing to teach through example and through sheer enthusiasm for the environment. Wicked Cool Shell Scripts endeavors to fill this gap and so far, based on the tremendous response from the Unix and open source community, it's hitting its mark.

What's your take on the SCO lawsuit?

I've always wondered about people who put more energy into dragging innovators back to the status quo than in innovating themselves, and I think that's exactly what the SCO team is doing. Last I checked, they weren't doing anything interesting or innovative with Unix, so why would they want to slow the rest of us down? I won't go into conspiracy theories, but there sure are a lot of curious coincidences in this situation. Ultimately, though, I'd like to see the open source community cut SCO off at the knees: work with legal people to identify exactly what code SCO believes is questionable and then have swarms of programmers en masse toss that code out of the Linux code base and rewrite all of it "black box" so that SCO is left holding... nothing.

And in the meantime, innovative work with GNOME, the new kernel, autodiscovery of network resources, further levels of compatibility with samba, and other innovations are the lifeblood of our community, and they're what I'd like to see everyone continue to focus on developing.

Your book also covers Mac OS X: What OS do you run on your main computer, and how Unix-y do you think Mac OS X really is, when compared to a distro like Fedora?

I have always been a huge fan of Macs, I have to admit. I remember many, many years ago when I first used a 512K Mac (which was loaned to me by the Whole Earth ‘Lectronic Link, of all groups) and realized that it was a whole new way of looking at usability. This was after years of HP's Windex and X (and I remember when Motif was state of the art, gawd!), but it was so clearly superior... I've been a die-hard Mac person ever since and now I have four Macs in my office, including a brand-new dual G5 system. They not only run Mac OS X but my Terminal window is always open too. It's a fabulous pairing of all the power and capabilities of Unix with the GUI and graphical good karma of Aqua, the Mac OS X graphical environment. It rocks!

And finally, what editor do you like, emacs or vi?

Oh boy. I'm a "vi" person and have been forever. Thank you Bill for your work in this area, even if it was oh, so many years ago. However, kudos to the vim team too: vim finally fixes all the annoying limitations of vi.

About the Author
Dave Taylor is author of 15 computer books, including Learning Unix for Mac OS X Panther and Creating Cool Web Sites. You can learn more about Wicked Cool Shell Scripts - and read through the scripts - online at

More Stories By Martin C. Brown

Martin C. Brown is a former IT director with experience in cross-platform integration. A keen developer, he has produced dynamic sites for blue-chip customers, including HP and Oracle, and is the technical director of Now a freelance writer and consultant, MC, as he is better known, works closely with Microsoft as an SME; has a regular column on both and IBM's DeveloperWorks Grid Computing site; is a core member of the team; and has written books such as XML Processing with Perl, Python and PHP, and the Microsoft IIS 6 Delta Guide.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.

