将字符串中指定的元素附加到bash数组的引号中 [英] Appending elements specified in a string with quotes to a bash array

问题描述

我正在尝试将一个项目追加到存储在变量中的数组中，但是它并没有完全按照我的期望进行操作.

I am trying to append an item to an array that is stored in a variable, however it's not acting entirely how I'd expect it to.

这就是我想要做的:

array=()

item_to_add="1 '2 3'"

array+=(${item_to_add})

for item in "${array[@]}"; do
    echo "item: ${item}"
done

我希望它能输出以下内容:

I'd expect this to output the following:

item: 1
item: '2 3'

但是我却得到以下输出:

However I get the following output instead:

item: 1
item: '2
item: 3'

有什么办法可以使它像这样的代码而无需使用 eval 之类的东西?

Is there any way to make it act like this code without using something like eval?

array=()

array+=(1 '2 3')

for item in "${array[@]}"; do
    echo "item: ${item}"
done

及其输出:

item: 1
item: '2 3'

推荐答案

xargs 解析其输入中的引号.这通常是一个(规范级别的)错误，而不是一个功能(它使具有文本引号的文件名在没有非POSIX扩展名(例如 -d 或 -0 覆盖行为)，但在当前情况下非常方便:

xargs parses quotes in its input. This is usually a (specification-level) bug rather than a feature (it makes filenames with literal quotations nearly impossible to work with without non-POSIX extensions such as -d or -0 overriding the behavior), but in present circumstances it comes in quite handy:

array=()

item_to_add="1 '2 3'"

while IFS= read -r -d '' item; do # read NUL-delimited stream
  array+=( "$item" )              # and add each piece to an array
done < <(xargs printf '%s\0' <<<"$item_to_add") # transform string to NUL-delimited stream

printf 'item: %s\n' "${array[@]}"

...发出...

item: 1
item: 2 3

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