use strict;
use XML::XPath;

my $date = "2-2004";
my @values =  findmax($date);
print join(",",@values),"\n";

sub findmax{
    my $date = shift;
    my $xp = XML::XPath->new(filename => 'test.xml');
    my $max = $xp->findvalue("/AnnualWeatherRecord/MonthlyWeatherRecor
+d[./date=\"$date\"]/temperature/maxdrybulb/\@number");
    return ($date,$max);
}
__END__
2-2004, 50.25
[download]

Hello johnny!
thanks a lot, this really helps. I needed to look in the daily weather records and not in the monthly
one's, but that meant a very minor change in the code, and I'm getting the results I need.

I'll have to come back here incase I need more help:)

*Thanks to all the others for their code too.*

Cheers
perl_seeker:)

Hello,
would you be able to tell me how to code this, still not able to use XML::XPath much:

I need to search the XML file in concern for all the DailyWeatherRecords for a particular month.

Say for the month of January, I need to search for those DailyWeatherRecords which have a "1" in the middle of the
date attribute value, for example "1-1-2004" and "2-1-2004".I'm not sure how to look in the middle of the date value.

The input to the sub that does this is the month i.e January or "1". For all the DailyWeatherRecords for the month of
January, I need to extract the value of maxdrybulb if it is greater than 30.0, and the date. The sub should
return as an array the list of dates and maxdrybulb values (only if it is greater than 30.0)

For example the array might look like:

1-1-2004 
33.95
2-1-2004
30.95
[download]

Thanks in advance.

perl_seeker
:)

If you insist on using XPath, here's a version. But in this case, I'd say using something like XML::Simple is simpler.

use strict;
use XML::XPath;

my $month = 1;
my $min = 30;
my $match = findmax($month,$min);
foreach my $t(@$match){
    print "$t->[0],$t->[1]\n";
}


sub findmax{
    my $month = shift;
    my $min = shift;
    $month = "-$month-";
    my @result = ();
    
    my $xp = XML::XPath->new(filename => 'test.xml');
    my $nodes = $xp->findnodes("//DailyWeatherRecord[contains(date,'$m
+onth') and temperature/maxdrybulb[\@number>$min]");
    foreach my $node($nodes->get_nodelist){
        push @result,[$xp->findvalue("./date",$node),$xp->findvalue(".
+//maxdrybulb/\@number",$node)];
    }
    return \@result;
}

__END__
1-1-2004,33.95
[download]

For this XML::Twig can be used.

In below code, input date is given via command line.

you can get the mindrybulb value also just by adding some more code in the handler part.

use XML::Twig;
undef $/;
my $date=$ARGV[0];
my $s=<DATA>;
my (@max,@min);
my $t=new XML::Twig(
   twig_handlers=>{
   "AnnualWeatherRecord"=>sub{my ($c)=$_[1]->get_xpath("//DailyWeather
+Record/date[string()=\"$date\"]/../temperature/maxdrybulb[\@number]")
+;
push @max,[$date,$c->att("number")] if (defined $c and defined $c->att
+("number"))} 
            }
        );
$t->parse($s);
local $"="\n";
print @$_ for @max;

__DATA__
<AnnualWeatherRecord>
 <DailyWeatherRecord>
  <date>1-1-2004</date> 
 <temperature>
 <maxdrybulb unit="degrees-centigrade" number="30.95"/>
  <mindrybulb unit="degrees-centigrade" number="30.95"/> 
  <maxwetbulb unit="degrees-centigrade" number="33.53"/> 
  <minwetbulb unit="degrees-centigrade" number="30.53"/> 
  </temperature>
  <totalrainfall unit="mm" number="0.5"/> 
  </DailyWeatherRecord>
   </AnnualWeatherRecord>
[download]

Just a quick comment: if you don't want to have to backslash quotes in the XPath expression, you can use custom delimiters, one of those features that make me love Perl:

get_xpath( qq{//DailyWeatherRecord/date[string()="$date"]})

use strict;
use warnings;
use XML::Simple;

# read in the XML data file
open( INFILE, '<', 'xml_input_file.xml' )
    or die "error opening input file!";
undef $/; # slurp mode
my $infile = <INFILE>;
close INFILE;

# parse the XML file using XML::Simple
my $dataref = XMLin( $infile );

# view the parsed data structure
use Data::Dumper;
print Dumper( $dataref );
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  use XML::Smart ;

  my $date = '1-2-2004' ;
  
  my $xml = new XML::Smart('your_file.xml') ;
  
  my $node = $xml->{AnnualWeatherRecord}{DailyWeatherRecord}('date' , 
+'eq' , $date) ;
  
  my $max = $node->{temperature}{maxdrybulb}{number} ;

  my @array = ($date , $max) ;
[download]