Sandra Henry-Stocker

Author Archives: Sandra Henry-Stocker

Using the Linux set command

The Linux set command allows you to change the value of shell options or to display the names and values of shell variables. Rarely used, it is a bash builtin, but is quite a bit more complicated than most builtins.If you use the command without any arguments, you will get a list of all the settings—the names and values of all shell variables and functions. Watch out though! You’ll end up with a torrent of output flowing down your screen. There are just short of 3,000 lines of output on my Fedora system:$ set | wc -l 2954 The top of the list looks like what you see below, but the output gets considerably more complicated as you move through it.To read this article in full, please click here

Using the Linux set command

The Linux set command allows you to change the value of shell options or to display the names and values of shell variables. Rarely used, it is a bash builtin, but is quite a bit more complicated than most builtins.If you use the command without any arguments, you will get a list of all the settings—the names and values of all shell variables and functions. Watch out though! You’ll end up with a torrent of output flowing down your screen. There are just short of 3,000 lines of output on my Fedora system:$ set | wc -l 2954 The top of the list looks like what you see below, but the output gets considerably more complicated as you move through it.To read this article in full, please click here

Linux turns 30

Something happened back in 1991 that dramatically changed the future of computing. Linus Torvalds, a Finnish-American software engineer, released the Linux kernel and the second version of the GNU General Public License (GPLv2). A good portion of the technology we use today would not be what it is had this not happened.It all started on August 25th of that year when Torvalds announced in a usenet post that he was working on a free OS and that it would be ready within a few months. He also said it "won't be big and professional like gnu," but that wasn't exactly how things turned out!The GPL The beauty of the Gnu GPL was that, instead of restricting what users can do with the Linux kernel, it maximized their rights. Richard Stallman, GNU founder, referred to these rights as the "four freedoms." They include the freedom to run, copy, study/improve and distribute. This was akin to turning the function of a license inside out.To read this article in full, please click here

Linux turns 30

Something happened back in 1991 that dramatically changed the future of computing. Linus Torvalds, a Finnish-American software engineer, released the Linux kernel and the second version of the GNU General Public License (GPLv2). A good portion of the technology we use today would not be what it is had this not happened.It all started on August 25th of that year when Torvalds announced in a usenet post that he was working on a free OS and that it would be ready within a few months. He also said it "won't be big and professional like gnu," but that wasn't exactly how things turned out!The GPL The beauty of the Gnu GPL was that, instead of restricting what users can do with the Linux kernel, it maximized their rights. Richard Stallman, GNU founder, referred to these rights as the "four freedoms." They include the freedom to run, copy, study/improve and distribute. This was akin to turning the function of a license inside out.To read this article in full, please click here

Choosing and changing your Linux shell

There are quite a few shells on Linux system and more that can be easily added. This post examines some of the more popular shells, how they differ and the files that contribute to their configuration.The default shell on most Linux systems is bash. Unless you make an effort, any user accounts added to the system will be assigned bash as their login shell. Bash has been around since 1989 and was meant to replace the Bourne shell (sh). In fact, if you take a look at /bin/sh, you'll probably find that it's nothing more than a symbolic link to /bin/bash.$ ls -l /bin/sh lrwxrwxrwx. 1 root root 4 Jan 25 2021 /bin/sh -> bash Summarizing your command-line usage on Linux   Popular Shells Some of the best and most popular shells include:To read this article in full, please click here

Choosing and changing your Linux shell

There are quite a few shells on Linux system and more that can be easily added. This post examines some of the more popular shells, how they differ and the files that contribute to their configuration.The default shell on most Linux systems is bash. Unless you make an effort, any user accounts added to the system will be assigned bash as their login shell. Bash has been around since 1989 and was meant to replace the Bourne shell (sh). In fact, if you take a look at /bin/sh, you'll probably find that it's nothing more than a symbolic link to /bin/bash.$ ls -l /bin/sh lrwxrwxrwx. 1 root root 4 Jan 25 2021 /bin/sh -> bash Summarizing your command-line usage on Linux   Popular Shells Some of the best and most popular shells include:To read this article in full, please click here

