编译安装php时报错的解决方法：
错误一：configure: error: mcrypt.h not found. please reinstall libmcrypt.
解决办法：需要安装libmcrypt
wget http://softlayer.dl.sourceforge.net/sourceforge/mcrypt/libmcrypt-2.5.8.tar.gz
tar -zxvf libmcrypt-2.5.8.tar.gz
cd /usr/local/src/libmcrypt-2.5.8
./configure --prefix=/usr/local
make
make install