#!/usr/bin/perl -w
use strict;

my $fname = "aaa.txt\0bla";
print "NAME: $fname\n";

if ( $fname =~ /\0/ ) {
    open( F, ">$fname" ) || die "could not open $fname, reason: $!";
    close(F);
}
else {
    print "No NULL BYTE in $fname\n";
}