How password hashing works on Linux

You may know that passwords are hashed on Linux systems, and the hashes are stored in the restricted access /etc/shadow file. But did you know that you can also determine the hash method that was used and report the number of days since a password was last changed from this file as well?To look at a user record in the /etc/shadow file, run a command like this:$ sudo grep nemo /etc/shadow You should see a line that looks something like this:nemo:$6$FVYIIgcEcObSsUcf$FsSBlV9soVt.Owbd4xnvhlZzjx73ZBQQBT0WMyah6qcdnH91tBf9C4EaYbRtr7jKGETP/TwBNjyrDFqhvK0NV1:18698:7:90:7::: Viewing and configuring password aging on Linux   In spite of how long that line is, it's quite easy to parse. The first two fields in the lines of this colon-separated file store:To read this article in full, please click here

How password hashing works on Linux

You may know that passwords are hashed on Linux systems, and the hashes are stored in the restricted access /etc/shadow file. But did you know that you can also determine the hash method that was used and report the number of days since a password was last changed from this file as well?To look at a user record in the /etc/shadow file, run a command like this:$ sudo grep nemo /etc/shadow You should see a line that looks something like this:nemo:$6$FVYIIgcEcObSsUcf$FsSBlV9soVt.Owbd4xnvhlZzjx73ZBQQBT0WMyah6qcdnH91tBf9C4EaYbRtr7jKGETP/TwBNjyrDFqhvK0NV1:18698:7:90:7::: Viewing and configuring password aging on Linux   In spite of how long that line is, it's quite easy to parse. The first two fields in the lines of this colon-separated file store:To read this article in full, please click here

Using the Linux cut command to grab portions of lines from files

One surprisingly easy command for grabbing a portion of every line in a text file on a Linux system is cut. It works something like awk in that it allows you to select only what you want to see from files, enabling you to pull fields (regardless of the delimiter used), characters or bytes. To check on cut, you can ask about its version like this:$ cut --version cut (GNU coreutils) 8.32 Copyright (C) 2020 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Written by David M. Ihnat, David MacKenzie, and Jim Meyering. Selecting by field To illustrate how the cut command works, we'll first run commands using a sample "cities" file that contains details of the largest cities in the US in a tab-separated format. The lines in this file look something like what is shown below:To read this article in full, please click here

Using the Linux cut command to grab portions of lines from files

One surprisingly easy command for grabbing a portion of every line in a text file on a Linux system is cut. It works something like awk in that it allows you to select only what you want to see from files, enabling you to pull fields (regardless of the delimiter used), characters or bytes. To check on cut, you can ask about its version like this:$ cut --version cut (GNU coreutils) 8.32 Copyright (C) 2020 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Written by David M. Ihnat, David MacKenzie, and Jim Meyering. Selecting by field To illustrate how the cut command works, we'll first run commands using a sample "cities" file that contains details of the largest cities in the US in a tab-separated format. The lines in this file look something like what is shown below:To read this article in full, please click here

The many faces of awk

If you only use awk when you need to select specific fields from lines of text, you might be missing out on a lot of other services that the command can provide. In this post, we'll look at this simple use along with many other things that awk can do for you with enough examples to show you that the command is a lot more flexible than you might have imagined.Plucking out columns of data The easiest and most commonly used service that awk provides is selecting specific fields from files or from data that is piped to it. With the default of using white space as a field separator, this is very simple:To read this article in full, please click here

Viewing enabled and running services on Linux with systemctl

A vast majority of Linux systems these days are using systemd – a suite of programs aimed at managing and interconnecting different parts of the system. Systemd started replacing the init process back in 2014 and is now the first process that starts when most Linux systems boot. To get a quick peek, you can run a command like this, which verifies that process 1 is indeed systemd. On this system, two additional systemd processes are currently also running.$ ps -C systemd PID TTY TIME CMD 1 ? 00:00:59 systemd <=== 1244 ? 00:00:00 systemd 54429 ? 00:00:00 systemd To see a little more detail, try the command below. The blank within the quotes is meant to prevent related processes like systemd-journald from showing up in the list.To read this article in full, please click here

Viewing enabled and running services on Linux with systemctl

A vast majority of Linux systems these days are using systemd – a suite of programs aimed at managing and interconnecting different parts of the system. Systemd started replacing the init process back in 2014 and is now the first process that starts when most Linux systems boot. To get a quick peek, you can run a command like this, which verifies that process 1 is indeed systemd. On this system, two additional systemd processes are currently also running.$ ps -C systemd PID TTY TIME CMD 1 ? 00:00:59 systemd <=== 1244 ? 00:00:00 systemd 54429 ? 00:00:00 systemd To see a little more detail, try the command below. The blank within the quotes is meant to prevent related processes like systemd-journald from showing up in the list.To read this article in full, please click here

