一个能生成各种模式随机字符串的函数
/** *随机字符串生成函数 * @param int $length 生成长度 * @param int $mode 字符模式 * @return string */function generate($length=5, $mode) { $str = $gen_str = ''; switch ($mode) { case 1: $str = '0123456789'; break; case 2: $str = 'abcdefghijklmnopqrstuvwxyz'; break; case 3: $str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'; break; case 4: $str = 'abcdefghijklmnopqrstuvwxyz0123456789'; break; case 5: $str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'; break; case 6: $str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'; break; default: $str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'; break; } for ($i = 0; $i < $length; $i++) { $num = mt_rand(0, strlen($str) - 1); $gen_str .= $str[$num]; } return $gen_str;}