以安装swoole为例：
#Ubuntu/Debian上是这样(php-pear包含pecl,php5-dev包含phpize,pecl依赖phpize)
apt-get install php-pear php5-dev
pecl install swoole

#CentOS/Redhat上应该是这样
yum install php-pear php-devel
pecl install swoole

#如果是自行编译的PHP(假设安装目录为/opt/php/7.0)
/opt/php/7.0/bin/phpize
/opt/php/7.0/bin/pecl