#!/usr/bin/perl -w
use strict;
use vars qw($ref);

$ref = [1,2,3,4];
print join(',',@$ref)."\n";

my $string = "$ref";
#print join(',',@$string)."\n";  # this does not work

my $getref = unstringify($string) || die "Cannot find ref!";
print join(',',@$getref)."\n";

sub unstringify {
    # works only on globals in package main !
    # but you could also use another hash 
    # ( instead of %main:: )
    my $string = shift;
    for (keys %{main::}) {
        my $value;
        next unless $value = ${${main::}{$_}};
        next unless ref($value);
        next unless $value eq $string;  # implicit stringification
        return $value;
    }
    return;
}