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.

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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.

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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.

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

4

Type the code.

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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.

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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.

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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.

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

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

Living Concrete

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

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How do I learn shell scripting?

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

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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

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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.

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Tips

By default, vim is not installed.

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Use vim <yourfile.sh> to edit your shell scripts.

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Enter your password and let Ubuntu do the magic.

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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.

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

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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.

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