CheckNotExist check if the file exists.

CheckPermission check if the file has permission.

CopyDir copies the source directory to the dest directory.

CopyFile copies the source file to the dest file.

GetExt get the file ext.

GetSize get the file size.

IsDir determines whether the specified path is a directory.

IsNotExistMkDir create a directory if it does not exist.

MkDir create a directory.

MustOpen maximize trying to open the file.

Open a file according to a specific mode.