I use it to sync files from windows to linux. Rules: 1.The file will be copy from src to dst if: dst file doesn't exists; src file new then dst; 2. The file will not be copy: the opposite side of rule 1. the src's mtime == its src's mtime of last sync Usages: 1. --file <setting_file_of_each_line_is_src:::dst> 2. --src --dest