1. 下载安装编译工具

yum groupinstall 'Development Tools'

2.安装依赖包

yum install libxml2 libxml2-devel openssl openssl-devel bzip2 bzip2-devel libcurl libcurl-devel libjpeg libjpeg-devel libpng libpng-devel freetype freetype-devel gmp gmp-devel libmcrypt libmcrypt-devel readline readline-devel libxslt libxslt-devel zlib zlib-devel glibc glibc-devel glib2 glib2-devel ncurses curl gdbm-devel db4-devel libXpm-devel libX11-devel gd-devel gmp-devel expat-devel xmlrpc-c xmlrpc-c-devel libicu-devel libmcrypt-devel libmemcached-devel

3.下载并解压php7.4

wget http://php.net/distributions/php-7.4.0.tar.gz
tar -zxvf php-7.4.0.tar.gz 
cd php-7.4.0

4.编译安装（./configure --help 查看编译参数）

 编译前，新增用户组，用户，用于编译使用

groupadd www
useradd -g www www

开始编译（根据自己需要增减）

./configure \ 
--prefix=/usr/local/php \ 
--with-config-file-path=/etc \ 
--with-fpm-user=www \ 
--with-fpm-group=www \  
--with-curl \ 
--with-freetype-dir \ 
--enable-gd \ 
--with-gettext \  
--with-iconv-dir \ 
--with-kerberos \ 
--with-libdir=lib64 \ 
--with-libxml-dir \ 
--with-mysqli \ 
--with-openssl \ 
--with-pcre-regex \ 
--with-pdo-mysql \ 
--with-pdo-sqlite \ 
--with-pear \ 
--with-png-dir \ 
--with-jpeg-dir \ 
--with-xmlrpc \ 
--with-xsl \ 
--with-zlib \ 
--with-bz2 \ 
--with-mhash \ 
--enable-fpm \ 
--enable-bcmath \ 
--enable-libxml \ 
--enable-inline-optimization \ 
--enable-mbregex \ 
--enable-mbstring \ 
--enable-opcache \ 
--enable-pcntl \ 
--enable-shmop \ 
--enable-soap \ 
--enable-sockets \ 
--enable-sysvsem \ 
--enable-sysvshm \ 
--enable-xml \  
--enable-zip \ 
--enable-fpm

这里需要注意的是在php7.4 编译参数 --with-gd  要改成了 --enable-gd

当报错checking for libzip... configure: error: system libzip must be upgraded to version >= 0.11

#先删除旧版本
yum remove -y libzip

#下载编译安装
wget https://nih.at/libzip/libzip-1.2.0.tar.gz
tar -zxvf libzip-1.2.0.tar.gz
cd libzip-1.2.0
./configure
make && make install

error： Package requirements (sqlite3 > 3.7.4) were not met

yum install libsqlite3x-devel -y

error: Package requirements (oniguruma) were not met

yum install oniguruma-devel -y

 当yum install 提示 "没可用软件包"

yum install -y epel-release

off_t undefined 报错

configure: error: off_t undefined; check your library configuration

off_t 类型是在 头文件 unistd.h中定义的，
在32位系统 编程成 long int ，64位系统则编译成 long long int ，
在进行编译的时候 是默认查找64位的动态链接库，
但是默认情况下 centos 的动态链接库配置文件/etc/ld.so.conf里并没有加入搜索路径，
这个时候需要将 /usr/local/lib64 /usr/lib64 这些针对64位的库文件路径加进去。

#添加搜索路径到配置文件
echo '/usr/local/lib64
/usr/local/lib
/usr/lib
/usr/lib64'>>/etc/ld.so.conf

#然后 更新配置
ldconfig -v

/usr/local/include/zip.h:59:21: fatal error: zipconf.h: No such file or directory

cp /usr/local/lib/libzip/include/zipconf.h /usr/local/include/zipconf.h

编译没问题了，执行make && make install  安装完毕

5.配置环境

执行完安装命令后php7.4就已经安装在到了/usr/local/php目录下了

/usr/local/php/bin/php -v

查看版本

添加环境变量

vim /etc/profile

添加到最后

PATH=$PATH:/usr/local/php/bin
export PATH

更新环境变量

source /etc/profile

查看版本

php -v

6.配置php-fpm

cp php.ini-production /etc/php.ini
cp /usr/local/php/etc/php-fpm.conf.default /usr/local/php/etc/php-fpm.conf
cp /usr/local/php/etc/php-fpm.d/www.conf.default /usr/local/php/etc/php-fpm.d/www.conf
cp sapi/fpm/init.d.php-fpm /etc/init.d/php-fpm
chmod +x /etc/init.d/php-fpm

启动php-fpm

/etc/init.d/php-fpm start
或者
service php-fpm start