Here's a quick linux command to show all the packages you have installed (on RPM based systems, like RHEL and Centos) and what repository they came from. NOTE: the "sort" command sorts the packages by name, and the "column" command outputs the list in a neatly formatted tab delimited display in your terminal.

Sample output:

And if you wanted to see all packages that came from external (non-Centos) repositories:

This morning, I encountered a PHP fatal error on my development environment. Upon further inspection, one of my third party modules (XML Sitemap) required a later version of PHP. A fresh installation of Centos 5.3 comes with version 5.1.6 of PHP. Here is an easy way to upgrade PHP to a later version by using the Utter Ramblings Yum repository.

I created a new yum repo file:

Ran a yum update:

After updating all these packages, I checked out my new PHP version:

Now, my PHP fatal error has been resolved.

NOTE: This blog entry is a re-post of a previous article.

Back in September 2008, I wrote an article on how to configure your virtual machine to deliver email locally (using postfix, cyrus, imap, and sasl). I've had to revisit this article recently to test some bulk emailing functionality. I wanted to change my email server configuration to deliver all email locally to ensure clients and coworkers do not receive test emails. After reading a bunch of web articles, I decided to use Postfix's transport functionality (located /etc/postfix/transport). This configuration file allows you to map email addresses and hostnames to message delivery transports.

I edited this file (/etc/postfix/transport) and added the following to the end of the file:

I then edited my postfix configuration file (/etc/postfix/main.cf) and added the following:

Reload the transport and restart postfix using the following commands:

The first configuration change discards all outgoing email, and the second automatically BCC's my user. Although this is a drastic configuration change, it does exactly what I want: it ensures that email will never be delivered to real world addresses, and any email sent from my development server will end up in my local inbox.

You may have to tweak these settings to find a configuration that works with your development situation. For instance, if you wanted to continue delivery to a certain domain, you could add the following transport:

I just encountered a PHP fatal error when running my cron.php:

A quick Google search, and I found the issue is documented here. The solution is to enable the Date PHP4 module. But, this issue does not happen in our production environment, so I decided to compare PHP versions:

It turns out, a fully updated installation of Centos 5.2 only supplies PHP 5.1.x. So, I decided to upgrade PHP in my development environment according to this documentation.

I created a new yum repo file:

And, ran another yum update:

After updating all these packages, I checked out my new PHP version:

Now, my PHP fatal error has been resolved :)

Here's a quick script to reset ownership on a directory and then commit all changes (deletions, additions, and modifications) to subversion...