Know About Bash Command in Linux

Know About Bash Command in Linux

4 mins read307 Views Comment
Updated on Mar 13, 2024 14:37 IST

Looking for a comprehensive list of Bash commands in Linux? Look no further! This guide covers all the major Bash commands, including ls, cd, mkdir, rm, grep, sed, awk, and more.

2023_02_Bash-Command-in-Linux.jpg

This article on the bash command in Linux focuses on the bash shell, one such well-liked shell. The majority of Linux distributions and Apple’s macOS use it as their default shell.

Introduction

There are two different user interface types that computers offer:

1. Graphical User Interface (GUI), and

2. Text-based interfaces (through the command line or terminal)

You can explore the operating system and file system using these interfaces. A command line interpreter, often known as a shell, is used in text-based interfaces to translate the user’s commands.

Bash

With the help of commands, users can specify what they wish to perform using Bash. When you open the command line (in Linux and macOS), bash displays a prompt like the one below before asking for the commands.

Code Syntax

 
user@localhost:~$
Copy code

Normally, this prompt would list the system’s hostname and the current username. By default, the user’s root (or home) directory will always be the terminal’s current directory.

This prompt will appear once again after a command has completed running to indicate that the shell is now prepared to run another command. Following the prompt, the commands you enter will be shown.

Bash Commands

Understanding bash’s various commands are essential to using it. Bash is incredibly strong when used in conjunction with a variety of settings and these commands. The majority of basic bash commands deal with system navigation. Take a look at the sample below, where the home directory appears as follows.  

echo

The most fundamental command in Bash is echo, which outputs its inputs on standard output (on the terminal).

Syntax

 
echo[option]<text>
Copy code

Code Snippet

 
user@localhost:~$ echo "Hello World!"
Hello World!
user@localhost:~$ echo Hello World!
Hello World!
Copy code

It should be noted that the text that follows the term echo does not require quotation marks. It is advised that you do this, though.

When you wish to display the value of system variables, you can also utilize echo. To do this, you must place a dollar symbol ($) before the name of the variable. For instance, the following command can be used to check the value of the current shell.

Code Snippet

 
user@localhost:~$ echo $SHELL
/bin/bash
Copy code

pwd

Print Working Directory is a command that goes by the abbreviation pwd. Your current working directory is shown as output.

Syntax

 
pwd[option]
Copy code

Code Snippet

 
user@localhost:~$ pwd
/home/user
Copy code

ls

ls in commands is short for list. It provides a list of a directory’s contents. It displays the contents of the current working directory by default. 

Syntax

 
ls[option]<location>
Copy code

Code Snippet

 
user@localhost:~$ ls
Documents Pictures Videos
Copy code

Unlike pwd or echo, which are typically used without them, ls is primarily used with options (even though options are available for them). The location of the directory can be supplied as an additional optional parameter to ls, which is specified after any options.

Let’s see how to use ls with the -a option. Using this option, we can see hidden files. The files in the code block below that have a dot before them do not appear. Unless you allow the option to view them, these hidden files are not visible on the GUI. In the below example, demo.txt is a hidden file, which we can access by adding -a to ls command.

Code Snippet

 
user@localhost:~$ ls -a
Documents Pictures Videos demo.txt
Copy code

cd

The bash command in Linux to change directories is cd. With this command, we can switch the current directory to a different directory by including a path. This command just modifies the directory; it does not produce an output. Later, you may check to see if the current directory has changed by using ls to view the directory contents.

Syntax

 
cd[option]<directory>
Copy code

Code Snippet

 
user@localhost:~$ cd Documents
user@localhost:~$ ls
file1.txt
user@localhost:~$ cd ..
user@localhost:~$ ls
Documents Pictures Videos
Copy code

In the above-mentioned illustration, we see that the shorthand for returning to the parent directory. This you can apply multiple times in a single route to move up the parent directory hierarchy. Of course, you may also supply the directory’s complete path.

Bash Commands for File Modifications

Working with files entails making any necessary modifications. The fundamental operations when working with files are renaming, transferring, creating, and deleting new files. In this part, we’ll look at these activities using bash.

mkdir

mkdir is short for Make Directory. With the given name, it is for creating a new directory.

Syntax

 
mkdir[option]<directory name>
Copy code

Code Snippet

 
user@localhost:~$ mkdir BashTutorial
user@localhost:~$ ls
BashTutorial Documents Pictures Videos
Copy code

rmdir

The command rmdir stands for Remove Directory. It deletes the chosen directory. The directory to remove must be empty for there to be no errors in the terminal.

Syntax

 
rmdir[option]<directory name>
Copy code

Code Snippet

 
user@localhost:~$ rmdir BashTutorial
user@localhost:~$ ls
Documents Pictures Videos
Copy code

touch

The command touch makes new, empty files. This command doesn’t contribute anything to the file; it only generates a blank one.

Syntax

 
touch[option]<filename>
Copy code

Code Snippet

 
user@localhost:~$ touch Newfile
user@localhost:~$ ls
Documents Newfile Pictures Videos
Copy code

rm

The command for deleting files is rm. Similar to rmdir, this action will not reverse. So take caution.

Syntax

 
rm[option]<filename>
Copy code

Code Snippet

 
user@localhost:~$ rm Newfile
user@localhost:~$ ls
Documents Pictures Videos
Copy code

rm has a useful option called -r. Because it recursively deletes all of the files and subdirectories inside a directory, adding this option enables us to easily remove non-empty directories.

 
user@localhost:~$ rmdir Videos
rmdir
: failed to remove 'Videos': Directory not empty
user@localhost:~$ rm -r Videos
user@localhost:~$ ls
Documents Pictures
Copy code

Conclusion

The blog explained the syntax and code snippets of bash commands in Linux. The basic bash commands include echo, pwd, ls, and different bash commands for file modifications, including mkdir, touch, and rm. Remember that bash commands are case-sensitive.

If you plan to learn more, check out the whole list of Linux courses.

Contributed by Megha Chadha

About the Author

This is a collection of insightful articles from domain experts in the fields of Cloud Computing, DevOps, AWS, Data Science, Machine Learning, AI, and Natural Language Processing. The range of topics caters to upski... Read Full Bio