my $tname = shift;
  $tname = untaint_var($tname);
...
  my $abslogdir = File::Spec->canonpath(Cwd::realpath("log"));
  $abslogdir  = untaint_var($abslogdir);
  $workdir = File::Spec->abs2rel(tempdir("$tname.XXXXXX", DIR => $abslogdir));