dear samxgf, almost similar to windows. when want to download, example mide00070, open terminal inside the download javit folder in linux
and run this command
@echo off
if not exist "download" mkdir download
./jav-it download -c r18.com_cookies.txt -o"download" -i mide00070
pause
u can get the cookies file via google chrome by using the get cookies extension. you need to login your r18 first btw