在RedHat Linux上安装php-5.2.5需要升级Linux自带的libxml2库，但是libxml2有很多的依赖（dependencies），下面是我的升级方式。
libxml2的官方下载地址是ftp://xmlsoft.org/libxml2/
首先移除libxml2-python-2.5.4-1，我的是libxml2-python-2.5.4-1
根据你自己系统的实际版本
[root@WebServer root]# rpm -e libxml2-python-2.5.4-1
error: Failed dependencies:
libxml2-python is needed by (installed) redhat-config-packages-1.1.8-1
发现有依赖关系，于是查询
[root@WebServer root]# rpm -qa | grep redhat-config-packages
redhat-config-packages-1.1.8-1
移除
[root@WebServer root]# rpm -e redhat-config-packages-1.1.8-1
然后再次移除libxml2-python-2.5.4-1
[root@WebServer root]# rpm -e libxml2-python-2.5.4-1
移除成功，查看确认
[root@WebServer root]# rpm -qa | grep libxml2
libxml2-2.5.4-1
libxml2-devel-2.5.4-1
移除libxml2-devel-2.5.4-1
[root@WebServer root]# rpm -e libxml2-devel-2.5.4-1
移除libxml2-2.5.4-1
[root@WebServer root]# rpm -e libxml2-2.5.4-1
error: Failed dependencies:
libxml2.so.2 is needed by (installed) libxslt-1.0.27-3
libxml2.so.2 is needed by (installed) alchemist-1.0.26-1
libxml2.so.2 is needed by (installed) foomatic-2.0.2-15
libxml2.so.2 is needed by (installed) bonobo-activation-2.2.0-4
libxml2.so.2 is needed by (installed) GConf2-2.2.0-1
libxml2.so.2 is needed by (installed) gnome-vfs2-2.2.2-4
libxml2.so.2 is needed by (installed) libglade2-2.0.1-3
libxml2.so.2 is needed by (installed) libgnome-2.2.0.1-8
libxml2.so.2 is needed by (installed) libgnomecanvas-2.2.0.1-1
libxml2.so.2 is needed by (installed) gtkhtml2-2.2.0-5
libxml2.so.2 is needed by (installed) gnome-python2-gtkhtml2-1.99.14-5
libxml2.so.2 is needed by (installed) libbonoboui-2.2.0-1
libxml2.so.2 is needed by (installed) libgnomeui-2.2.0.1-5
libxml2.so.2 is needed by (installed) pygtk2-libglade-1.99.14-4
libxml2.so.2 is needed by (installed) gnome-python2-bonobo-1.99.14-5
libxml2.so.2 is needed by (installed) gnome-python2-1.99.14-5
libxml2.so.2 is needed by (installed) usermode-gtk-1.67-2
libxml2.so.2 is needed by (installed) memprof-0.5.1-3
libxml2 >= 2.5.2 is needed by (installed) libxslt-1.0.27-3
libxml2 >= 2.3.8 is needed by (installed) alchemist-1.0.26-1
libxml2 >= 2.4.12-0.7 is needed by (installed) libglade2-2.0.1-3
libxml2 >= 2.5 is needed by (installed) libgnome-2.2.0.1-8
libxml2 >= 2.4.20 is needed by (installed) gtkhtml2-2.2.0-5
libxml2 >= 2.5 is needed by (installed) libbonoboui-2.2.0-1
libxml2 >= 2.5 is needed by (installed) libgnomeui-2.2.0.1-5
由于依赖关系移除失败
用升级方式覆盖安装
[root@WebServer home]# rpm -Uvh libxml2-2.6.11-1.i386.rpm
warning: libxml2-2.6.11-1.i386.rpm: V3 DSA signature: NOKEY, key ID de95bc1f
Preparing... ############ [100%]
1:libxml2 ############ [100%]
[root@WebServer home]# rpm -qa | grep libxml2
libxml2-2.6.11-1
安装libxml2-devel-2.6.11-1
[root@WebServer home]# rpm -ivh libxml2-devel-2.6.11-1.i386.rpm
warning: libxml2-devel-2.6.11-1.i386.rpm: V3 DSA signature: NOKEY, key ID de95bc1f
Preparing... ############## [100%]
1:libxml2-devel ############## [100%]
[root@WebServer home]# rpm -ivh libxml2-python-2.6.11-1.i386.rpm
warning: libxml2-python-2.6.11-1.i386.rpm: V3 DSA signature: NOKEY, key ID de95bc1f
Preparing... ################ [100%]
1:libxml2-python ################ [100%]
查看安装结果
[root@WebServer home]# rpm -qa | grep libxml2
libxml2-2.6.11-1
libxml2-devel-2.6.11-1
libxml2-python-2.6.11-1