查看现有php版本：
[root@localhost local]# php -vPHP 5.5.38 (cli) (built: Oct 24 2017 15:58:09) 备份，由于不是覆盖安装，这里也可以不备份，但是，作为日常操作习惯来说，备份还是很有必要的。
[root@localhost ~]# cd /usr/local/[root@localhost local]# cp -a php php5538二，下载解压PHP的最新稳定版7.2.2
[root@localhost ~]# cd soft[root@localhost soft]# wget http://cn2.php.net/distributions/php-7.2.2.tar.bz2[root@localhost soft]# tar xf php-7.2.2.tar.bz2[root@localhost soft]# cd php-7.2.2/三，查看之前php的configure信息
升级自然要重新安装，那么之前的configure自然要知晓，怎么查看之前的configure信息呢，一般来说有两种方法，第一种，是通过phpinfo()信息：
第二种，通过命令的方式：
[root@localhost ~]# php -i | grep configureConfigure Command => ?‘./configure‘ ?‘--prefix=/usr/local/php‘ ‘--with-config-file-path=/usr/local/php/etc‘ ‘--with-config-file-scan-dir=/usr/local/php/conf.d‘ ‘--enable-fpm‘ ‘--with-fpm-user=www‘ ‘--with-fpm-group=www‘ ‘--with-mysql=mysqlnd‘ ‘--with-mysqli=mysqlnd‘ ‘--with-pdo-mysql=mysqlnd‘ ‘--with-iconv-dir‘ ‘--with-freetype-dir=/usr/local/freetype‘ ‘--with-jpeg-dir‘ ‘--with-png-dir‘ ‘--with-zlib‘ ‘--with-libxml-dir=/usr‘ ‘--enable-xml‘ ‘--disable-rpath‘ ‘--enable-bcmath‘ ‘--enable-shmop‘ ‘--enable-sysvsem‘ ‘--enable-inline-optimization‘ ‘--with-curl‘ ‘--enable-mbregex‘ ‘--enable-mbstring‘ ‘--with-mcrypt‘ ‘--enable-ftp‘ ‘--with-gd‘ ‘--enable-gd-native-ttf‘ ‘--with-openssl‘ ‘--with-mhash‘ ‘--enable-pcntl‘ ‘--enable-sockets‘ ‘--with-xmlrpc‘ ‘--enable-zip‘ ‘--enable-soap‘ ‘--with-gettext‘ ‘--disable-fileinfo‘ ‘--enable-opcache‘ ‘--enable-intl‘ ‘--with-xsl‘通过sed 将configure命令提取出来：
[root@localhost ~]# php -i | grep configure | sed -e "s/Configure Command => //; s/‘//g" ./configure ?--prefix=/usr/local/php --with-config-file-path=/usr/local/php/etc --with-config-file-scan-dir=/usr/local/php/conf.d --enable-fpm --with-fpm-user=www --with-fpm-group=www --with-mysql=mysqlnd --with-mysqli=mysqlnd --with-pdo-mysql=mysqlnd --with-iconv-dir --with-freetype-dir=/usr/local/freetype --with-jpeg-dir --with-png-dir --with-zlib --with-libxml-dir=/usr --enable-xml --disable-rpath --enable-bcmath --enable-shmop --enable-sysvsem --enable-inline-optimization --with-curl --enable-mbregex --enable-mbstring --with-mcrypt --enable-ftp --with-gd --enable-gd-native-ttf --with-openssl --with-mhash --enable-pcntl --enable-sockets --with-xmlrpc --enable-zip --enable-soap --with-gettext --disable-fileinfo --enable-opcache --enable-intl --with-xsl四，开始编译安装php7.2.2
[root@localhost php-7.2.2]# ./configure ?--prefix=/usr/local/php7 --with-config-file-path=/usr/local/php7/etc --with-config-file-scan-dir=/usr/local/php7/conf.d --enable-fpm --with-fpm-user=www --with-fpm-group=www --with-mysql=mysqlnd --with-mysqli=mysqlnd --with-pdo-mysql=mysqlnd --with-iconv-dir --with-freetype-dir=/usr/local/freetype --with-jpeg-dir --with-png-dir --with-zlib --with-libxml-dir=/usr --enable-xml --disable-rpath --enable-bcmath --enable-shmop --enable-sysvsem --enable-inline-optimization --with-curl --enable-mbregex --enable-mbstring --with-mcrypt --enable-ftp --with-gd --enable-gd-native-ttf --with-openssl --with-mhash --enable-pcntl --enable-sockets --with-xmlrpc --enable-zip --enable-soap --with-gettext --disable-fileinfo --enable-opcache --enable-intl --with-xslconfigure的过程中会报一个警告信息：
