Use of CMD command

Input the execution results into the file

@echo off

adb devices >> .\ConnectDevice.txt
pause

Read the second line of the file ：

@echo off
for /f "tokens=*" %%a in  ('more +1 "ConnectDevice.txt"') do (
	set "var=%%a"
	echo var=%%a
	if defined var (
		echo var is not empty
	) else echo var is empty
)