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Fileutil
string basename(string filename);
  Return filename with directory part removed.
string dirname(string filename);
  Return just directory part of filename.
*(string, string) split_filename(string filename);
  Return (part of filename up to last dot, part of filename after last dot), or (filename, "") if there is no dot.
string find_in_path(<string>list path, string filename);
  Lookup filename in each directory in path. Return filename with path where it was found, or raise Not_found.
void report_error(string msg);
  Print msg on stderr, prepending Array::get(Sys::argv, 0).