在OS X 10.11 El Capitan，macOS 10.12 Sierra，macOS 10.13 High Sierra(< 10.13.3)上安装pecl和pear
问题描述：
So it looks like the new 'System Integrity Protection' lockdown of /usr (among other directories) makes pear and pecl a non-starter. Has anyone found a workaround short of disabling it?
答
有一种更简单的方法-无需禁用SIP或下载自己的副本:
There's a much easier way — no need to disable SIP or download your own copy:
sudo php /usr/lib/php/install-pear-nozlib.phar -d /usr/local/lib/php -b /usr/local/bin