Bash 4 关联数组：错误“声明：-A：无效选项”

Bash 4 associative arrays: error "declare: -A: invalid option"

提问by Joel

I've written a script that uses associative arrays in bash (v 4).

我编写了一个在 bash (v 4) 中使用关联数组的脚本。

It works fine on my local machine which is using 4.1.5(1)-release.

它在我使用4.1.5(1)-release.

On the production machine, using 4.1.0(1)-releasethe following line, which declares the assoc array, fails:

在生产机器上，使用4.1.0(1)-release以下声明 assoc 数组的行失败：

declare -A uniqjars

with the message:

消息：

/script.sh: line 11: declare: -A: invalid option
declare: usage: declare [-afFirtx] [-p] [name[=value] ...]

I was under the impression this was a general bash 4 feature?

我的印象是这是一个通用的 bash 4 功能？

In the man for bash on the production machine it discusses using -Aso I assume it shouldwork.

在生产机器上的 bash 人中，它讨论了使用，-A所以我认为它应该可以工作。

Associative arrays are created using declare -A name.

关联数组是使用 .declare -A name

I can confirm the script is using the right version of bash by printing out the value of echo 'bash -version.

我可以通过打印 .bash 的值来确认脚本使用的是正确版本的 bash echo 'bash -version。

What could I be doing wrong?

我可能做错了什么？

采纳答案by Richard H

Make sure the version of bash being invoked as interpreter at the top of your shell script (#!/bin/bashor whatever) is also version 4. If you're doing:

确保在 shell 脚本（#!/bin/bash或其他任何）顶部作为解释器调用的 bash 版本也是版本 4。如果你正在做：

bash --version

and it's giving you v4, do a which bashto check it's location.

它给你 v4，做一个which bash检查它的位置。

回答by meigrafd

Here is a Workaround, if you want to use chars as array index with bash v3:

这是一个解决方法，如果您想在 bash v3 中使用字符作为数组索引：

array=(
    'hello::world.'
    'nice::to meet you'
)

for index in "${array[@]}" ; do
    KEY="${index%%::*}"
    VALUE="${index##*::}"
    echo "$KEY - $VALUE"
done

Output:

输出：

hello - world.
nice - to meet you

回答by Benjamin W.

The following seems to be a typical scenario on macOS after installing a newer Bash with Homebrew:

使用 Homebrew 安装较新的 Bash 后，以下似乎是 macOS 上的典型场景：

• /bin/bashis the old Bash, 3.2
• /usr/local/bin/bashis the new Bash that knows about associative arrays (4.0 or newer)
• type bashpoints to /usr/local/bin/bashand bash --versionis the new one (because it resolves to /usr/local/bin/bash --version)

• /bin/bash是旧的 Bash，3.2
• /usr/local/bin/bash是了解关联数组的新 Bash（4.0 或更高版本）
• type bash指向/usr/local/bin/bash并且bash --version是新的（因为它解析为/usr/local/bin/bash --version）

However, scripts with a #!/bin/bashshebang line that are run with ./scriptwill use the old Bash (the scenario in the question). Solutions are:

但是，#!/bin/bash运行带有 shebang 行的脚本./script将使用旧的 Bash（问题中的场景）。解决办法是：

• Call the script with bash script: the new Bash will be used. Disadvantage:you always have to call it like that.
• Change the shebang line to #!/usr/local/bin/bash. Disadvantage:on many systems, there is no Bash in /usr/local/binand your script isn't portable any longer.
• Change the shebang line to #!/usr/bin/env bash.This will use the first bashin your PATH, which should be the new one. This is pretty portable; the only downside is that you don't know exactly which Bash will be executed.

• 使用以下命令调用脚本bash script：将使用新的 Bash。缺点：你总是要这样称呼它。
• 将 shebang 行更改为#!/usr/local/bin/bash. 缺点：在许多系统上，没有 Bash/usr/local/bin并且您的脚本不再具有可移植性。
• 将 shebang 行更改为#!/usr/bin/env bash. 这将使用bash您的 中的第一个PATH，这应该是新的。这是非常便携的；唯一的缺点是您不确切知道将执行哪个 Bash。

See also these Q&A:

另请参阅这些问答：

• What is the difference between "#!/usr/bin/env bash" and "#!/usr/bin/bash"?
• Why is #!/usr/bin/env bash superior to #!/bin/bash?
• Why is it better to use “#!/usr/bin/env NAME” instead of “#!/path/to/NAME” as my shebang?on Unix & Linux

• "#!/usr/bin/env bash" 和 "#!/usr/bin/bash" 有什么区别？
• 为什么#!/usr/bin/env bash 优于#!/bin/bash？
• 为什么最好使用“#!/usr/bin/env NAME”而不是“#!/path/to/NAME”作为我的shebang？在 Unix 和 Linux 上

回答by khancell

Here is how to get the updated bashversion on OS X, you should install brewand then bash.

