升级php到5.5的版本

apt-get install libxml2-dev apache2-prefork-dev libcurl4-openssl-dev libmcrypt-dev  libreadline6-dev libbz2-dev  libpng12-dev libjpeg62-dev libt1-dev libfreetype6-dev

wget http://cn2.php.net/distributions/php-5.5.33.tar.gz
tar zxf php-5.5.33.tar.gz
cd php-5.5.33
./configure  --prefix=/usr/local/php5.5  --with-mysql --with-mysqli --with-pdo-mysql --with-apxs2=/usr/bin/apxs2  --enable-opcache --with-curl --enable-mbstring --with-mcrypt --enable-pcntl --with-openssl --with-zlib --enable-calendar --with-readline --enable-soap --enable-sockets --enable-sysvmsg --enable-sysvsem --enable-sysvshm --enable-zip  --enable-bcmath --with-bz2 --enable-exif --enable-ftp --with-gettext --enable-shmop --with-gd --with-jpeg-dir --with-png-dir --with-freetype-dir --with-t1lib --with-zlib-dir --enable-gd-native-ttf --with-mssql
make && make install

执行`make install`可能会报错，因为ubuntu的apache配置目录中httpd.conf默认是个空文件：

    apxs:Error: Activation failed for custom /etc/apache2/httpd.conf file..
    apxs:Error: At least one `LoadModule‘ directive already has to exist..
    make: *** [install-sapi] Error 1

解决方法：采取欺骗的方法，
在httpd.conf中添加如下注释，假装加在模个模块：
# Dummy LoadModule directive to aid module installations
# LoadModule dummy_module /usr/lib/apache2/modules/mod_dummy.so
之后再make install，通过。

cp php.ini-production /usr/local/php/lib/php.ini
   
编辑/usr/local/php/lib/php.ini，需要修改几个设置：

    expose_php＝Off
    upload_max_filesize＝30M
    memory_limit = 32M
    date.timezone = Asia/Shanghai

　需要手工添加下面一行到/etc/apache2/httpd.conf (并且在前后加上空行)

  LoadModule php5_module /usr/lib/apache2/modules/libphp5.so

  删除/etc/apache2/mods-enabled/php5.load 

  重启apache即可