Bash数组循环处理问题：无法正确获取var实际值，求修正

问题描述 #

遍历数组bazel_paths_array时，无法正确获取当前元素值，输出a[0]这类错误格式；需要实现每次循环将数组中一个元素设为var，剩余元素组成排除该元素的集合，用于bazel coverage命令。

原脚本 #

bazel_paths_array=(a b c d)
    for ele in "${!bazel_paths_array[@]}"
    do
        b=("${bazel_paths_array[@]}")
        unset b[$ele]
        echo "${b[@]}"
        if [[ ! "${na2[*]}" =~ "$abp" ]]
        then
            var=$bazel_paths_array["${abp}"]
        fi
        na2="${b[*]}"
        printf "var to run bazel on: %s
" "${var}"
        printf "new array to skip bazel on: %s

" "${na2}"
        #bazel coverage "$var" "${na2[*]}"
    done

当前错误输出 #

b c d
var to run bazel on: a[0]
new array to skip bazel on: b c d

a c d
var to run bazel on: a[1]
new array to skip bazel on: a c d

a b d
var to run bazel on: a[2]
new array to skip bazel on: a b d

a b c
var to run bazel on: a[3]
new array to skip bazel on: a b c

期望输出 #

length of bazel paths array is 4:

b c d
var to run bazel on: a
new array to skip bazel on: b c d

a c d
var to run bazel on: b
new array to skip bazel on: a c d

a b d
var to run bazel on: c 
new array to skip bazel on: a b d

a b c
var to run bazel on: d
new array to skip bazel on: a b c

问题根源 #

1. 数组取值语法错误：原脚本中var=$bazel_paths_array["${abp}"]，Bash中数组元素必须用${数组名[索引]}格式取值，直接写$数组名[索引]会被解析为字符串拼接，加上abp变量未定义，最终输出a[0]这类错误结果。
2. 无效逻辑判断：if [[ ! "${na2[*]}" =~ "$abp" ]]完全多余，abp未定义、na2初始为空，该判断无法起到任何作用。

修正后的脚本 #

bazel_paths_array=(a b c d)
echo "length of bazel paths array is ${#bazel_paths_array[@]}:"
echo

for ele in "${!bazel_paths_array[@]}"
do
    # 复制原数组到临时数组
    b=("${bazel_paths_array[@]}")
    # 删除当前循环索引对应的元素
    unset b[$ele]
    # 直接通过当前索引获取目标元素
    var="${bazel_paths_array[$ele]}"
    # 剩余元素保持数组类型（避免含空格元素出错）
    na2=("${b[@]}")
    
    # 打印调试信息
    echo "${b[@]}"
    printf "var to run bazel on: %s\n" "$var"
    printf "new array to skip bazel on: %s\n\n" "${na2[*]}"
    
    # 启用bazel命令时取消注释
    # bazel coverage "$var" "${na2[@]}"
done

修正后输出 #

length of bazel paths array is 4:

b c d
var to run bazel on: a
new array to skip bazel on: b c d

a c d
var to run bazel on: b
new array to skip bazel on: a c d

a b d
var to run bazel on: c
new array to skip bazel on: a b d

a b c
var to run bazel on: d
new array to skip bazel on: a b c

修改说明 #

• 添加数组长度打印，匹配期望输出格式。
• 移除无效的if判断，直接通过循环索引$ele获取对应数组元素，确保var值正确。
• 将na2定义为数组类型，后续使用${na2[@]}传递参数更稳妥（避免元素包含空格时出现拆分错误）。
• 调整输出格式，与期望结果完全对齐。

内容的提问来源于stack exchange，提问作者AhmFM