Set desktop wallpaper

change-wallpaper.sh

#!/bin/sh

if [ -z "$1" ]; then
    echo "Usage: $0 <path-to-wallpaper>"
    exit 1
fi

realpath() {
    [[ $1 = /* ]] && echo "$1" || echo "$PWD/${1#./}"
}

IMG=$(realpath $1)
echo "Changing wallpaper to $IMG"

DB=~/Library/Application\ Support/Dock/desktoppicture.db

IMGID=$(sqlite3 "$DB" "select rowid from data where value = '$IMG'")
if [ -z "$IMGID" ]; then
    sqlite3 "$DB" "insert into data (value) values ('$IMG')"
    IMGID=$(sqlite3 "$DB" "select rowid from data where value = '$IMG'")
fi

sqlite3 "$DB" "delete from preferences where key = 1"
sqlite3 "$DB" "insert into preferences (key, data_id, picture_id) select 1, $IMGID, rowid from pictures"
killall Dock