10、Linux Shell 笔记（3）

 

Function Recursion

function factorial {

if [ $1 -eq 1 ]

then

echo 1

else

local temp=$[ $1 - 1 ]

local result=`factorial $temp`

echo $[ $result * $1 ]

fi

}

Creating a Library

Just as with environment variables, shell functions are only valid for the shell session in which you define them. If you run the myfuncs shell script from your shell command line interface prompt, the shell creates a new shell, and runs the script in that new shell.

The key to using function libraries is the source command. The source command executes commands within the current shell context instead of creating a new shell to execute them. You use the source command to run the library file script inside of your shell script. This makes the functions available to the script.

The source command has a shortcut alias, called the dot operator. To source the myfuncs library file in a shell script, all you need to do is add the following line:

. ./myfuncs //第一个点代表source,第二个./表示当前目录

可以使用echo返回数据。

参考：

［1］ Linux命令行和SHELL脚本编程