#!/usr/bin/perl

use CGI::Carp 'fatalsToBrowser';
use strict;
use warnings;
use CGI;
my $query = CGI->new;
my $usedpw = "logfile.txt";
my @chars;
print $query->header;

# opening for reading
open(USEDPW, "< $usedpw") or die "poo poo on reading $!";
flock USEDPW, 1;
# Storing the file handle, not a scalar, into an array for full reading
my @used_pw = <USEDPW>;
close(USEDPW);
# remove trailing whitespace
chomp my $used_pw;

while (<USEDPW>)
{
my $pw = @chars[map{rand @chars} (1..17)];
}
unless ($_ ne my $pw) {
print "Your unique ID is: $pw\n";
}

my $pw;
open(USEDPW, "> $usedpw") or die "crap on me for writing $!";
flock USEDPW, 2;
print USEDPW "$pw\n";
close(USEDPW);