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

my $filename = 'a@b';

open my $out, '>', $filename or die $!;
print {$out} 'Contents';
close $out or die $!;

opendir my $dir, '.' or die $!;
my @files = grep /@/, readdir $dir;

die 'Not found' unless grep $filename eq $_, @files;
print "Found\n";

unlink $filename;