simple console ruler

#!/usr/bin/env bash
# tivasyk <[email protected]>
# Draw a simple screen-wide ruler
TICK_0='┼'
TICK_5='┴'
TICK_1='─'
SCREEN_WIDTH=$(tput cols)
# Prepare the ruler
for (( i=1; i<=SCREEN_WIDTH; i++)); do
    if [[ $(( i % 10 )) == 0 ]]; then
        RULER_STRING+=$TICK_0
        if [[ ${#i} > 1 ]]; then
            RULER_LABELS=${RULER_LABELS::(-$(( ${#i} -1 )) ) }
        fi
        RULER_LABELS+="${i}"
    elif [[ $(( i % 5 )) == 0 ]]; then
        RULER_STRING+=$TICK_5
        RULER_LABELS+=' '
    else
        RULER_STRING+=$TICK_1
        RULER_LABELS+=' '
    fi
done
# Print the ruler in invented colors
tput rev
printf "%s\n%s\n" "${RULER_LABELS}" "${RULER_STRING}"
tput sgr0