check for one-time codes coming as notifications via KDE connect and copy them to clipboard

notification-watch.sh

#!/usr/bin/env bash
# check for one-time codes coming as notifications via KDE connect and copy them to clipboard
# requirements: qdbus(qt-tools), dbus-monitor, kde-connect, klipper
# the script must be run in user session

set -euo pipefail
shopt -s lastpipe

if [[ $# -eq 0 ]]
then
    echo "Usage: $0 [deviceid]"
    echo "Usage: $0 --all"
    echo "Available devices:"
    kdeconnect-cli --list-available
    exit 2
fi

if [[ "$1" == "--all" ]]
then
    # run a process per available device
    kdeconnect-cli --list-available --id-only | xargs --max-procs=0 --max-args=1 --no-run-if-empty -- "$0"
    exit $?
fi

device="$1"

echo "Listening for notifications from device $device"


# modern solution for an uncivilized age

# listen for dbus signals when a notification is posted or updated
path="/modules/kdeconnect/devices/${device}/notifications"
interface="org.kde.kdeconnect.device.notifications"
dbus-monitor --session --monitor \
    "type=signal, interface=$interface, path=$path, member=notificationPosted" \
    "type=signal, interface=$interface.notification, member=ready" \
    | sed -u -n "s%^.* path=$path/\([0-9]*\);.*$%\1%p;s%^ *string \"\([0-9]*\)\"$%\1%p" \
    | while read -r id
do
    # extract notification app title and text
    appname="$(qdbus org.kde.kdeconnect "$path/$id" $interface.notification.appName)"
    title="$(qdbus org.kde.kdeconnect "$path/$id" $interface.notification.title)"
    text="$(qdbus org.kde.kdeconnect "$path/$id" $interface.notification.text)"

    # extract one time code
    code="$(echo "$text" | grep --only-matching --perl-regexp ' \d{4,8}\b' | tail -n 1 || true)" # ignore error

    echo "$appname $title $text $code"

    # copy code to clipboard (klipper)
    [[ -n $code ]] && qdbus org.kde.klipper /klipper org.kde.klipper.klipper.setClipboardContents $code

done