1.touch hello.sh

2.vim hello.sh

　　use "i" to write into the file 

　   write:

　　　　#!/bin/sh

　　　　echo hello world;

3.use"esc"、 "wq" to save the file

4.chmod 700 hello.sh (change the binary file mode)

5.execute the file by the commond: bash ./hello.sh