Create usernames - based on FIRST & LAST name

#!/usr/local/ActivePerl-5.6/bin/perl -w

#
# make_usernames FIRST LAST NUM_USERNAMES
# 
# FIRST : First name
# LAST  : Last name
# NUM   : A maximum number of usernames to create
#
# Note : NUM usernames will not always be created because
#        the usernames are guaranteed to be unique.  So, if a 
#        duplicate username is generated, it is ignored
#        and not added to the list again.
#


$first = $ARGV[0];
$last = $ARGV[1];
$num_names = $ARGV[2];

$max_username_len = 10;

$num=0;
while($num < $num_names)
{
    # Flip a coin for first or last name
    $rnd = int(rand(2));
    if ($rnd == 0) {
        $username = $first;
               $other = $last;
    } else {
        $other = $first;
        $username = $last;
    }

    # Append or prepend
    $rnd = int(rand(2));

    while (length $username < $max_username_len)
    {
        # Retrieve a random character from the unchosen name
        $k = int(rand(length $other));
    
        if($rnd == 0)
        {
            # Append it to the user name
            $username = $username . substr($other, $k, 1);
        } else {
            # Prepend it to the user name
            $username = substr($other, $k, 1) . $username;
        }
    }
    $users{$username} = $num++;
}

# Get the keys - they are the usernames
@unique = keys(%users);

# Pring them in a list of commas
$with_commas = join(",", @unique);
print "$with_commas\n";
exit(0)