configure:error:cannot find output from lex,give up，此错误是说 缺少flex.rpm，从linux 6.0光盘中找到flex-2.5.4a-29.i386.rpm
／＊原因可能出在我这次安装redhat，有很多东西没选上，所以出此问题。＊／
根据错误提示，安装libxml2。RHEL_5.2的安装光盘上提供了很多rpm包，我的是dvd光盘，位置在/media/RHEL_5.2 i386 DVD/Server，
cd /media/RHEL_5.2 i386 DVD/Server
ls *libxml*
[root@localhost Server]# ls *libxml*
libxml2-2.6.26-2.1.2.1.i386.rpm libxml2-python-2.6.26-2.1.2.1.i386.rpm
libxml2-devel-2.6.26-2.1.2.1.i386.rpm perl-libxml-perl-0.08-1.2.1.noarch.rpm
[root@localhost Server]# rpm -ivh libxml2-python-2.6.26-2.1.2.1.i386.rpm
warning: libxml2-python-2.6.26-2.1.2.1.i386.rpm: Header V3 DSA signature: NOKEY, key ID 37017186
Preparing... ########################################### [100%]
package libxml2-python-2.6.26-2.1.2.1 is already installed /*提示我已经安装过了＊／
[root@localhost Server]# rpm -ivh libxml2-devel-2.6.26-2.1.2.1.i386.rpm
warning: libxml2-devel-2.6.26-2.1.2.1.i386.rpm: Header V3 DSA signature: NOKEY, key ID 37017186
error: Failed dependencies:
zlib-devel is needed by libxml2-devel-2.6.26-2.1.2.1.i386
[root@localhost Server]# ls *zlib-devel*
zlib-devel-1.2.3-3.i386.rpm
[root@localhost Server]# rpm -ivh zlib-devel-1.2.3-3.i386.rpm
warning: zlib-devel-1.2.3-3.i386.rpm: Header V3 DSA signature: NOKEY, key ID 37017186
Preparing... ########################################### [100%]
1:zlib-devel ########################################### [100%]
[root@localhost Server]# rpm -ivh libxml2-devel-2.6.26-2.1.2.1.i386.rpm
warning: libxml2-devel-2.6.26-2.1.2.1.i386.rpm: Header V3 DSA signature: NOKEY, key ID 37017186
Preparing... ########################################### [100%]
1:libxml2-devel ########################################### [100%]
[root@localhost Server]#
好了，没有问题了