Re: RegEx Riddle

[prasadbabu]

in reply to RegEx Riddle

Hi ferddle,

You can use negative look ahead regex to accomplish your job. If you have whole file in a string $kml, then

use strict;
use warnings;
use Data::Dumper;

my $kml = do { local $/, <DATA>};

my %hash;

while ($kml =~ m/<name>((?:(?!<name>).)*)<\/name>\s*(<coordinates>(?:(
+?:(?!<coordinates>).)*)<\/coordinates>)/gs){

$hash{$1} = $2;

}

print Dumper \%hash;

output:
-------
$VAR1 = {
          'One more' => '<coordinates>56,78,0</coordinates>',
          'This is the title' => '<coordinates>12,34,0</coordinates>'
        };

You can learn more about positive look ahead at perlre.

updated, added code. Thanks to ikegami for pointing out the mistake.

[reasonablekeith]

I'd take a different tack, and loop through the placemark nodes.

I've also assumed the OP wants all coords, rather than the last one as per your example, so have dumped them in a hash of arrays...

my $xml = 'your xml...';
my %coords_by_name;

while ($xml =~ m{<Placemark>(.*?)</Placemark>}gs ) {
    my $placemark_snippet = $1;
    if ( $placemark_snippet =~ m{(<name>.*?</name>)}gs ) {
        my $name = $1;
        while ( $placemark_snippet =~ m{(<coordinates>.*?</coordinates
+>)}gs ) {
            push @{$coords_by_name{$name}}, $1;
        }
    }
}

use Data::Dumper;
print Dumper(\%coords_by_name);

I agree with the other comments though, you need a good reason to not use a proper xml parser, the above code won't be very robust, and only supports a fraction of the valid ways you could write that xml.