Simple blur lock screen that works with i3lock, xsslock, scrot and ImageMagick

lock.sh

#!/bin/bash
## CONFIGURATION ##############################################################

# Options to pass to i3lock
i3lock_options="-d"
TMPBG=/tmp/screen.png
MUTED=""

# Run before starting the locker
pre_lock() {
    # Uncomment when you automatically want to pause cmus playback on lock
    # cmus-remote -U

    MUTED=$(pactl list sinks | grep '^[[:space:]]Mute:' | sed "s/^[[:space:]]Mute: //")

    # Uncomment to pause the Media player daemon on lock
    # mpc pause

    # Mute the audio sink on lock, you might need to change the id of your sink.
    # For now this only works with one audio output activated.
    # With more it will fail to auto unmute on unlock
    # pactl set-sink-mute 0 1
    
    # Place your lock icon here or change path accordingly.
    ICON=$HOME/.icons/lock.png

    if [ -f "$TMPBG" ]; then
        rm $TMPBG
    fi
    scrot /tmp/screen.png
    convert $TMPBG -scale 10% -scale 1000% $TMPBG
    # If you have multiple monitors, you might have to play around with the geometry option (-geometry (+/-)x_off(+/-)y_off) a bit
    # to center the icon on your main screen.
    convert $TMPBG $ICON -gravity center -geometry 0+0 -composite -matte $TMPBG
    i3lock_options+=" -i $TMPBG"
    return
}

# Run after the locker exits
post_lock() {
    ## If the sink was unmuted before locking, umute it on unlock
    # if [ "$MUTED" == "no" ]; then
    #     pactl set-sink-mute 0 0
    # fi
    rm $TMPBG
    return
}

###############################################################################

pre_lock

# We set a trap to kill the locker if we get killed, then start the locker and
# wait for it to exit. The waiting is not that straightforward when the locker
# forks, so we use this polling only if we have a sleep lock to deal with.
if [[ -e /dev/fd/${XSS_SLEEP_LOCK_FD:--1} ]]; then
    kill_i3lock() {
        pkill -xu $EUID "$@" i3lock
    }

    trap kill_i3lock TERM INT

    # we have to make sure the locker does not inherit a copy of the lock fd
    i3lock $i3lock_options {XSS_SLEEP_LOCK_FD}<&-

    # now close our fd (only remaining copy) to indicate we're ready to sleep
    exec {XSS_SLEEP_LOCK_FD}<&-

    while kill_i3lock -0; do
        sleep 0.5
    done
else
    trap 'kill %%' TERM INT
    i3lock -n $i3lock_options &
    wait
fi

post_lock