Recently I wrote a review for the Linux Journal Web
site on the Purism Librem 15 laptop. The goal of this laptop is to provide a piece of modern hardware that
can run 100% free software not just for the OS, but also all device drivers
and firmware up to and including the BIOS. more>>
I admit it, some tools confuse me. I know they must be amazing, because
programs don’t get popular by being dumb (well, reality TV, but that’s
another story). I have the same sort of confusion with Vagrant that I
have with Wine, Docker, Chef and countless other amazing tools people
constantly rave about. So in this article, I’m going to break down Vagrant into
its simplest form.
The last three days, I’ve created a small bash script that outputs some important server health information. I’m using this script for displaying the server health on my Raspberry Pi at home. I’ll buy one of these official 7 inch touch screen displays for the Raspberry Pi and then show these health information on it. […]
Connect to the Internet, work with your files, lock your workspace,
listen to music and do so much more with the
help of Bluetooth technology.
Gerhard Gappmeier has submitted a really cool and useful bash script, that he is using for years now. It is very helpful for developers. This scripts can replace file headers from C/C++/JAVA header and source files. Often it’s necessary to replace the license conditions in multiple source files, update the copyright year, or simply make […]
The following script was written by me to be able to get the really used amount of memory for one single application. Since it isn’t that easy to get the used memory through “top” or “ps” or similar tools, this may be helpful for somebody. The output is in megabytes and looks like this:
The following small script was written by me in order to be able to simply cut parts from very large text files. It is very useful for database administrators to for example cut the SQL statements for creating and restoring one single table from a really large SQL dump. For this you would need to […]
How to Do That Thing You Do
I love to learn. I’ve always been a learner, so grade school and
college were both extremely enjoyable for me. more>>
Most of you probably have heard of Wireshark, a very popular and capable
network protocol analyzer. What you may not know is that there exists a
console version of Wireshark called tshark. The two main advantages of
tshark are that it can be used in scripts and on a remote computer through
an SSH connection. more>>
I’ve been promising my 11-year-old for a long time now that I’d write a
program that would let you build custom word searches based on a list of
words given by the user. I wrote one years and years ago in C, but since I
can’t find that code any more and wanted to tackle another interesting
project for this column, that’s what I’m going to look at herein.
Containers can be considered the third wave in service provision after
physical boxes (the first wave) and virtual machines (the second
wave). Instead of working with complete servers
(hardware or virtual), you
have virtual operating systems, which are far more lightweight. more>>
In my last two articles, I looked at the Django Web application
framework, written in Python. Django’s documentation describes it as
an MTV framework, in which the acronym stands for model, template
Through the years, I have settled on maintaining my sensitive data in
files that I then encrypt asymmetrically. Although I take care to harden my
system and encrypt partitions with LUKS wherever possible, I want to secure my
most important data using higher-level tools, thereby lessening dependence on
the underlying system configuration. more>>
The target vehicle for this project is a vintage intercity transport bus (think
Greyhound) whose instrument panel was sparse and mostly nonfunctional.
The speedometer cable was twisted off some place back in 40 feet of
and the fuel sensor had sunk long ago. What I wanted was an instrument
panel more in line with modern practice.
The Raspberry Pi has been very popular among hobbyists and educators
ever since its launch in 2011. The Raspberry Pi is a credit-card-sized
single-board computer with a Broadcom BCM 2835 SoC, 256MB to 512MB of RAM,
USB ports, GPIO pins, Ethernet, HDMI out, camera header and an SD card
After years of making it clear that I’m not a developer in just
about every article I’ve written here at Linux Journal, I do have a
confession to make. I can write the “Hello World” equivalent in almost
every programming language out there. In assembly, it might have been
“1+1”, but my lack of advanced skills should be evident. more>>
Would you change what you said on the phone, if you knew someone malicious was listening?
Whether or not you view the NSA as malicious, I imagine that after reading the NSA coverage on
Linux Journal, some of you found yourselves modifying your behavior. The same thing
happened to me when I started deploying servers into a public cloud (EC2 in my case).
In my last article (February 2015), I explained how to create a simple
Django project (“atfproject”) and
inside that, create a simple application (atfapp). The
application worked in that if you went to the URL
you got the text “hello, Reuven”.
In last month’s issue, I talked about Linux permissions (see “It’s
Better to Ask Forgiveness…” in the May 2015 UpFront section).
I could have
covered SUID, GUID and sticky bit in the same article, but it seemed
like a lot to cover in one sitting. more>>
The first time I used vi was in a college programming course. It was the
default editor on the computer lab’s UNIX systems we used to compile our
assignments. I remember when our professor first introduced vi and
explained that you used the hjkl keys to move your cursor around instead of
the arrow keys. more>>
With Hiera, you can externalize your systems’ configuration data and
easily understand how those values are assigned to your servers. With
that data separated from your Puppet code, you then can encrypt sensitive
values, such as passwords and keys.
…than to understand Linux permissions! Honestly though, that’s
not really true. Linux permissions are simple and elegant, and once you
understand them, they’re easy to work with. Octal notation gets a little funky,
but even that makes sense once you understand why it exists.
Users and Groups:
Every linux adminsitrator knows this problem: You have a very, really very big file like a great MySQL dump and now you need to cut a small part from it, like the create table definition of one single table. It is quiet simple to find the line numbers that you want to cut from the […]