Linux is a family of open-source Unix operating systems based on the Linux Kernel. They include Ubuntu, Fedora, Debian, openSUSE, and Red Hat. Using Linux to manage a Virtual Private Server (VPS) is common practice.

However, we recommend utilizing the command-line interface (CLI) because it’s quicker and offers more control. Tasks that require multiple steps on the GUI can be done in a matter of seconds by entering commands into the CLI.

By the end of this article, we will be able to learn most commonly command that are being used in Linux :

Firstly, What is a linux command ?

A Linux command is a program or utility that runs on the CLI – a console that interacts with the system via texts and processes. It’s similar to the Command Prompt application in Windows.

Syntax for a Linux Command :

Here’s what a Linux command’s general syntax looks like:

CommandName [option(s)] [parameter(s)]

A command may contain an option or a parameter. In some cases, it can still run without them. These are the three most common parts of a command:

• CommandName is the rule that you want to perform.

• Option or flag modifies a command’s operation. To invoke it, use hyphens (–) or double hyphens (—).

• Parameter or argument specifies any necessary information for the command.

NOTE : Linux commands are case-sensitive.

Here is the list of basic Linux commands:

1. sudo command

Short for superuser do, sudo is one of the most popular basic Linux commands that lets you perform tasks that require administrative or root permissions.

Here’s the general syntax: sudo (command)

2. pwd command

Use the pwd command to find the path of your current working directory. Simply entering pwd will return the full current path – a path of all the directories that starts with a forward slash (/). For example, /home/username.

The pwd command uses the following syntax: pwd

3. cd command

To navigate through the Linux files and directories, use the cd command. Depending on your current working directory, it requires either the full path or the directory name.

• cd .. moves one directory up.

• cd- moves to your previous directory

4. ls command

The ls command lists files and directories within a system. Running it without a flag or parameter will show the current working directory’s content.

To see other directories’ content, type ls followed by the desired path. For example, to view files in the Documents folder, enter:

ls /home/username/Documents

5. cat command

Concatenate, or cat, is one of the most frequently used Linux commands. It lists, combines, and writes file content to the standard output. To run the cat command, type cat followed by the file name and its extension. For instance:

cat filename.txt.

6. cp command

Use the cp command to copy files or directories and their content. Take a look at the following use cases.

To copy one file from the current directory to another, enter cp followed by the file name and the destination directory. For example:

cp filename.txt /home/username/Documents

7. mv command

The primary use of the mv command is to move and rename files and directories. Additionally, it doesn’t produce an output upon execution.

Simply type mv followed by the filename and the destination directory. For example, you want to move filename.txt to the /home/username/Documents directory:

mv filename.txt /home/username/Documents.

You can also use the mv command to rename a file:

mv old_filename.txt new_filename.txt

8. mkdir command

Use the mkdir command to create one or multiple directories at once and set permissions for each of them. The user executing this command must have the privilege to make a new folder in the parent directory, or they may receive a permission denied error.

Here’s the basic syntax:

mkdir [option] directory_name

For example, you want to create a directory called Music:

mkdir Music

9. rmdir command

To permanently delete an empty directory, use the rmdir command. Remember that the user running this command should have sudo privileges in the parent directory.

For example, you want to remove an empty subdirectory named personal1 and its main folder mydir:

rmdir -p mydir/personal1

10. rm command

The rm command is used to delete files within a directory. Make sure that the user performing this command has write permissions.

Remember the directory’s location as this will remove the file(s) and you can’t undo it.

Here’s the general syntax:

rm filename

To remove multiple files, enter the following command:

rm filename1 filename2 filename3

11. touch command

The touch command allows you to create an empty file or generate and modify a timestamp in the Linux command line.

For example, enter the following command to create an HTML file named Web in the Documents directory:

touch /home/username/Documents/Web.html

12. locate command

The locate command can find a file in the database system.

Moreover, adding the -i argument will turn off case sensitivity, so you can search for a file even if you don’t remember its exact name.

To look for content that contains two or more words, use an asterisk (*). For example:

locate -i school*note

The command will search for files that contain the words school and note, whether they use uppercase or lowercase letters.

13. find command

Use the find command to search for files within a specific directory and perform subsequent operations. Here’s the general syntax:

find [option] [path] [expression]

For example, you want to look for a file called notes.txt within the home directory and its subfolders:

find /home -name notes.txt

14. grep command

Another basic Linux command on the list is grep or global regular expression print. It lets you find a word by searching through all the texts in a specific file.

Once the grep command finds a match, it prints all lines that contain the specific pattern. This command helps filter through large log files.

For example, you want to search for the word blue in the notepad.txt file:

grep blue notepad.txt

The command’s output will display lines that contain blue.

15. df command

Use the df command to report the system’s disk space usage, shown in percentage and kilobyte (KB). Here’s the general syntax:

df [options] [file]

For example, enter the following command if you want to see the current directory’s system disk space usage in a human-readable format:

df -h

16. du command

If you want to check how much space a file or a directory takes up, use the du command. You can run this command to identify which part of the system uses the storage excessively.

Remember, you must specify the directory path when using the du command. For example, to check /home/user/Documents enter:

du /home/user/Documents

17. head command

The head command allows you to view the first ten lines of a text. Adding an option lets you change the number of lines shown. The head command is also used to output piped data to the CLI.

Here’s the general syntax:

head [option] [file]

18. tail command

The tail command displays the last ten lines of a file. It allows users to check whether a file has new data or to read error messages.

Here’s the general format:

tail [option] [file]

19. diff command

Short for difference, the diff command compares two contents of a file line by line. After analyzing them, it will display the parts that do not match.

Programmers often use the diff command to alter a program instead of rewriting the entire source code.

Here’s the general format:

diff [option] file1 file2

20. tar command

The tar command archives multiple files into a TAR file – a common Linux format similar to ZIP, with optional compression.

Here’s the basic syntax:

tar [options] [archive_file] [file or directory to be archived]

21. chmod command

chmod is a common command that modifies a file or directory’s read, write, and execute permissions. In Linux, each file is associated with three user classes – owner, group member, and others.

Here’s the basic syntax:

chmod [option] [permission] [file_name]

22. chown command

The chown command lets you change the ownership of a file, directory, or symbolic link to a specified username.

Here’s the basic format:

chown [option] owner[:group] file(s)

For example, you want to make linuxuser2 the owner of filename.txt:

chown linuxuser2 filename.txt

23. jobs command

A job is a process that the shell starts. The jobs command will display all the running processes along with their statuses. Remember that this command is only available in csh, bash, tcsh, and ksh shells.

This is the basic syntax:

jobs [options] jobID

24. kill command

Use the kill command to terminate an unresponsive program manually. It will signal misbehaving applications and instruct them to close their processes.

To kill a program, you must know its process identification number (PID). If you don’t know the PID, run the following command:

ps ux

After knowing what signal to use and the program’s PID, enter the following syntax:

kill [signal_option] pid

25. ping command

The ping command is one of the most used basic Linux commands for checking whether a network or a server is reachable. In addition, it is used to troubleshoot various connectivity issues.

Here’s the general format:

ping [option] [hostname_or_IP_address]

For example, you want to know whether you can connect to Google and measure its response time:

ping google.com

I am Sunil kumar, Please do follow me here and support #devOps #trainwithshubham #github #devopscommunity #devops #cloud #devoparticles #trainwithshubham

sunil kumar

@ Shubham Londhe

Please connect with me at Linkedin : https://www.linkedin.com/in/sunilkumar2807/