Windows Batch: Add and Remove from Hosts

add_remove_dns_hosts.bat

@REM ==
@REM Windows Batch: Add and Remove from Hosts
@REM ==

@ECHO OFF
SETLOCAL EnableDelayedExpansion

SET HOSTS=C:\Windows\System32\drivers\etc\hosts
SET DNS[0]=1.1.1.1 cat.example.com x-cat.example.com
SET DNS[1]=2.2.2.2 dog.example.com x-dog.example.com
SET DNS[2]=3.3.3.3 yak.example.com x-yak.example.com

for /l %%N in (0,1,2) do (
  >NUL findstr /m /c:"!DNS[%%N]!" %HOSTS% && (
    findstr /v /c:"!DNS[%%N]!" %HOSTS% > %TEMP%\hosts.tmp
    move /y %TEMP%\hosts.tmp %HOSTS% > NUL
  ) || (
    echo !DNS[%%N]! >> %HOSTS%
  )
)