#!/usr/bin/php
<?php

$length =   12;
array_shift($_SERVER['argv']);
foreach ($_SERVER['argv'] as $a) {
    if (is_numeric($a)) {
        $length =   $a;
        continue;
    }
}

class PasswordMaker
{
    /**
     * create a random obscure code
     *
     * Make an alphanumeric random string to be used to obscure ids.
     * Be careful, those obscure codes are case sensitive. Hence one
     * actually can't compare it using WHERE clause for case insensive
     * table (which is pretty much defualt). Therefore, use an additional
     * (numeric) primary key to load record from databse and compare
     * the obscure code wwith PHP's strink functions.
     *
     * @param int $length length between 2 and 255
     * @param bool $startLetter fist character will be a letter
     * @param bool $endLetter last character will be a letter
     * @param bool $capitalOnly use only capital letters
     * @return string
     */
    public function getRandom($length = 8, $startLetter = false, $endLetter = false, $capitalOnly = false)
    {
        if ($length > 255) {
            $length = 255;
        }
        if ($length < 2) {
            $length = 2;
        }

        $alpha  =   range('0', '9');
        $alpha  =   array_merge($alpha, array(
                    '!', '§', '$', '%', '&', '/', '(', ')', '=', '?'
                    , '-', '_', '+', '#', '.', ','
                ));
        $cntN   =   count($alpha);
        $alpha  =   array_merge($alpha, range('A', 'Z'));
        if (!$capitalOnly) {
            $alpha  =   array_merge($alpha, range('a', 'z'));
        }

        $cnt    =   count($alpha) - 1;
        $rc     =   array();

        // force obscurce code to start with a letter
        if ($startLetter) {
            $rc[]   =   $alpha[rand($cntN, $cnt)];
            --$length;
        }
        if ($endLetter) {
            --$length;
        }

        // fill with random letters and digists
        for ($i = 0; $i < $length; ++$i) {
            $rc[]   =   $alpha[rand(0, $cnt)];
        }

        if ($endLetter) {
            $rc[]   =   $alpha[rand($cntN, $cnt)];
        }

        return implode('', $rc);
    }
}

$maker  =   new PasswordMaker();
echo $maker->getRandom($length) . "\n";