@ThingsExpo Stories
The Internet of Things is clearly many things: data collection and analytics, wearables, Smart Grids and Smart Cities, the Industrial Internet, and more. Cool platforms like Arduino, Raspberry Pi, Intel's Galileo and Edison, and a diverse world of sensors are making the IoT a great toy box for developers in all these areas. In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists discussed what things are the most important, which will have the most profound effect on the world, and what should we expect to see over the next couple of years.
Growth hacking is common for startups to make unheard-of progress in building their business. Career Hacks can help Geek Girls and those who support them (yes, that's you too, Dad!) to excel in this typically male-dominated world. Get ready to learn the facts: Is there a bias against women in the tech / developer communities? Why are women 50% of the workforce, but hold only 24% of the STEM or IT positions? Some beginnings of what to do about it! In her Day 2 Keynote at 17th Cloud Expo, Sandy Carter, IBM General Manager Cloud Ecosystem and Developers, and a Social Business Evangelist, wil...
PubNub has announced the release of BLOCKS, a set of customizable microservices that give developers a simple way to add code and deploy features for realtime apps.PubNub BLOCKS executes business logic directly on the data streaming through PubNub’s network without splitting it off to an intermediary server controlled by the customer. This revolutionary approach streamlines app development, reduces endpoint-to-endpoint latency, and allows apps to better leverage the enormous scalability of PubNub’s Data Stream Network.
Discussions of cloud computing have evolved in recent years from a focus on specific types of cloud, to a world of hybrid cloud, and to a world dominated by the APIs that make today's multi-cloud environments and hybrid clouds possible. In this Power Panel at 17th Cloud Expo, moderated by Conference Chair Roger Strukhoff, panelists addressed the importance of customers being able to use the specific technologies they need, through environments and ecosystems that expose their APIs to make true change and transformation possible.
Microservices are a very exciting architectural approach that many organizations are looking to as a way to accelerate innovation. Microservices promise to allow teams to move away from monolithic "ball of mud" systems, but the reality is that, in the vast majority of organizations, different projects and technologies will continue to be developed at different speeds. How to handle the dependencies between these disparate systems with different iteration cycles? Consider the "canoncial problem" in this scenario: microservice A (releases daily) depends on a couple of additions to backend B (re...
I recently attended and was a speaker at the 4th International Internet of @ThingsExpo at the Santa Clara Convention Center. I also had the opportunity to attend this event last year and I wrote a blog from that show talking about how the “Enterprise Impact of IoT” was a key theme of last year’s show. I was curious to see if the same theme would still resonate 365 days later and what, if any, changes I would see in the content presented.
Apps and devices shouldn't stop working when there's limited or no network connectivity. Learn how to bring data stored in a cloud database to the edge of the network (and back again) whenever an Internet connection is available. In his session at 17th Cloud Expo, Ben Perlmutter, a Sales Engineer with IBM Cloudant, demonstrated techniques for replicating cloud databases with devices in order to build offline-first mobile or Internet of Things (IoT) apps that can provide a better, faster user experience, both offline and online. The focus of this talk was on IBM Cloudant, Apache CouchDB, and ...
Container technology is shaping the future of DevOps and it’s also changing the way organizations think about application development. With the rise of mobile applications in the enterprise, businesses are abandoning year-long development cycles and embracing technologies that enable rapid development and continuous deployment of apps. In his session at DevOps Summit, Kurt Collins, Developer Evangelist at, examined how Docker has evolved into a highly effective tool for application delivery by allowing increasingly popular Mobile Backend-as-a-Service (mBaaS) platforms to quickly crea...
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York and Silicon Valley. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound cha...
Internet of @ThingsExpo, taking place June 7-9, 2016 at Javits Center, New York City and Nov 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with the 18th International @CloudExpo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world and ThingsExpo New York Call for Papers is now open.
The cloud. Like a comic book superhero, there seems to be no problem it can’t fix or cost it can’t slash. Yet making the transition is not always easy and production environments are still largely on premise. Taking some practical and sensible steps to reduce risk can also help provide a basis for a successful cloud transition. A plethora of surveys from the likes of IDG and Gartner show that more than 70 percent of enterprises have deployed at least one or more cloud application or workload. Yet a closer inspection at the data reveals less than half of these cloud projects involve production...
Cloud computing delivers on-demand resources that provide businesses with flexibility and cost-savings. The challenge in moving workloads to the cloud has been the cost and complexity of ensuring the initial and ongoing security and regulatory (PCI, HIPAA, FFIEC) compliance across private and public clouds. Manual security compliance is slow, prone to human error, and represents over 50% of the cost of managing cloud applications. Determining how to automate cloud security compliance is critical to maintaining positive ROI. Raxak Protect is an automated security compliance SaaS platform and ma...
In his keynote at @ThingsExpo, Chris Matthieu, Director of IoT Engineering at Citrix and co-founder and CTO of Octoblu, focused on building an IoT platform and company. He provided a behind-the-scenes look at Octoblu’s platform, business, and pivots along the way (including the Citrix acquisition of Octoblu).
Today air travel is a minefield of delays, hassles and customer disappointment. Airlines struggle to revitalize the experience. GE and M2Mi will demonstrate practical examples of how IoT solutions are helping airlines bring back personalization, reduce trip time and improve reliability. In their session at @ThingsExpo, Shyam Varan Nath, Principal Architect with GE, and Dr. Sarah Cooper, M2Mi’s VP Business Development and Engineering, explored the IoT cloud-based platform technologies driving this change including privacy controls, data transparency and integration of real time context with p...
There are over 120 breakout sessions in all, with Keynotes, General Sessions, and Power Panels adding to three days of incredibly rich presentations and content. Join @ThingsExpo conference chair Roger Strukhoff (@IoT2040), June 7-9, 2016 in New York City, for three days of intense 'Internet of Things' discussion and focus, including Big Data's indespensable role in IoT, Smart Grids and Industrial Internet of Things, Wearables and Consumer IoT, as well as (new) IoT's use in Vertical Markets.
The Internet of Things (IoT) is growing rapidly by extending current technologies, products and networks. By 2020, Cisco estimates there will be 50 billion connected devices. Gartner has forecast revenues of over $300 billion, just to IoT suppliers. Now is the time to figure out how you’ll make money – not just create innovative products. With hundreds of new products and companies jumping into the IoT fray every month, there’s no shortage of innovation. Despite this, McKinsey/VisionMobile data shows "less than 10 percent of IoT developers are making enough to support a reasonably sized team....
We all know that data growth is exploding and storage budgets are shrinking. Instead of showing you charts on about how much data there is, in his General Session at 17th Cloud Expo, Scott Cleland, Senior Director of Product Marketing at HGST, showed how to capture all of your data in one place. After you have your data under control, you can then analyze it in one place, saving time and resources.
Just over a week ago I received a long and loud sustained applause for a presentation I delivered at this year’s Cloud Expo in Santa Clara. I was extremely pleased with the turnout and had some very good conversations with many of the attendees. Over the next few days I had many more meaningful conversations and was not only happy with the results but also learned a few new things. Here is everything I learned in those three days distilled into three short points.
As organizations realize the scope of the Internet of Things, gaining key insights from Big Data, through the use of advanced analytics, becomes crucial. However, IoT also creates the need for petabyte scale storage of data from millions of devices. A new type of Storage is required which seamlessly integrates robust data analytics with massive scale. These storage systems will act as “smart systems” provide in-place analytics that speed discovery and enable businesses to quickly derive meaningful and actionable insights. In his session at @ThingsExpo, Paul Turner, Chief Marketing Officer at...
DevOps is about increasing efficiency, but nothing is more inefficient than building the same application twice. However, this is a routine occurrence with enterprise applications that need both a rich desktop web interface and strong mobile support. With recent technological advances from Isomorphic Software and others, rich desktop and tuned mobile experiences can now be created with a single codebase – without compromising functionality, performance or usability. In his session at DevOps Summit, Charles Kendrick, CTO and Chief Architect at Isomorphic Software, demonstrated examples of com...