I have learned a cool command line "yum provides". "yum provides" help you search for the packages that will install either a file or directory. For example
# yum provides bash
bash-3.2-24.el5.x86_64 : The GNU Bourne Again shell (bash) version 3.2
Repo : base
Matched from:
bash-3.2-24.el5.x86_64 : The GNU Bourne Again shell (bash) version 3.1.
Repo : installed
Matched from:
Other : Provides-match: bash