Question

I would like to write a xml parsing script in Perl that prints all the firstname values from the following xml file using XML::SAX module.

<employees>
    <employee>
        <firstname>John</firstname>
        <lastname>Doe</lastname>
        <age>gg</age>
        <department>Operations</department>
        <amount Ccy="EUR">100</amount>
        </employee>
        <employee>
        <firstname>Larry</firstname>
        <lastname>Page</lastname>
        <age>45</age>
        <department>Accounts</department>
        <amount Ccy="EUR">200</amount>
    </employee>
    <employee>
        <firstname>Harry</firstname>
        <lastname>Potter</lastname> 
        <age>50</age>
        <department>Human Resources</department>
        <amount Ccy="EUR">300</amount>
    </employee>
</employees>

Can anyone help me with sample script?
I am a new to Perl.

Answer 1

Here’s an example using XML::SAX. I’ve used XML::SAX::PurePerl.

#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
use XML::SAX::ParserFactory;
use XML::SAX::PurePerl;

my $characters;
my @firstnames;

my $factory = new XML::SAX::ParserFactory;
#Let's see which handlers we have available
#print Dumper $factory;
my $handler = new XML::SAX::PurePerl;
my $parser = $factory->parser(
              Handler => $handler,
              Methods => {
                  characters => sub {
                      $characters = shift->{Data};
                  },
                  end_element => sub {
                      push @firstnames, $characters if shift->{LocalName} eq 'firstname';
                  }
              }
          );

$parser->parse_uri("sample.xml");
print Dumper \@firstnames;

Output:

$VAR1 = [
          'John',
          'Larry',
          'Harry'
        ];

I use $characters to hold character data, and push its contents onto @firstnames whenever I see a closing firstname tag.