PHP中的用户名建议

Question

I want to create a function in php to suggest usernames, if the entered username is not available. For example, username entered is 'bingo' and it not available, then the system should suggest a list of usernames like this

bi_n_go
go-nbi
b-n_gio
b-ng-oi
...

Rules for creating username are :

• minimum length 6
• username can contain maximum 3 symbols(only hyphens, underscores)
• username must start with alphanumeric and end with alphanumeric

Any help and suggestions will be highly appreciable. Thanks.

Answer 1

Try following code:

<?php
//mutates given user name, producing possibly incorrect username
function mutate($uname)
{
    $x = str_split($uname);

    //sort with custom function, that tries to produce only slightly
    //random user name (as opposed to completely shuffling)
    uksort($x, function($a, $b)
    {
        $chance = mt_rand(0, 3);
        if ($chance == 0)
        {
            return $b - $a;
        }
        return $a - $b;
    });

    //insert randomly dashes and underscores
    //(multiplication for getting more often 0 than 3)
    $chance = mt_rand(0, 3) * mt_rand(0, 3) / 3.;
    for ($i = 0; $i < $chance; $i ++)
    {
        $symbol = mt_rand() & 1 ? '-' : '_';
        $pos = mt_rand(0, count($x));
        array_splice($x, $pos, 0, $symbol);
    }
    return join('', $x);
}

//validates the output so you can check whether new user name is correct
function validate($uname)
{
    //does not start nor end with alphanumeric characters
    if (!preg_match('/^[a-zA-Z0-9].*[a-zA-Z0-9]$/', $uname))
    {
        return false;
    }
    //does contain more than 3 symbols
    $noSymbols = preg_replace('/[^a-zA-Z0-9]+/', '', $uname);
    if (strlen($uname) - strlen($noSymbols) > 3)
    {
        return false;
    }
    //shorter than 6 characters
    if (strlen($uname) < 6)
    {
        return false;
    }
    return true;
}

Example usage:

$uname = 'bingo';
$desired_num = 5;
$sug = [];
while (count($sug) < $desired_num)
{
    $mut = mutate($uname);
    if (!validate($mut))
    {
        continue;
    }
    if (!in_array($mut, $sug) and $mut != $uname)
    {
        $sug []= $mut;
    }
}
print_r($sug);

Example output:

Array
(
    [0] => i-g-obn
    [1] => bi-gno
    [2] => bi_ngo
    [3] => i-bnog
    [4] => bign-o
)