Learn how to use a host of Linux commands in these 2-minute video tutorials from Sandra Henry-Stocker, author of the Unix as a Second Language blog.
In this Linux tip, learn how to use the bzcat and zcat commands. They allow you to look at the contents of files compressed with the bzip2 and gzip commands without having to uncompress the files first. Instead, these commands uncompress the files and send the output to standard out while the compressed files are left intact.
In this Linux tip, learn how to use bash shell's "debugging mode". It can help you pinpoint problems, especially in long or complicated scripts.
In this Linux tip, learn how to use exiftool. It's an app that you can install on your Linux system to pull metadata from jpg and png files. That metadata provides information such as the date the image was created or last modified, the image size in pixels and the image resolution.
In this Linux tip, learn how to use the help command. It's a command that provides useful information on bash "builtins". Those are commands that are built into, in other words "part of" the bash shell, not executables on their own.
In this Linux tip, learn how to use the traceroute command. It reports on the route taken to reach a remote system and provides timing details for each "hop" along the way (the time between routers).
In this Linux tip, learn how to use the tool called speedtest. It allows you to check the speed of your connection to your Internet provider. The tool is not installed on Linux systems by default, but is easy to find and install.
In this Linux tip, learn how to use the cat command. It's one of the most basic Linux commands, though it's used for two very different operations and not everyone is likely familiar with the second.
In this Linux tip, learn how to use the blkid command. It gives you a very useful view of block devices on your Linux system. First, it shows the devices (e.g., /dev/sda1). It shows the UUIDs (the 128 bit long "universally unique identifiers") associated with each of them, the block sizes, the file system types and, when available, the PARTUUIDs.
In this Linux tip, learn how to use the ps command. It displays information on running processes. If you want to see only certain processes, you can pass the output of a ps command to grep and specify what you want to see – for example, by username or process name.
In this Linux tip, learn how to use the nmap command. It's generally used for security auditing, but provides interesting and useful information on systems connecting to your local network.
In this Linux tip, learn how to use the more and less commands. They each allow you to browse the content of text files.
In this Linux tip, learn how to use the head and tail commands. They're basic commands that every Linux user should know. The head command is generally used to display the top lines in a text file, and the tail command shows the last lines in a file.
In this Linux tutorial, learn how to use the pi command. You probably won't need it very often, but, if you need to calculate pi to some arbitrary number of digits, you'll probably be surprised at how easy this can be.
In this Linux tip, learn how to use the rig command. It randomly generates name, address and phone number listings. It's useful when you're testing an application and need hundreds or thousands of addresses to make sure that it works correctly.
In this Linux tip, learn how to use the lslogins command. It provides some useful details on user accounts and logins. In its simplest form, you could just type lslogins, but without using sudo, some of the details you'll probably want to see won't be available because the files in which it's stored won't be readable.
In this Linux tip, learn how to use the autoexpect command. You can use it to build expect scripts that let you run scripts without having to provide answers interactively.
In this Linux tip, learn how to use expect. It's a tool that allows you to automate interactions with other scripts so that you can run them with a set of predefined answers.
In this Linux tip, learn how to use the ip neigh command. It works a lot like the arp command, but is considerably newer and still in active development. It provides network details – IP and MAC addresses -- along with an indication of each system's accessibility, but only for systems on your local network.
In this Linux tip, learn how to use the arping command. If it sounds like a combination of arp and ping, that should serve as a hint for how it works. It's a command that you can use to discover or probe systems on your local network.
In this Linux tip, learn how to use the pidof and pgrep commands. Both help you to find the process IDs (PIDs) of running processes. All you have to do is enter the command followed by the name of the process you're interested in.
In this Linux tip, learn how to use the screenfetch and neofetch commands. They're actually both bash scripts that you'll need to install if you haven't already. Once installed, without anything more than invoking them by name, either one will fetch important information from your system and display it alongside an ASCII representation of your Linux distribution's logo.
In this Linux tip, learn how to use the groupmod command. It’s a command that allows you to change the name of a user group. It does this by changing the entry in the /etc/group file (the line that connects the group name with the group number) and, thus, the group that shows up when you do a long file listing.
In this Linux tip, learn how to use the usermod command. It’s a command that allows you to make a lot of different changes to user accounts without having to edit configuration files.
