sub get_file {
  my $name = shift;
  my $no_backup_flag = shift;
  unless ($no_backup_flag) {
    my $suffix = "aaa";
    $suffix++ while -e "$name.$suffix";
    local $^I = ".$suffix";
    local $/ = \4096;
    local *ARGV; @ARGV = $name;
    print while <>;
  }
  local *ARGV; @ARGV = $name;
  local $/ = wantarray ? $/ : undef; # act like `` in scalar vs list context
  <>;
}