How to Write SHELL scripts on LINUX

On the LINUX platform, how to write a SHELL script-general Linux technology-Linux programming and kernel information is as follows. 1: create a file
Touch wt

2: open the file
Vi wt

3: insert an opened file
Press the "I" key to enter the editing status.

4. edit the file content and write the code.
#! /Bin/sh
Echo "hello world! "

Note:
The first line is required, where the SHELL is executed; the second line begins with the place where you write your own code;

5. Save and exit the file.
Press the "ESC" key and enter "ZZ" in upper case.

6. Change the File Permission and change the file to an executable file.
Chmod + x wt

7: execute this file
./Wt