Bash printf 输出的函数有时缺少格式

Question

我有一个带有四个参数并输出格式化标题的函数。大部分时间此功能有效，但偶尔会决定无效。

yelB=$'\e[1;33m'
fclr=$'\e[0m'

format_title() {
    # USAGE
    #   format_title "TITLE" "{h1/h2/h3}" "${color}" "{fill_character}"
    # EXMAPLE
    #   format_title "Heading 1" "h2" "$yelB" "="
    #   ============================ Heading 1 ============================

    ftitle=
    heading=
    color=
    fill=

    total_length=100
    ftitle_spacing=" "
    ftitle_border=$'\n' # variable implemented in h1 instances only
    formatted_ftitle=""

    if [[ $heading == "h1" ]]; then
        for (( i=1; i<=$total_length; i++ )); do
            ftitle_border=$ftitle_border$fill
        done
    fi

    if [[ $heading == "h1" || $heading == "h2" ]]; then
        ftitle_spacing="          "
    fi

    ftitle_fill=$(( ( $total_length / 2 ) - ( ${#ftitle} / 2 ) - ${#ftitle_spacing} ))

    for (( i=0; i<=$ftitle_fill; i++ )); do
        formatted_ftitle=$formatted_ftitle$fill

        if (( i == $ftitle_fill - 1 )); then

            formatted_ftitle=$formatted_ftitle$ftitle_spacing$color$ftitle$fclr$ftitle_spacing$formatted_ftitle

            # Check if the fill will be even or odd; if odd, remove the last fill character
            if (( $ftitle_fill % 2 )); then
                formatted_ftitle="${formatted_ftitle::-1}"
            fi

            if [[ $heading == "h1" ]]; then
                formatted_ftitle=$ftitle_border$'\n'$formatted_ftitle$ftitle_border$'\n'
            fi

            break
        fi
    done

    printf "%s\n" "$formatted_ftitle"
}

format_title "TEST HEADING ONE WITH EVEN NUMBER CHARACTERS" "h1" "$yelB" "#"
format_title "TEST HEADING TWO WITH ODD NUMBER CHARACTERS" "h1" "$yelB" "#"
format_title "TEST HEADING ONE WITH EVEN NUMBER CHARACTERS" "h2" "$yelB" "="
format_title "TEST HEADING TWO WITH ODD NUMBER CHARACTERS" "h2" "$yelB" "="
format_title "TEST HEADING ONE WITH EVEN NUMBER CHARACTERS" "h3" "$yelB" "-"
format_title "TEST HEADING TWO WITH ODD NUMBER CHARACTERS" "h3" "$yelB" "-"

Shell Output 这个想法是，所有标题最多可排成 100 个字符，并为少于 100 个字符的标题填充字符。

如您所见，有些标题没有对齐；虽然微不足道，但非常烦人（忽略未着色的标题——当我打印输出时变量被错误命名）。

我不知道是什么导致了某些标题出现问题。连接字符串时 Bash 是字符解释错误吗？

Answer 1

对于 h1/h2 你有 ${#formatted_ftitle} = 18/19 对于 even/odd ${#ftitle}（即偶数=偶数，奇数=奇数）。

但是对于 h3 你有 ${#formatted_ftitle} = 27/28 和 even/odd ${#ftitle}（即奇=偶，偶=奇）。

因此，看起来您不仅需要考虑填充符的 odd/even-ness，还需要考虑标题...在确定是否应该删除尾随字符时。

实际上，它看起来可以归结为只需要担心 ${#ftitle} 的 even/odd-ness，例如：

yelB=$'\e[1;33m'
fclr=$'\e[0m'

format_title() {
    # USAGE
    #   format_title "TITLE" "{h1/h2/h3}" "${color}" "{fill_character}"
    # EXMAPLE
    #   format_title "Heading 1" "h2" "$yelB" "="
    #   ============================ Heading 1 ============================

    ftitle=
    heading=
    color=
    fill=

    total_length=100
    ftitle_spacing=" "
    ftitle_border=$'\n' # variable implemented in h1 instances only
    formatted_ftitle=""

    if [[ $heading == "h1" ]]; then
        for (( i=1; i<=$total_length; i++ )); do
            ftitle_border=$ftitle_border$fill
        done
    fi

    if [[ $heading == "h1" || $heading == "h2" ]]; then
        ftitle_spacing="          "
    fi

    ftitle_fill=$(( ( $total_length / 2 ) - ( ${#ftitle} / 2 ) - ${#ftitle_spacing} ))

    for (( i=0; i<$ftitle_fill; i++ )); do
        formatted_ftitle=$formatted_ftitle$fill
    done

    formatted_ftitle=$formatted_ftitle$ftitle_spacing$color$ftitle$fclr$ftitle_spacing$formatted_ftitle

    # if the length of ftitle is odd, remove the last fill character

    if (( ${#ftitle} % 2 )); then
        formatted_ftitle="${formatted_ftitle::-1}"
    fi


    if [[ $heading == "h1" ]]; then
        formatted_ftitle=$ftitle_border$'\n'$formatted_ftitle$ftitle_border$'\n'
    fi

    printf "%s\n" "${formatted_ftitle}"
}

format_title "TEST HEADING ONE WITH EVEN NUMBER CHARACTERS" "h1" "$yelB" "#"
format_title "TEST HEADING TWO WITH ODD NUMBER CHARACTERS" "h1" "$yelB" "#"
format_title "TEST HEADING ONE WITH EVEN NUMBER CHARACTERS" "h2" "$yelB" "="
format_title "TEST HEADING TWO WITH ODD NUMBER CHARACTERS" "h2" "$yelB" "="
format_title "TEST HEADING ONE WITH EVEN NUMBER CHARACTERS" "h3" "$yelB" "-"
format_title "TEST HEADING TWO WITH ODD NUMBER CHARACTERS" "h3" "$yelB" "-"

####################################################################################################
##################          TEST HEADING ONE WITH EVEN NUMBER CHARACTERS          ##################
####################################################################################################


####################################################################################################
###################          TEST HEADING TWO WITH ODD NUMBER CHARACTERS          ##################
####################################################################################################

==================          TEST HEADING ONE WITH EVEN NUMBER CHARACTERS          ==================
===================          TEST HEADING TWO WITH ODD NUMBER CHARACTERS          ==================
--------------------------- TEST HEADING ONE WITH EVEN NUMBER CHARACTERS ---------------------------
---------------------------- TEST HEADING TWO WITH ODD NUMBER CHARACTERS ---------------------------

Bash printf 输出的函数有时缺少格式

Bash function with printf output missing formatting only sometimes

bash

shell

printf

string-formatting