可重复运行 如何将这段代码用hash和getopts的方式编写？

alphafighter

<code>
#！perl
use strict;
use warnings;

my $filename = 'dummy.pepmasses';
my $from     = 0;
my $to       = 0;
print "What range of information do you want to know ?\n";
{
    my $str = <STDIN>;
    chomp $str;
    ($from, $to) =  split /\.\./, $str;
}

# open file
my $ifile_fh;
open $ifile_fh, '<', $filename or
    die "Cannot open file $filename: $!\n";

# skip header
readline $ifile_fh;

my $prepnumber = 0;
my $summass = 0;
while (defined (my $line = <$ifile_fh>) ) {
    # read each line in file
    chomp $line;
    my $mz_value = (split /\s+/, $line)[2];
    if ($mz_value >= $from and $mz_value <= $to) {
        # print matched line
        print "$line\n";
        ++$prepnumber;
                $summass = $mz_value+$summass;
    }
}
print "prepnumber=$prepnumber\n" if $prepnumber;
print "average m/z number = $summass/$prepnumber\n";

close $ifile_fh;

__END__
</code>

网上看了不少getopts的例子但是看不懂。还有我的这段代码如果使用起来就会一遍遍扫描整个文件，据说用hash就会好很多。

另外求一个能够像elipse编辑java那样能够在编写中提示错误的perl编辑软件。

谢谢帮忙~~