dynamically add tags to hlwm using dmenu

dmenu_hlwm_add_tags

#!/bin/bash

### License: GPL3+
#
# Author: Kyle Andrews
#
# This script enables dynamic creation of new tags in hlwm.
#
###

hc() {
    herbstclient "$@"
}

# return the first integer index of the value in the array
index_of() {
    local x="$1"
    local -n xs="${2}"
    for i in "${!xs[@]}"; do
	if [[ "${xs[$i]}" = "${x}" ]]; then
	    echo "${i}";
	    break
	fi
    done
}

print_array() {
    local -n xs="${1}"
    printf '%s\n' "${xs[@]}"    
}

# What are the available tags?
# .  empty
# :  not empty
# +  viewed on the specified unfocused monitor
# -  viewed on a different unfocused monitor
# %  viewed on a different monitor and is focused
# !  tag contains an urgent window
eval $(hc tag_status | txr -B -c '	@(coll)@{status /[#:.]/}@{tag /[^\t]+/}@(end)')

fidx=$(index_of '#' status)
focused=${tag[$fidx]}

new=$(print_array tag | dmenu -i -p "new tag:")
Mod=Mod4
nidx=$(index_of $new tag)
len=${#tag[@]}
keys=({1..9} 0)
if [[ -z $nidx ]]
then
    hc add $new
    if [[ $len -lt 9 ]]
    then
	key="${keys[$len]}"
	hc keybind "$Mod-$key" use_index "$len"
	hc keybind "$Mod-Shift-$key" use_index "$len"
    fi
fi