这是bash在 OS X 上获取更新版本的方法，您应该安装brew，然后安装bash.

$ /bin/bash --version    
GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin14)

$ brew install bash    
... install

$ /usr/local/bin/bash --version    
GNU bash, version 4.3.46(1)-release (x86_64-apple-darwin14.5.0)

回答by Tyler

1. Check the current shell you are using with this cmd:

   echo $SHELL
   

   E.g. it could say /bin/bash

2. Run --versionon that $SHELL:

   /bin/bash --version
   

   It may output something like GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin16)

   If it is before version 4, you'll have to upgrade.

3. Check if you already have a bash shell with version 4. Try running:

   bash --version
   

   If so, you just need to change your default shell to that shell.

   You can use these cmds to do so:

   sudo bash -c 'echo /usr/local/bin/bash >> /etc/shells'
   sudo chsh -s /usr/local/bin/bash
   

   The first adds the shell to the allowed shells. The second actually changes your default shell.

1. 检查您正在使用此 cmd 的当前 shell：

   echo $SHELL
   

   例如它可以说 /bin/bash

2. 运行--version上$SHELL：

   /bin/bash --version
   

   它可能会输出类似 GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin16)

   如果是版本 4 之前的版本，则必须升级。

3. 检查您是否已经有版本 4 的 bash shell。尝试运行：

   bash --version
   

   如果是这样，您只需要将默认 shell 更改为该 shell。

   您可以使用这些 cmds 来执行此操作：

   sudo bash -c 'echo /usr/local/bin/bash >> /etc/shells'
   sudo chsh -s /usr/local/bin/bash
   

   第一个将外壳添加到允许的外壳中。第二个实际上更改了您的默认外壳。

回答by KeithJ

meigrafd's answer solved my problem, so if using an incorrect shebang or still on bash version 3 the following allowed me to return a value based on it's associated key:

meigrafd的回答解决了我的问题，所以如果使用不正确的 shebang 或仍然在 bash 版本 3 上，以下允许我根据它的关联键返回一个值：

array=(
    'hello::world.'
    'nice::to meet you'
)

for index in "${array[@]}" ; do
  KEY="${index%%::*}"
  VALUE="${index##*::}"
  if [ "$KEY" == "nice" ]; then
    echo "$VALUE"
    break
  fi
done

This will return the value "to meet you".

这将返回值“遇见你”。

回答by Mihey Mik

Nothing above helped me, so I opened /etc/shells and changed the line - /bin/bashto /usr/local/bin/bash, and then reloaded it with source /etc/shellsand now I can enjoy new possibilities of v4 of bash

上面没有什么帮助了我，所以我打开/ etc / shells中，改变了线-/bin/bash到/usr/local/bin/bash，然后重新加载它 source /etc/shells，现在我可以享受庆典的V4的新的可能性

回答by anubhava

Old BASH version didn't support declare -Asyntax of declaring arrays. I suggest using either of these 2 forms to declare arrays in bash to make it compatible with older bash version of your production system:

旧的 BASH 版本不支持declare -A声明数组的语法。我建议使用这两种形式中的任何一种在 bash 中声明数组，以使其与生产系统的旧 bash 版本兼容：

arr=( '10' '20' '30' )
echo ${arr[@]}

or

或者

arr[0]=10
arr[1]=20
arr[2]=30
echo ${arr[@]}

回答by EnterUserNameHere

Per the command:

根据命令：

help declare
declare: declare [-aAfFgilnrtux] [-p] [name[=value] ...]
  Set variable values and attributes.

Declare variables and give them attributes.  If no NAMEs are given,
display the attributes and values of all variables.
Options which are set attributes:
  -a        to make NAMEs indexed arrays (if supported)
  -A        to make NAMEs associative arrays (if supported)

Notice lowercase "-a" and uppercase "-A" are "(if supported)". Also if you look at the posted error message for declare usage:

注意小写的“-a”和大写的“-A”是“（如果支持）”。另外，如果您查看已发布的错误消息以了解声明用法：

/script.sh: line 11: declare: -A: invalid option
declare: usage: declare [-afFirtx] [-p] [name[=value] ...]

The given options are "[-afFirtx]" showing to use a lowercase "-a" but no uppercase "-A". Compare that to the usage string from the help command. It looks as if it's just not supported on the given machine.

给定的选项是“[-afFirtx]”，显示使用小写的“-a”但不使用大写的“-A”。将其与 help 命令中的用法字符串进行比较。看起来好像在给定的机器上不支持它。

回答by Khanan

Try using a different shebang. On my Mac:

尝试使用不同的shebang。在我的 Mac 上：

$ which bash
/usr/local/bin/bash

So, this script runs fine, producing "Hello World":

所以，这个脚本运行良好，产生了“Hello World”：

#!/usr/local/bin/bash
declare -A assoc
assoc[hello]="Hello World"
echo ${assoc[hello]}