yum remove yum

[root@localhost ~]# yum 
-bash: /usr/bin/yum: No such file or directory

rpm -ivh --nodeps <a href="http://mirrors.163.com/centos/5/os/x86_64/CentOS/yum-fastestmirror-1.1.16-14.el5.centos.1.noarch.rpm">http://mirrors.163.com/centos/5/os/x86_64/CentOS/yum-fastestmirror-1.1.16-14.el5.centos.1.noarch.rpm</a> 
rpm -ivh --nodeps <a href="http://mirrors.163.com/centos/5/os/x86_64/CentOS/yum-metadata-parser-1.1.2-3.el5.centos.x86_64.rpm">http://mirrors.163.com/centos/5/os/x86_64/CentOS/yum-metadata-parser-1.1.2-3.el5.centos.x86_64.rpm</a> 
rpm -ivh --nodeps <a href="http://mirrors.163.com/centos/5/os/x86_64/CentOS/yum-3.2.22-26.el5.centos.noarch.rpm[/code">http://mirrors.163.com/centos/5/os/x86_64/CentOS/yum-3.2.22-26.el5.centos.noarch.rpm[/code</a>]
关于rpm --nodeps的解释
[code]
--nodeps don't verify package dependencies

[root@localhost ~]# yum 
There was a problem importing one of the Python modules 
required to run yum. The error leading to this problem was: 

libxml2.so.2: cannot open shared object file: No such file or directory 

Please install a package which provides this module, or 
verify that the module is installed correctly. 

It's possible that the above module doesn't match the 
current version of Python, which is: 
2.4.3 (#1, Nov 11 2010, 13:30:19) 
[GCC 4.1.2 20080704 (Red Hat 4.1.2-48)] 

If you cannot solve this problem yourself, please go to 
the yum faq at: 
<a href="http://wiki.linux.duke.edu/YumFaq">http://wiki.linux.duke.edu/YumFaq</a> 

[root@localhost~]# python 
Python 2.4.3 (#1, Nov 11 2010, 13:30:19) 
[GCC 4.1.2 20080704 Red Hat 4.1.2-48)] on linux2 
Type "help", "copyright", "credits" or "license" for more information. 
>>> import yum 
Traceback (most recent call last): 
File "<stdin>", line 1, in ? 
File "/usr/lib/python2.4/site-packages/yum/__init__.py", line 54, in ? 
import transactioninfo 
File "/usr/lib/python2.4/site-packages/yum/transactioninfo.py", line 31, in ? 
from sqlitesack import YumAvailablePackageSqlite 
File "/usr/lib/python2.4/site-packages/yum/sqlitesack.py", line 26, in ? 
import yumRepo 
File "/usr/lib/python2.4/site-packages/yum/yumRepo.py", line 32, in ? 
import sqlitecachec 
File "/usr/lib64/python2.4/site-packages/sqlitecachec.py", line 19, in ? 
import _sqlitecache 
ImportError: libxml2.so.2: cannot open shared object file: No such file or directory 
>>> 

rpm -ivh <a href="http://mirrors.163.com/centos/5/os/x86_64/CentOS/libxml2-2.6.26-2.1.2.8.x86_64.rpm[/code">http://mirrors.163.com/centos/5/os/x86_64/CentOS/libxml2-2.6.26-2.1.2.8.x86_64.rpm[/code</a>]
再次测试运行下yum命令，结果正常了，大喜
[code]
[root@localhost ~]# yum 
Loaded plugins: fastestmirror 
You need to give some command 
usage: yum [options] COMMAND 

List of Commands: 

check-update Check for available package updates 
clean Remove cached data 
deplist List a package's dependencies 
downgrade downgrade a package 
erase Remove a package or packages from your system 
groupinfo Display details about a package group 
groupinstall Install the packages in a group on your system 
grouplist List available package groups 
groupremove Remove the packages in a group from your system 
help Display a helpful usage message 
info Display details about a package or group of packages 
install Install a package or packages on your system 
list List a package or groups of packages 
localinstall Install a local RPM 
makecache Generate the metadata cache 
provides Find what package provides the given value 
reinstall reinstall a package 
repolist Display the configured software repositories 
resolvedep Determine which package provides the given dependency 
search Search package details for the given string 
shell Run an interactive yum shell 
update Update a package or packages on your system 
upgrade Update packages taking obsoletes into account 


options: 
-h, --help show this help message and exit 
-t, --tolerant be tolerant of errors 
-C run entirely from cache, don't update cache 
-c [config file] config file location 
-R [minutes] maximum command wait time 
-d [debug level] debugging output level 
--showduplicates show duplicates, in repos, in list/search commands 
-e [error level] error output level 
-q, --quiet quiet operation 
-v, --verbose verbose operation 
-y answer yes for all questions 
--version show Yum version and exit 
--installroot=[path] set install root 
--enablerepo=[repo] enable one or more repositories (wildcards allowed) 
--disablerepo=[repo] disable one or more repositories (wildcards allowed) 
-x [package], --exclude=[package] 
exclude package(s) by name or glob 
--disableexcludes=[repo] 
disable exclude from main, for a repo or for 
everything 
--obsoletes enable obsoletes processing during updates 
--noplugins disable Yum plugins 
--nogpgcheck disable gpg signature checking 
--disableplugin=[plugin] 
disable plugins by name 
--enableplugin=[plugin] 
enable plugins by name 
--skip-broken skip packages with depsolving problems 
--color=COLOR control whether color is used 

Plugin Options: 

yum update