Show desktop script I

#!/bin/bash

#
#
#
# Written by reddit user u/casualContributorNZ
# Available under the GLWT Public Licence:
# https://github.com/me-shaon/GLWTPL/blob/master/LICENSE
#
#
# This script emulates the 'show desktop' functionality in i3wm
#
#
# First finds the currently active workspace using i3-msg and jq
#
#
# Then using i3-msg and (ugly) jq will determine whether there are any windows open on the
# current work space. This is done by determining the number of nodes open, so if there are
# some extra nodes open by default (ie. you are running something which automatically has a
# node within a workspace) then you will need to change the comparator in the first if statement
#
#
# If the workspace is empty, you will be bounced back to your most recently preiously accessed
# workspace with the i3 back_and_forth builtin.
# This means you can get some slightly weird behaviour if you close all of the windows in your
# current workspace and then run this, because the workspace you will be taken to has no/minimal
# pertinence to the current one.
#
#
# If you are on a non-empty workspace then you will be taken to the lowest-number free workspace.
# Note that if you have workspaces 1-10 already open then it will take you to workspace 11.
#
#
# You can also pass a function to then execute on the new workspace. I suppose that actually this
# is kinda pointless as it is just doing:
# `i3-msg workspace ##; exec $1`
# Which is equivalent to:
# ./thisScript.sh; $1
# So therefore then only saving is a semi-colon. Efficiency.
#
# If you run this script with an argument in an empty workspace the argument will be ignored,
# thus you can run './thisScript firefox' close firefox, and then re-run it, and it will take you
# back to where you were WITHOUT opening firefox when you get there
#



currentWS=$(i3-msg -t get_workspaces | jq '.[] | select(.focused==true).num')

isEmpty=$(i3-msg -t get_tree | jq --arg currWS "$currentWS" '.nodes | .[] | .nodes | .[] |
select(.type=="con") | .nodes | .[] | select(.type=="workspace") | select(.name==$currWS) |
.nodes | length')


if [ $isEmpty -eq 0 ]
        then
                i3-msg workspace back_and_forth
        else
                readarray -t activeWorkspaces < <(i3-msg -t get_workspaces | jq 'map(.num)' | tr -dc '[:alnum:]\n\r' | sort -g)

                number=$(echo "${activeWorkspaces[@]}" | awk -v RS='\\s+' '{ a[$1] } END { for(i=1; i in a; ++i);
                print i }')

                if [ $# -eq 0 ]
                        then
                                i3-msg workspace $number
                        else
                                i3-msg workspace $number; exec $1
                fi

fi