#!/usr/bin/perl
use strict;
use warnings;

my @files = glob('./*.xml');

my %results;

foreach my $xmlname (@files) {
	open my $fh, '<', $xmlname or die "$xmlname: $!";
	
	while ( my $line = <$fh> ) {
		my ($name) = $line =~ /\<info_name\>([^<]+)\<\/info_name\>/
			or next;
		while ( my $l = <$fh> ) {
			$l =~ /\<it_size\>([^<]+)\<\/it_size\>/ or next;
			$results{$name} = $1;
			last;
		}
	}
}

print map { "$_ => $results{$_}\n" } keys %results;

##</code><code>##

jth@reina:~/tmp$ perl 848551.pl 
FZGA34177.b1 => 35000

##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;
use XML::LibXML;


my @files = glob('./*.xml');

my %results;

foreach my $xmlname (@files) {
	my $dom = XML::LibXML->load_xml(
		location => $xmlname,
		recover => 1, # no </t_volume> in example
	) or die $!;
	
	foreach my $node ( $dom->findnodes('//info') ) {
		$results{ $node->find('info_name') } = $node->find('it_size');
	}
}

print map { "$_ => $results{$_}\n" } keys %results;

##</code><code>##

jth@reina:~/tmp$ perl 848551.pl 
./848551.xml:55: parser error : Premature end of data in tag t_volume line 54

^
./848551.xml:55: parser error : Premature end of data in tag t_volume line 2

^
FZGA34177.b1 => 35000