2-Minute Linux Tips

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.

Ep.154
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2-Minute Linux Tips: How to use the iotop command

In this Linux Tip, learn to use the iotop command, which helps to monitor I/O usage for your disks.

Ep.154
Nov 22, 2024 1 mins
Operating Systems
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Ep.153
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How to use the W diff command

In this Linux Tip, you'll learn to use the W diff command, which displays the content of compared files, showing one copy if the files are identical.

Ep.153
Nov 15, 2024 1 mins
Operating Systems
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Ep.152
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2-Minute Linux Tips: How to use the sdiff command

In this Linux Tip, you'll learn to use the sdiff command, which compares text files side by side.

Ep.152
Nov 14, 2024 1 mins
Operating Systems
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Ep.151
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How to use the diff3 command

In this Linux tip, we’re going to look at the diff3 command. It’s similar to the diff command, but allows you to compare the contents of three text files instead of just two. In addition, the formatting of the output makes it easy to understand how the files are different. In this command, we compare three simple text files: $ diff3 file1 file2 file3 ====3 1:1,3c 2:1,3c Kids, the seven basic food groups are gum, puff pastry, pizza, pesticides, antibiotics, 3:1,3c Kids, the six basic food groups are fruits, vegetables, grains, protein and dairy The ====3 included in the output below means that the third file is different. If all the files were different, this would show just ====. The output then shows the differences between the first two files (which are the same) and the third which has a different third line. Looking at file3, we can see a 4th line. This line didn’t show up in the diff3 output because it’s the same in all three files. The diff3 command only displays differences.

Ep.151
Sep 26, 2024 2 mins
Engineer
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Ep.150
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How to use the colordiff command

In this Linux tip, we’re going to look at the colordiff command. It displays the differences between two files like the diff command, but adds color whenever the content is different. This first command has no output because the files are the same. $ colordiff file1 file2 Now let’s compare two files with a difference. $ colordiff file1 file3 1,3c1,3 Kids, the seven basic food a groups are gum, puff pastry, pizza, pesticides, antibiotics, --- Kids, the six basic food groups are fruits, vegetables, grains, protein and dairy Notice how the colors highlight the differences between the two files. Here’s the full content of file3 showing the only line the files share (line 4). $ cat file3 Kids, the six basic food groups are fruits, vegetables, grains, protein and dairy and milk duds!!

Ep.150
Sep 24, 2024 1 mins
Engineer
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Ep.149
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How to use the CMP command

In this Linux tip, we’re going to look at the cmp command. It’s a command that allows you to compare the content of two text files. If the files that you are comparing are identical, there will be no output.

Ep.149
Sep 17, 2024 2 mins
Engineer
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Ep.148
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How to determine if a string contains a regular expression

In this Linux tip, we’ll take a look at how you can test whether a string or variable includes some regular expression or substring you want to test for.

Ep.148
Sep 3, 2024 2 mins
Engineer
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Ep.147
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How to use the grep command

In this Linux tip, we’ll look at how you can use the grep command to look for more than one value in a single command. This can be useful when you want to select lines of two forms, but ensure they will appear in the same order as they do in the file.

Ep.147
Aug 29, 2024 2 mins
Engineer
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Ep.145
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How to see how many days passed since the beginning of the Linux epoch

In this Linux tip, we’re going to look at a command that allows you see how many days have passed since the beginning of the Linux epoch – Jan 1, 1970. To begin, we use the command below to display the number of seconds since the epoch began on Jan 1, 1970.

Ep.145
Jul 15, 2024 1 mins
Operating Systems
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Ep.144
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How to use the pv command

In this Linux tip, we’re going to take a look at the pv (pipe viewer) command that can provide some reassuring visual feedback when some process you will be running might take a long time to complete. In this simple example, everything will run very quickly, but this kind of output for long-running commands will let you know that the process isn’t “hanging” and that, instead, progress is being made.

Ep.144
Jul 9, 2024 2 mins
Operating Systems
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Ep.143
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How to use the stat command

In this Linux tip, we look at the stat command. Like the ls command, stat displays important details about a file – like permissions and ownership, but in a much different and surprisingly useful way.

Ep.143
Jun 27, 2024 2 mins
Operating Systems
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Ep.142
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The SL command easter egg

In this Linux tip, we’re going to look at what happens on many Linux systems when someone mistypes “ls” – typing “sl” instead. What you can anticipating seeing (provided the sl command has been installed with one of the commands shown below is a rather entertaining image – a steam locomotive that drives across your screen.

Ep.142
Jun 27, 2024 1 mins
Operating Systems
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Ep.141
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How to use the shuf command

In this Linux tip, we're going to take a look at the shuf command.

Ep.141
Jun 27, 2024 1 mins
Operating Systems
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Ep.140
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How to use the chmod command

In this Linux tip, we’ll take a look at the chmod command for changing permissions on a Linux file.

