Ubuntu 16.04 安装 swoole

1. 执行 sudo pecl install swoole

   Build process completed successfully
   Installing '/usr/lib/php/20160303/swoole.so'
   install ok: channel://pecl.php.net/swoole-1.9.20
   configuration option "php_ini" is not set to php.ini location
   You should add "extension=swoole.so" to php.ini

2. php.ini中 添加  extension=/usr/lib/php/20160303/swoole.so
3. 注：需要在cli下的php.ini中加入，否则只会在phpinfo()能看到 php -m 却没有 

   Configuration File (php.ini) Path: /etc/php/7.1/cli
   Loaded Configuration File:         /etc/php/7.1/cli/php.ini
   Scan for additional .ini files in: /etc/php/7.1/cli/conf.d
   Additional .ini files parsed:      /etc/php/7.1/cli/conf.d/10-mysqlnd.ini,

4. 在 

   Loaded Configuration File: /etc/php/7.1/cli/php.ini 中添加 然后重启

参考：http://www.cnblogs.com/cxscode/p/7376711.html