The CLI bard is a very simple command line application that displays the last
notifications received on the D-Bus (the common notification system under Linux).

It is not an interactive application, it just displays incoming notifications.
At any time, as much as possible of the last notifications are displayed.
The display refreshes when a notification is received.

The CLI bard is written in Python and is available under the AGPLv3 license.

The CLI bard relies on your terminal using a font patched with the “Powerline”
characters. The recommended fonts are the ones from the
Nerd font project.

usage: clibard.py [-h] [-l {h,v,horizontal,vertical}] [–test NB_ITEMS]
[–send NB_ITEMS]

options:
-h, –help show this help message and exit
-l {h,v,horizontal,vertical}, –layout {h,v,horizontal,vertical}
How to display notifications. horizontal = as many of
the last notifications that fit on a single line, clear
out the old ones. vertical = keep printing new
notifications on new lines.
–test NB_ITEMS Print NB_ITEMS fake notifications and quit.
–send NB_ITEMS Send NB_ITEMS fake notifications on the D-Bus and quit.

Each notification is displayed as a colored block made of up to four segments,
showing in order:

1. the date,
2. the application having issued the notification,
3. the summary of the notification (e.g. chat systems usually display the user, here),
4. the body of the message.

The color of the notification block’s application and summary depends
on the urgency of the notification:

• low in green,
• normal in blue,
• critical in orange,
• unknown in light purple.

The CLI bard does respond to POSIX “user signals”.
Signals can be issued with the kill command, using the --signal flag along
with 10 (SIGUSR1) or 12 (SIGUSR2) as an argument.
SIGUSR1 will refresh the display, SIGUSR2 will erase any notification in the
cache and clear the display (if it can).

Note that with the horizontal layout, refreshing the display actually changes
the display. Erasing the cache will remove any on-screen notification
if you use the horizontal layout.
With the vertical layout, this does nothing on the display.

The default layout is the horizontal one.

This will display on a single line, and overwrite it as soon as an update is
received.
Dates are given in a “natural” human-readable way.
When refreshing its display in the horizontal layout, the displayed dates will
be refreshed as well.
However, it does not show all the cached notifications, but only the few last
ones that can fit the current width of the terminal.

The vertical layout simply prints a new line as soon as the CLI bard receive
a notification. The display cannot be cleared nor refreshed.
Most notably, date is displayed in the ISO-8601 format, down to the minute.
However, your terminal should retain all the received notifications,
if you can scroll back enough.