Sandra Henry-Stocker
Author Archives: Sandra Henry-Stocker
- Home → Author's archive:
Sandra Henry-Stocker
0
Linux command history: Choosing what to remember and how
Linux history — the record of commands that you’ve used on the command line — can simplify repeating commands and provide some very useful information when you’re trying to track down how recent system or account changes might have come about.Two things you need to understand before you begin your sleuthing, however, are that the shell’s command memory can be selective and that dates and times for when commands were run are optional.Basic Linux history Let’s first look at how dates and times are recorded when commands are entered on the command line. By default, they are not. The history command simply provides a list of previously used commands. That’s all that is saved in the history file. For bash users, this information all gets stuffed into the .bash_history file; for other shells, it might be just .history.To read this article in full, please click here
0
Linux: To recurse or not
Linux and recursion are on very good speaking terms. In fact, a number of Linux command recurse without ever being asked while others have to be coaxed with just the right option. When is recursion most helpful and how can you use it to make your tasks easier? Let’s run through some useful examples and see.Easy recursion with ls First, the ls command seems like a good place to start. This command will only list the files and directories in the current or specified directory unless asked to work a little harder. It will include the contents of directories only if you add a -R option. It provides a -r option, but that option causes the listing to be in reverse order as shown below while -R delves into the various subdirectories.To read this article in full, please click here
0
What is a Linux “oops”?
If you check the processes running on your Linux systems, you might be curious about one called "kerneloops". And that’s “kernel oops”, not “kerne loops” just in case you didn’t parse that correctly. Put very bluntly, an “oops” is a deviation from correct behavior on the part of the Linux kernel. Did you do something wrong? Probably not. But something did. And the process that did something wrong has probably at least just been summarily knocked off the CPU. At worst, the kernel may have panicked and abruptly shut the system down.For the record, “oops” is NOT an acronym. It doesn’t stand for something like “object-oriented programming and systems” or “out of procedural specs”; it actually means “oops” like you just dropped your glass of wine or stepped on your cat. Oops! The plural of "oops" os "oopses".To read this article in full, please click here
0
What is a Linux ‘oops’?
If you check the processes running on your Linux systems, you might be curious about one called "kerneloops." And that’s “kernel oops,” not “kerne loops” just in case you didn’t parse that correctly.Put very bluntly, an “oops” is a deviation from correct behavior on the part of the Linux kernel. Did you do something wrong? Probably not. But something did. And the process that did something wrong has probably at least just been summarily knocked off the CPU. At worst, the kernel may have panicked and abruptly shut the system down.For the record, “oops” is NOT an acronym. It doesn’t stand for something like “object-oriented programming and systems” or “out of procedural specs”; it actually means “oops” like you just dropped your glass of wine or stepped on your cat. Oops! The plural of "oops" is "oopses."To read this article in full, please click here
0
It’s launch day for Sylabs: Promoting portable high-performance containers for Linux
Today is launch day for Sylabs — a new company focused on promoting Singularity within the enterprise and high-performance computing (HPC) environments and on advancing the fields of artificial intelligence (AI), machine/deep learning, and advanced analytics.And while it's launch day for Sylabs, it's not launch day for the technology it will be promoting. Singularity has already made great strides for HPC and has given Linux itself more prominence in HPC as it has moved more deeply into the areas of scientific and enterprise computing. With its roots at Lawrence Berkeley National Laboratory (Berkeley Lab), Singularity is already providing a platform for a lot of heavy-duty scientific research and is expected to move into many other areas, such as machine learning, and may even change the way some difficult analytical problems are approached.To read this article in full, please click here
0
The Linux ranger: What is it and how do you use it?
For those of us who cut our technical teeth on the Unix/Linux command line, the relatively new ranger makes examining files a very different experience. A file manager that works inside a terminal window, ranger provides useful information and makes it very easy to move into directories, view file content or jump into an editor to make changes.Unlike most file managers that work on the desktop but leave you to the whims of ls, cat and more to get a solid handle on files and contents, ranger provides a very nice mix of file listing and contents displays with an easy way to start editing. In fact, among some Linux users, ranger has become very popular.To read this article in full, please click here
0
Why use named pipes on Linux?