Commands to find Linux-package updates

Did you know that you can ask your Linux system to tell you what upgrades are available for the packages installed on it? You might be surprised by how many you’ll see, especially if you’re using the current release and don’t have your system set up for frequent or automatic updates.Updates play an important role in keeping your Linux systems secure and performing well. Since most packages are updated as fixes or improvements to the code become available, it’s hard to predict how many will show up on any particular day. (Note: Updates should be done when your system is not performing other important tasks.)Finding installed packages on Fedora Linux systems Fedora and related systems To check what updates are currently available for your Fedora or related system, use a command like this:To read this article in full, please click here

Commands to find Linux-package updates

Did you know that you can ask your Linux system to tell you what upgrades are available for the packages installed on it? You might be surprised by how many you’ll see, especially if you’re using the current release and don’t have your system set up for frequent or automatic updates.Updates play an important role in keeping your Linux systems secure and performing well. Since most packages are updated as fixes or improvements to the code become available, it’s hard to predict how many will show up on any particular day. (Note: Updates should be done when your system is not performing other important tasks.)Finding installed packages on Fedora Linux systems Fedora and related systems To check what updates are currently available for your Fedora or related system, use a command like this:To read this article in full, please click here

Find out what packages are installed on your Fedora system

If you're curious about how many packages are installed on your Fedora system or how you can check on them, you might be surprised at how much information you have at your fingertips. With just a few commands, you can find out just about anything you might want know about packages and the repositories they came from.What is a package? To get started, a Linux package is simply a collection of files that performs some particular tasks. For example, the popular image-editing program GIMP is installed as a package, and it includes all of the files that you need to do some impressive image editing. You can easily ask if GIMP is installed with a command like this:To read this article in full, please click here

Find out what packages are installed on your Fedora system

If you're curious about how many packages are installed on your Fedora system or how you can check on them, you might be surprised at how much information you have at your fingertips. With just a few commands, you can find out just about anything you might want know about packages and the repositories they came from.What is a package? To get started, a Linux package is simply a collection of files that performs some particular tasks. For example, the popular image-editing program GIMP is installed as a package, and it includes all of the files that you need to do some impressive image editing. You can easily ask if GIMP is installed with a command like this:To read this article in full, please click here

Installing fonts on your Linux system

Linux systems generally start out with a large number of fonts available, especially once you've installed LibreOffice. Even so, you might find yourself craving some highly distinctive or unusual fonts to add a special tone to some of your projects. If so, you're in luck. You're likely to find many thousands of free fonts available online – bold, italic, calligraphy, modern, script, hand lettering, cursive, brush lettering, symbolic and more.Here's a small sampling of popular sites that provide free fonts for easy downloading: dafont.com fontzone.net fonts.google.com fontspace.com You can also type "free fonts" into your favorite search engine. Expect to see a huge number of responses. Keep in mind that not all fonts are free, but plenty of free fonts are available, and they're easy to view, download and install.To read this article in full, please click here

Installing fonts on your Linux system

Linux systems generally start out with a large number of fonts available, especially once you've installed LibreOffice. Even so, you might find yourself craving some highly distinctive or unusual fonts to add a special tone to some of your projects. If so, you're in luck. You're likely to find many thousands of free fonts available online – bold, italic, calligraphy, modern, script, hand lettering, cursive, brush lettering, symbolic and more.Here's a small sampling of popular sites that provide free fonts for easy downloading: dafont.com fontzone.net fonts.google.com fontspace.com You can also type "free fonts" into your favorite search engine. Expect to see a huge number of responses. Keep in mind that not all fonts are free, but plenty of free fonts are available, and they're easy to view, download and install.To read this article in full, please click here

Backing up not just your data, but your productivity

Everyone knows that backups are important, but most of us tend to think of backups solely as the process of backing up our data files -- not necessarily our applications, our passwords or our computers. And, when we run into a serious problem that threatens our ability to get our work done, it just might be time to rethink what "backing up" should involve.Even if you have more than one computer at your disposal, it could easily be that only one of them is ready to help you with passwords you rarely use, provide access to your cloud backups, allow you to connect to the VPN you use for special projects, probe your network for problems or offer you a way to log into remote systems.To read this article in full, please click here

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