mjhjmtu

Either GUI message boxes, or message boxes that show inside the terminal.

It would also be interesting to be able to get simple input back from the user, e.g. yes / no or radio buttons.

For a standard "box around a message", use boxes:

echo 'This is a test' | boxes

boxes will look like this (First one. Second one is a custom like cowsay):

If you mean an alert box, use notify-send:

notify-send 'title' 'message'

notify-send looks like this:

You also can use zenity for a popup window:

zenity --error --text="An error occurred!" --title="Warning!"

Zenity is more graphical and has more options, like having the window appear as a question, using:

zenity --question --text="Do you wish to continue/?"

or even progress bars, using:

find /usr | zenity --progress --pulsate --auto-close --auto-kill --text="Working..."

zenity looks like this:

Or use dialog, for a command-line only message box:

dialog --checklist "Choose OS:" 15 40 5 
1 Linux off 
2 Solaris on 
3 'HP UX' off 
4 AIX off

dialog looks like this:

Another option is whiptail:

whiptail --title "Example Dialog" --msgbox "This is an example of a message box. You must hit OK to continue." 8 78

whiptail looks like this:

And if you are truly crazy, use toilet:

toilet -F border -F gay "CRAZY"

toilet looks like this:

• Source for boxes


• Source for dialog 1


• Source for dialog 2


• Source for zenity 1


• Source for zenity 2


• Source for whiptail 1


• Source for whiptail 2


• Source for toilet

xmessage

This is the granddaddy of GUI alerts:

xmessage -center "Hello, World!"

Pure retro goodness.

I also bet that it should be widely available on X11 systems.

SO thread: How to show a GUI message box from a bash script in linux? | Stack Overflow

Tested in Ubuntu 18.04.

And then just because @polym's completely over the top answer missed the classic messaging:

write <username> [<terminal>] - send a message to another user. Either interactively or as part of a pipe with echo "message" | write username

And the complement to write, wall to send a message to all users

If you are willing to pipe the text to a Python wrapper, you can use terminaltables:

pip3 install colorclass
pip3 install terminaltables

Then in the GitHub Repo, you can use one of the examples to write a python wrapper.