#!/usr/bin/perl
use strict;
use warnings;
my @against = qw( hi $hi @hi %hi );
foreach my $outer (@against) {
    foreach (@against) {
        my $inner = quotemeta;
        print "[$outer] against [$inner]: ";
        if ($outer =~ /$inner/) {
            print "MATCHES\n";
        }
        else {
            print "NO WAY\n";
        }
    }
}

__END__

[hi] against [hi]: MATCHES
[hi] against [\$hi]: NO WAY
[hi] against [\@hi]: NO WAY
[hi] against [\%hi]: NO WAY
[$hi] against [hi]: MATCHES
[$hi] against [\$hi]: MATCHES
[$hi] against [\@hi]: NO WAY
[$hi] against [\%hi]: NO WAY
[@hi] against [hi]: MATCHES
[@hi] against [\$hi]: NO WAY
[@hi] against [\@hi]: MATCHES
[@hi] against [\%hi]: NO WAY
[%hi] against [hi]: MATCHES
[%hi] against [\$hi]: NO WAY
[%hi] against [\@hi]: NO WAY
[%hi] against [\%hi]: MATCHES
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