先看重点：CAVEATS:
1. If you are using php-gearman, you need to add ppa:ondrej/pkg-gearman
2. If you are using apache2, you are advised to add ppa:ondrej/apache2
3. If you are using nginx, you are advise to add ppa:ondrej/nginx-mainline
or ppa:ondrej/nginx
通过下列命令安装PHP 7.3
$ sudo apt-get install software-properties-common
$ sudo add-apt-repository ppa:ondrej/php
$ sudo apt-get update
$ sudo apt-get install -y php7.3
安装完成后，使用如下命令检查PHP的版本
$ php -v
PHP 7.3.3-1+ubuntu18.04.1+deb.sury.org+1 (cli) (built: Mar 7 2019 20:31:49) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.3.3, Copyright (c) 1998-2018 Zend Technologies
with Zend OPcache v7.3.3-1+ubuntu18.04.1+deb.sury.org+1, Copyright (c) 1999-2018, by Zend Technologies
安装PHP 7.2
通过下列命令安装PHP 7.2
$ sudo apt-get install software-properties-common
$ sudo add-apt-repository ppa:ondrej/php
$ sudo apt-get update
$ sudo apt-get install -y php7.2
安装完成后，使用如下命令检查PHP的版本
$ php -v
PHP 7.2.16-1+ubuntu18.04.1+deb.sury.org+1 (cli) (built: Mar 7 2019 20:23:29) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
with Zend OPcache v7.2.16-1+ubuntu18.04.1+deb.sury.org+1, Copyright (c) 1999-2018, by Zend Technologies
安装PHP 7.1
通过下列命令安装PHP 7.1
$ sudo apt-get install software-properties-common
$ sudo add-apt-repository ppa:ondrej/php
$ sudo apt-get update
$ sudo apt-get install -y php7.1
安装完成后，使用如下命令检查PHP的版本
$ php -v
PHP 7.1.27-1+ubuntu18.04.1+deb.sury.org+1 (cli) (built: Mar 7 2019 20:02:25) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2018 Zend Technologies
with Zend OPcache v7.1.27-1+ubuntu18.04.1+deb.sury.org+1, Copyright (c) 1999-2018, by Zend Technologies
安装PHP 7.0
通过下列命令安装PHP 7.0
$ sudo apt-get install software-properties-common
$ sudo add-apt-repository ppa:ondrej/php
$ sudo apt-get update
$ sudo apt-get install -y php7.0
安装完成后，使用如下命令检查PHP的版本
$ php -v
PHP 7.0.33-5+ubuntu18.04.1+deb.sury.org+1 (cli) (built: Mar 8 2019 09:49:15) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.0.0, Copyright (c) 1998-2017 Zend Technologies
with Zend OPcache v7.0.33-5+ubuntu18.04.1+deb.sury.org+1, Copyright (c) 1999-2017, by Zend Technologies
安装PHP 7模块
使用如下命令安装PHP 7模块
$ sudo apt-cache search php7*
php-all-dev - package depending on all supported PHP development packages
php7.0 - server-side, HTML-embedded scripting language (metapackage)
php7.0-cgi - server-side, HTML-embedded scripting language (CGI binary)
php7.0-cli - command-line interpreter for the PHP scripting language
php7.0-common - documentation, examples and common module for PHP
php7.0-curl - CURL module for PHP
php7.0-dev - Files for PHP7.0 module development
php7.0-gd - GD module for PHP
php7.0-gmp - GMP module for PHP
...
php7.1-xml - DOM, SimpleXML, WDDX, XML, and XSL module for PHP
php7.1-xmlrpc - XMLRPC-EPI module for PHP
php7.1-zip - Zip module for PHP
php7.1-opcache - Zend OpCache module for PHP
php7.1 - server-side, HTML-embedded scripting language (metapackage)
php7.1-xsl - XSL module for PHP (dummy)
...
php7.2-bcmath - Bcmath module for PHP
php7.2-bz2 - bzip2 module for PHP
php7.2-cgi - server-side, HTML-embedded scripting language (CGI binary)
php7.2-cli - command-line interpreter for the PHP scripting language
php7.2-common - documentation, examples and common module for PHP
php7.2-curl - CURL module for PHP
php7.2-dba - DBA module for PHP
用如下命令，按需安装PHP扩展模块，安装之前，确保安装正确的PHP版本。
$ sudo apt-get install php7.2-mysql php7.2-curl php7.2-json php7.2-cgi php7.2-xsl
安装完成后，现在就可以开始php开发了。