configure: WARNING: unrecognized options: --with-mysql, --with-mcrypt, --enable-gd-native-ttf表示php7.2.2不支持以上三个选项，删掉即可。
下面开始编译：
[root@localhost php-7.2.2]# make && make install这个过程非常耗时，需要耐心等待。
这里会报一个错误：
/root/soft/php-7.2.2/ext/xmlrpc/libxmlrpc/encodings.c:65: undefined reference to `libiconv_open‘/root/soft/php-7.2.2/ext/xmlrpc/libxmlrpc/encodings.c:73: undefined reference to `libiconv‘/root/soft/php-7.2.2/ext/xmlrpc/libxmlrpc/encodings.c:93: undefined reference to `libiconv_close‘/root/soft/php-7.2.2/ext/xmlrpc/libxmlrpc/encodings.c:93: undefined reference to `libiconv_close‘collect2: error: ld returned 1 exit statusmake: *** [sapi/cli/php] Error 1报错提示缺少libiconv这个库，缺啥就装啥。
wget http://ftp.gnu.org/pub/gnu/libiconv/libiconv-1.13.1.tar.gztar xf libiconv-1.13.1.tar.gzcd libiconv-1.13.1/./configure --prefix=/usr/local/libiconvmake && make install安装完后需要在configure时加入--with-iconv=/usr/local/libiconv参数，然后再次编译就不会报错了
五，复制修改配置文件，启动php-fpm
[root@localhost local]# cp php/etc/php.ini php7/etc/[root@localhost local]# cp php/etc/php-fpm.conf php7/etc/[root@localhost ~]# service php-fpm stop Gracefully shutting down php-fpm . done#关闭原来的php-fpm修改php-fpm.conf
[global]pid = /usr/local/php7/var/run/php-fpm.piderror_log = /usr/local/php7/var/log/php-fpm.log删除/usr/local/php目录
[root@localhost local]# rm -rf php创建指向php7的软链接
[root@localhost local]# ln -sv php7 php启动php-fpm
[root@localhost etc]# service php-fpm start Starting php-fpm [23-Feb-2018 20:48:41] NOTICE: PHP message: PHP Warning: ?PHP Startup: Unable to load dynamic library ‘/usr/local/php/lib/php/extensions/no-debug-non-zts-20121212/redis.so‘ (tried: /usr/local/php/lib/php/extensions/no-debug-non-zts-20121212/redis.so (/usr/local/php/lib/php/extensions/no-debug-non-zts-20121212/redis.so: undefined symbol: zval_used_for_init), /usr/local/php7/lib/php/extensions/no-debug-non-zts-20170718//usr/local/php/lib/php/extensions/no-debug-non-zts-20121212/redis.so.so (/usr/local/php7/lib/php/extensions/no-debug-non-zts-20170718//usr/local/php/lib/php/extensions/no-debug-non-zts-20121212/redis.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0[23-Feb-2018 20:48:41] ERROR: An another FPM instance seems to already listen on /tmp/php-cgi.sock[23-Feb-2018 20:48:41] ERROR: FPM initialization failed failed报错了，提示redis扩展没有装。
六，安装redis扩展
下载地址
https://github.com/phpredis/phpredis/archive/php7.zip
unzip php7.zipcd soft/phpredis-php7//usr/local/php7/bin/phpize./configure --with-php-config=/usr/local/php7/bin/php-configmake && make install在php.ini中添加如下一行
extension=redis.so重启php-fpm
[root@localhost etc]# service php-fpm restart Gracefully shutting down php-fpm . doneStarting php-fpm ?done查看php版本
[root@localhost etc]# php -vPHP 7.2.2 (cli) (built: Feb 23 2018 19:25:46) ( NTS )Copyright (c) 1997-2018 The PHP GroupZend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies查看phpinfo()
至此，php升级完成。
CentOS7下PHP5.5.38升级PHP7.2.2
原文地址：http://blog.51cto.com/hld1992/2072576