modify command prompt

1. Execute and display the value of the system prompt environment variable PS1

echo $PS1   #显示提示符格式

        

2. Change the value of the user variable prompt

ls -a   #查看
vi .bash_profile    #修改
PS1="[\u@@@\h]****" #重新赋值
source .bash_profle #生效

vi editor

         

modified result

        

Executing the bash command will restore the original environment

         

 After the test, I found that the bash command can only be restored temporarily. To restore it permanently, it is necessary to modify the PS1 back in the vi editor.