Sniffer::unknown(): string

127    public function unknown()128    {129        $body = $this->file->get_body_content();130 131        $ws = strspn($body, "\x09\x0A\x0B\x0C\x0D\x20");132        if (strtolower(substr($body, $ws, 14)) === '<!doctype html'133            || strtolower(substr($body, $ws, 5)) === '<html'134            || strtolower(substr($body, $ws, 7)) === '<script') {135            return 'text/html';136        } elseif (substr($body, 0, 5) === '%PDF-') {137            return 'application/pdf';138        } elseif (substr($body, 0, 11) === '%!PS-Adobe-') {139            return 'application/postscript';140        } elseif (substr($body, 0, 6) === 'GIF87a'141            || substr($body, 0, 6) === 'GIF89a') {142            return 'image/gif';143        } elseif (substr($body, 0, 8) === "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A") {144            return 'image/png';145        } elseif (substr($body, 0, 3) === "\xFF\xD8\xFF") {146            return 'image/jpeg';147        } elseif (substr($body, 0, 2) === "\x42\x4D") {148            return 'image/bmp';149        } elseif (substr($body, 0, 4) === "\x00\x00\x01\x00") {150            return 'image/vnd.microsoft.icon';151        }152 153        return $this->text_or_binary();154    }