nginx 配置
root /var/www/php;  // 新版本 root 要放在这里次啊能起作用
location   ~\.php$ {
                        root            /var/www/php;
                        index          index.php index.htmlindex.htm;
                        fastcgi_pass    unix:/run/php/php7.4-fpm.sock;
                        fastcgi_index   index.php;
                        include         fastcgi_params;
                }
服务器 安装 php-fpm
然后 nginx 通过unix:/run/php/php7.4-fpm.sock 转发请求到php-fpm上
tips : fastcgi_params 添加以下配置(若访问首页空白)
fastcgi_param SCRIPT_FILENAME     $document_root$fastcgi_script_name;
fastcgi_param PATH_INFO           $fastcgi_script_name;
//从nginx变量 传到  cgi变量(即php变量)
fastcgi_param 参数详解  就是从nginx传过去的变量 可以通过_SERVER 获取
关键变量是 
DOCUMENT_ROOT  php 项目文件所在文件夹
SCRIPT_NAME  php 项目文件
SCRIPT_FILENAME  $document_root$fastcgi_script_name; //php 文件全路径
nginx变量 都是$开头小写下划线组合
fastcgi_param  QUERY_STRING       $query_string;
fastcgi_param  REQUEST_METHOD     $request_method;
fastcgi_param  CONTENT_TYPE       $content_type;
fastcgi_param  CONTENT_LENGTH     $content_length;
fastcgi_param  SCRIPT_NAME        $fastcgi_script_name;
fastcgi_param  REQUEST_URI        $request_uri;
fastcgi_param  DOCUMENT_URI       $document_uri;
fastcgi_param  DOCUMENT_ROOT      $document_root;
fastcgi_param  SERVER_PROTOCOL    $server_protocol;
fastcgi_param  REQUEST_SCHEME     $scheme;
fastcgi_param  HTTPS              $https if_not_empty;
fastcgi_param  GATEWAY_INTERFACE  CGI/1.1;
fastcgi_param  SERVER_SOFTWARE    nginx/$nginx_version;
fastcgi_param  REMOTE_ADDR        $remote_addr;
fastcgi_param  REMOTE_PORT        $remote_port;
fastcgi_param  SERVER_ADDR        $server_addr;
fastcgi_param  SERVER_PORT        $server_port;
fastcgi_param  SERVER_NAME        $server_name;
# PHP only, required if PHP was built with --enable-force-cgi-redirect
fastcgi_param  REDIRECT_STATUS    200;
以上参数可以通过 php  $_SERVER[‘SERVER_NAME’]  获取变量值