添加更新源
sudo vi /etc/apt/sources.list
deb http://mirrors.163.com/debian/ stable main
deb-src http://mirrors.163.com/debian/ stable main
卸载php5
sudo apt-cache search php5
sudo apt-get autoremove --purge php5
dpkg -l
sudo apt-get autoremove --purge php5*
安装php7
sudo apt-get install php7.0
sudo apt-get install php7.0-fpm php7.0-mysql php7.0-common php7.0-gd php7.0-json php7.0-cli php7.0-curl php7.0-mbstring
