wget https://pecl.php.net/get/mcrypt-1.0.3.tgz
tar -zxvf mcrypt-1.0.3.tgz
cd mcrypt-1.0.3
/usr/local/php73/bin/phpize
------------------------------------------
如果还是centos 6 会出现如下问题：
configure.ac:3: error: Autoconf version 2.68 or higher is required
操作步骤
wget ftp://ftp.gnu.org/gnu/autoconf/autoconf-2.69.tar.gz
tar zxvf autoconf-2.69.tar.gz
cd autoconf-2.69
./configure
make
make install
-----------------------------------------
./configure --with-php-config=/usr/local/php73/bin/php-config
make
make install
vim /usr/local/php73/etc/php.ini
文件最后加：
extension=mcrypt.so
/etc/init.d/php73-fpm stop
/etc/init.d/php73-fpm start
OK
-------------------------------------------------
还是不要编译了，用remi 源更快更好。。。。