生成随机用户名

function generateRandomString($length = 10) {
    $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    $randomString = '';
    for ($i = 0; $i < $length; $i++) {
        $randomString .= $characters[rand(0, strlen($characters) - 1)];
    }
    return $randomString;
}

 

function getRandomString($length = 6) 
{
    $validCharacters = "abcdefghijklmnopqrstuxyvwzABCDEFGHIJKLMNOPQRSTUXYVWZ+-*#&@!?"; 
    $validCharNumber = strlen($validCharacters);
    $result = "";
    for ($i = 0; $i < $length; $i++) {       
        $index = mt_rand(0, $validCharNumber - 1);        
        $result .= $validCharacters[$index];    
    }
     return $result;
}

http://www.phpf1.com/tutorial/generate-random-string.html