How to Write a Shell Script Using Bash Shell in Ubuntu

Last Updated: August 27, 2023 Tested

Have you ever wanted to automate operations in your operating system? This wikiHow article teaches you how to write a shell script using Bash Shell in Ubuntu.

1

Open a Terminal window.

Download Article

{"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/f\/f3\/Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-1-Version-4.jpg\/v4-460px-Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-1-Version-4.jpg","bigUrl":"\/images\/thumb\/f\/f3\/Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-1-Version-4.jpg\/aid933493-v4-728px-Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-1-Version-4.jpg","smallWidth":460,"smallHeight":346,"bigWidth":728,"bigHeight":547,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/en.wikipedia.org\/wiki\/Fair_use\">Fair Use<\/a> (screenshot)<br>\n<\/p><\/div>"}

You can launch the terminal by opening the dash and searching for it by name. You could also open it using the keyboard shortcut Ctrl + Alt + T .

2

Create a file with your text editor.

Download Article

{"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/f\/f4\/Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-3-Version-4.jpg\/v4-460px-Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-3-Version-4.jpg","bigUrl":"\/images\/thumb\/f\/f4\/Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-3-Version-4.jpg\/aid933493-v4-728px-Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-3-Version-4.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/en.wikipedia.org\/wiki\/Fair_use\">Fair Use<\/a> (screenshot)<br>\n<\/p><\/div>"}
Launch the vi or vim editor and create a new script. Vim is a free and popular text editor that uses the command line interface. To create a script called ListDir.sh:
- Type vim ListDir.sh and hit ↵ Enter .
- Once inside the Editor, type "I" or "i." This will allow you to insert/start typing your shell script.

3

Begin your script.

Download Article

{"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/c\/c6\/Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-4-Version-4.jpg\/v4-460px-Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-4-Version-4.jpg","bigUrl":"\/images\/thumb\/c\/c6\/Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-4-Version-4.jpg\/aid933493-v4-728px-Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-4-Version-4.jpg","smallWidth":460,"smallHeight":343,"bigWidth":728,"bigHeight":543,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/en.wikipedia.org\/wiki\/Fair_use\">Fair Use<\/a> (screenshot)<br>\n<\/p><\/div>"}

#!/bin/bash . This is known as a Shebang line.

4

Type the code.

Download Article

{"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/1\/1a\/Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-5-Version-4.jpg\/v4-460px-Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-5-Version-4.jpg","bigUrl":"\/images\/thumb\/1\/1a\/Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-5-Version-4.jpg\/aid933493-v4-728px-Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-5-Version-4.jpg","smallWidth":460,"smallHeight":342,"bigWidth":728,"bigHeight":541,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/en.wikipedia.org\/wiki\/Fair_use\">Fair Use<\/a> (screenshot)<br>\n<\/p><\/div>"}

The first line (echo "Welcome") prints the line "Welcome" into the terminal. echo is used to return the given text and a new line. The second line (ls) lists the contents of the directory. ls is short for list . The final line (another echo statement) returns the text This completes the list of directories .

5

Save and exit your editor.

Download Article

{"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/7\/7c\/Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-6-Version-4.jpg\/v4-460px-Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-6-Version-4.jpg","bigUrl":"\/images\/thumb\/7\/7c\/Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-6-Version-4.jpg\/aid933493-v4-728px-Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-6-Version-4.jpg","smallWidth":460,"smallHeight":344,"bigWidth":728,"bigHeight":544,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/en.wikipedia.org\/wiki\/Fair_use\">Fair Use<\/a> (screenshot)<br>\n<\/p><\/div>"}

Type Esc , then : , and then + wq to save and quit. This will write the changes to the file and bring you back to the terminal. Save the file as ListDir.sh

6

Make the script executable.

Download Article

{"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/9\/9a\/Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-7-Version-4.jpg\/v4-460px-Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-7-Version-4.jpg","bigUrl":"\/images\/thumb\/9\/9a\/Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-7-Version-4.jpg\/aid933493-v4-728px-Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-7-Version-4.jpg","smallWidth":460,"smallHeight":346,"bigWidth":728,"bigHeight":547,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/en.wikipedia.org\/wiki\/Fair_use\">Fair Use<\/a> (screenshot)<br>\n<\/p><\/div>"}

Enter the following command: chmod +x ListDir.sh . chmod is a command used in Unix like operating systems to change the access permissions to a file.

7

Run your shell script.

Download Article

{"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/5\/56\/Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-8-Version-4.jpg\/v4-460px-Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-8-Version-4.jpg","bigUrl":"\/images\/thumb\/5\/56\/Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-8-Version-4.jpg\/aid933493-v4-728px-Write-a-Shell-Script-Using-Bash-Shell-in-Ubuntu-Step-8-Version-4.jpg","smallWidth":460,"smallHeight":350,"bigWidth":728,"bigHeight":554,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/en.wikipedia.org\/wiki\/Fair_use\">Fair Use<\/a> (screenshot)<br>\n<\/p><\/div>"}

Type ./ListDir.sh to run this script. You should get the list of directories and the message as shown in the above image.

Community Q&A

Search

Add New Question

Question

After typing in "sudo apt install", "(sudo) password for jenneta" appears. What do I do?

Living Concrete

Top Answerer

It is prompting you for the password to your account. Type in your password and then press Enter.

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 2 Helpful 5
Question

How do I learn shell scripting?

Aryaa Vashisth

Community Answer

Install Python shell scripting and watch tutorials of how to script on Python.

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 15 Helpful 5
Question

How? I would like to stop the "file already exists" function at the OS level and instead rename the file on the disk before writing whatever to the original file name specified.

Nithik R

Community Answer

You may have a file of the exact same name and that is why it shows up. Try using another name for your shell script "vim " Or if you want to rename an existing file, do "mv " without the quotes and the angular brackets.

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 1 Helpful 0

Ask a Question

200 characters left

Include your email address to get a message when this question is answered.

Submit

Tips

By default, vim is not installed.

Thanks
Helpful 0 Not Helpful 0
Use vim <yourfile.sh> to edit your shell scripts.

Thanks
Helpful 0 Not Helpful 0
Enter your password and let Ubuntu do the magic.

Thanks
Helpful 0 Not Helpful 0

Show More Tips

Submit a Tip

All tip submissions are carefully reviewed before being published

Submit

Thanks for submitting a tip for review!

Warnings

For starters, place your shell scripts in your home directory as you begin your shell script journey. Once comfortable, place them in your required directory system.

Thanks
Helpful 0 Not Helpful 0
Ensure that the files you create, do not reside in any system directories of the / = root file system.

Thanks
Helpful 0 Not Helpful 0

Log in

How to Write a Shell Script Using Bash Shell in Ubuntu

Steps

Open a Terminal window.

Create a file with your text editor.

Begin your script.

Type the code.

Save and exit your editor.

Make the script executable.

Run your shell script.

Community Q&A

Tips

Warnings

You Might Also Like

About This Article

Is this article up to date?

Quizzes

You Might Also Like

Featured Articles

Trending Articles

Featured Articles

Featured Articles

Watch Articles

Trending Articles

Explore Categories