#!/usr/bin/env perl

use strict;
use warnings;

use XML::Parser;

my $parser = XML::Parser::->new(Handlers => {
    Start   => \&hdl_start,
    End     => \&hdl_end,
    Char    => \&hdl_char,
    Default => \&hdl_def,
    Final   => \&hdl_final,
});

my @xml_files
    = qw{./pm_xml_parser_test_file1.xml ./pm_xml_parser_test_file2.xml};

for (@xml_files) {
    _init_handler_vars('filename');
    get_value($_);
}

sub get_value {
    my $file = shift;

    my $returned = $parser->parsefile($file);

    if (defined $returned) {
        print "Wanted content: '$returned'\n";
    }
    else {
        print "Wanted content not found!\n";
    }

    return;
}

# Private scope for handler variables
{
    my ($wanted_element, $in_wanted_element,
        $wanted_content, $found_wanted_content);

    sub _init_handler_vars {
        $wanted_element = shift;
        $in_wanted_element = 0;
        $wanted_content = '';
        $found_wanted_content = 0;

        return;
    }

    sub hdl_start {
        my ($expat, $element, $attr, @vals) = @_;

        if ($element eq $wanted_element) {
            $in_wanted_element = 1;
        }

        return;
    }

    sub hdl_end {
        my ($expat, $element) = @_;

        if ($element eq $wanted_element) {
            $in_wanted_element = 0;
        }

        return;
    }

    sub hdl_char {
        my ($expat, $string) = @_;

        if ($in_wanted_element) {
            if ($string) {
                $found_wanted_content = 1;
                $wanted_content =  $string;
            }
        }

        return;
    }

    sub hdl_def {
        my ($expat, $string) = @_;

        # Default handler actions here

        return;
    }

    sub hdl_final {
        my ($expat) = @_;

        return unless $found_wanted_content;
        return $wanted_content;
    }
}

##</code><code>##

$ cat ./pm_xml_parser_test_file1.xml
<root_element>
    <filename>pm_xml_parser_test_file1.xml</filename>
</root_element>

$ cat ./pm_xml_parser_test_file2.xml
<root_element>
    <filename>pm_xml_parser_test_file2.xml</filename>
</root_element>

##</code><code>##

$ pm_xml_parser_test.pl
Wanted content: 'pm_xml_parser_test_file1.xml'
Wanted content: 'pm_xml_parser_test_file2.xml'