今天扫描linux服务器，发现httpd服务存在一些安全隐患。因为之前安装了新版本的apache，所以在系统中安装linux时没有必要离开httpd服务。所以：
#rpm -e httpd
因此，出现了以下错误。
httpd-mmn=20020628 is needed by (installed) mod_perl-1.99_07-5
httpd-mmn=20020628 is needed by (installed) mod_python-3.0.1-3
httpd-mmn=20020628 is needed by (installed) mod_ssl-2.0.40-21
httpd-mmn=20020628 is needed by (installed) php-4.2.2-17
libapr.so.0 is needed by (installed) mod_perl-1.99_07-5
libaprutil.so.0 is needed by (installed) mod_perl-1.99_07-5
webserver is needed by (installed) webalizer-2.01_10-11
httpd=2.0.40 is needed by (installed) mod_perl-1.99_07-5
httpd=2.0.40 is needed by (installed) mod_python-3.0.1-3
httpd is needed by (installed) mod_ssl-2.0.40-21
看来要卸载这些东西，也要卸载它的依赖包，所以
#rpm -e mod_ssl
#rpm -e mod_python
#rpm -e mod_perl
#rpm -e webalizer
卸载所有相关软件包后。
#rpm -e httpd又成功了！
我在网上找到了下面的rpm，我可以添加一些参数
比如# rpm-e httpd-nodeps，就不用卸载这些依赖包了。