sub print_tempDB_report_from_file {
    my ($DB_FName, $RPT_FName) = @_;
    my $tempDB = parse_db_file($DB_FName);
    my $report = generate_db_report($tempDB);
    open my $OFH, '>', $RPT_FName or die "meaningless death!";
    print $OFH $report;
}

sub parse_db_file {
    my $DB_FName = shift;

    . . . code to parse DB File into data structure . . .

    return $tmpDB;
}

sub generate_db_report {
    my $tmpDB = shift;

    my $text;

    . . . code to turn data structure into a string . . .

    return $text;
}