introduce
have a set of Win32 console commands built in.
The Command shell was the first shell built into Windows to automate routine tasks, like user account management or nightly backups, with batch (.bat) files. 通过shell，你可以直接和OS或者application通信
type:
-
command shell
-
powershell cdmlets (扩展，推荐使用)
commands
:: 这是注释
:: file extension '.cmd' or '.bat'
:: basic
echo "first line"
:: do not show the command
@echo off
echo "first line"
:: variable, caution: no whitespace
:: default global variable
SET v1=abc
SETLOCAL localV1=cde
echo %v1%
pause