helper_func.sh

#!/bin/bash

center_text() {
    local terminal_width
    terminal_width=$(tput cols) # query the Terminfo database: number of columns
    local text="${1:?}"         # text to center
    local glyph="${2:-=}"       # glyph to compose the border
    local padding="${3:-2}"     # spacing around the text

    local text_width=${#text}

    local border_width=$(((terminal_width - (padding * 2) - text_width) / 2))

    local border= # shape of the border

    # create the border (left side or right side)
    for ((i = 0; i < border_width; i++)); do
        border+="${glyph}"
    done

    # a side of the border may be longer (e.g. the right border)
    if (((terminal_width - (padding * 2) - text_width) % 2 == 0)); then
        # the left and right borders have the same width
        local left_border=$border
        local right_border=$left_border
    else
        # the right border has one more character than the left border
        # the text is aligned leftmost
        local left_border=$border
        local right_border="${border}${glyph}"
    fi

    # space between the text and borders
    local spacing=

    for ((i = 0; i < padding; i++)); do
        spacing+=" "
    done

    # displays the text in the center of the screen, surrounded by borders.
    printf "${left_border}${spacing}${text}${spacing}${right_border}\n"
}

center_text_prompt() {
    local terminal_width
    terminal_width=$(tput cols) # query the Terminfo database: number of columns
    local text="${1:?}"         # text to center
    local glyph="${2:-=}"       # glyph to compose the border
    local padding="${3:-2}"     # spacing around the text

    local text_width=${#text}

    local border_width=$(((terminal_width - (padding * 2) - text_width) / 2))

    local border= # shape of the border

    # create the border (left side or right side)
    for ((i = 0; i < border_width; i++)); do
        border+="${glyph}"
    done

    # a side of the border may be longer (e.g. the right border)
    if (((terminal_width - (padding * 2) - text_width) % 2 == 0)); then
        # the left and right borders have the same width
        local left_border=$border
        local right_border=$left_border
    else
        # the right border has one more character than the left border
        # the text is aligned leftmost
        local left_border=$border
        local right_border="${border}${glyph}"
    fi

    # space between the text and borders
    local spacing=

    for ((i = 0; i < padding; i++)); do
        spacing+=" "
    done

    # displays the text in the center of the screen, surrounded by borders.
    printf "${left_border}${spacing}${text}"
}