apache rewrite模块安装和使用
最近工作需要用到apache rewrite功能，之前本机已经安装apache，但没有安装rewrite模块。下面总结一下rewrite模块的安装过程和相关知识。本机已安装的apache版本为2.2.16，操作系统为ubuntu10.10。

一、 安装过程
1. 在apache源码目录下查找mod_rewrite.c文件。
find . -name mod_rewrite.c

2. 进入mod_rewrite.c文件所在目录。
cd modules/mappers

3. 将C程序编译成共享模块，以便在运行时加载到apache服务器中。
/usr/alibaba/install/httpd-2.2.16/bin/apxs  -c mod_rewrite.c
其中/usr/alibaba/install/httpd-2.2.16为本机的apache安装目录。
console输出如下:
/usr/alibaba/install/httpd-2.2.16/build/libtool --silent --mode=compile gcc -prefer-pic   -DLINUX=2 -D_REENTRANT -D_GNU_SOURCE -D_LARGEFILE64_SOURCE -g -O2 -pthread -I/usr/alibaba/install/httpd-2.2.16/include  -I/usr/alibaba/install/httpd-2.2.16/include   -I/usr/alibaba/install/httpd-2.2.16/include   -c -o mod_rewrite.lo mod_rewrite.c && touch mod_rewrite.slo
/usr/alibaba/install/httpd-2.2.16/build/libtool --silent --mode=link gcc -o mod_rewrite.la  -rpath /usr/alibaba/install/httpd-2.2.16/modules -module -avoid-version    mod_rewrite.lo

4. 安装动态共享对象到服务器的module目录中，并修改httpd.conf文件配置。
/usr/alibaba/install/httpd-2.2.16/bin/apxs -i -a -n rewrite mod_rewrite.la
console输出如下:
/usr/alibaba/install/httpd-2.2.16/build/instdso.sh SH_LIBTOOL='/usr/alibaba/install/httpd-2.2.16/build/libtool' mod_rewrite.la /usr/alibaba/install/httpd-2.2.16/modules
/usr/alibaba/install/httpd-2.2.16/build/libtool --mode=install cp mod_rewrite.la /usr/alibaba/install/httpd-2.2.16/modules/
cp .libs/mod_rewrite.so /usr/alibaba/install/httpd-2.2.16/modules/mod_rewrite.so
cp .libs/mod_rewrite.lai /usr/alibaba/install/httpd-2.2.16/modules/mod_rewrite.la
cp .libs/mod_rewrite.a /usr/alibaba/install/httpd-2.2.16/modules/mod_rewrite.a
chmod 644 /usr/alibaba/install/httpd-2.2.16/modules/mod_rewrite.a
ranlib /usr/alibaba/install/httpd-2.2.16/modules/mod_rewrite.a
PATH="$PATH:/sbin" ldconfig -n /usr/alibaba/install/httpd-2.2.16/modules
----------------------------------
Libraries have been installed in:
   /usr/alibaba/install/httpd-2.2.16/modules

If you ever happen to want to link against installed libraries
in a given directory, LIBDIR, you must either use libtool, and
specify the full pathname of the library, or use the `-LLIBDIR'
flag during linking and do at least one of the following:
   - add LIBDIR to the `LD_LIBRARY_PATH' environment variable
     during execution
   - add LIBDIR to the `LD_RUN_PATH' environment variable
     during linking
   - use the `-Wl,--rpath -Wl,LIBDIR' linker flag
   - have your system administrator add LIBDIR to `/etc/ld.so.conf'

See any operating system documentation about shared libraries for
more information, such as the ld(1) and ld.so(8) manual pages.
----------------------------------
chmod 755 /usr/alibaba/install/httpd-2.2.16/modules/mod_rewrite.so
[activating module `rewrite' in /usr/alibaba/install/httpd-2.2.16/conf/httpd.conf]

参数含义:
-i  表示需要执行安装操作。
-a  自动增加一个LoadModule行到httpd.conf文件中，以激活此模块，或者，如果此行已经存在，则启用之。
-n  增加或启用的模块名称。

5. 打开apache安装目录下的conf/httpd.conf文件，检查是否有如下行:
LoadModule rewrite_module     modules/mod_rewrite.so
如果包含此行，则安装成功。

6. 重新启动apache。
/usr/alibaba/install/httpd-2.2.16/bin/apachectl stop
/usr/alibaba/install/httpd-2.2.16/bin/apachectl start

二、 安装错误解决方法
1. 现象: Can`t loacte API module staructure `mod_rewrite_module` in file 
/usr/local/apache2/modules/mod_rewrite.so:/usr/local/apache2/lib/libapr-
0.so.0:undefined symbol:mod_rewrite_module
解决方法: httpd.conf里面写的mod_rewrite_module改成rewrite_module。

2. 现象: module rewrite_module is built-in and can't be loaded.
解