windows 操作:exp test/test@dbbase grants=y File=D:/data_back/yx_user_data.%date:~0,4%%date:~5,2%%date:~8,2%.dmp
linux 操作:exp test/test@dbbase grants=y File=D:/data_back/yx_user_data.`date +%Y%m%d`..dmp
linux 操作:exp test/test@dbbase grants=y File=D:/data_back/yx_user_data.`date +%Y%m%d`..dmp