留言无法显示，php server.php报错（看不懂啥原因）

留言发送出去没有在上面显示，是空白的

这是php -S 192.168.121.136:9901 -d ./ 运行时相关代码

还有php server.php报错：

connection open: 1/var/www/html/websocket/server/server.php:11:

bool(false)

PHP Fatal error:  Uncaught Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php:41

Stack trace:

#0 [internal function]: {closure}(Object(swoole_websocket_server), Object(swoole_websocket_frame))

#1 /var/www/html/websocket/server/server.php(53): swoole_http_server->start()

#2 {main}

  thrown in /var/www/html/websocket/server/server.php on line 41

PHP Stack trace:

PHP   1. {main}() /var/www/html/websocket/server/server.php:0

PHP   2. swoole_websocket_server->start() /var/www/html/websocket/server/server.php:53

Fatal error: Uncaught Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php on line 41

Call Stack:

    0.0005     395760   1. {main}() /var/www/html/websocket/server/server.php:0

    0.0051     399368   2. swoole_websocket_server->start() /var/www/html/websocket/server/server.php:53

Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php on line 41

Call Stack:

    0.0005     395760   1. {main}() /var/www/html/websocket/server/server.php:0

    0.0051     399368   2. swoole_websocket_server->start() /var/www/html/websocket/server/server.php:53

   73.8491     405720   3. {closure:/var/www/html/websocket/server/server.php:16-46}() /var/www/html/websocket/server/server.php:53

[2019-12-03 21:12:18 *15942.1] ERROR zm_deactivate_swoole (ERROR 503): Fatal error: Uncaught Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php:41

Stack trace:

#0 [internal function]: {closure}(Object(swoole_websocket_server), Object(swoole_websocket_frame))

#1 /var/www/html/websocket/server/server.php(53): swoole_http_server->start()

#2 {main}

  thrown in /var/www/html/websocket/server/server.php on line 41.

[2019-12-03 21:12:18 $15938.0] WARNING swManager_check_exit_status: worker#1 abnormal exit, status=255, signal=0

connection close: 1

connection open: 2/var/www/html/websocket/server/server.php:11:

bool(false)

PHP Fatal error:  Uncaught Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php:41

Stack trace:

#0 [internal function]: {closure}(Object(swoole_websocket_server), Object(swoole_websocket_frame))

#1 /var/www/html/websocket/server/server.php(53): swoole_http_server->start()

#2 {main}

  thrown in /var/www/html/websocket/server/server.php on line 41

PHP Stack trace:

PHP   1. {main}() /var/www/html/websocket/server/server.php:0

PHP   2. swoole_websocket_server->start() /var/www/html/websocket/server/server.php:53

Fatal error: Uncaught Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php on line 41

Call Stack:

    0.0005     395760   1. {main}() /var/www/html/websocket/server/server.php:0

    0.0051     399368   2. swoole_websocket_server->start() /var/www/html/websocket/server/server.php:53

Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php on line 41

Call Stack:

    0.0005     395760   1. {main}() /var/www/html/websocket/server/server.php:0

    0.0051     399368   2. swoole_websocket_server->start() /var/www/html/websocket/server/server.php:53

  104.4516     405704   3. {closure:/var/www/html/websocket/server/server.php:16-46}() /var/www/html/websocket/server/server.php:53

[2019-12-03 21:12:48 *16002.1] ERROR zm_deactivate_swoole (ERROR 503): Fatal error: Uncaught Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php:41

Stack trace:

#0 [internal function]: {closure}(Object(swoole_websocket_server), Object(swoole_websocket_frame))

#1 /var/www/html/websocket/server/server.php(53): swoole_http_server->start()

#2 {main}

  thrown in /var/www/html/websocket/server/server.php on line 41.

[2019-12-03 21:12:48 $15938.0] WARNING swManager_check_exit_status: worker#1 abnormal exit, status=255, signal=0

connection open: 3/var/www/html/websocket/server/server.php:11:

bool(false)

PHP Fatal error:  Uncaught Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php:41

Stack trace:

#0 [internal function]: {closure}(Object(swoole_websocket_server), Object(swoole_websocket_frame))

#1 /var/www/html/websocket/server/server.php(53): swoole_http_server->start()

#2 {main}

  thrown in /var/www/html/websocket/server/server.php on line 41

PHP Stack trace:

PHP   1. {main}() /var/www/html/websocket/server/server.php:0

PHP   2. swoole_websocket_server->start() /var/www/html/websocket/server/server.php:53

Fatal error: Uncaught Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php on line 41

Call Stack:

    0.0005     395760   1. {main}() /var/www/html/websocket/server/server.php:0

    0.0051     399368   2. swoole_websocket_server->start() /var/www/html/websocket/server/server.php:53

Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php on line 41

Call Stack:

    0.0005     395760   1. {main}() /var/www/html/websocket/server/server.php:0

    0.0051     399368   2. swoole_websocket_server->start() /var/www/html/websocket/server/server.php:53

  117.7138     405704   3. {closure:/var/www/html/websocket/server/server.php:16-46}() /var/www/html/websocket/server/server.php:53

[2019-12-03 21:13:02 *15941.0] ERROR zm_deactivate_swoole (ERROR 503): Fatal error: Uncaught Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php:41

Stack trace:

#0 [internal function]: {closure}(Object(swoole_websocket_server), Object(swoole_websocket_frame))

#1 /var/www/html/websocket/server/server.php(53): swoole_http_server->start()

#2 {main}

  thrown in /var/www/html/websocket/server/server.php on line 41.

[2019-12-03 21:13:02 $15938.0] WARNING swManager_check_exit_status: worker#0 abnormal exit, status=255, signal=0

connection close: 4

connection close: 2

connection close: 5

connection open: 7/var/www/html/websocket/server/server.php:11:

bool(false)

connection close: 6

PHP Fatal error:  Uncaught Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php:41

Stack trace:

#0 [internal function]: {closure}(Object(swoole_websocket_server), Object(swoole_websocket_frame))

#1 /var/www/html/websocket/server/server.php(53): swoole_http_server->start()

#2 {main}

  thrown in /var/www/html/websocket/server/server.php on line 41

PHP Stack trace:

PHP   1. {main}() /var/www/html/websocket/server/server.php:0

PHP   2. swoole_websocket_server->start() /var/www/html/websocket/server/server.php:53

Fatal error: Uncaught Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php on line 41

Call Stack:

    0.0005     395760   1. {main}() /var/www/html/websocket/server/server.php:0

    0.0051     399368   2. swoole_websocket_server->start() /var/www/html/websocket/server/server.php:53

Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php on line 41

Call Stack:

    0.0005     395760   1. {main}() /var/www/html/websocket/server/server.php:0

    0.0051     399368   2. swoole_websocket_server->start() /var/www/html/websocket/server/server.php:53

  190.4915     414496   3. {closure:/var/www/html/websocket/server/server.php:16-46}() /var/www/html/websocket/server/server.php:53

[2019-12-03 21:14:14 *16028.1] ERROR zm_deactivate_swoole (ERROR 503): Fatal error: Uncaught Error: Call to undefined function apc_fetch() in /var/www/html/websocket/server/server.php:41

Stack trace:

#0 [internal function]: {closure}(Object(swoole_websocket_server), Object(swoole_websocket_frame))

#1 /var/www/html/websocket/server/server.php(53): swoole_http_server->start()

#2 {main}

  thrown in /var/www/html/websocket/server/server.php on line 41.

[2019-12-03 21:14:15 $15938.0] WARNING swManager_check_exit_status: worker#1 abnormal exit, status=255, signal=0