Just about every Linux user is familiar with the process of piping data from one process to another using | signs. It provides an easy way to send output from one command to another and end up with only the data you want to see without having to write scripts to do all of the selecting and reformatting. There is another type of pipe, however -- one that warrants the name "pipe", but has a very different personality. It's one that you may have never tried or even thought about -- the named pipe.One of the key differences between regular pipes and named pipes is that named pipes have a presense in the file system. That is, they show up as files. But, unlike most files, they never appear to have contents. Even if you write a lot of data to a named pipe, the file appears to be empty.To read this article in full, please click here
0
Why you should use named pipes on Linux
Just about every Linux user is familiar with the process of piping data from one process to another using | signs. It provides an easy way to send output from one command to another and end up with only the data you want to see without having to write scripts to do all of the selecting and reformatting.There is another type of pipe, however, one that warrants the name "pipe" but has a very different personality. It's one that you may have never tried or even thought about — the named pipe.Also read: 11 pointless but awesome Linux terminal tricks One of the key differences between regular pipes and named pipes is that named pipes have a presense in the file system. That is, they show up as files. But unlike most files, they never appear to have contents. Even if you write a lot of data to a named pipe, the file appears to be empty.To read this article in full, please click here
0
Get ready to use Linux containers
One of the most exciting things to happen in the Linux world in the past few years is the emergence of containers — self-contained Linux environments that live inside another OS and provide a way to package and isolate applications.They're not quite virtual systems, since they rely on the host OS to operate, nor are they simply applications. Dan Walsh from Red Hat has said that on Linux, "everything is a container," reminding me of the days when people claimed that everything on Unix was a file. But the vision has less to do with the guts of the OS and more to do with explaining how containers work and how they are different than virtual systems in some very interesting and important ways.To read this article in full, please click here
0
2018 state of resilience: the pressure is on
As we swerve onto the runway in 2018, IT leaders are finding themselves under increased pressure to ensure security, high availability and disaster recovery for the applications and systems under their care. The results of several surveys underscore the concerns of nearly 6,000 IT professionals around the globe.These surveys, conducted in 2017 by Vision Solutions, now part of Syncsort, collected responses from 5,632 professionals to determine their key business continuity concerns and their strategies for addressing high-profile hacking attacks, data breaches, disruptive natural disasters and escalating storage and data accessibility needs. The results highlight their areas of greatest concern and the key initiatives they are putting into place for moving forward.To read this article in full, please click here
0
2018 state of resilience: the pressure is on
As we swerve onto the runway in 2018, IT leaders are finding themselves under increased pressure to ensure security, high availability and disaster recovery for the applications and systems under their care. The results of several surveys underscore the concerns of nearly 6,000 IT professionals around the globe.These surveys, conducted in 2017 by Vision Solutions, now part of Syncsort, collected responses from 5,632 professionals to determine their key business continuity concerns and their strategies for addressing high-profile hacking attacks, data breaches, disruptive natural disasters and escalating storage and data accessibility needs. The results highlight their areas of greatest concern and the key initiatives they are putting into place for moving forward.To read this article in full, please click here
0
2018 state of resilience: The pressure is on
As we swerve onto the runway in 2018, IT leaders are finding themselves under increased pressure to ensure security, high availability and disaster recovery for the applications and systems under their care. The results of several surveys underscore the concerns of nearly 6,000 IT professionals around the globe.These surveys, conducted in 2017 by Vision Solutions, now part of Syncsort, collected responses from 5,632 professionals to determine their key business continuity concerns and their strategies for addressing high-profile hacking attacks, data breaches, disruptive natural disasters, and escalating storage and data accessibility needs. The results highlight their areas of greatest concern and the key initiatives they are putting into place for moving forward.To read this article in full, please click here
0
2018 state of resilience: The pressure is on
As we swerve onto the runway in 2018, IT leaders are finding themselves under increased pressure to ensure security, high availability and disaster recovery for the applications and systems under their care. The results of several surveys underscore the concerns of nearly 6,000 IT professionals around the globe.These surveys, conducted in 2017 by Vision Solutions, now part of Syncsort, collected responses from 5,632 professionals to determine their key business continuity concerns and their strategies for addressing high-profile hacking attacks, data breaches, disruptive natural disasters, and escalating storage and data accessibility needs. The results highlight their areas of greatest concern and the key initiatives they are putting into place for moving forward.To read this article in full, please click here
