Note that the XML chunk you posted is not a well-formed XML, as it lacks a root node. I wrapped it into
<root>
...
</root>
and used XML::LibXML to get the desired output:
#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };
use XML::LibXML;
my @files = @ARGV[0, 1];
my %extracted;
for my $xml_file (@files) {
my $dom = 'XML::LibXML'->load_xml(location => $xml_file);
for my $file ($dom->findnodes('/root/file')) {
my $original = $file->{original};
for my $unit ($file->findnodes('body/unit')) {
my $id = $unit->{id};
my $title = $unit->findvalue('title');
$extracted{$original}{$id}{$xml_file} = $title;
}
}
}
for my $file (keys %extracted) {
for my $id (keys %{ $extracted{$file} }) {
say join "\t", $file, $id, @{ $extracted{$file}{$id} }{@files}
+;
}
}
($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,