ref:
Close button on notify-osd?

Bookmark:
Can org.freedesktop.Notifications.CloseNotification(uint id) be triggered and invoked via DBus?

Currently, this script

dbus-monitor "interface='org.freedesktop.Notifications'" |             \
grep --line-buffered "member=Notify"                     |             \
sed -u -e  's/.*/killall notify-osd/g'                   |             \
bash

will kill all pending notifications.

It would be better to finesse the specific target OSD notification to cancel, by using org.freedesktop.Notifications.CloseNotification(uint id). Is there an interface method that can put this on (in?) the DBus to fire when a particular notify event occurs?

The method will need to get the notify PID to use as the argument for CloseNotification(uint id). Alternatively,

  qdbus    org.freedesktop.Notifications                \
          /org/freedesktop/Notifications                \
           org.freedesktop.Notifications.CloseNotification(uint id)

could be used from the shell, if the (uint id) argument could be determined. The actual command syntax would use an integer in place of (uint id).

Perhaps a better question to ask first might be "How is the DBus address for a notification found?".

In hindsight the previous question "How is the (uint id) for a notification found?" is rhetorical! This previous answer:
http://askubuntu.com/a/186311/89468
provided details so either method below can be used:

gdbus call --session --dest org.freedesktop.DBus                                   \
              --object-path /                                                      \
                   --method org.freedesktop.DBus.GetConnectionUnixProcessID :1.16

returning:

(uint32 8957,)

or

qdbus --literal --session  org.freedesktop.DBus  /                                 \
                           org.freedesktop.DBus.GetConnectionUnixProcessID :1.16

returning:

8957