bat批处理速战速决

显示空行，blank line

echo.

ref:
https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/echo

命令是否回显

@, 当前命令不回显
@echo on，打开回显
@echo off，关闭回显

@copy a.txt b.txt
copy a.txt b.txt
@echo off
copy a.txt b.txt
@echo on
copy a.txt b.txt

条件语句

set mode=all
if %mode%==all (
    echo mode is all  
) else if %mode%==single (
    echo mode is single
) else (
    echo none
)

ref:
https://www.cnblogs.com/xiongzaiqiren/p/11364452.html

延时变量概念

https://www.cnblogs.com/habibah-chang/p/3532125.html

是否存在文件夹

if exist apkDir (
    echo exist apkDir
) else (
    echo mkdir apkDir
    mkdir apkDir
)

读取文件

for /f "delims=" %%i in (%text_file%) do set var_line=%%i

超级好文ref:
https://devblogs.microsoft.com/oldnewthing/20120731-00/?p=7003

查看使用方法

在command窗口中 /?

set /?
if /?
for /?
mkdir /?