In this script, I compared two directories, compared two files from those directories, and did a diff on the two files.

#!/usr/bin/perl

use strict;
use warnings;
use File::Compare;
use File::DirCompare;
use Text::Diff;
use Text::Diff::Table;
use YAML;
use YAML::Dumper;

my $dir1 = '/usr/lib/perl5/5.8.8/CGI';
my $dir2 = '/usr/lib/perl5/5.8.8/Shell';

File::DirCompare->compare($dir1, $dir2, sub {
    my  ($a, $b) = @_;
    if (! $b) {
        printf "Only in %s: %s\n", dirname($a), basename($a);
    }
    elsif (! $a) {
        printf "Only in %s: %s\n", dirname($b), basename($b);
    }
    else {
        print "Files $a and $b differ\n";
    }
});

if ($dir1 eq $dir2) {
    print "They're equal\n";
} 
else {
    print "They're not equal\n";
}     

my $tst1 = '/usr/lib/perl5/5.8.8/CGI.pm';
my $tst2 = '/usr/lib/perl5/5.8.8/Shell.pm';

my $diff = Text::Diff::Table->new;
$diff = diff $tst1, $tst2, { STYLE => "Table" };

my $dumper = YAML::Dumper->new;
$dumper->indent_width(4);
print $dumper->dump($diff); 

if (compare($tst1, $tst2) == 0) {
    print "They're equal\n";
}
else {
    print "They're not equal\n";
}
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