How to Easily Show a GUI Message Box from a Bash Script in Linux

When writing Bash scripts in Linux, especially on Ubuntu, you might find yourself needing to present information or require user input without relying on the terminal interface. The need for a graphical dialog can arise in many situations, such as displaying confirmation prompts, alert messages, or simple notifications.

This blog post will guide you through using Zenity, a tool available in Ubuntu, to easily create GUI dialog boxes from your Bash scripts. Let’s dive into the steps to implement this solution.

Why Use a GUI Message Box?

Using a GUI message box in your scripts helps to:

• Enhance User Experience: A graphical interface is more intuitive for users, making scripts easier to use.
• Avoid Terminal Dependency: Users can interact with scripts directly without needing to engage with the terminal.
• Improve Feedback: Providing immediate feedback or prompts via dialog boxes keeps users informed.

What is Zenity?

Zenity is a command-line tool that allows you to create GTK dialog boxes in scripts. This means you can incorporate various message box styles, such as information alerts, question prompts, or file selectors, directly from your bash scripts.

Zenity is available as an Ubuntu package, so you won’t need to install additional software (unless for some special features).

Installation

In most cases, Zenity comes pre-installed on Ubuntu. To check if it’s installed, you can simply run:

zenity --version

If it’s not installed, you can easily add it using:

sudo apt-get install zenity

How to Use Zenity in Your Bash Scripts

Here’s a breakdown of how to create different types of GUI dialog boxes using Zenity.

Displaying an Information Message

To show a simple information dialog, you can use the following command:

zenity --info --text="Your message here"

Asking a Question

To prompt users with a question, you can use:

zenity --question --text="Do you want to continue?"

This will return a success or failure exit code based on the user’s choice.

Getting User Input

If you need to get input from users, use:

USER_INPUT=$(zenity --entry --text="Please enter your name:")

This will prompt the user for their name and store it in the variable USER_INPUT.

Example Script

Here’s a simple Bash script that combines several Zenity dialogs:

#!/bin/bash

zenity --info --text="Welcome to the Script!"

if zenity --question --text="Do you want to continue?"; then
    NAME=$(zenity --entry --text="What is your name?")
    zenity --info --text="Hello, $NAME!"
else
    zenity --warning --text="Operation canceled."
fi

Running the Script

1. Save the script as your_script.sh.
2. Make it executable:

   chmod +x your_script.sh
   

3. Execute it:

   ./your_script.sh
   

Now, when you run your script, you will see a welcoming message box followed by a question and, depending on the input, a greeting or a cancellation notice.

Conclusion

Incorporating GUI message boxes into your Bash scripts can significantly improve user interaction and experience. With Zenity, you can effortlessly implement various dialog types while ensuring you do not burden users with terminal output.

By following the steps outlined above, you can create engaging and user-friendly scripts that can operate smoothly on Ubuntu or any Linux distribution with GTK support. Happy scripting!