// If fi describes a directory, a slash is appended to the name.
//
// Since fs.FileInfo's Name method only returns the base name of
// the file it describes, it may be necessary to modify Header.Name
// to provide the full path name of the file.
//
// If fi implements [FileInfoNames]
// Header.Gname and Header.Uname
// are provided by the methods of the interface.
func FileInfoHeader(fi fs.FileInfo, link string) (*Header, error) {