#!/usr/bin/
#program to generate 6 Million unique codes, Oct 15, 2011.

open(MYOUTFILE, ">codesSixMil.txt"); #open for write, overwrite (>)

$count = 0; #keep track of how many codes generated
$count1 = 0; #keep track of how many codes duplicated
$desiredQuantity = 6000001;
@arrayOfResults =();

sub generate_random_string {
   my $stringsize = shift;
   my @alphanumeric = ('a'..'z', 3,4,6,7,9);
   my $randstring = join '', (map { $alphanumeric[rand@alphanumeric] } @alphanumeric)[0 .. $stringsize];
   return $randstring;
}

for ($i=0;$i<$desiredQuantity;$i++) {
   $returnvalue = generate_random_string(10);
   push(@arrayOfResults, $returnvalue);
   $count++;
}

#remove any potential duplicates 
@unique = grep { ++$count{$_} < 2 } @arrayOfResults;

#loop through array to output each code on its own line
#with a carriage return as required.

for ($i=0;$i<$desiredQuantity;$i++) {
    print @unique[$i], "\n";
    print MYOUTFILE @unique[$i], "\r\n";
    $count1++;
}
#do some rudimentary checking and output result.
print "\n---Code generation report--- \n\n";
print "First array: $count \n";
print "     Unique array: $count1 \n\n";
print "---There are ", $count-$count1, " code duplicates in this listing of ", $desiredQuantity, " ---\n\n\n";
 
#*** Close the file ***
close(MYOUTFILE);