# Shell函数

shell脚本可以定义函数，供其他脚本调。

### 1. 函数的定义

shell脚本使用`function`关键字和 `{}` 来定义函数。\
​

```shell
function func1() {

echo "this is func1"

}
```

* 函数的定义可以使用`function`关键字，也可以不用
* 函数不会显式的定义参数，只用一个占位用的 `()`
* 函数体定义在`{}`之间
* 函数的返回值可以通过 `return` 显式返回，如果不使用 `return` , 将使用最后一条命令的运行结果作为返回值， 返回的范围在\[0,255]

### 2. 函数的参数

在函数体中，使用 `$n` 这样的模式访问参数\
​

​

### 3. 调用函数

调用函数就像执行一条命令一样\
​

```shell
# 调用函数func1
func1 

# 调用函数并传递参数 
func1 1 2 2 3
```

​

​


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