View source for Check the Version of Package

==Check the Version of an Installed Package/Software==

From time to time, you will find yourself needing to know which package you are currently running.  You can do this in one of two ways, rpm or yum.  

Every time a package is installed, upgraded, or erased, the changes are logged in RPM's database. It's necessary for RPM to keep track of this information; otherwise it wouldn't be able to perform these operations correctly. You can think of the RPM database (and the disk space it consumes) as being the "price of admission" for the easy package management that RPM provides. 

===Use RPM to check Package Version===

Lets say you need to check what version of httpd you are currently running.

Now you can use RPM to figure this information out run the following

 rpm -qa | grep httpd

You should get something like

 httpd-2.2.15-29.el6.centos.x86_64
 httpd-tools-2.2.15-29.el6.centos.x86_64

Now you know you are running version 2.2.15-29.

===Use YUM to check Package Version===

To accomplish the same objective, you would type

 yum info httpd

You should get something like

 Installed Packages
 Name        : httpd
 Arch        : x86_64
 Version     : 2.2.15
 Release     : 29.el6.centos
 Size        : 2.9 M
 Repo        : installed
 From repo   : updates
 Summary     : Apache HTTP Server
 URL         : http://httpd.apache.org/
 License     : ASL 2.0
 Description : The Apache HTTP Server is a powerful, efficient, and extensible web server.

Sometimes, I find that yum does not have all packages and rpm has yet to let me down.  But most of the time either method will work.