0
Improved telepresence — in your face with the new BeamPro 2
For those of us intrigued by telepresence technology, the new BeamPro 2 might be just what Santa should have left under our trees – except, well, that it wouldn’t have fit. But on other scales, the release of this new and improved device promises more realistic visits with colleagues, customers, patients, and others with respect to video, audio and maneuverability.Available this summer, The BeamPro 2 provides better face-to-face interactions with its enlarged multi-touch display and vertical screen height adjustment. It has been engineered to move more easily around crowded spaces with its wide angle cameras and additional sensors for detecting obstacles. It also provides improved audio and video.To read this article in full, please click here
0
Improved telepresence: In your face with the new BeamPro 2
For those of us intrigued by telepresence technology, the new BeamPro 2 might be what Santa should have left under our trees — except, well, that it wouldn’t have fit. But on other scales, the release of this new and improved device promises more realistic visits with colleagues, customers, patients, and others with respect to video, audio and maneuverability.Available this summer, the BeamPro 2 provides better face-to-face interactions with its enlarged multi-touch display and vertical screen height adjustment. It has been engineered to move more easily around crowded spaces with its wide-angle cameras and additional sensors for detecting obstacles. It also provides improved audio and video.To read this article in full, please click here
0
Red Hat responds to the Intel processor flaw
How are the Linux vendors addressing the recently-exposed Intel processor flaw? I asked Red Hat and got some solid answers.What is the nature of the problem? Discovered some time ago, but only just yesterday brought into public view, the CPU flaw allows an attacker to bypass restrictions to gain access to privileged memory (which should be inaccessible) -- possibly stealing sensitive information from computer systems, mobile devices, and cloud deployments. There are actually two problems and they've been dubbed "Meltdown" and "Spectre". They potentially affect 90% of computer servers and virtually every Intel microprocessor.The Meltdown flaw is specific to Intel while Spectre is a design flaw that has been used by many processor manufacturers for decades.To read this article in full, please click here
0
Linux resolutions for 2018
It’s always a good idea to start a new year with renewed intentions to be even better users and administrators of our Linux systems. For auld lang syne (for the sake of old times), let's touch on some of the ways we might improve our system practices in 2018.1: Automate more of the boring stuff There are several good reasons to turn tedious tasks into scripts. The first is to make them less annoying. The second is to make them less error-prone. And the last is to make them easier to turn over to new team members who haven't been around long enough to be bored. Add a small dose of meaningful comments to your scripts and you have a better chance of passing on some of your wisdom about how things should be done.To read this article in full, please click here
0
Squinting at ASCII on Linux
Back when I started working with computers, understanding the nature of ASCII was exciting. In fact, just knowing how to convert binary to hex was fun.That was a lot of years ago — berfore ASCII had yet reached drinking age — but character encoding standards are as important as ever today with the internet being so much a part of our business and our personal lives. They're also more complex and more numerous than you might imagine. So, let’s dive into some of the details of what ASCII is and some of the commands that make it easier to see coding standards in action.Why ASCII? ASCII came about to circumvent the problem that different types of electronic systems were storing text in different ways. They all used some form of ones and zeroes (or ONs and OFFs), but the issue of compatibility became important when they needed to interact. So, ASCII was developed primarily to provide encoding consistency. It became a standard in the U.S. in 1960. Initially, ASCII characters used only 7 bits. Some years later, ASCII was extended to use all 8 bits in each byte.To read this article in full, please click here
0
How to extract content from compressed files on Linux
The easiest way to extract the content of compressed files (and compressed archives) on Linux is to prepare a script that both recognizes files by type and uses the proper commands for extracting their contents. Almost every compressed file will have an easily recognizable file extension — .Z, .gz, .tgz etc. And while the commands aren’t very complex, there sure are a lot of them and many options for each.So, why not attack the problem with a script that saves your precious brain cells for more challenging work? Let's look at an example that you might want to consider.To read this article in full, please click here
0
Peeking into your Linux packages
Do you ever wonder how many thousands of packages are installed on your Linux system? And, yes, I said "thousands." Even a fairly modest Linux system is likely to have well over a thousand packages installed. And there are many ways to get details on what they are.First, to get a quick count of your installed packages on a Debian-based distribution such as Ubuntu, use the command apt list --installed like this:$ apt list --installed | wc -l 2067 This number is actually one too high because the output contains "Listing..." as its first line. This command would be more accurate:$ apt list --installed | grep -v "^Listing" | wc -l 2066 To get some details on what all these packages are, browse the list like this:To read this article in full, please click here