preserve: 保留，存，区
--preserve[=ATTR_LIST] preserve the specified attributes (default: mode,ownership,timestamps).
allocate 分配，配置
mode 模式
ownership 从属关系
timestamp 时间戳
destine 注定
destination 目的地
-f ,--force if an existing destination file cannot be opened, remove it and try again (this option is ignored when the -n
option is also used)
clobber 重写，覆盖
-n,--no-clobber do not overwrie an existing file (overrides a previous -i option)
previous 先前的
hard link 硬链接
-l, --link hard link files instead of copying
interactive 交互的
-i, --interactive prompt before overwrite (overrides a previous -n option)
removal 删除
rm -i prompt before every removal
proceed 开始，继续
-r, --recursive are given,then rm prompts the user for whether to proceed with the entire operation.