Ep.140
Jun 27, 2024 2 mins
Operating Systems
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Ep.139
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How to use the apropos command

In this Linux tip, we’ll take a look at the apropos command and how it can help you identify commands that you want to use. The meaning of the word apropos is “fitting and to the point”. When you use this command on the Linux command line, you can expect it to generate a list of commands that fit what you’re asking about.

Ep.139
Jun 27, 2024 2 mins
Operating Systems
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Ep.138
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How to use the shred command

In this Linux tip, we’re going to examine the shred command – a command that allows you to overwrite the content of a file with randomized data so that it is no longer readable and basically impossible to recover.

Ep.138
Jun 27, 2024 2 mins
Operating Systems
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Ep.137
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How to access directories in Linux

In this Linux tip, we’re going to look at directories on Linux – basically folders that are set up to house related files. Whenever you use a command like “ls dirname” for a directory, you will see a list of the files it contains.

Ep.137
Jun 27, 2024 2 mins
Operating Systems
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Ep.136
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How to see login activity

In this Linux tip, we’re going to examine some commands for generating reports on who is logging into a Linux server. The data for login activity is stored in the /var/log/wtmp file.

Ep.136
Jun 27, 2024 2 mins
Operating Systems
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Ep.135
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How to use the cal command

In this Linux tip, we’re going to look at the cal (calendar) command. This command allows you to display a calendar for a month or even for a year. Using a command like this, you display a calendar for the current month with the today highlighted.

Ep.135
Jun 27, 2024 1 mins
Operating Systems
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Ep.134
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How to use the shadow file format in Linux

In this Linux tip, we’re going to take a quick look at the /etc/shadow file on Linux systems. It contains a lot of useful information pertaining to user accounts – and is a file that can only be viewed or changed with root or sudo access.

Ep.134
Jun 27, 2024 2 mins
Operating Systems
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Ep.133
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How to source files on the Linux command line

In this Linux tip, we’ll look at how you can “source” files on the Linux command line. “Sourcing” means reading the file and running the commands that it contains – even if the file isn’t set up with execute permissions. There are two ways to do this. One involves using the source command as in the command “source myfile”. The second way is to replace the word “source” with a dot as in “. myfile”. The results will be the same.

Ep.133
Jun 27, 2024 2 mins
Operating Systems
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Ep.132
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Timestamps in Linux

In this Linux tip, we’re going to look at timestamps used on Linux systems. There are actually three of them and they represent the date and time that the file was last accessed, the time it was last modified and the time it was last changed. Modified and changed may suggest the same thing but “modified” implies content changes and “changed” will capture other changes – like permissions.

Ep.132
Jun 27, 2024 2 mins
Operating Systems
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Ep.131
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How to use the who command

In this Linux tip, we take a look at the who command – a command that tells you who is logged into the system. If you’re working on a Linux server, you might see that a number of people are logged in. The who command also tells you where the users are logged in from.

Ep.131
Jun 27, 2024 2 mins
Operating Systems
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Ep.130
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How does Linux and Unix store dates and times?

In this Linux tip, we’re going to take a look at epoch time – the way Unix and Linux systems store dates and times. Unix and Linux systems don’t store dates and times in a way that includes months, days and years in the way that you see them displayed on the system. Instead, they are stored as the number of seconds since the beginning of 1970. While this method of recording dates and times may seem odd, it requires little storage space and is consistently interpreted.

Ep.130
Jun 27, 2024 2 mins
Operating Systems
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Ep.129
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How to use the help command

In this Linux tip, we’re going to look at the –help option that is available with most Linux commands. Type a command name followed by the argument --help and you will get some information on the command and its options.

Ep.129
Jun 27, 2024 2 mins
Operating Systems
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Ep.128
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How to locate files based on various criteria

This Linux tip explains how to locate files based on several different criteria.

Ep.128
Jun 27, 2024 2 mins
Operating Systems
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Ep.127
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How to use long file listings

In this Linux tip, we take a look at long file listings – using the ls -l command to examine the provided details.

Ep.127
Jun 27, 2024 3 mins
Operating Systems
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Ep.126
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How to empty a file in Linux without deleting the file

In this Linux tip, we’re going to look at the easiest way to empty a file of its contents while not deleting the file. All you have to do is point a greater-than sign at a file and its contents are removed.

Ep.126
Jun 27, 2024 1 mins
Operating Systems
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Ep.125
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How to use if-then-else commands

In this Linux tip, we’re going to look at if-then-else and if-then-elsif commands. Both are frequently used in bash scripts to make running a series of commands much easier.

Ep.125
Jun 27, 2024 2 mins
Operating Systems
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Ep.124
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How to use case statement commands

In this Linux tip, we’re going to look at case statements – commands that are used in bash scripting to run shell commands depending on the value of some variable or command output.

Ep.124
Jun 27, 2024 2 mins
Operating Systems
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Ep.123
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How to use the greater than symbols

In this Linux tip, we’re going to look at how the greater than symbols work. Both allow you to save the output of Linux commands to files, but they’re not the same.

