fs

BaseNameWithoutExt return basename without extension of `filename`, in which `filename` may contains directory.

Copy copies src to dest, doesn't matter if src is a directory or a file.

IsWritable test if directory path is writable or not.

LocateFile 定位protofile目录路径 要想保证protofile能够被搜索到，protodirs需要提供protofile的父路径，不能是父路径的父路径.

Move move `src` to `dest` the behavior of fs.Move is consistent with bash shell `mv` command: when move a file, actions are following: ------------------------------------------------------------------------------------------------ | No.

PrepareOutputdir create outputdir if it doesn't exist, return error if `outputdir` existed while it is not a directory, return error if any other error occurs.

UniqFilePath 文件系统路径去重.