在 Bash 中使用变量作为案例模式 [英] Using variable as case pattern in Bash

问题描述

我正在尝试编写一个在 case 语句中使用变量作为模式的 Bash 脚本.但是我就是无法让它工作.

I'm trying to write a Bash script that uses a variable as a pattern in a case statement. However I just cannot get it to work.

案例陈述:

case "$1" in
    $test)
        echo "matched"
        ;;
    *)
        echo "didn't match"
        ;;
esac

我已经尝试将 $test 分配为 aaa|bbb|ccc, (aaa|bbb|ccc), [aaa,bbb,ccc] 和其他几种组合.我还尝试了这些作为案例语句中的模式: @($test), @($(echo $test)), $($test).也没有成功.

I've tried this with assigning $test as aaa|bbb|ccc, (aaa|bbb|ccc), [aaa,bbb,ccc] and several other combinations. I also tried these as the pattern in the case statement: @($test), @($(echo $test)), $($test). Also no success.

编辑

为清楚起见，我希望该变量代表多个模式，如下所示:

For clarity, I would like the variable to represent multiple patterns like this:

case "$1" in
    aaa|bbb|ccc)
        echo "matched"
        ;;
    *)
        echo "didn't match"
        ;;
esac

推荐答案

您可以使用 extglob 选项:

#! /bin/bash

shopt -s extglob         # enables pattern lists like +(...|...)
test='+(aaa|bbb|ccc)'

for x in aaa bbb ccc ddd ; do
    echo -n "$x "
    case "$x" in
        $test) echo Matches.
        ;;
        *) echo Does not match.
    esac
done

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