Ep.123
Jun 27, 2024 2 mins
Operating Systems
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Ep.122
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How to use the touch command

In this Linux tip, we’ll look at the touch command. It’s a command that can be used to create an empty file or update the time stamp on an existing file.

Ep.122
Jun 27, 2024 1 mins
Operating Systems
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Ep.121
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How to use the whoami command

In this Linux tip, we’ll look at the whoami command. It’s a very simple command that displays your username.

Ep.121
Jun 27, 2024 2 mins
Operating Systems
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Ep.120
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How to calculate factorials in Linux

In this video transcript, Sandra Henry-Stocker discusses how to calculate factorials on a Linux system. She explains that factorials are the multiplication of numbers starting with a specified number and decreasing incrementally until reaching 1. To calculate factorials on Linux, you can use commands like "seq" and "bc." The "seq" command is used to generate a list of sequential numbers, and the "bc" command is used to perform the factorial calculations.

Ep.120
Nov 2, 2023 2 mins
Operating Systems
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Ep.119
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How to use the nohup command

In this episode, Sandra Henry-Stocker, author of the "Unix as a Second Language" blog on NetworkWorld, explores the use of the "nohup" (no hangup) command in Linux.

Ep.119
Oct 31, 2023 2 mins
Operating Systems
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Ep.118
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How to use date command options

In this episode, Sandra Henry-Stocker, the author of the "Unix as a Second Language" blog on NetworkWorld, introduces various ways to use the Linux date command. She demonstrates how to use the "date" command to display the current day of the week, date, time, and time zone.

Ep.118
Oct 26, 2023 2 mins
Operating Systems
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Ep.117
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How to increment and decrement numeric variables in bash

In this Linux tip, we’re going to look at several ways to increment and decrement numeric variables in bash.

Ep.117
Oct 10, 2023 2 mins
Operating Systems
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Ep.116
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How to view every Nth line in a text file

In this Linux tip, we’re going to look at a way that you can view every Nth line in a text file – whether every other line, every third line, every eleventh line or whatever you want to see.

Ep.116
Oct 5, 2023 2 mins
Operating Systems
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Ep.115
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How to use the Comm command

In this Linux tip, we’re going to look at the comm command – a Linux command that provides a report on the lines that are common in two text files along with those that only exist in one file or the other.

Ep.115
Oct 3, 2023 1 mins
Operating Systems
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Ep.114
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How to omit command history with ignoredups

In this Linux tip, we’re going to look at how you can get your command history to omit commands when you enter them more than once in a row.

Ep.114
Sep 5, 2023 2 mins
Operating Systems
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Ep.113
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How to use the more command

In this Linux tip, we’re going to look at using the more command to view text files a selected number of lines at a time.

Ep.113
Aug 31, 2023 2 mins
Operating Systems
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Ep.112
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How to use the redirect command

In this Linux tip, we’re going to look at the greater than and greater than x2 operators and how they work. The greater than operator will take the output of the command preceding it and put it into the file that follows it.

Ep.112
Aug 3, 2023 1 mins
Operating Systems
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Ep.111
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How to give sudo privileges on Fedora

In this Linux tip, we’re going to look at setting up sudo privileges for users on Fedora. The key is to make them members of the “wheel” group.

Ep.111
Aug 1, 2023 2 mins
Operating Systems
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Ep.110
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How to password protect with Vim

In this Linux tip we will learn how to encrypt using Vim

Ep.110
Jun 27, 2023 1 mins
Operating Systems
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Ep.109
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How to move around the Linux command line

In this Linux tip, we will look at how to move around on the Linux command line. There may be some tricks that you don’t know.

Ep.109
Jun 6, 2023 2 mins
Operating Systems
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Ep.108
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How to use Ctrl-r to rerun prior commands

In this video, we're going to take a look at how you can search for commands in your command history -- in reverse order – and then rerun one.

Ep.108
Jun 1, 2023 2 mins
Operating Systems
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Ep.107
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How to use the grep command

In this video, we're going to take a look at the grep command and some of the things you can do with it.

Ep.107
May 23, 2023 2 mins
Operating Systems
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Ep.106
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How to use the netstat-s command

In this Linux tip, we’re going to look at the netstat -s command that displays network statistics. The numbers reflect activity since the system’s last boot so some counts will change fairly frequently.

Ep.106
May 11, 2023 2 mins
Operating Systems
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Ep.105
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How to use the df -Th command

In this Linux tip, we’re going to look at the df -Th command. It provides details on your file systems but, unlike du -h, it adds the file system type – a good thing to take a look at from time to time and understand.

Ep.105
Apr 27, 2023 2 mins
Operating Systems
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Ep.104
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How to use the fortune command

In this Linux tip, we’re going to look at the fortune command. Yes, fortune. It’s a command that will tell you your fortune though, I have to admit, it’s entirely random.

Ep.104
Mar 30, 2023 2 mins
Operating Systems
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