SMTP::get_lines(): string

1261    protected function get_lines()1262    {1263        //If the connection is bad, give up straight away1264        if (!is_resource($this->smtp_conn)) {1265            return '';1266        }1267        $data = '';1268        $endtime = 0;1269        stream_set_timeout($this->smtp_conn, $this->Timeout);1270        if ($this->Timelimit > 0) {1271            $endtime = time() + $this->Timelimit;1272        }1273        $selR = [$this->smtp_conn];1274        $selW = null;1275        while (is_resource($this->smtp_conn) && !feof($this->smtp_conn)) {1276            //Must pass vars in here as params are by reference1277            //solution for signals inspired by https://github.com/symfony/symfony/pull/65401278            set_error_handler(function () {1279                call_user_func_array([$this, 'errorHandler'], func_get_args());1280            });1281            $n = stream_select($selR, $selW, $selW, $this->Timelimit);1282            restore_error_handler();1283 1284            if ($n === false) {1285                $message = $this->getError()['detail'];1286 1287                $this->edebug(1288                    'SMTP -> get_lines(): select failed (' . $message . ')',1289                    self::DEBUG_LOWLEVEL1290                );1291 1292                //stream_select returns false when the `select` system call is interrupted1293                //by an incoming signal, try the select again1294                if (stripos($message, 'interrupted system call') !== false) {1295                    $this->edebug(1296                        'SMTP -> get_lines(): retrying stream_select',1297                        self::DEBUG_LOWLEVEL1298                    );1299                    $this->setError('');1300                    continue;1301                }1302 1303                break;1304            }1305 1306            if (!$n) {1307                $this->edebug(1308                    'SMTP -> get_lines(): select timed-out in (' . $this->Timelimit . ' sec)',1309                    self::DEBUG_LOWLEVEL1310                );1311                break;1312            }1313 1314            //Deliberate noise suppression - errors are handled afterwards1315            $str = @fgets($this->smtp_conn, self::MAX_REPLY_LENGTH);1316            $this->edebug('SMTP INBOUND: "' . trim($str) . '"', self::DEBUG_LOWLEVEL);1317            $data .= $str;1318            //If response is only 3 chars (not valid, but RFC5321 S4.2 says it must be handled),1319            //or 4th character is a space or a line break char, we are done reading, break the loop.1320            //String array access is a significant micro-optimisation over strlen1321            if (!isset($str[3]) || $str[3] === ' ' || $str[3] === "\r" || $str[3] === "\n") {1322                break;1323            }1324            //Timed-out? Log and break1325            $info = stream_get_meta_data($this->smtp_conn);1326            if ($info['timed_out']) {1327                $this->edebug(1328                    'SMTP -> get_lines(): stream timed-out (' . $this->Timeout . ' sec)',1329                    self::DEBUG_LOWLEVEL1330                );1331                break;1332            }1333            //Now check if reads took too long1334            if ($endtime && time() > $endtime) {1335                $this->edebug(1336                    'SMTP -> get_lines(): timelimit reached (' .1337                    $this->Timelimit . ' sec)',1338                    self::DEBUG_LOWLEVEL1339                );1340                break;