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如何将 bash 环境变量存储在数组中然后访问/修改？

tag-icon • tag-icon bash environment-variables array
如何将 bash 环境变量存储在数组中然后访问/修改？

我想将环境变量存储在 bash 数组中，然后在对所有环境变量执行相同操作（取消设置、导出等）的情况下使用它们。例如，如果我想打印数组中的所有环境变量：

envVar1="firstVar"
envVar2="secondVar"
envVar3="thirdVar"
envVars=(envVar1 envVar2 envVar3)
for currentEnvVar in "${envVars[@]}" 
do
    # print env var name and value
    printf "Initial Value: %s = %s\n" "${currentEnvVar}" "${currentEnvVar}"
    # unset env var
    printf "Unsetting %s\n" "${currentEnvVar}"
    unset "${currentEnvVar}"

    # print env var name and value
    printf "Unset Variable (nothing should be to right of '=') %s = %s\n\n" "${currentEnvVar}" "${currentEnvVar}"

    # set env var 
    printf "Setting %s\n" "${currentEnvVar}"
    export "${currentEnvVar}"="${currentEnvVar}""_new"

    # print env var name and new value...
    printf "New Value %s =  %s\n\n" "${currentEnvVar}" "${currentEnvVar}"

done

我不确定的是如何存储变量envVars以及如何在循环中使用它们。

我的目标是上述循环的输出为：

Initial Value: envVar1 = firstVar
Unsetting envVar1
Unset Variable (nothing should be to right of '=') envVar1 =

Setting envVar1
New Value envVar1 =  firstVar_new

Initial Value: envVar2 = secondVar
Unsetting envVar2
Unset Variable (nothing should be to right of '=') envVar2 =

Setting envVar2
New Value envVar2 =  secondVar_new

Initial Value: envVar3 = thirdVar
Unsetting envVar3
Unset Variable (nothing should be to right of '=') envVar3 =

Setting envVar3
New Value envVar3 = thirdVar_new

但我得到的是这样的：

Initial Value: envVar1 = envVar1
Unsetting envVar1
Unset Variable (nothing should be to right of '=') envVar1 = envVar1

Setting envVar1
New Value envVar1 =  envVar1

Initial Value: envVar2 = envVar2
Unsetting envVar2
Unset Variable (nothing should be to right of '=') envVar2 = envVar2

Setting envVar2
New Value envVar2 =  envVar2

Initial Value: envVar3 = envVar3
Unsetting envVar3
Unset Variable (nothing should be to right of '=') envVar3 = envVar3

Setting envVar3
New Value envVar3 =  envVar3

这可能吗？如何设置环境变量名称数组，然后使用或修改它们的值？

答案1

您似乎正在尝试做的事情有几个不同的部分。

对于unset名称在另一个变量中的变量，可以使用-vso

unset -v "$currentEnvVar"

对于那部分。看这里

要分配给变量，您可以使用printf喜欢

printf -v "$currentEnvVar" %s 'new value'

要打印该值，您可以使用间接引用喜欢

printf 'The value is %s\n' "${!currentEnvVar}"

在大括号扩展中，如果第一个字符是，!则其余字符被视为包含您要实际使用的变量名称的变量名称。

您还可以考虑使用关联数组相反，如果它适合您的需求：

declare -A envVarsByName
envVarsByName[$currentEnvVar]='new value'
printf 'New val: %s\n' "${envVarsByName[$currentEnvVar]]}"

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