安装php7请参考:https://blog.yongit.com/note/211000.html

本人有一台服务器有三个php版本，预览一下：

[root@hostname /]# ps -ef |grep php
root        1013       1  0 Jan30 ?        00:01:54 php-fpm: master process (/usr/local/php5/etc/php-fpm.conf)
www         1069    1013  0 Jan30 ?        00:00:01 php-fpm: pool www
www         1070    1013  0 Jan30 ?        00:00:01 php-fpm: pool www
root      485245       1  0 Feb01 ?        00:01:48 php-fpm: master process (/usr/local/php/etc/php-fpm.conf)
www       485246  485245  0 Feb01 ?        00:00:01 php-fpm: pool www
www       485247  485245  0 Feb01 ?        00:00:01 php-fpm: pool www
root     3720590       1  0 18:50 ?        00:00:00 php-fpm: master process (/usr/local/php72/etc/php-fpm.conf)
www      3720591 3720590  0 18:50 ?        00:00:00 php-fpm: pool www
www      3720592 3720590  0 18:50 ?        00:00:00 php-fpm: pool www
root     3720601 3566741  0 18:50 pts/1    00:00:00 grep --color=auto php

注意事项（如openssl版本是openssl-1.0.2请忽略）

看看你的openssl是什么版本openssl version，如果版本过高，如：

[root@fouryear php-5.6.40]# openssl version
OpenSSL 1.1.1g FIPS  21 Apr 2020

会在编译--with-openssl的时候提示：make: *** [Makefile:623: ext/openssl/openssl.lo] Error 1
则需要安装与5.6.40兼容的版本：openssl1.0.2，完整步骤：

wget https://www.openssl.org/source/openssl-1.0.2k.tar.gz
tar xvf openssl-1.0.2k.tar.gz
cd openssl-1.0.2k
./config
make && make install

确认一下：

[root@fouryear php-5.6.40]# /usr/local/ssl/bin/openssl version
OpenSSL 1.0.2k  26 Jan 2017

然后就可以使用：--with-openssl=/usr/local/ssl
需要确认ssl目录，也可能需要如此：--with-openssl-dir=/usr/include/openssl，或直接-with-openssl就行

下载解压

wget -c http://cn2.php.net/distributions/php-5.6.40.tar.gz
tar -zxvf php-5.6.40.tar.gz
cd php-5.6.40/

编译 php5.6

./configure  --prefix=/usr/local/php5 --enable-fpm --with-mysql  --with-mysqli --with-zlib --with-curl --with-gd --with-jpeg-dir --with-png-dir --with-freetype-dir --with-openssl --enable-mbstring --enable-xml --enable-session --enable-ftp --enable-pdo --with-fpm-user=www --with-fpm-group=www --with-pdo-mysql

编译php7.4.3 （注意编译参数）

./configure  --prefix=/usr/local/php73 --enable-fpm --with-mysqli --with-zlib --with-curl --enable-gd --with-jpeg --with-freetype --with-openssl --enable-mbstring --enable-xml --enable-session --enable-ftp --enable-pdo --with-fpm-user=toutiao --with-fpm-group=toutiao --with-pdo-mysql

如果提示：

configure: error: Package requirements (sqlite3 > 3.7.4) were not met:
No package 'sqlite3' found

则安装一下：yum -y install sqlite-devel
可能也要：yum -y install libcurl-devel
可能也要：yum -y install libpng-devel
可能也要：yum -y install libjpeg-devel
可能也要：yum -y install oniguruma-devel

安装

make && make install

完成提示

[root@fiveyear php-5.6.40]# make install
Installing shared extensions:     /usr/local/php5/lib/php/extensions/no-debug-non-zts-20131226/
Installing PHP CLI binary:        /usr/local/php5/bin/
Installing PHP CLI man page:      /usr/local/php5/php/man/man1/
Installing PHP FPM binary:        /usr/local/php5/sbin/
Installing PHP FPM config:        /usr/local/php5/etc/
Installing PHP FPM man page:      /usr/local/php5/php/man/man8/
Installing PHP FPM status page:   /usr/local/php5/php/php/fpm/
Installing PHP CGI binary:        /usr/local/php5/bin/
Installing PHP CGI man page:      /usr/local/php5/php/man/man1/
Installing build environment:     /usr/local/php5/lib/php/build/
Installing header files:           /usr/local/php5/include/php/
Installing helper programs:       /usr/local/php5/bin/
  program: phpize
  program: php-config
Installing man pages:             /usr/local/php5/php/man/man1/
  page: phpize.1
  page: php-config.1
Installing PEAR environment:      /usr/local/php5/lib/php/
[PEAR] Archive_Tar    - installed: 1.4.4
[PEAR] Console_Getopt - installed: 1.4.1
[PEAR] Structures_Graph- installed: 1.1.1
[PEAR] XML_Util       - installed: 1.4.3
[PEAR] PEAR           - installed: 1.10.7
Wrote PEAR system config file at: /usr/local/php5/etc/pear.conf
You may want to add: /usr/local/php5/lib/php to your php.ini include_path
/root/php-5.6.40/build/shtool install -c ext/phar/phar.phar /usr/local/php5/bin
ln -s -f phar.phar /usr/local/php5/bin/phar
Installing PDO headers:           /usr/local/php5/include/php/ext/pdo/

完成收尾

php.ini的配置就自行调整：
/usr/local/php5/bin/php -v
cp php.ini-development /usr/local/php5/lib/php.ini

重点1：是需要修改php-fpm的listen端口（因为默认的socket端口9000已经被php7使用了）
cp /usr/local/php5/etc/php-fpm.conf.default /usr/local/php5/etc/php-fpm.conf
vim /usr/local/php5/etc/php-fpm.conf
找到listen = 127.0.0.1:9000改成listen = 127.0.0.1:9056

重点2：配置php5的php-fpm服务(作为系统服务，开启自启，也可以通过init.d/xxx自主管理)

cp /root/php-5.6.40/sapi/fpm/php-fpm.service /usr/lib/systemd/system/php5-fpm.service
vim /usr/lib/systemd/system/php5-fpm.service

[Unit]
Description=The PHP FastCGI Process Manager
After=syslog.target network.target

[Service]
Type=simple
PIDFile=${prefix}/var/run/php-fpm.pid
ExecStart=${exec_prefix}/sbin/php-fpm --nodaemonize --fpm-config ${prefix}/etc/php-fpm.conf
ExecReload=/bin/kill -USR2 $MAINPID

[Install]
WantedBy=multi-user.target

将PIDFile和ExecStart改成：

PIDFile=/usr/local/php5/var/run/php-fpm.pid
ExecStart=/usr/local/php5/sbin/php-fpm --nodaemonize --fpm-config /usr/local/php5/etc/php-fpm.conf

重新载入：systemctl daemon-reload
开机启动：systemctl enable php5-fpm
立即启动：systemctl start php5-fpm
查看状态：systemctl status php5-fpm或ps -ef |grep php

完成，然后就是在nginx配置的时候，配置到底fastcgi_pass你想用php5还是php7的socket来处理请求了。