# 切分字符串赋值给多个变量

很多时候，需要将一行字符分割成多个变量，例如处理文本

这里需要注意，默认分割符是空格，如果是不同分割符，则需要设置 `IFS`

```bash
IFS="," read -r v_space v_email v_name v_sn <<< ",myname@example.com,不一样的烟火,123456"
```

然后我们就可以随便使用变量了

```bash
echo $v_name
```

显示输出

```
不一样的烟火
```

## json和多变量案例

我在结合上述方法，采用循环方式根据 `app` 名字访问API来获得应用的配置(json)。

例如，单条命令

```bash
app=ABC
AK=XXXXXXXX

curl -s --location --request GET "http://api.example.com/getAppInfo.json?appName=$app" --header "apiauth-token: $AK" | jq
```

可以获得某个应用的信息如下

```javascript
{
  "app": {
    ...
    "owner": {
      ...
      "email": "xyz@example.com",
      "nickName": "dogfood",
      "staffNo": "123",
      ...
    },
...
```

则我通过jq多变量读取：

```bash
curl -s --location --request GET "http://api.example.com/getAppInfo.json?appName=$app" --header "apiauth-token: $AK" | jq -r '.app.owner | .email + "," + .nickName + "," + .staffNo'
```

可以输出

```
xyz@example.com,dogfood,123
```

* 然后我们可以通过多变量赋值直接读取到3个变量，方便后续shell处理

```bash
IFS="," read -r owner_email owner_nickName onwer_staffNo <<< $(curl -s --location --request GET "http://api.example.com/getAppInfo.json?appName=$app" --header "apiauth-token: $AK" | jq -r '.app.owner | .email + "," + .nickName + "," + .staffNo')
```

不过，上述采用 `$()` 来把执行结果转换为字符串变量然后通过 `<<<` 输入给左边3个变量的方法，如果使用了循环，则只能在高版本bash上正常工作(例如bash 4.4.19):

```bash
for app in `cat $APP_LIST`; do
  IFS="," read -r owner_email owner_nickName onwer_staffNo <<< $(curl -s --location --request GET "http://api.example.com/getAppInfo.json?appName=$app" --header "apiauth-token: $AK" | jq -r '.app.owner | .email + "," + .nickName + "," + .staffNo')

  echo "owner_nickName: $owner_email"
  echo "owner_email: $owner_nickName"
  echo "onwer_staffNo: $onwer_staffNo"
done
```

则在 macOS的bash 3.2.57上执行结果是错误的

```
owner_email: xyz@example.com dogfood 123
owner_nickName:
onwer_staffNo: 
...
```

但是，如果运行环境是高版本 bash 4.4.19 (linux)，则完全正常

```
owner_email: xyz@example.com
owner_nickName: dogfood
onwer_staffNo: 123
...
```

为了兼容低版本bash，脚本需要修订成 `<<<` 右边直接使用字符串变量 `"$string"` :

```bash
for app in `cat $APP_LIST`; do
  AppInfo=`curl -s --location --request GET "http://api.example.com/getAppInfo.json?appName=$app" --header "apiauth-token: $AK" | jq -r '.app.owner | .email + "," + .nickName + "," + .staffNo'`
  IFS="," read -r owner_email owner_nickName onwer_staffNo <<< "$AppInfo"
done
```

则通用能够正常工作输出正确结果

## 参考

* [Bash: How to split a string and assign multiple variables](https://stackoverflow.com/questions/33320584/bash-how-to-split-a-string-and-assign-multiple-variables)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://huataihuang.gitbook.io/cloud-atlas-draft/develop/shell/bash/split_string_assign_multiple_variables.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.