mt_rand()를 이용하여 해당 길이만큼의 랜덤문자열을 생성하는 함수를 소개합니다.

[code]

    function numeric($length)
    {
        $chars = "1234567890";
        $clen   = strlen( $chars )-1;
        $id  = '';

        for ($i = 0; $i < $length; $i++) {
            $id .= $chars[mt_rand(0,$clen)];
        }
        return ($id);
    }

    function alphabets($length)
    {
        $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
        $clen   = strlen( $chars )-1;
        $id  = '';

        for ($i = 0; $i < $length; $i++) {
            $id .= $chars[mt_rand(0,$clen)];
        }
        return ($id);
    }

    function alphaNumeric($length)
    {
        $chars = "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
        $clen   = strlen( $chars )-1;
        $id  = '';

        for ($i = 0; $i < $length; $i++) {
            $id .= $chars[mt_rand(0,$clen)];
        }
        return ($id);
    }

    function alphaNumericWithoutCase($length)
    {
        $chars = "1234567890abcdefghijklmnopqrstuvwxyz";
        $clen   = strlen( $chars )-1;
        $id  = '';

        for ($i = 0; $i < $length; $i++) {
            $id .= $chars[mt_rand(0,$clen)];
        }
        return ($id);
    }

[/code]
$length는 생성할 랜덤문자열 길이값입니다.