Advice for everyday Unix systems administration and some clever ways to approach more challenging problems.
If you work with file archives that come in many different "flavors", you might find this little trick to be a handy one.
A waterproof safe dropped into the deepest part of the ocean is not as 'secure' as it is useless.
Using fail2ban to dynamically block attackers
Making use of HTTP status codes to make everyday life run more smoothly
One way to restrict what users can do on your Linux systems is by using rbash -- the restricted Bourne Again shell -- but only if you take some additional steps to ensure that your users can't break out of their cells
Black Hat Python: Python Programming for Hackers and Pentesters Justin Seitz no starch press, 2015
The Unix command line provides numerous ways to make our work easier. Here are 15 "tricks" that I use often to make quick work of various tasks.
2014 drawing to a close presents us all with an opportunity to consider what we might do better in the year to come. And, hint hint, it's not all about working harder.
Building apps for Android or thinking about it? This book on Android Security is a must read.
I've heard that those who can't remember history are condemned to repeat it but for Unix users, repeating history is not only advantageous, it's something of a skill.
Sometimes, the simplest command line challenges can leave you leaning over your keyboard with that "What just happened?" look on your face. There's (almost) always a good explanation, but it might take a little head scratching before ....
If you want to learn one of the most effective modern tools for web site development -- quickly, easily and well -- this book is for you. This crash course will take you from concepts to deploying web applications quickly and securely if you just si....
Unix errors often seem cryptic and sometimes even obtuse, but they're actually well designed and useful. A little insight into the whys and hows of common error messages might help you appreciate not just error messages, but why you're bum....
The name might make you feel a little spaced out, but the tool could provide you with a clear view of the outer reaches of your security domain.
Breaking out of the traditional owner/group/world way of managing file permissions, setfacl and getfacl provide a lot of flexibility and fair share of complexity.
The chage command allows you to easily expire user passwords, but how it works depends in part on how your accounts are set up to begin with.
Log files on Unix systems can easily grow to hundreds of thousands or even millions of lines. Here's a simple way to pluck out every Nth line.
For more than 20 years, a very serious bug in our beloved bash simply went unnoticed. What have we learned?
Log file rotation of Unix systems just sort of happens ... or does it? You may have a lot more options that you've ever imagined.
Tired of the ls command and want to see more interesting information on your files? Try stat!
One of the best ways to write scripts quickly and effectively is to never start from scratch.
When building bash scripts, a little consistency and care can pay off in the long run.
Traceroute is still a great tool, but mtr ("my traceroute") provides even more insights when you're looking into network routing problems.
The ethtool command can tell you a lot more about your ethernet interfaces than ifconfig ever will.
The /proc file system brings the processes on your Unix systems into view in some very useful ways, but only if you take the time to cd over to /proc and see all it can tell you.
Think you know what's happening on your network? Pull out tcpdump and you might be surprised how much it can tell you.
If you find your thrill delving into the networking side of Unix, you'll find that there are lots of commands to give you all the insights you might want.
One of the most important things you can do for security on a Unix system is restrict root access. But the issue is more complicated than who knows root's password.
Don't forget that tomorrow is Sysadmins Day -- a good day to show love to the folks who save your butt again and again when you mess up your computer. Here are some poems, tailored just for them.
Memory is one of the most important parts of your Unix system for performance. Let's look at some commands that will tell you what you need to know about the memory on the systems you manage is being used.
It's no longer just a matter of "Can you remember them?". Your passwords can serve as a form of catharsis or a way to remind yourself of where you want to be in life.
The top command is one of the most commonly used tools for getting a quick glimpse at performance, but it's rarely used to capture performance in the middle of the night. With just a little effort, however, it could become one of your favorite t....
The diff command can be your best friend when you’re troubleshooting problems on a Unix system, but are you using it effectively as you could?
Most everything you need to know to get started as a penetration tester in less than 500 pages? This book provides a very practical hands-on introduction to the art of hacking. But you will need to sit yourself down and let your fingers get a lot of ....
If you're going to be shooting out email messages as part of your job, you really ought to think about your recipients' reactions. Here are some of the least reader-friendly subject lines and why they likely won't work.
History repeats itself and so will system problems if you don't get to the root of what is causing them.
Discovering hosts and services isn't just something that hackers do. A good sysadmin needs to work with an up-to-date view of the systems they manage or those they want to keep an eye on.
Long before the Internet, the web, flat screen monitors, Google, Facebook, languages like Python and Ruby, interactive games, and wireless just about anything, some of us were fascinated by what we could do with large, clunky systems that today look ....
Before you try to try to get your Unix system collecting data from a database that someone else manages, you might want to run some simple tests from a Windows desktop. Yes, I said "Windows".
Keeping an up-to-date inventory of your Unix servers can be less painful if you throw a bunch of helpful Linux commands into a script that you run periodically.
If you've been managing Unix systems for any length of time, you've undoubtedly noticed that the systems you manage develop personalities and start to feel like family.
Get yourself a $35 computer, a copy of this book, and you will likely discover a side of computing that expands your view of what computing is all about.