在Ubuntu16.04LTS上安装php5.6

1. Add PHP 5.6 package sources to your system:

sudo add-apt-repository ppa:ondrej/php5-5.6

2. Update

sudo apt-get update

3. Install PHP

sudo apt-get install php5.6

4.Integrated with Apache2

libapache2-mod-php5.6

5. Enable php5.6

a2dismod php7.0
a2enmod php5.6
service apache2 restart