In this Linux tip, learn how to use the factor command. It’s not one that you will likely need very often, but it can be very useful when you’re doing math on the command line. It provides the factors for any number you offer as an argument.
In this Linux tip, learn how to use the disown command. It provides a way to detach a process you’re running from your login session so that it isn’t killed (hung up on) when you log out. This means that the process can continue running after you log off.
In this Linux tip, learn how to use ranger. It’s a tool that allows you to easily browse files in a terminal window, but in a much different manner than you normally would on the command line.
In this Linux tip, learn how to use the tar command. It’s used to create (and extract contents from) file archives. The name “tar” stands for “tape archive” though “tape” is rarely part of the equation anymore.
In this Linux tip, we’re going to look at the lscpu command that provides a lot of information on your system’s CPU or CPUs.
In this Linux tip, learn how to use the unset command. It’s a command that removes an environment variable from your current login session.
In this Linux tip, learn how to use the look command. It allows you to easily pick out lines that begin with a given string from a file that you specify. The look command only matches beginnings of lines and doesn’t work with wild cards. For more complex searches, you’re better off using grep which isn’t limited to the beginnings of lines and has a lot more options.
In this Linux tip, learn how to use the df command. It reports on disk space. It’s important to check disk space from time to time to ensure that the system is not about to run out of space.
In this Linux tip, we’re going to look at the chkrootkit command. It’s a command that will examine your system for rootkits -- generally malicious software that enables unauthorized access to a system.
In this Linux tip, we’re going to look at the dig command. It’s generally used to troubleshoot problems with DNS (the domain naming system). Learn how to get information on what DNS can tell you about a system you’re hoping to connect to.
In this Linux tip, learn how to use the diff command. It’s one of a number of commands that can report on file differences. If the files are text files, the command will display the differences line by line. If they’re some other kind of files – image files or binaries, diff will only tell you whether the files are the same or different.
In this Linux tip, learn how to use the mkdir (make directory) command. It’s one of the basic commands that every Linux user ought to know, but there are some rules and a couple options that aren’t obvious.
In this Linux tip, learn how to use the uptime command. It tells us how long the system has been up and running – and provides some additional information as well.
In this Linux tip, learn how to use the finger command. It provides information on the selected user account. Once it’s installed, all you have to do to use the finger command is type “finger” followed by the username of the account you want to check.
In this Linux tip, we’re going to look at the && operator that provides a useful functionality in scripts. It represents an AND operator. But, first, to demonstrate how this operator works, we’ll run some simple commands on the command line.
In this Linux tip, learn how to use the OR (||) operator that provides a useful functionality in scripts. But, first, to demonstrate how this operator works, we’ll run a couple simple commands on the command line.
In this Linux tip, learn how to use the chage command. The name stands for “change age” and allows Linux admins to manipulate aging settings for user accounts – when passwords will must be changed or accounts will expire.
In this Linux tip, learn how to use the mv (move) command. It allows you to rename files, move files to other places in the file system or do both of those things at the same time.
How to use the script command to capture a series of commands that you run along with any output that they generate. This be helpful when you are documenting a process or testing a series of commands.
In this Linux tip, we’re going to look at xz command. It’s a relatively new command for compressing and decompressing files and works a lot like zip and bzip2. With xz, compressed files will take on the extension “xz”.
The at command allows you to schedule tasks to run at some other time – whether later that same day or way in the future. It allows you to schedule simple commands or complex scripts to run when you need them to run. Unlike the cron command, at is used to set up a one-time task.
The convert command allows you to manipulate image files on the command line and has a LOT of options. We’ll just look at a few of the many kinds of changes you can make.
The tac command displays text files “upside-down” — the last lines show up first and the first last. If you ever need to invert a file, you’ll find this quick and easy command ready to make the task easy.
In this Linux tip, learn to use the ln command, which can create either type of link on Linux systems.
In this Linux tip, learn how to use the pwd (present working directory) command, which can tell you where in the file system you are currently located.
In this Linux tip, learn how to use tabs for autocompletion. This practice means that you don’t have to type complete file names or even complete commands – and you’ll probably avoid some typos in the process.
In this Linux tip, learn how to use the umask command. You can use it to set the default permissions for files that you create.